--- /dev/null | 0 linux-2.6.18-rc6-ming/fs/Kconfig | 107 linux-2.6.18-rc6-ming/fs/Makefile | 2 linux-2.6.18-rc6-ming/fs/ext4/Makefile | 12 linux-2.6.18-rc6-ming/fs/ext4/acl.c | 551 +++ linux-2.6.18-rc6-ming/fs/ext4/acl.h | 81 linux-2.6.18-rc6-ming/fs/ext4/balloc.c | 1622 +++++++++ linux-2.6.18-rc6-ming/fs/ext4/bitmap.c | 32 linux-2.6.18-rc6-ming/fs/ext4/dir.c | 515 ++ linux-2.6.18-rc6-ming/fs/ext4/extents.c | 2151 +++++++++++ linux-2.6.18-rc6-ming/fs/ext4/file.c | 137 linux-2.6.18-rc6-ming/fs/ext4/fsync.c | 88 linux-2.6.18-rc6-ming/fs/ext4/hash.c | 152 linux-2.6.18-rc6-ming/fs/ext4/ialloc.c | 775 ++++ linux-2.6.18-rc6-ming/fs/ext4/inode.c | 3232 ++++++++++++++++++ linux-2.6.18-rc6-ming/fs/ext4/ioctl.c | 253 + linux-2.6.18-rc6-ming/fs/ext4/namei.c | 2396 +++++++++++++ linux-2.6.18-rc6-ming/fs/ext4/namei.h | 8 linux-2.6.18-rc6-ming/fs/ext4/resize.c | 1038 +++++ linux-2.6.18-rc6-ming/fs/ext4/super.c | 2768 +++++++++++++++ linux-2.6.18-rc6-ming/fs/ext4/symlink.c | 54 linux-2.6.18-rc6-ming/fs/ext4/xattr.c | 1317 +++++++ linux-2.6.18-rc6-ming/fs/ext4/xattr.h | 145 linux-2.6.18-rc6-ming/fs/ext4/xattr_security.c | 77 linux-2.6.18-rc6-ming/fs/ext4/xattr_trusted.c | 62 linux-2.6.18-rc6-ming/fs/ext4/xattr_user.c | 64 linux-2.6.18-rc6-ming/fs/jbd2/Makefile | 7 linux-2.6.18-rc6-ming/fs/jbd2/checkpoint.c | 696 +++ linux-2.6.18-rc6-ming/fs/jbd2/commit.c | 876 ++++ linux-2.6.18-rc6-ming/fs/jbd2/journal.c | 2090 +++++++++++ linux-2.6.18-rc6-ming/fs/jbd2/recovery.c | 609 +++ linux-2.6.18-rc6-ming/fs/jbd2/revoke.c | 712 +++ linux-2.6.18-rc6-ming/fs/jbd2/transaction.c | 2080 +++++++++++ linux-2.6.18-rc6-ming/include/linux/ext4_fs.h | 965 +++++ linux-2.6.18-rc6-ming/include/linux/ext4_fs_extents.h | 198 + linux-2.6.18-rc6-ming/include/linux/ext4_fs_i.h | 158 linux-2.6.18-rc6-ming/include/linux/ext4_fs_sb.h | 93 linux-2.6.18-rc6-ming/include/linux/ext4_jbd2.h | 273 + linux-2.6.18-rc6-ming/include/linux/jbd2.h | 1108 ++++++ 39 files changed, 27500 insertions(+), 4 deletions(-) diff -puN /dev/null fs/ext4/acl.c --- /dev/null 2006-09-07 07:04:09.114355360 -0700 +++ linux-2.6.18-rc6-ming/fs/ext4/acl.c 2006-09-07 23:19:15.435804935 -0700 @@ -0,0 +1,551 @@ +/* + * linux/fs/ext4/acl.c + * + * Copyright (C) 2001-2003 Andreas Gruenbacher, + */ + +#include +#include +#include +#include +#include +#include +#include +#include "xattr.h" +#include "acl.h" + +/* + * Convert from filesystem to in-memory representation. + */ +static struct posix_acl * +ext4_acl_from_disk(const void *value, size_t size) +{ + const char *end = (char *)value + size; + int n, count; + struct posix_acl *acl; + + if (!value) + return NULL; + if (size < sizeof(ext4_acl_header)) + return ERR_PTR(-EINVAL); + if (((ext4_acl_header *)value)->a_version != + cpu_to_le32(EXT4_ACL_VERSION)) + return ERR_PTR(-EINVAL); + value = (char *)value + sizeof(ext4_acl_header); + count = ext4_acl_count(size); + if (count < 0) + return ERR_PTR(-EINVAL); + if (count == 0) + return NULL; + acl = posix_acl_alloc(count, GFP_KERNEL); + if (!acl) + return ERR_PTR(-ENOMEM); + for (n=0; n < count; n++) { + ext4_acl_entry *entry = + (ext4_acl_entry *)value; + if ((char *)value + sizeof(ext4_acl_entry_short) > end) + goto fail; + acl->a_entries[n].e_tag = le16_to_cpu(entry->e_tag); + acl->a_entries[n].e_perm = le16_to_cpu(entry->e_perm); + switch(acl->a_entries[n].e_tag) { + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + value = (char *)value + + sizeof(ext4_acl_entry_short); + acl->a_entries[n].e_id = ACL_UNDEFINED_ID; + break; + + case ACL_USER: + case ACL_GROUP: + value = (char *)value + sizeof(ext4_acl_entry); + if ((char *)value > end) + goto fail; + acl->a_entries[n].e_id = + le32_to_cpu(entry->e_id); + break; + + default: + goto fail; + } + } + if (value != end) + goto fail; + return acl; + +fail: + posix_acl_release(acl); + return ERR_PTR(-EINVAL); +} + +/* + * Convert from in-memory to filesystem representation. + */ +static void * +ext4_acl_to_disk(const struct posix_acl *acl, size_t *size) +{ + ext4_acl_header *ext_acl; + char *e; + size_t n; + + *size = ext4_acl_size(acl->a_count); + ext_acl = (ext4_acl_header *)kmalloc(sizeof(ext4_acl_header) + + acl->a_count * sizeof(ext4_acl_entry), GFP_KERNEL); + if (!ext_acl) + return ERR_PTR(-ENOMEM); + ext_acl->a_version = cpu_to_le32(EXT4_ACL_VERSION); + e = (char *)ext_acl + sizeof(ext4_acl_header); + for (n=0; n < acl->a_count; n++) { + ext4_acl_entry *entry = (ext4_acl_entry *)e; + entry->e_tag = cpu_to_le16(acl->a_entries[n].e_tag); + entry->e_perm = cpu_to_le16(acl->a_entries[n].e_perm); + switch(acl->a_entries[n].e_tag) { + case ACL_USER: + case ACL_GROUP: + entry->e_id = + cpu_to_le32(acl->a_entries[n].e_id); + e += sizeof(ext4_acl_entry); + break; + + case ACL_USER_OBJ: + case ACL_GROUP_OBJ: + case ACL_MASK: + case ACL_OTHER: + e += sizeof(ext4_acl_entry_short); + break; + + default: + goto fail; + } + } + return (char *)ext_acl; + +fail: + kfree(ext_acl); + return ERR_PTR(-EINVAL); +} + +static inline struct posix_acl * +ext4_iget_acl(struct inode *inode, struct posix_acl **i_acl) +{ + struct posix_acl *acl = EXT4_ACL_NOT_CACHED; + + spin_lock(&inode->i_lock); + if (*i_acl != EXT4_ACL_NOT_CACHED) + acl = posix_acl_dup(*i_acl); + spin_unlock(&inode->i_lock); + + return acl; +} + +static inline void +ext4_iset_acl(struct inode *inode, struct posix_acl **i_acl, + struct posix_acl *acl) +{ + spin_lock(&inode->i_lock); + if (*i_acl != EXT4_ACL_NOT_CACHED) + posix_acl_release(*i_acl); + *i_acl = posix_acl_dup(acl); + spin_unlock(&inode->i_lock); +} + +/* + * Inode operation get_posix_acl(). + * + * inode->i_mutex: don't care + */ +static struct posix_acl * +ext4_get_acl(struct inode *inode, int type) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + int name_index; + char *value = NULL; + struct posix_acl *acl; + int retval; + + if (!test_opt(inode->i_sb, POSIX_ACL)) + return NULL; + + switch(type) { + case ACL_TYPE_ACCESS: + acl = ext4_iget_acl(inode, &ei->i_acl); + if (acl != EXT4_ACL_NOT_CACHED) + return acl; + name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; + break; + + case ACL_TYPE_DEFAULT: + acl = ext4_iget_acl(inode, &ei->i_default_acl); + if (acl != EXT4_ACL_NOT_CACHED) + return acl; + name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; + break; + + default: + return ERR_PTR(-EINVAL); + } + retval = ext4_xattr_get(inode, name_index, "", NULL, 0); + if (retval > 0) { + value = kmalloc(retval, GFP_KERNEL); + if (!value) + return ERR_PTR(-ENOMEM); + retval = ext4_xattr_get(inode, name_index, "", value, retval); + } + if (retval > 0) + acl = ext4_acl_from_disk(value, retval); + else if (retval == -ENODATA || retval == -ENOSYS) + acl = NULL; + else + acl = ERR_PTR(retval); + kfree(value); + + if (!IS_ERR(acl)) { + switch(type) { + case ACL_TYPE_ACCESS: + ext4_iset_acl(inode, &ei->i_acl, acl); + break; + + case ACL_TYPE_DEFAULT: + ext4_iset_acl(inode, &ei->i_default_acl, acl); + break; + } + } + return acl; +} + +/* + * Set the access or default ACL of an inode. + * + * inode->i_mutex: down unless called from ext4_new_inode + */ +static int +ext4_set_acl(handle_t *handle, struct inode *inode, int type, + struct posix_acl *acl) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + int name_index; + void *value = NULL; + size_t size = 0; + int error; + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + + switch(type) { + case ACL_TYPE_ACCESS: + name_index = EXT4_XATTR_INDEX_POSIX_ACL_ACCESS; + if (acl) { + mode_t mode = inode->i_mode; + error = posix_acl_equiv_mode(acl, &mode); + if (error < 0) + return error; + else { + inode->i_mode = mode; + ext4_mark_inode_dirty(handle, inode); + if (error == 0) + acl = NULL; + } + } + break; + + case ACL_TYPE_DEFAULT: + name_index = EXT4_XATTR_INDEX_POSIX_ACL_DEFAULT; + if (!S_ISDIR(inode->i_mode)) + return acl ? -EACCES : 0; + break; + + default: + return -EINVAL; + } + if (acl) { + value = ext4_acl_to_disk(acl, &size); + if (IS_ERR(value)) + return (int)PTR_ERR(value); + } + + error = ext4_xattr_set_handle(handle, inode, name_index, "", + value, size, 0); + + kfree(value); + if (!error) { + switch(type) { + case ACL_TYPE_ACCESS: + ext4_iset_acl(inode, &ei->i_acl, acl); + break; + + case ACL_TYPE_DEFAULT: + ext4_iset_acl(inode, &ei->i_default_acl, acl); + break; + } + } + return error; +} + +static int +ext4_check_acl(struct inode *inode, int mask) +{ + struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); + + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl) { + int error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + return error; + } + + return -EAGAIN; +} + +int +ext4_permission(struct inode *inode, int mask, struct nameidata *nd) +{ + return generic_permission(inode, mask, ext4_check_acl); +} + +/* + * Initialize the ACLs of a new inode. Called from ext4_new_inode. + * + * dir->i_mutex: down + * inode->i_mutex: up (access to inode is still exclusive) + */ +int +ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir) +{ + struct posix_acl *acl = NULL; + int error = 0; + + if (!S_ISLNK(inode->i_mode)) { + if (test_opt(dir->i_sb, POSIX_ACL)) { + acl = ext4_get_acl(dir, ACL_TYPE_DEFAULT); + if (IS_ERR(acl)) + return PTR_ERR(acl); + } + if (!acl) + inode->i_mode &= ~current->fs->umask; + } + if (test_opt(inode->i_sb, POSIX_ACL) && acl) { + struct posix_acl *clone; + mode_t mode; + + if (S_ISDIR(inode->i_mode)) { + error = ext4_set_acl(handle, inode, + ACL_TYPE_DEFAULT, acl); + if (error) + goto cleanup; + } + clone = posix_acl_clone(acl, GFP_KERNEL); + error = -ENOMEM; + if (!clone) + goto cleanup; + + mode = inode->i_mode; + error = posix_acl_create_masq(clone, &mode); + if (error >= 0) { + inode->i_mode = mode; + if (error > 0) { + /* This is an extended ACL */ + error = ext4_set_acl(handle, inode, + ACL_TYPE_ACCESS, clone); + } + } + posix_acl_release(clone); + } +cleanup: + posix_acl_release(acl); + return error; +} + +/* + * Does chmod for an inode that may have an Access Control List. The + * inode->i_mode field must be updated to the desired value by the caller + * before calling this function. + * Returns 0 on success, or a negative error number. + * + * We change the ACL rather than storing some ACL entries in the file + * mode permission bits (which would be more efficient), because that + * would break once additional permissions (like ACL_APPEND, ACL_DELETE + * for directories) are added. There are no more bits available in the + * file mode. + * + * inode->i_mutex: down + */ +int +ext4_acl_chmod(struct inode *inode) +{ + struct posix_acl *acl, *clone; + int error; + + if (S_ISLNK(inode->i_mode)) + return -EOPNOTSUPP; + if (!test_opt(inode->i_sb, POSIX_ACL)) + return 0; + acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); + if (IS_ERR(acl) || !acl) + return PTR_ERR(acl); + clone = posix_acl_clone(acl, GFP_KERNEL); + posix_acl_release(acl); + if (!clone) + return -ENOMEM; + error = posix_acl_chmod_masq(clone, inode->i_mode); + if (!error) { + handle_t *handle; + int retries = 0; + + retry: + handle = ext4_journal_start(inode, + EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); + if (IS_ERR(handle)) { + error = PTR_ERR(handle); + ext4_std_error(inode->i_sb, error); + goto out; + } + error = ext4_set_acl(handle, inode, ACL_TYPE_ACCESS, clone); + ext4_journal_stop(handle); + if (error == -ENOSPC && + ext4_should_retry_alloc(inode->i_sb, &retries)) + goto retry; + } +out: + posix_acl_release(clone); + return error; +} + +/* + * Extended attribute handlers + */ +static size_t +ext4_xattr_list_acl_access(struct inode *inode, char *list, size_t list_len, + const char *name, size_t name_len) +{ + const size_t size = sizeof(POSIX_ACL_XATTR_ACCESS); + + if (!test_opt(inode->i_sb, POSIX_ACL)) + return 0; + if (list && size <= list_len) + memcpy(list, POSIX_ACL_XATTR_ACCESS, size); + return size; +} + +static size_t +ext4_xattr_list_acl_default(struct inode *inode, char *list, size_t list_len, + const char *name, size_t name_len) +{ + const size_t size = sizeof(POSIX_ACL_XATTR_DEFAULT); + + if (!test_opt(inode->i_sb, POSIX_ACL)) + return 0; + if (list && size <= list_len) + memcpy(list, POSIX_ACL_XATTR_DEFAULT, size); + return size; +} + +static int +ext4_xattr_get_acl(struct inode *inode, int type, void *buffer, size_t size) +{ + struct posix_acl *acl; + int error; + + if (!test_opt(inode->i_sb, POSIX_ACL)) + return -EOPNOTSUPP; + + acl = ext4_get_acl(inode, type); + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl == NULL) + return -ENODATA; + error = posix_acl_to_xattr(acl, buffer, size); + posix_acl_release(acl); + + return error; +} + +static int +ext4_xattr_get_acl_access(struct inode *inode, const char *name, + void *buffer, size_t size) +{ + if (strcmp(name, "") != 0) + return -EINVAL; + return ext4_xattr_get_acl(inode, ACL_TYPE_ACCESS, buffer, size); +} + +static int +ext4_xattr_get_acl_default(struct inode *inode, const char *name, + void *buffer, size_t size) +{ + if (strcmp(name, "") != 0) + return -EINVAL; + return ext4_xattr_get_acl(inode, ACL_TYPE_DEFAULT, buffer, size); +} + +static int +ext4_xattr_set_acl(struct inode *inode, int type, const void *value, + size_t size) +{ + handle_t *handle; + struct posix_acl *acl; + int error, retries = 0; + + if (!test_opt(inode->i_sb, POSIX_ACL)) + return -EOPNOTSUPP; + if ((current->fsuid != inode->i_uid) && !capable(CAP_FOWNER)) + return -EPERM; + + if (value) { + acl = posix_acl_from_xattr(value, size); + if (IS_ERR(acl)) + return PTR_ERR(acl); + else if (acl) { + error = posix_acl_valid(acl); + if (error) + goto release_and_out; + } + } else + acl = NULL; + +retry: + handle = ext4_journal_start(inode, EXT4_DATA_TRANS_BLOCKS(inode->i_sb)); + if (IS_ERR(handle)) + return PTR_ERR(handle); + error = ext4_set_acl(handle, inode, type, acl); + ext4_journal_stop(handle); + if (error == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) + goto retry; + +release_and_out: + posix_acl_release(acl); + return error; +} + +static int +ext4_xattr_set_acl_access(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + if (strcmp(name, "") != 0) + return -EINVAL; + return ext4_xattr_set_acl(inode, ACL_TYPE_ACCESS, value, size); +} + +static int +ext4_xattr_set_acl_default(struct inode *inode, const char *name, + const void *value, size_t size, int flags) +{ + if (strcmp(name, "") != 0) + return -EINVAL; + return ext4_xattr_set_acl(inode, ACL_TYPE_DEFAULT, value, size); +} + +struct xattr_handler ext4_xattr_acl_access_handler = { + .prefix = POSIX_ACL_XATTR_ACCESS, + .list = ext4_xattr_list_acl_access, + .get = ext4_xattr_get_acl_access, + .set = ext4_xattr_set_acl_access, +}; + +struct xattr_handler ext4_xattr_acl_default_handler = { + .prefix = POSIX_ACL_XATTR_DEFAULT, + .list = ext4_xattr_list_acl_default, + .get = ext4_xattr_get_acl_default, + .set = ext4_xattr_set_acl_default, +}; diff -puN /dev/null fs/ext4/acl.h --- /dev/null 2006-09-07 07:04:09.114355360 -0700 +++ linux-2.6.18-rc6-ming/fs/ext4/acl.h 2006-09-07 23:19:15.436804813 -0700 @@ -0,0 +1,81 @@ +/* + File: fs/ext4/acl.h + + (C) 2001 Andreas Gruenbacher, +*/ + +#include + +#define EXT4_ACL_VERSION 0x0001 + +typedef struct { + __le16 e_tag; + __le16 e_perm; + __le32 e_id; +} ext4_acl_entry; + +typedef struct { + __le16 e_tag; + __le16 e_perm; +} ext4_acl_entry_short; + +typedef struct { + __le32 a_version; +} ext4_acl_header; + +static inline size_t ext4_acl_size(int count) +{ + if (count <= 4) { + return sizeof(ext4_acl_header) + + count * sizeof(ext4_acl_entry_short); + } else { + return sizeof(ext4_acl_header) + + 4 * sizeof(ext4_acl_entry_short) + + (count - 4) * sizeof(ext4_acl_entry); + } +} + +static inline int ext4_acl_count(size_t size) +{ + ssize_t s; + size -= sizeof(ext4_acl_header); + s = size - 4 * sizeof(ext4_acl_entry_short); + if (s < 0) { + if (size % sizeof(ext4_acl_entry_short)) + return -1; + return size / sizeof(ext4_acl_entry_short); + } else { + if (s % sizeof(ext4_acl_entry)) + return -1; + return s / sizeof(ext4_acl_entry) + 4; + } +} + +#ifdef CONFIG_EXT4DEV_FS_POSIX_ACL + +/* Value for inode->u.ext4_i.i_acl and inode->u.ext4_i.i_default_acl + if the ACL has not been cached */ +#define EXT4_ACL_NOT_CACHED ((void *)-1) + +/* acl.c */ +extern int ext4_permission (struct inode *, int, struct nameidata *); +extern int ext4_acl_chmod (struct inode *); +extern int ext4_init_acl (handle_t *, struct inode *, struct inode *); + +#else /* CONFIG_EXT4DEV_FS_POSIX_ACL */ +#include +#define ext4_permission NULL + +static inline int +ext4_acl_chmod(struct inode *inode) +{ + return 0; +} + +static inline int +ext4_init_acl(handle_t *handle, struct inode *inode, struct inode *dir) +{ + return 0; +} +#endif /* CONFIG_EXT4DEV_FS_POSIX_ACL */ + diff -puN /dev/null fs/ext4/balloc.c --- /dev/null 2006-09-07 07:04:09.114355360 -0700 +++ linux-2.6.18-rc6-ming/fs/ext4/balloc.c 2006-09-07 23:19:15.471800520 -0700 @@ -0,0 +1,1622 @@ +/* + * linux/fs/ext4/balloc.c + * + * Copyright (C) 1992, 1993, 1994, 1995 + * Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * + * Enhanced block allocation by Stephen Tweedie (sct@redhat.com), 1993 + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + */ + +#include +#include +#include +#include +#include +#include +#include +#include + +/* + * balloc.c contains the blocks allocation and deallocation routines + */ + +/* + * The free blocks are managed by bitmaps. A file system contains several + * blocks groups. Each group contains 1 bitmap block for blocks, 1 bitmap + * block for inodes, N blocks for the inode table and data blocks. + * + * The file system contains group descriptors which are located after the + * super block. Each descriptor contains the number of the bitmap block and + * the free blocks count in the block. The descriptors are loaded in memory + * when a file system is mounted (see ext4_read_super). + */ + + +#define in_range(b, first, len) ((b) >= (first) && (b) <= (first) + (len) - 1) +struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb, + unsigned int block_group, + struct buffer_head ** bh) +{ + unsigned long group_desc; + unsigned long offset; + struct ext4_group_desc * desc; + struct ext4_sb_info *sbi = EXT4_SB(sb); + + if (block_group >= sbi->s_groups_count) { + ext4_error (sb, "ext4_get_group_desc", + "block_group >= groups_count - " + "block_group = %d, groups_count = %lu", + block_group, sbi->s_groups_count); + + return NULL; + } + smp_rmb(); + + group_desc = block_group >> EXT4_DESC_PER_BLOCK_BITS(sb); + offset = block_group & (EXT4_DESC_PER_BLOCK(sb) - 1); + if (!sbi->s_group_desc[group_desc]) { + ext4_error (sb, "ext4_get_group_desc", + "Group descriptor not loaded - " + "block_group = %d, group_desc = %lu, desc = %lu", + block_group, group_desc, offset); + return NULL; + } + + desc = (struct ext4_group_desc *) sbi->s_group_desc[group_desc]->b_data; + if (bh) + *bh = sbi->s_group_desc[group_desc]; + return desc + offset; +} + +/* + * Read the bitmap for a given block_group, reading into the specified + * slot in the superblock's bitmap cache. + * + * Return buffer_head on success or NULL in case of failure. + */ +static struct buffer_head * +read_block_bitmap(struct super_block *sb, unsigned int block_group) +{ + struct ext4_group_desc * desc; + struct buffer_head * bh = NULL; + + desc = ext4_get_group_desc (sb, block_group, NULL); + if (!desc) + goto error_out; + bh = sb_bread(sb, + EXT4_BLOCK_BITMAP(desc, + ext4_group_first_block_no(sb, block_group))); + if (!bh) + ext4_error (sb, "read_block_bitmap", + "Cannot read block bitmap - " + "block_group = %d, block_bitmap = %llu", + block_group, + EXT4_BLOCK_BITMAP(desc, + ext4_group_first_block_no(sb, block_group))); +error_out: + return bh; +} +/* + * The reservation window structure operations + * -------------------------------------------- + * Operations include: + * dump, find, add, remove, is_empty, find_next_reservable_window, etc. + * + * We use sorted double linked list for the per-filesystem reservation + * window list. (like in vm_region). + * + * Initially, we keep those small operations in the abstract functions, + * so later if we need a better searching tree than double linked-list, + * we could easily switch to that without changing too much + * code. + */ +#if 0 +static void __rsv_window_dump(struct rb_root *root, int verbose, + const char *fn) +{ + struct rb_node *n; + struct ext4_reserve_window_node *rsv, *prev; + int bad; + +restart: + n = rb_first(root); + bad = 0; + prev = NULL; + + printk("Block Allocation Reservation Windows Map (%s):\n", fn); + while (n) { + rsv = list_entry(n, struct ext4_reserve_window_node, rsv_node); + if (verbose) + printk("reservation window 0x%p " + "start: %d, end: %d\n", + rsv, rsv->rsv_start, rsv->rsv_end); + if (rsv->rsv_start && rsv->rsv_start >= rsv->rsv_end) { + printk("Bad reservation %p (start >= end)\n", + rsv); + bad = 1; + } + if (prev && prev->rsv_end >= rsv->rsv_start) { + printk("Bad reservation %p (prev->end >= start)\n", + rsv); + bad = 1; + } + if (bad) { + if (!verbose) { + printk("Restarting reservation walk in verbose mode\n"); + verbose = 1; + goto restart; + } + } + n = rb_next(n); + prev = rsv; + } + printk("Window map complete.\n"); + if (bad) + BUG(); +} +#define rsv_window_dump(root, verbose) \ + __rsv_window_dump((root), (verbose), __FUNCTION__) +#else +#define rsv_window_dump(root, verbose) do {} while (0) +#endif + +static int +goal_in_my_reservation(struct ext4_reserve_window *rsv, ext4_grpblk_t grp_goal, + unsigned int group, struct super_block * sb) +{ + ext4_fsblk_t group_first_block, group_last_block; + + group_first_block = ext4_group_first_block_no(sb, group); + group_last_block = group_first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1; + + if ((rsv->_rsv_start > group_last_block) || + (rsv->_rsv_end < group_first_block)) + return 0; + if ((grp_goal >= 0) && ((grp_goal + group_first_block < rsv->_rsv_start) + || (grp_goal + group_first_block > rsv->_rsv_end))) + return 0; + return 1; +} + +/* + * Find the reserved window which includes the goal, or the previous one + * if the goal is not in any window. + * Returns NULL if there are no windows or if all windows start after the goal. + */ +static struct ext4_reserve_window_node * +search_reserve_window(struct rb_root *root, ext4_fsblk_t goal) +{ + struct rb_node *n = root->rb_node; + struct ext4_reserve_window_node *rsv; + + if (!n) + return NULL; + + do { + rsv = rb_entry(n, struct ext4_reserve_window_node, rsv_node); + + if (goal < rsv->rsv_start) + n = n->rb_left; + else if (goal > rsv->rsv_end) + n = n->rb_right; + else + return rsv; + } while (n); + /* + * We've fallen off the end of the tree: the goal wasn't inside + * any particular node. OK, the previous node must be to one + * side of the interval containing the goal. If it's the RHS, + * we need to back up one. + */ + if (rsv->rsv_start > goal) { + n = rb_prev(&rsv->rsv_node); + rsv = rb_entry(n, struct ext4_reserve_window_node, rsv_node); + } + return rsv; +} + +void ext4_rsv_window_add(struct super_block *sb, + struct ext4_reserve_window_node *rsv) +{ + struct rb_root *root = &EXT4_SB(sb)->s_rsv_window_root; + struct rb_node *node = &rsv->rsv_node; + ext4_fsblk_t start = rsv->rsv_start; + + struct rb_node ** p = &root->rb_node; + struct rb_node * parent = NULL; + struct ext4_reserve_window_node *this; + + while (*p) + { + parent = *p; + this = rb_entry(parent, struct ext4_reserve_window_node, rsv_node); + + if (start < this->rsv_start) + p = &(*p)->rb_left; + else if (start > this->rsv_end) + p = &(*p)->rb_right; + else + BUG(); + } + + rb_link_node(node, parent, p); + rb_insert_color(node, root); +} + +static void rsv_window_remove(struct super_block *sb, + struct ext4_reserve_window_node *rsv) +{ + rsv->rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_alloc_hit = 0; + rb_erase(&rsv->rsv_node, &EXT4_SB(sb)->s_rsv_window_root); +} + +static inline int rsv_is_empty(struct ext4_reserve_window *rsv) +{ + /* a valid reservation end block could not be 0 */ + return (rsv->_rsv_end == EXT4_RESERVE_WINDOW_NOT_ALLOCATED); +} +void ext4_init_block_alloc_info(struct inode *inode) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_block_alloc_info *block_i = ei->i_block_alloc_info; + struct super_block *sb = inode->i_sb; + + block_i = kmalloc(sizeof(*block_i), GFP_NOFS); + if (block_i) { + struct ext4_reserve_window_node *rsv = &block_i->rsv_window_node; + + rsv->rsv_start = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; + rsv->rsv_end = EXT4_RESERVE_WINDOW_NOT_ALLOCATED; + + /* + * if filesystem is mounted with NORESERVATION, the goal + * reservation window size is set to zero to indicate + * block reservation is off + */ + if (!test_opt(sb, RESERVATION)) + rsv->rsv_goal_size = 0; + else + rsv->rsv_goal_size = EXT4_DEFAULT_RESERVE_BLOCKS; + rsv->rsv_alloc_hit = 0; + block_i->last_alloc_logical_block = 0; + block_i->last_alloc_physical_block = 0; + } + ei->i_block_alloc_info = block_i; +} + +void ext4_discard_reservation(struct inode *inode) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + struct ext4_block_alloc_info *block_i = ei->i_block_alloc_info; + struct ext4_reserve_window_node *rsv; + spinlock_t *rsv_lock = &EXT4_SB(inode->i_sb)->s_rsv_window_lock; + + if (!block_i) + return; + + rsv = &block_i->rsv_window_node; + if (!rsv_is_empty(&rsv->rsv_window)) { + spin_lock(rsv_lock); + if (!rsv_is_empty(&rsv->rsv_window)) + rsv_window_remove(inode->i_sb, rsv); + spin_unlock(rsv_lock); + } +} + +/* Free given blocks, update quota and i_blocks field */ +void ext4_free_blocks_sb(handle_t *handle, struct super_block *sb, + ext4_fsblk_t block, unsigned long count, + unsigned long *pdquot_freed_blocks) +{ + struct buffer_head *bitmap_bh = NULL; + struct buffer_head *gd_bh; + unsigned long block_group; + ext4_grpblk_t bit; + unsigned long i; + unsigned long overflow; + struct ext4_group_desc * desc; + struct ext4_super_block * es; + struct ext4_sb_info *sbi; + int err = 0, ret; + ext4_grpblk_t group_freed; + + *pdquot_freed_blocks = 0; + sbi = EXT4_SB(sb); + es = sbi->s_es; + if (block < le32_to_cpu(es->s_first_data_block) || + block + count < block || + block + count > ext4_blocks_count(es)) { + ext4_error (sb, "ext4_free_blocks", + "Freeing blocks not in datazone - " + "block = %llu, count = %lu", block, count); + goto error_return; + } + + ext4_debug ("freeing block(s) %lu-%lu\n", block, block + count - 1); + +do_more: + overflow = 0; + ext4_get_group_no_and_offset(sb, block, &block_group, &bit); + /* + * Check to see if we are freeing blocks across a group + * boundary. + */ + if (bit + count > EXT4_BLOCKS_PER_GROUP(sb)) { + overflow = bit + count - EXT4_BLOCKS_PER_GROUP(sb); + count -= overflow; + } + brelse(bitmap_bh); + bitmap_bh = read_block_bitmap(sb, block_group); + if (!bitmap_bh) + goto error_return; + desc = ext4_get_group_desc (sb, block_group, &gd_bh); + if (!desc) + goto error_return; + + if (in_range (EXT4_BLOCK_BITMAP(desc, + ext4_group_first_block_no(sb, block_group)), + block, count) || + in_range (EXT4_INODE_BITMAP(desc, + ext4_group_first_block_no(sb, block_group)), + block, count) || + in_range (block, + EXT4_INODE_TABLE(desc, + ext4_group_first_block_no(sb, block_group)), + sbi->s_itb_per_group) || + in_range (block + count - 1, + EXT4_INODE_TABLE(desc, + ext4_group_first_block_no(sb, block_group)), + sbi->s_itb_per_group)) + ext4_error (sb, "ext4_free_blocks", + "Freeing blocks in system zones - " + "Block = %llu, count = %lu", + block, count); + + /* + * We are about to start releasing blocks in the bitmap, + * so we need undo access. + */ + /* @@@ check errors */ + BUFFER_TRACE(bitmap_bh, "getting undo access"); + err = ext4_journal_get_undo_access(handle, bitmap_bh); + if (err) + goto error_return; + + /* + * We are about to modify some metadata. Call the journal APIs + * to unshare ->b_data if a currently-committing transaction is + * using it + */ + BUFFER_TRACE(gd_bh, "get_write_access"); + err = ext4_journal_get_write_access(handle, gd_bh); + if (err) + goto error_return; + + jbd_lock_bh_state(bitmap_bh); + + for (i = 0, group_freed = 0; i < count; i++) { + /* + * An HJ special. This is expensive... + */ +#ifdef CONFIG_JBD_DEBUG + jbd_unlock_bh_state(bitmap_bh); + { + struct buffer_head *debug_bh; + debug_bh = sb_find_get_block(sb, block + i); + if (debug_bh) { + BUFFER_TRACE(debug_bh, "Deleted!"); + if (!bh2jh(bitmap_bh)->b_committed_data) + BUFFER_TRACE(debug_bh, + "No commited data in bitmap"); + BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap"); + __brelse(debug_bh); + } + } + jbd_lock_bh_state(bitmap_bh); +#endif + if (need_resched()) { + jbd_unlock_bh_state(bitmap_bh); + cond_resched(); + jbd_lock_bh_state(bitmap_bh); + } + /* @@@ This prevents newly-allocated data from being + * freed and then reallocated within the same + * transaction. + * + * Ideally we would want to allow that to happen, but to + * do so requires making jbd2_journal_forget() capable of + * revoking the queued write of a data block, which + * implies blocking on the journal lock. *forget() + * cannot block due to truncate races. + * + * Eventually we can fix this by making jbd2_journal_forget() + * return a status indicating whether or not it was able + * to revoke the buffer. On successful revoke, it is + * safe not to set the allocation bit in the committed + * bitmap, because we know that there is no outstanding + * activity on the buffer any more and so it is safe to + * reallocate it. + */ + BUFFER_TRACE(bitmap_bh, "set in b_committed_data"); + J_ASSERT_BH(bitmap_bh, + bh2jh(bitmap_bh)->b_committed_data != NULL); + ext4_set_bit_atomic(sb_bgl_lock(sbi, block_group), bit + i, + bh2jh(bitmap_bh)->b_committed_data); + + /* + * We clear the bit in the bitmap after setting the committed + * data bit, because this is the reverse order to that which + * the allocator uses. + */ + BUFFER_TRACE(bitmap_bh, "clear bit"); + if (!ext4_clear_bit_atomic(sb_bgl_lock(sbi, block_group), + bit + i, bitmap_bh->b_data)) { + jbd_unlock_bh_state(bitmap_bh); + ext4_error(sb, __FUNCTION__, + "bit already cleared for block %llu", + block + i); + jbd_lock_bh_state(bitmap_bh); + BUFFER_TRACE(bitmap_bh, "bit already cleared"); + } else { + group_freed++; + } + } + jbd_unlock_bh_state(bitmap_bh); + + spin_lock(sb_bgl_lock(sbi, block_group)); + desc->bg_free_blocks_count = + cpu_to_le16(le16_to_cpu(desc->bg_free_blocks_count) + + group_freed); + spin_unlock(sb_bgl_lock(sbi, block_group)); + percpu_counter_mod(&sbi->s_freeblocks_counter, count); + + /* We dirtied the bitmap block */ + BUFFER_TRACE(bitmap_bh, "dirtied bitmap block"); + err = ext4_journal_dirty_metadata(handle, bitmap_bh); + + /* And the group descriptor block */ + BUFFER_TRACE(gd_bh, "dirtied group descriptor block"); + ret = ext4_journal_dirty_metadata(handle, gd_bh); + if (!err) err = ret; + *pdquot_freed_blocks += group_freed; + + if (overflow && !err) { + block += count; + count = overflow; + goto do_more; + } + sb->s_dirt = 1; +error_return: + brelse(bitmap_bh); + ext4_std_error(sb, err); + return; +} + +/* Free given blocks, update quota and i_blocks field */ +void ext4_free_blocks(handle_t *handle, struct inode *inode, + ext4_fsblk_t block, unsigned long count) +{ + struct super_block * sb; + unsigned long dquot_freed_blocks; + + sb = inode->i_sb; + if (!sb) { + printk ("ext4_free_blocks: nonexistent device"); + return; + } + ext4_free_blocks_sb(handle, sb, block, count, &dquot_freed_blocks); + if (dquot_freed_blocks) + DQUOT_FREE_BLOCK(inode, dquot_freed_blocks); + return; +} + +/* + * For ext4 allocations, we must not reuse any blocks which are + * allocated in the bitmap buffer's "last committed data" copy. This + * prevents deletes from freeing up the page for reuse until we have + * committed the delete transaction. + * + * If we didn't do this, then deleting something and reallocating it as + * data would allow the old block to be overwritten before the + * transaction committed (because we force data to disk before commit). + * This would lead to corruption if we crashed between overwriting the + * data and committing the delete. + * + * @@@ We may want to make this allocation behaviour conditional on + * data-writes at some point, and disable it for metadata allocations or + * sync-data inodes. + */ +static int ext4_test_allocatable(ext4_grpblk_t nr, struct buffer_head *bh) +{ + int ret; + struct journal_head *jh = bh2jh(bh); + + if (ext4_test_bit(nr, bh->b_data)) + return 0; + + jbd_lock_bh_state(bh); + if (!jh->b_committed_data) + ret = 1; + else + ret = !ext4_test_bit(nr, jh->b_committed_data); + jbd_unlock_bh_state(bh); + return ret; +} + +static ext4_grpblk_t +bitmap_search_next_usable_block(ext4_grpblk_t start, struct buffer_head *bh, + ext4_grpblk_t maxblocks) +{ + ext4_grpblk_t next; + struct journal_head *jh = bh2jh(bh); + + /* + * The bitmap search --- search forward alternately through the actual + * bitmap and the last-committed copy until we find a bit free in + * both + */ + while (start < maxblocks) { + next = ext4_find_next_zero_bit(bh->b_data, maxblocks, start); + if (next >= maxblocks) + return -1; + if (ext4_test_allocatable(next, bh)) + return next; + jbd_lock_bh_state(bh); + if (jh->b_committed_data) + start = ext4_find_next_zero_bit(jh->b_committed_data, + maxblocks, next); + jbd_unlock_bh_state(bh); + } + return -1; +} + +/* + * Find an allocatable block in a bitmap. We honour both the bitmap and + * its last-committed copy (if that exists), and perform the "most + * appropriate allocation" algorithm of looking for a free block near + * the initial goal; then for a free byte somewhere in the bitmap; then + * for any free bit in the bitmap. + */ +static ext4_grpblk_t +find_next_usable_block(ext4_grpblk_t start, struct buffer_head *bh, + ext4_grpblk_t maxblocks) +{ + ext4_grpblk_t here, next; + char *p, *r; + + if (start > 0) { + /* + * The goal was occupied; search forward for a free + * block within the next XX blocks. + * + * end_goal is more or less random, but it has to be + * less than EXT4_BLOCKS_PER_GROUP. Aligning up to the + * next 64-bit boundary is simple.. + */ + ext4_grpblk_t end_goal = (start + 63) & ~63; + if (end_goal > maxblocks) + end_goal = maxblocks; + here = ext4_find_next_zero_bit(bh->b_data, end_goal, start); + if (here < end_goal && ext4_test_allocatable(here, bh)) + return here; + ext4_debug("Bit not found near goal\n"); + } + + here = start; + if (here < 0) + here = 0; + + p = ((char *)bh->b_data) + (here >> 3); + r = memscan(p, 0, (maxblocks - here + 7) >> 3); + next = (r - ((char *)bh->b_data)) << 3; + + if (next < maxblocks && next >= start && ext4_test_allocatable(next, bh)) + return next; + + /* + * The bitmap search --- search forward alternately through the actual + * bitmap and the last-committed copy until we find a bit free in + * both + */ + here = bitmap_search_next_usable_block(here, bh, maxblocks); + return here; +} + +/* + * We think we can allocate this block in this bitmap. Try to set the bit. + * If that succeeds then check that nobody has allocated and then freed the + * block since we saw that is was not marked in b_committed_data. If it _was_ + * allocated and freed then clear the bit in the bitmap again and return + * zero (failure). + */ +static inline int +claim_block(spinlock_t *lock, ext4_grpblk_t block, struct buffer_head *bh) +{ + struct journal_head *jh = bh2jh(bh); + int ret; + + if (ext4_set_bit_atomic(lock, block, bh->b_data)) + return 0; + jbd_lock_bh_state(bh); + if (jh->b_committed_data && ext4_test_bit(block,jh->b_committed_data)) { + ext4_clear_bit_atomic(lock, block, bh->b_data); + ret = 0; + } else { + ret = 1; + } + jbd_unlock_bh_state(bh); + return ret; +} + +/* + * If we failed to allocate the desired block then we may end up crossing to a + * new bitmap. In that case we must release write access to the old one via + * ext4_journal_release_buffer(), else we'll run out of credits. + */ +static ext4_grpblk_t +ext4_try_to_allocate(struct super_block *sb, handle_t *handle, int group, + struct buffer_head *bitmap_bh, ext4_grpblk_t grp_goal, + unsigned long *count, struct ext4_reserve_window *my_rsv) +{ + ext4_fsblk_t group_first_block; + ext4_grpblk_t start, end; + unsigned long num = 0; + + /* we do allocation within the reservation window if we have a window */ + if (my_rsv) { + group_first_block = ext4_group_first_block_no(sb, group); + if (my_rsv->_rsv_start >= group_first_block) + start = my_rsv->_rsv_start - group_first_block; + else + /* reservation window cross group boundary */ + start = 0; + end = my_rsv->_rsv_end - group_first_block + 1; + if (end > EXT4_BLOCKS_PER_GROUP(sb)) + /* reservation window crosses group boundary */ + end = EXT4_BLOCKS_PER_GROUP(sb); + if ((start <= grp_goal) && (grp_goal < end)) + start = grp_goal; + else + grp_goal = -1; + } else { + if (grp_goal > 0) + start = grp_goal; + else + start = 0; + end = EXT4_BLOCKS_PER_GROUP(sb); + } + + BUG_ON(start > EXT4_BLOCKS_PER_GROUP(sb)); + +repeat: + if (grp_goal < 0 || !ext4_test_allocatable(grp_goal, bitmap_bh)) { + grp_goal = find_next_usable_block(start, bitmap_bh, end); + if (grp_goal < 0) + goto fail_access; + if (!my_rsv) { + int i; + + for (i = 0; i < 7 && grp_goal > start && + ext4_test_allocatable(grp_goal - 1, + bitmap_bh); + i++, grp_goal--) + ; + } + } + start = grp_goal; + + if (!claim_block(sb_bgl_lock(EXT4_SB(sb), group), grp_goal, bitmap_bh)) { + /* + * The block was allocated by another thread, or it was + * allocated and then freed by another thread + */ + start++; + grp_goal++; + if (start >= end) + goto fail_access; + goto repeat; + } + num++; + grp_goal++; + while (num < *count && grp_goal < end + && ext4_test_allocatable(grp_goal, bitmap_bh) + && claim_block(sb_bgl_lock(EXT4_SB(sb), group), grp_goal, bitmap_bh)) { + num++; + grp_goal++; + } + *count = num; + return grp_goal - num; +fail_access: + *count = num; + return -1; +} + +/** + * find_next_reservable_window(): + * find a reservable space within the given range. + * It does not allocate the reservation window for now: + * alloc_new_reservation() will do the work later. + * + * @search_head: the head of the searching list; + * This is not necessarily the list head of the whole filesystem + * + * We have both head and start_block to assist the search + * for the reservable space. The list starts from head, + * but we will shift to the place where start_block is, + * then start from there, when looking for a reservable space. + * + * @size: the target new reservation window size + * + * @group_first_block: the first block we consider to start + * the real search from + * + * @last_block: + * the maximum block number that our goal reservable space + * could start from. This is normally the last block in this + * group. The search will end when we found the start of next + * possible reservable space is out of this boundary. + * This could handle the cross boundary reservation window + * request. + * + * basically we search from the given range, rather than the whole + * reservation double linked list, (start_block, last_block) + * to find a free region that is of my size and has not + * been reserved. + * + */ +static int find_next_reservable_window( + struct ext4_reserve_window_node *search_head, + struct ext4_reserve_window_node *my_rsv, + struct super_block * sb, + ext4_fsblk_t start_block, + ext4_fsblk_t last_block) +{ + struct rb_node *next; + struct ext4_reserve_window_node *rsv, *prev; + ext4_fsblk_t cur; + int size = my_rsv->rsv_goal_size; + + /* TODO: make the start of the reservation window byte-aligned */ + /* cur = *start_block & ~7;*/ + cur = start_block; + rsv = search_head; + if (!rsv) + return -1; + + while (1) { + if (cur <= rsv->rsv_end) + cur = rsv->rsv_end + 1; + + /* TODO? + * in the case we could not find a reservable space + * that is what is expected, during the re-search, we could + * remember what's the largest reservable space we could have + * and return that one. + * + * For now it will fail if we could not find the reservable + * space with expected-size (or more)... + */ + if (cur > last_block) + return -1; /* fail */ + + prev = rsv; + next = rb_next(&rsv->rsv_node); + rsv = list_entry(next,struct ext4_reserve_window_node,rsv_node); + + /* + * Reached the last reservation, we can just append to the + * previous one. + */ + if (!next) + break; + + if (cur + size <= rsv->rsv_start) { + /* + * Found a reserveable space big enough. We could + * have a reservation across the group boundary here + */ + break; + } + } + /* + * we come here either : + * when we reach the end of the whole list, + * and there is empty reservable space after last entry in the list. + * append it to the end of the list. + * + * or we found one reservable space in the middle of the list, + * return the reservation window that we could append to. + * succeed. + */ + + if ((prev != my_rsv) && (!rsv_is_empty(&my_rsv->rsv_window))) + rsv_window_remove(sb, my_rsv); + + /* + * Let's book the whole avaliable window for now. We will check the + * disk bitmap later and then, if there are free blocks then we adjust + * the window size if it's larger than requested. + * Otherwise, we will remove this node from the tree next time + * call find_next_reservable_window. + */ + my_rsv->rsv_start = cur; + my_rsv->rsv_end = cur + size - 1; + my_rsv->rsv_alloc_hit = 0; + + if (prev != my_rsv) + ext4_rsv_window_add(sb, my_rsv); + + return 0; +} + +/** + * alloc_new_reservation()--allocate a new reservation window + * + * To make a new reservation, we search part of the filesystem + * reservation list (the list that inside the group). We try to + * allocate a new reservation window near the allocation goal, + * or the beginning of the group, if there is no goal. + * + * We first find a reservable space after the goal, then from + * there, we check the bitmap for the first free block after + * it. If there is no free block until the end of group, then the + * whole group is full, we failed. Otherwise, check if the free + * block is inside the expected reservable space, if so, we + * succeed. + * If the first free block is outside the reservable space, then + * start from the first free block, we search for next available + * space, and go on. + * + * on succeed, a new reservation will be found and inserted into the list + * It contains at least one free block, and it does not overlap with other + * reservation windows. + * + * failed: we failed to find a reservation window in this group + * + * @rsv: the reservation + * + * @grp_goal: The goal (group-relative). It is where the search for a + * free reservable space should start from. + * if we have a grp_goal(grp_goal >0 ), then start from there, + * no grp_goal(grp_goal = -1), we start from the first block + * of the group. + * + * @sb: the super block + * @group: the group we are trying to allocate in + * @bitmap_bh: the block group block bitmap + * + */ +static int alloc_new_reservation(struct ext4_reserve_window_node *my_rsv, + ext4_grpblk_t grp_goal, struct super_block *sb, + unsigned int group, struct buffer_head *bitmap_bh) +{ + struct ext4_reserve_window_node *search_head; + ext4_fsblk_t group_first_block, group_end_block, start_block; + ext4_grpblk_t first_free_block; + struct rb_root *fs_rsv_root = &EXT4_SB(sb)->s_rsv_window_root; + unsigned long size; + int ret; + spinlock_t *rsv_lock = &EXT4_SB(sb)->s_rsv_window_lock; + + group_first_block = ext4_group_first_block_no(sb, group); + group_end_block = group_first_block + EXT4_BLOCKS_PER_GROUP(sb) - 1; + + if (grp_goal < 0) + start_block = group_first_block; + else + start_block = grp_goal + group_first_block; + + size = my_rsv->rsv_goal_size; + + if (!rsv_is_empty(&my_rsv->rsv_window)) { + /* + * if the old reservation is cross group boundary + * and if the goal is inside the old reservation window, + * we will come here when we just failed to allocate from + * the first part of the window. We still have another part + * that belongs to the next group. In this case, there is no + * point to discard our window and try to allocate a new one + * in this group(which will fail). we should + * keep the reservation window, just simply move on. + * + * Maybe we could shift the start block of the reservation + * window to the first block of next group. + */ + + if ((my_rsv->rsv_start <= group_end_block) && + (my_rsv->rsv_end > group_end_block) && + (start_block >= my_rsv->rsv_start)) + return -1; + + if ((my_rsv->rsv_alloc_hit > + (my_rsv->rsv_end - my_rsv->rsv_start + 1) / 2)) { + /* + * if we previously allocation hit ration is greater than half + * we double the size of reservation window next time + * otherwise keep the same + */ + size = size * 2; + if (size > EXT4_MAX_RESERVE_BLOCKS) + size = EXT4_MAX_RESERVE_BLOCKS; + my_rsv->rsv_goal_size= size; + } + } + + spin_lock(rsv_lock); + /* + * shift the search start to the window near the goal block + */ + search_head = search_reserve_window(fs_rsv_root, start_block); + + /* + * find_next_reservable_window() simply finds a reservable window + * inside the given range(start_block, group_end_block). + * + * To make sure the reservation window has a free bit inside it, we + * need to check the bitmap after we found a reservable window. + */ +retry: + ret = find_next_reservable_window(search_head, my_rsv, sb, + start_block, group_end_block); + + if (ret == -1) { + if (!rsv_is_empty(&my_rsv->rsv_window)) + rsv_window_remove(sb, my_rsv); + spin_unlock(rsv_lock); + return -1; + } + + /* + * On success, find_next_reservable_window() returns the + * reservation window where there is a reservable space after it. + * Before we reserve this reservable space, we need + * to make sure there is at least a free block inside this region. + * + * searching the first free bit on the block bitmap and copy of + * last committed bitmap alternatively, until we found a allocatable + * block. Search start from the start block of the reservable space + * we just found. + */ + spin_unlock(rsv_lock); + first_free_block = bitmap_search_next_usable_block( + my_rsv->rsv_start - group_first_block, + bitmap_bh, group_end_block - group_first_block + 1); + + if (first_free_block < 0) { + /* + * no free block left on the bitmap, no point + * to reserve the space. return failed. + */ + spin_lock(rsv_lock); + if (!rsv_is_empty(&my_rsv->rsv_window)) + rsv_window_remove(sb, my_rsv); + spin_unlock(rsv_lock); + return -1; /* failed */ + } + + start_block = first_free_block + group_first_block; + /* + * check if the first free block is within the + * free space we just reserved + */ + if (start_block >= my_rsv->rsv_start && start_block < my_rsv->rsv_end) + return 0; /* success */ + /* + * if the first free bit we found is out of the reservable space + * continue search for next reservable space, + * start from where the free block is, + * we also shift the list head to where we stopped last time + */ + search_head = my_rsv; + spin_lock(rsv_lock); + goto retry; +} + +static void try_to_extend_reservation(struct ext4_reserve_window_node *my_rsv, + struct super_block *sb, int size) +{ + struct ext4_reserve_window_node *next_rsv; + struct rb_node *next; + spinlock_t *rsv_lock = &EXT4_SB(sb)->s_rsv_window_lock; + + if (!spin_trylock(rsv_lock)) + return; + + next = rb_next(&my_rsv->rsv_node); + + if (!next) + my_rsv->rsv_end += size; + else { + next_rsv = list_entry(next, struct ext4_reserve_window_node, rsv_node); + + if ((next_rsv->rsv_start - my_rsv->rsv_end - 1) >= size) + my_rsv->rsv_end += size; + else + my_rsv->rsv_end = next_rsv->rsv_start - 1; + } + spin_unlock(rsv_lock); +} + +/* + * This is the main function used to allocate a new block and its reservation + * window. + * + * Each time when a new block allocation is need, first try to allocate from + * its own reservation. If it does not have a reservation window, instead of + * looking for a free bit on bitmap first, then look up the reservation list to + * see if it is inside somebody else's reservation window, we try to allocate a + * reservation window for it starting from the goal first. Then do the block + * allocation within the reservation window. + * + * This will avoid keeping on searching the reservation list again and + * again when somebody is looking for a free block (without + * reservation), and there are lots of free blocks, but they are all + * being reserved. + * + * We use a sorted double linked list for the per-filesystem reservation list. + * The insert, remove and find a free space(non-reserved) operations for the + * sorted double linked list should be fast. + * + */ +static ext4_grpblk_t +ext4_try_to_allocate_with_rsv(struct super_block *sb, handle_t *handle, + unsigned int group, struct buffer_head *bitmap_bh, + ext4_grpblk_t grp_goal, + struct ext4_reserve_window_node * my_rsv, + unsigned long *count, int *errp) +{ + ext4_fsblk_t group_first_block; + ext4_grpblk_t ret = 0; + int fatal; + unsigned long num = *count; + + *errp = 0; + + /* + * Make sure we use undo access for the bitmap, because it is critical + * that we do the frozen_data COW on bitmap buffers in all cases even + * if the buffer is in BJ_Forget state in the committing transaction. + */ + BUFFER_TRACE(bitmap_bh, "get undo access for new block"); + fatal = ext4_journal_get_undo_access(handle, bitmap_bh); + if (fatal) { + *errp = fatal; + return -1; + } + + /* + * we don't deal with reservation when + * filesystem is mounted without reservation + * or the file is not a regular file + * or last attempt to allocate a block with reservation turned on failed + */ + if (my_rsv == NULL ) { + ret = ext4_try_to_allocate(sb, handle, group, bitmap_bh, + grp_goal, count, NULL); + goto out; + } + /* + * grp_goal is a group relative block number (if there is a goal) + * 0 < grp_goal < EXT4_BLOCKS_PER_GROUP(sb) + * first block is a filesystem wide block number + * first block is the block number of the first block in this group + */ + group_first_block = ext4_group_first_block_no(sb, group); + + /* + * Basically we will allocate a new block from inode's reservation + * window. + * + * We need to allocate a new reservation window, if: + * a) inode does not have a reservation window; or + * b) last attempt to allocate a block from existing reservation + * failed; or + * c) we come here with a goal and with a reservation window + * + * We do not need to allocate a new reservation window if we come here + * at the beginning with a goal and the goal is inside the window, or + * we don't have a goal but already have a reservation window. + * then we could go to allocate from the reservation window directly. + */ + while (1) { + if (rsv_is_empty(&my_rsv->rsv_window) || (ret < 0) || + !goal_in_my_reservation(&my_rsv->rsv_window, grp_goal, group, sb)) { + if (my_rsv->rsv_goal_size < *count) + my_rsv->rsv_goal_size = *count; + ret = alloc_new_reservation(my_rsv, grp_goal, sb, + group, bitmap_bh); + if (ret < 0) + break; /* failed */ + + if (!goal_in_my_reservation(&my_rsv->rsv_window, grp_goal, group, sb)) + grp_goal = -1; + } else if (grp_goal > 0 && (my_rsv->rsv_end-grp_goal+1) < *count) + try_to_extend_reservation(my_rsv, sb, + *count-my_rsv->rsv_end + grp_goal - 1); + + if ((my_rsv->rsv_start >= group_first_block + EXT4_BLOCKS_PER_GROUP(sb)) + || (my_rsv->rsv_end < group_first_block)) + BUG(); + ret = ext4_try_to_allocate(sb, handle, group, bitmap_bh, grp_goal, + &num, &my_rsv->rsv_window); + if (ret >= 0) { + my_rsv->rsv_alloc_hit += num; + *count = num; + break; /* succeed */ + } + num = *count; + } +out: + if (ret >= 0) { + BUFFER_TRACE(bitmap_bh, "journal_dirty_metadata for " + "bitmap block"); + fatal = ext4_journal_dirty_metadata(handle, bitmap_bh); + if (fatal) { + *errp = fatal; + return -1; + } + return ret; + } + + BUFFER_TRACE(bitmap_bh, "journal_release_buffer"); + ext4_journal_release_buffer(handle, bitmap_bh); + return ret; +} + +static int ext4_has_free_blocks(struct ext4_sb_info *sbi) +{ + ext4_fsblk_t free_blocks, root_blocks; + + free_blocks = percpu_counter_read_positive(&sbi->s_freeblocks_counter); + root_blocks = ext4_r_blocks_count(sbi->s_es); + if (free_blocks < root_blocks + 1 && !capable(CAP_SYS_RESOURCE) && + sbi->s_resuid != current->fsuid && + (sbi->s_resgid == 0 || !in_group_p (sbi->s_resgid))) { + return 0; + } + return 1; +} + +/* + * ext4_should_retry_alloc() is called when ENOSPC is returned, and if + * it is profitable to retry the operation, this function will wait + * for the current or commiting transaction to complete, and then + * return TRUE. + */ +int ext4_should_retry_alloc(struct super_block *sb, int *retries) +{ + if (!ext4_has_free_blocks(EXT4_SB(sb)) || (*retries)++ > 3) + return 0; + + jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id); + + return jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal); +} + +/* + * ext4_new_block uses a goal block to assist allocation. If the goal is + * free, or there is a free block within 32 blocks of the goal, that block + * is allocated. Otherwise a forward search is made for a free block; within + * each block group the search first looks for an entire free byte in the block + * bitmap, and then for any free bit if that fails. + * This function also updates quota and i_blocks field. + */ +ext4_fsblk_t ext4_new_blocks(handle_t *handle, struct inode *inode, + ext4_fsblk_t goal, unsigned long *count, int *errp) +{ + struct buffer_head *bitmap_bh = NULL; + struct buffer_head *gdp_bh; + unsigned long group_no; + int goal_group; + ext4_grpblk_t grp_target_blk; /* blockgroup relative goal block */ + ext4_grpblk_t grp_alloc_blk; /* blockgroup-relative allocated block*/ + ext4_fsblk_t ret_block; /* filesyetem-wide allocated block */ + int bgi; /* blockgroup iteration index */ + int fatal = 0, err; + int performed_allocation = 0; + ext4_grpblk_t free_blocks; /* number of free blocks in a group */ + struct super_block *sb; + struct ext4_group_desc *gdp; + struct ext4_super_block *es; + struct ext4_sb_info *sbi; + struct ext4_reserve_window_node *my_rsv = NULL; + struct ext4_block_alloc_info *block_i; + unsigned short windowsz = 0; +#ifdef EXT4FS_DEBUG + static int goal_hits, goal_attempts; +#endif + unsigned long ngroups; + unsigned long num = *count; + + *errp = -ENOSPC; + sb = inode->i_sb; + if (!sb) { + printk("ext4_new_block: nonexistent device"); + return 0; + } + + /* + * Check quota for allocation of this block. + */ + if (DQUOT_ALLOC_BLOCK(inode, num)) { + *errp = -EDQUOT; + return 0; + } + + sbi = EXT4_SB(sb); + es = EXT4_SB(sb)->s_es; + ext4_debug("goal=%lu.\n", goal); + /* + * Allocate a block from reservation only when + * filesystem is mounted with reservation(default,-o reservation), and + * it's a regular file, and + * the desired window size is greater than 0 (One could use ioctl + * command EXT4_IOC_SETRSVSZ to set the window size to 0 to turn off + * reservation on that particular file) + */ + block_i = EXT4_I(inode)->i_block_alloc_info; + if (block_i && ((windowsz = block_i->rsv_window_node.rsv_goal_size) > 0)) + my_rsv = &block_i->rsv_window_node; + + if (!ext4_has_free_blocks(sbi)) { + *errp = -ENOSPC; + goto out; + } + + /* + * First, test whether the goal block is free. + */ + if (goal < le32_to_cpu(es->s_first_data_block) || + goal >= ext4_blocks_count(es)) + goal = le32_to_cpu(es->s_first_data_block); + ext4_get_group_no_and_offset(sb, goal, &group_no, &grp_target_blk); + goal_group = group_no; +retry_alloc: + gdp = ext4_get_group_desc(sb, group_no, &gdp_bh); + if (!gdp) + goto io_error; + + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); + /* + * if there is not enough free blocks to make a new resevation + * turn off reservation for this allocation + */ + if (my_rsv && (free_blocks < windowsz) + && (rsv_is_empty(&my_rsv->rsv_window))) + my_rsv = NULL; + + if (free_blocks > 0) { + bitmap_bh = read_block_bitmap(sb, group_no); + if (!bitmap_bh) + goto io_error; + grp_alloc_blk = ext4_try_to_allocate_with_rsv(sb, handle, + group_no, bitmap_bh, grp_target_blk, + my_rsv, &num, &fatal); + if (fatal) + goto out; + if (grp_alloc_blk >= 0) + goto allocated; + } + + ngroups = EXT4_SB(sb)->s_groups_count; + smp_rmb(); + + /* + * Now search the rest of the groups. We assume that + * i and gdp correctly point to the last group visited. + */ + for (bgi = 0; bgi < ngroups; bgi++) { + group_no++; + if (group_no >= ngroups) + group_no = 0; + gdp = ext4_get_group_desc(sb, group_no, &gdp_bh); + if (!gdp) { + *errp = -EIO; + goto out; + } + free_blocks = le16_to_cpu(gdp->bg_free_blocks_count); + /* + * skip this group if the number of + * free blocks is less than half of the reservation + * window size. + */ + if (free_blocks <= (windowsz/2)) + continue; + + brelse(bitmap_bh); + bitmap_bh = read_block_bitmap(sb, group_no); + if (!bitmap_bh) + goto io_error; + /* + * try to allocate block(s) from this group, without a goal(-1). + */ + grp_alloc_blk = ext4_try_to_allocate_with_rsv(sb, handle, + group_no, bitmap_bh, -1, my_rsv, + &num, &fatal); + if (fatal) + goto out; + if (grp_alloc_blk >= 0) + goto allocated; + } + /* + * We may end up a bogus ealier ENOSPC error due to + * filesystem is "full" of reservations, but + * there maybe indeed free blocks avaliable on disk + * In this case, we just forget about the reservations + * just do block allocation as without reservations. + */ + if (my_rsv) { + my_rsv = NULL; + group_no = goal_group; + goto retry_alloc; + } + /* No space left on the device */ + *errp = -ENOSPC; + goto out; + +allocated: + + ext4_debug("using block group %d(%d)\n", + group_no, gdp->bg_free_blocks_count); + + BUFFER_TRACE(gdp_bh, "get_write_access"); + fatal = ext4_journal_get_write_access(handle, gdp_bh); + if (fatal) + goto out; + + ret_block = grp_alloc_blk + ext4_group_first_block_no(sb, group_no); + + if (in_range(EXT4_BLOCK_BITMAP(gdp, ext4_group_first_block_no(sb, group_no)), + ret_block, num) || + in_range(EXT4_BLOCK_BITMAP(gdp, ext4_group_first_block_no(sb, group_no)), + ret_block, num) || + in_range(ret_block, EXT4_INODE_TABLE(gdp, + ext4_group_first_block_no(sb, group_no)), + EXT4_SB(sb)->s_itb_per_group) || + in_range(ret_block + num - 1, EXT4_INODE_TABLE(gdp, + ext4_group_first_block_no(sb, group_no)), + EXT4_SB(sb)->s_itb_per_group)) + ext4_error(sb, "ext4_new_block", + "Allocating block in system zone - " + "blocks from %llu, length %lu", + ret_block, num); + + performed_allocation = 1; + +#ifdef CONFIG_JBD_DEBUG + { + struct buffer_head *debug_bh; + + /* Record bitmap buffer state in the newly allocated block */ + debug_bh = sb_find_get_block(sb, ret_block); + if (debug_bh) { + BUFFER_TRACE(debug_bh, "state when allocated"); + BUFFER_TRACE2(debug_bh, bitmap_bh, "bitmap state"); + brelse(debug_bh); + } + } + jbd_lock_bh_state(bitmap_bh); + spin_lock(sb_bgl_lock(sbi, group_no)); + if (buffer_jbd(bitmap_bh) && bh2jh(bitmap_bh)->b_committed_data) { + int i; + + for (i = 0; i < num; i++) { + if (ext4_test_bit(grp_alloc_blk+i, + bh2jh(bitmap_bh)->b_committed_data)) { + printk("%s: block was unexpectedly set in " + "b_committed_data\n", __FUNCTION__); + } + } + } + ext4_debug("found bit %d\n", grp_alloc_blk); + spin_unlock(sb_bgl_lock(sbi, group_no)); + jbd_unlock_bh_state(bitmap_bh); +#endif + + if (ret_block + num - 1 >= ext4_blocks_count(es)) { + ext4_error(sb, "ext4_new_block", + "block(%llu) >= blocks count(%llu) - " + "block_group = %lu, es == %p ", ret_block, + ext4_blocks_count(es), group_no, es); + goto out; + } + + /* + * It is up to the caller to add the new buffer to a journal + * list of some description. We don't know in advance whether + * the caller wants to use it as metadata or data. + */ + ext4_debug("allocating block %lu. Goal hits %d of %d.\n", + ret_block, goal_hits, goal_attempts); + + spin_lock(sb_bgl_lock(sbi, group_no)); + gdp->bg_free_blocks_count = + cpu_to_le16(le16_to_cpu(gdp->bg_free_blocks_count) - num); + spin_unlock(sb_bgl_lock(sbi, group_no)); + percpu_counter_mod(&sbi->s_freeblocks_counter, -num); + + BUFFER_TRACE(gdp_bh, "journal_dirty_metadata for group descriptor"); + err = ext4_journal_dirty_metadata(handle, gdp_bh); + if (!fatal) + fatal = err; + + sb->s_dirt = 1; + if (fatal) + goto out; + + *errp = 0; + brelse(bitmap_bh); + DQUOT_FREE_BLOCK(inode, *count-num); + *count = num; + return ret_block; + +io_error: + *errp = -EIO; +out: + if (fatal) { + *errp = fatal; + ext4_std_error(sb, fatal); + } + /* + * Undo the block allocation + */ + if (!performed_allocation) + DQUOT_FREE_BLOCK(inode, *count); + brelse(bitmap_bh); + return 0; +} + +ext4_fsblk_t ext4_new_block(handle_t *handle, struct inode *inode, + ext4_fsblk_t goal, int *errp) +{ + unsigned long count = 1; + + return ext4_new_blocks(handle, inode, goal, &count, errp); +} + +ext4_fsblk_t ext4_count_free_blocks(struct super_block *sb) +{ + ext4_fsblk_t desc_count; + struct ext4_group_desc *gdp; + int i; + unsigned long ngroups = EXT4_SB(sb)->s_groups_count; +#ifdef EXT4FS_DEBUG + struct ext4_super_block *es; + ext4_fsblk_t bitmap_count; + unsigned long x; + struct buffer_head *bitmap_bh = NULL; + + es = EXT4_SB(sb)->s_es; + desc_count = 0; + bitmap_count = 0; + gdp = NULL; + + smp_rmb(); + for (i = 0; i < ngroups; i++) { + gdp = ext4_get_group_desc(sb, i, NULL); + if (!gdp) + continue; + desc_count += le16_to_cpu(gdp->bg_free_blocks_count); + brelse(bitmap_bh); + bitmap_bh = read_block_bitmap(sb, i); + if (bitmap_bh == NULL) + continue; + + x = ext4_count_free(bitmap_bh, sb->s_blocksize); + printk("group %d: stored = %d, counted = %lu\n", + i, le16_to_cpu(gdp->bg_free_blocks_count), x); + bitmap_count += x; + } + brelse(bitmap_bh); + printk("ext4_count_free_blocks: stored = %llu" + ", computed = %llu, %llu\n", + EXT4_FREE_BLOCKS_COUNT(es), + desc_count, bitmap_count); + return bitmap_count; +#else + desc_count = 0; + smp_rmb(); + for (i = 0; i < ngroups; i++) { + gdp = ext4_get_group_desc(sb, i, NULL); + if (!gdp) + continue; + desc_count += le16_to_cpu(gdp->bg_free_blocks_count); + } + + return desc_count; +#endif +} + +static inline int +block_in_use(ext4_fsblk_t block, struct super_block *sb, unsigned char *map) +{ + ext4_grpblk_t offset; + + ext4_get_group_no_and_offset(sb, block, NULL, &offset); + return ext4_test_bit (offset, map); +} + +static inline int test_root(int a, int b) +{ + int num = b; + + while (a > num) + num *= b; + return num == a; +} + +static int ext4_group_sparse(int group) +{ + if (group <= 1) + return 1; + if (!(group & 1)) + return 0; + return (test_root(group, 7) || test_root(group, 5) || + test_root(group, 3)); +} + +/** + * ext4_bg_has_super - number of blocks used by the superblock in group + * @sb: superblock for filesystem + * @group: group number to check + * + * Return the number of blocks used by the superblock (primary or backup) + * in this group. Currently this will be only 0 or 1. + */ +int ext4_bg_has_super(struct super_block *sb, int group) +{ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) && + !ext4_group_sparse(group)) + return 0; + return 1; +} + +static unsigned long ext4_bg_num_gdb_meta(struct super_block *sb, int group) +{ + unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb); + unsigned long first = metagroup * EXT4_DESC_PER_BLOCK(sb); + unsigned long last = first + EXT4_DESC_PER_BLOCK(sb) - 1; + + if (group == first || group == first + 1 || group == last) + return 1; + return 0; +} + +static unsigned long ext4_bg_num_gdb_nometa(struct super_block *sb, int group) +{ + if (EXT4_HAS_RO_COMPAT_FEATURE(sb, + EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER) && + !ext4_group_sparse(group)) + return 0; + return EXT4_SB(sb)->s_gdb_count; +} + +/** + * ext4_bg_num_gdb - number of blocks used by the group table in group + * @sb: superblock for filesystem + * @group: group number to check + * + * Return the number of blocks used by the group descriptor table + * (primary or backup) in this group. In the future there may be a + * different number of descriptor blocks in each group. + */ +unsigned long ext4_bg_num_gdb(struct super_block *sb, int group) +{ + unsigned long first_meta_bg = + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_meta_bg); + unsigned long metagroup = group / EXT4_DESC_PER_BLOCK(sb); + + if (!EXT4_HAS_INCOMPAT_FEATURE(sb,EXT4_FEATURE_INCOMPAT_META_BG) || + metagroup < first_meta_bg) + return ext4_bg_num_gdb_nometa(sb,group); + + return ext4_bg_num_gdb_meta(sb,group); + +} diff -puN /dev/null fs/ext4/bitmap.c --- /dev/null 2006-09-07 07:04:09.114355360 -0700 +++ linux-2.6.18-rc6-ming/fs/ext4/bitmap.c 2006-09-07 23:19:15.472800397 -0700 @@ -0,0 +1,32 @@ +/* + * linux/fs/ext4/bitmap.c + * + * Copyright (C) 1992, 1993, 1994, 1995 + * Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + */ + +#include +#include +#include + +#ifdef EXT4FS_DEBUG + +static int nibblemap[] = {4, 3, 3, 2, 3, 2, 2, 1, 3, 2, 2, 1, 2, 1, 1, 0}; + +unsigned long ext4_count_free (struct buffer_head * map, unsigned int numchars) +{ + unsigned int i; + unsigned long sum = 0; + + if (!map) + return (0); + for (i = 0; i < numchars; i++) + sum += nibblemap[map->b_data[i] & 0xf] + + nibblemap[(map->b_data[i] >> 4) & 0xf]; + return (sum); +} + +#endif /* EXT4FS_DEBUG */ + diff -puN /dev/null fs/ext4/dir.c --- /dev/null 2006-09-07 07:04:09.114355360 -0700 +++ linux-2.6.18-rc6-ming/fs/ext4/dir.c 2006-09-07 23:19:15.501796840 -0700 @@ -0,0 +1,515 @@ +/* + * linux/fs/ext4/dir.c + * + * Copyright (C) 1992, 1993, 1994, 1995 + * Remy Card (card@masi.ibp.fr) + * Laboratoire MASI - Institut Blaise Pascal + * Universite Pierre et Marie Curie (Paris VI) + * + * from + * + * linux/fs/minix/dir.c + * + * Copyright (C) 1991, 1992 Linus Torvalds + * + * ext4 directory handling functions + * + * Big-endian to little-endian byte-swapping/bitmaps by + * David S. Miller (davem@caip.rutgers.edu), 1995 + * + * Hash Tree Directory indexing (c) 2001 Daniel Phillips + * + */ + +#include +#include +#include +#include +#include +#include +#include + +static unsigned char ext4_filetype_table[] = { + DT_UNKNOWN, DT_REG, DT_DIR, DT_CHR, DT_BLK, DT_FIFO, DT_SOCK, DT_LNK +}; + +static int ext4_readdir(struct file *, void *, filldir_t); +static int ext4_dx_readdir(struct file * filp, + void * dirent, filldir_t filldir); +static int ext4_release_dir (struct inode * inode, + struct file * filp); + +const struct file_operations ext4_dir_operations = { + .llseek = generic_file_llseek, + .read = generic_read_dir, + .readdir = ext4_readdir, /* we take BKL. needed?*/ + .ioctl = ext4_ioctl, /* BKL held */ + .fsync = ext4_sync_file, /* BKL held */ +#ifdef CONFIG_EXT4_INDEX + .release = ext4_release_dir, +#endif +}; + + +static unsigned char get_dtype(struct super_block *sb, int filetype) +{ + if (!EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_FILETYPE) || + (filetype >= EXT4_FT_MAX)) + return DT_UNKNOWN; + + return (ext4_filetype_table[filetype]); +} + + +int ext4_check_dir_entry (const char * function, struct inode * dir, + struct ext4_dir_entry_2 * de, + struct buffer_head * bh, + unsigned long offset) +{ + const char * error_msg = NULL; + const int rlen = le16_to_cpu(de->rec_len); + + if (rlen < EXT4_DIR_REC_LEN(1)) + error_msg = "rec_len is smaller than minimal"; + else if (rlen % 4 != 0) + error_msg = "rec_len % 4 != 0"; + else if (rlen < EXT4_DIR_REC_LEN(de->name_len)) + error_msg = "rec_len is too small for name_len"; + else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize) + error_msg = "directory entry across blocks"; + else if (le32_to_cpu(de->inode) > + le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)) + error_msg = "inode out of bounds"; + + if (error_msg != NULL) + ext4_error (dir->i_sb, function, + "bad entry in directory #%lu: %s - " + "offset=%lu, inode=%lu, rec_len=%d, name_len=%d", + dir->i_ino, error_msg, offset, + (unsigned long) le32_to_cpu(de->inode), + rlen, de->name_len); + return error_msg == NULL ? 1 : 0; +} + +static int ext4_readdir(struct file * filp, + void * dirent, filldir_t filldir) +{ + int error = 0; + unsigned long offset; + int i, stored; + struct ext4_dir_entry_2 *de; + struct super_block *sb; + int err; + struct inode *inode = filp->f_dentry->d_inode; + int ret = 0; + + sb = inode->i_sb; + +#ifdef CONFIG_EXT4_INDEX + if (EXT4_HAS_COMPAT_FEATURE(inode->i_sb, + EXT4_FEATURE_COMPAT_DIR_INDEX) && + ((EXT4_I(inode)->i_flags & EXT4_INDEX_FL) || + ((inode->i_size >> sb->s_blocksize_bits) == 1))) { + err = ext4_dx_readdir(filp, dirent, filldir); + if (err != ERR_BAD_DX_DIR) { + ret = err; + goto out; + } + /* + * We don't set the inode dirty flag since it's not + * critical that it get flushed back to the disk. + */ + EXT4_I(filp->f_dentry->d_inode)->i_flags &= ~EXT4_INDEX_FL; + } +#endif + stored = 0; + offset = filp->f_pos & (sb->s_blocksize - 1); + + while (!error && !stored && filp->f_pos < inode->i_size) { + unsigned long blk = filp->f_pos >> EXT4_BLOCK_SIZE_BITS(sb); + struct buffer_head map_bh; + struct buffer_head *bh = NULL; + + map_bh.b_state = 0; + err = ext4_get_blocks_wrap(NULL, inode, blk, 1, &map_bh, 0, 0); + if (err > 0) { + page_cache_readahead(sb->s_bdev->bd_inode->i_mapping, + &filp->f_ra, + filp, + map_bh.b_blocknr >> + (PAGE_CACHE_SHIFT - inode->i_blkbits), + 1); + bh = ext4_bread(NULL, inode, blk, 0, &err); + } + + /* + * We ignore I/O errors on directories so users have a chance + * of recovering data when there's a bad sector + */ + if (!bh) { + ext4_error (sb, "ext4_readdir", + "directory #%lu contains a hole at offset %lu", + inode->i_ino, (unsigned long)filp->f_pos); + filp->f_pos += sb->s_blocksize - offset; + continue; + } + +revalidate: + /* If the dir block has changed since the last call to + * readdir(2), then we might be pointing to an invalid + * dirent right now. Scan from the start of the block + * to make sure. */ + if (filp->f_version != inode->i_version) { + for (i = 0; i < sb->s_blocksize && i < offset; ) { + de = (struct ext4_dir_entry_2 *) + (bh->b_data + i); + /* It's too expensive to do a full + * dirent test each time round this + * loop, but we do have to test at + * least that it is non-zero. A + * failure will be detected in the + * dirent test below. */ + if (le16_to_cpu(de->rec_len) < + EXT4_DIR_REC_LEN(1)) + break; + i += le16_to_cpu(de->rec_len); + } + offset = i; + filp->f_pos = (filp->f_pos & ~(sb->s_blocksize - 1)) + | offset; + filp->f_version = inode->i_version; + } + + while (!error && filp->f_pos < inode->i_size + && offset < sb->s_blocksize) { + de = (struct ext4_dir_entry_2 *) (bh->b_data + offset); + if (!ext4_check_dir_entry ("ext4_readdir", inode, de, + bh, offset)) { + /* On error, skip the f_pos to the + next block. */ + filp->f_pos = (filp->f_pos | + (sb->s_blocksize - 1)) + 1; + brelse (bh); + ret = stored; + goto out; + } + offset += le16_to_cpu(de->rec_len); + if (le32_to_cpu(de->inode)) { + /* We might block in the next section + * if the data destination is + * currently swapped out. So, use a + * version stamp to detect whether or + * not the directory has been modified + * during the copy operation. + */ + unsigned long version = filp->f_version; + + error = filldir(dirent, de->name, + de->name_len, + filp->f_pos, + le32_to_cpu(de->inode), + get_dtype(sb, de->file_type)); + if (error) + break; + if (version != filp->f_version) + goto revalidate; + stored ++; + } + filp->f_pos += le16_to_cpu(de->rec_len); + } + offset = 0; + brelse (bh); + } +out: + return ret; +} + +#ifdef CONFIG_EXT4_INDEX +/* + * These functions convert from the major/minor hash to an f_pos + * value. + * + * Currently we only use major hash numer. This is unfortunate, but + * on 32-bit machines, the same VFS interface is used for lseek and + * llseek, so if we use the 64 bit offset, then the 32-bit versions of + * lseek/telldir/seekdir will blow out spectacularly, and from within + * the ext2 low-level routine, we don't know if we're being called by + * a 64-bit version of the system call or the 32-bit version of the + * system call. Worse yet, NFSv2 only allows for a 32-bit readdir + * cookie. Sigh. + */ +#define hash2pos(major, minor) (major >> 1) +#define pos2maj_hash(pos) ((pos << 1) & 0xffffffff) +#define pos2min_hash(pos) (0) + +/* + * This structure holds the nodes of the red-black tree used to store + * the directory entry in hash order. + */ +struct fname { + __u32 hash; + __u32 minor_hash; + struct rb_node rb_hash; + struct fname *next; + __u32 inode; + __u8 name_len; + __u8 file_type; + char name[0]; +}; + +/* + * This functoin implements a non-recursive way of freeing all of the + * nodes in the red-black tree. + */ +static void free_rb_tree_fname(struct rb_root *root) +{ + struct rb_node *n = root->rb_node; + struct rb_node *parent; + struct fname *fname; + + while (n) { + /* Do the node's children first */ + if ((n)->rb_left) { + n = n->rb_left; + continue; + } + if (n->rb_right) { + n = n->rb_right; + continue; + } + /* + * The node has no children; free it, and then zero + * out parent's link to it. Finally go to the + * beginning of the loop and try to free the parent + * node. + */ + parent = rb_parent(n); + fname = rb_entry(n, struct fname, rb_hash); + while (fname) { + struct fname * old = fname; + fname = fname->next; + kfree (old); + } + if (!parent) + root->rb_node = NULL; + else if (parent->rb_left == n) + parent->rb_left = NULL; + else if (parent->rb_right == n) + parent->rb_right = NULL; + n = parent; + } + root->rb_node = NULL; +} + + +static struct dir_private_info *create_dir_info(loff_t pos) +{ + struct dir_private_info *p; + + p = kmalloc(sizeof(struct dir_private_info), GFP_KERNEL); + if (!p) + return NULL; + p->root.rb_node = NULL; + p->curr_node = NULL; + p->extra_fname = NULL; + p->last_pos = 0; + p->curr_hash = pos2maj_hash(pos); + p->curr_minor_hash = pos2min_hash(pos); + p->next_hash = 0; + return p; +} + +void ext4_htree_free_dir_info(struct dir_private_info *p) +{ + free_rb_tree_fname(&p->root); + kfree(p); +} + +/* + * Given a directory entry, enter it into the fname rb tree. + */ +int ext4_htree_store_dirent(struct file *dir_file, __u32 hash, + __u32 minor_hash, + struct ext4_dir_entry_2 *dirent) +{ + struct rb_node **p, *parent = NULL; + struct fname * fname, *new_fn; + struct dir_private_info *info; + int len; + + info = (struct dir_private_info *) dir_file->private_data; + p = &info->root.rb_node; + + /* Create and allocate the fname structure */ + len = sizeof(struct fname) + dirent->name_len + 1; + new_fn = kmalloc(len, GFP_KERNEL); + if (!new_fn) + return -ENOMEM; + memset(new_fn, 0, len); + new_fn->hash = hash; + new_fn->minor_hash = minor_hash; + new_fn->inode = le32_to_cpu(dirent->inode); + new_fn->name_len = dirent->name_len; + new_fn->file_type = dirent->file_type; + memcpy(new_fn->name, dirent->name, dirent->name_len); + new_fn->name[dirent->name_len] = 0; + + while (*p) { + parent = *p; + fname = rb_entry(parent, struct fname, rb_hash); + + /* + * If the hash and minor hash match up, then we put + * them on a linked list. This rarely happens... + */ + if ((new_fn->hash == fname->hash) && + (new_fn->minor_hash == fname->minor_hash)) { + new_fn->next = fname->next; + fname->next = new_fn; + return 0; + } + + if (new_fn->hash < fname->hash) + p = &(*p)->rb_left; + else if (new_fn->hash > fname->hash) + p = &(*p)->rb_right; + else if (new_fn->minor_hash < fname->minor_hash) + p = &(*p)->rb_left; + else /* if (new_fn->minor_hash > fname->minor_hash) */ + p = &(*p)->rb_right; + } + + rb_link_node(&new_fn->rb_hash, parent, p); + rb_insert_color(&new_fn->rb_hash, &info->root); + return 0; +} + + + +/* + * This is a helper function for ext4_dx_readdir. It calls filldir + * for all entres on the fname linked list. (Normally there is only + * one entry on the linked list, unless there are 62 bit hash collisions.) + */ +static int call_filldir(struct file * filp, void * dirent, + filldir_t filldir, struct fname *fname) +{ + struct dir_private_info *info = filp->private_data; + loff_t curr_pos; + struct inode *inode = filp->f_dentry->d_inode; + struct super_block * sb; + int error; + + sb = inode->i_sb; + + if (!fname) { + printk("call_filldir: called with null fname?!?\n"); + return 0; + } + curr_pos = hash2pos(fname->hash, fname->minor_hash); + while (fname) { + error = filldir(dirent, fname->name, + fname->name_len, curr_pos, + fname->inode, + get_dtype(sb, fname->file_type)); + if (error) { + filp->f_pos = curr_pos; + info->extra_fname = fname->next; + return error; + } + fname = fname->next; + } + return 0; +} + +static int ext4_dx_readdir(struct file * filp, + void * dirent, filldir_t filldir) +{ + struct dir_private_info *info = filp->private_data; + struct inode *inode = filp->f_dentry->d_inode; + struct fname *fname; + int ret; + + if (!info) { + info = create_dir_info(filp->f_pos); + if (!info) + return -ENOMEM; + filp->private_data = info; + } + + if (filp->f_pos == EXT4_HTREE_EOF) + return 0; /* EOF */ + + /* Some one has messed with f_pos; reset the world */ + if (info->last_pos != filp->f_pos) { + free_rb_tree_fname(&info->root); + info->curr_node = NULL; + info->extra_fname = NULL; + info->curr_hash = pos2maj_hash(filp->f_pos); + info->curr_minor_hash = pos2min_hash(filp->f_pos); + } + + /* + * If there are any leftover names on the hash collision + * chain, return them first. + */ + if (info->extra_fname && + call_filldir(filp, dirent, filldir, info->extra_fname)) + goto finished; + + if (!info->curr_node) + info->curr_node = rb_first(&info->root); + + while (1) { + /* + * Fill the rbtree if we have no more entries, + * or the inode has changed since we last read in the + * cached entries. + */ + if ((!info->curr_node) || + (filp->f_version != inode->i_version)) { + info->curr_node = NULL; + free_rb_tree_fname(&info->root); + filp->f_version = inode->i_version; + ret = ext4_htree_fill_tree(filp, info->curr_hash, + info->curr_minor_hash, + &info->next_hash); + if (ret < 0) + return ret; + if (ret == 0) { + filp->f_pos = EXT4_HTREE_EOF; + break; + } + info->curr_node = rb_first(&info->root); + } + + fname = rb_entry(info->curr_node, struct fname, rb_hash); + info->curr_hash = fname->hash; + info->curr_minor_hash = fname->minor_hash; + if (call_filldir(filp, dirent, filldir, fname)) + break; + + info->curr_node = rb_next(info->curr_node); + if (!info->curr_node) { + if (info->next_hash == ~0) { + filp->f_pos = EXT4_HTREE_EOF; + break; + } + info->curr_hash = info->next_hash; + info->curr_minor_hash = 0; + } + } +finished: + info->last_pos = filp->f_pos; + return 0; +} + +static int ext4_release_dir (struct inode * inode, struct file * filp) +{ + if (filp->private_data) + ext4_htree_free_dir_info(filp->private_data); + + return 0; +} + +#endif diff -puN /dev/null fs/ext4/extents.c --- /dev/null 2006-09-07 07:04:09.114355360 -0700 +++ linux-2.6.18-rc6-ming/fs/ext4/extents.c 2006-09-07 23:19:16.093724231 -0700 @@ -0,0 +1,2151 @@ +/* + * Copyright (c) 2003-2006, Cluster File Systems, Inc, info@clusterfs.com + * Written by Alex Tomas + * + * Architecture independence: + * Copyright (c) 2005, Bull S.A. + * Written by Pierre Peiffer + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public Licens + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111- + */ + +/* + * Extents support for EXT4 + * + * TODO: + * - ext4*_error() should be used in some situations + * - analyze all BUG()/BUG_ON(), use -EIO where appropriate + * - smart tree reduction + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + + +/* + * ext_pblock: + * combine low and high parts of physical block number into ext4_fsblk_t + */ +static inline ext4_fsblk_t ext_pblock(struct ext4_extent *ex) +{ + ext4_fsblk_t block; + + block = le32_to_cpu(ex->ee_start); + block |= ((ext4_fsblk_t) le16_to_cpu(ex->ee_start_hi) << 31) << 1; + return block; +} + +/* + * idx_pblock: + * combine low and high parts of a leaf physical block number into ext4_fsblk_t + */ +static inline ext4_fsblk_t idx_pblock(struct ext4_extent_idx *ix) +{ + ext4_fsblk_t block; + + block = le32_to_cpu(ix->ei_leaf); + block |= ((ext4_fsblk_t) le16_to_cpu(ix->ei_leaf_hi) << 31) << 1; + return block; +} + +/* + * ext4_ext_store_pblock: + * stores a large physical block number into an extent struct, + * breaking it into parts + */ +static inline void ext4_ext_store_pblock(struct ext4_extent *ex, ext4_fsblk_t pb) +{ + ex->ee_start = cpu_to_le32((unsigned long) (pb & 0xffffffff)); + ex->ee_start_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); +} + +/* + * ext4_idx_store_pblock: + * stores a large physical block number into an index struct, + * breaking it into parts + */ +static inline void ext4_idx_store_pblock(struct ext4_extent_idx *ix, ext4_fsblk_t pb) +{ + ix->ei_leaf = cpu_to_le32((unsigned long) (pb & 0xffffffff)); + ix->ei_leaf_hi = cpu_to_le16((unsigned long) ((pb >> 31) >> 1) & 0xffff); +} + +static int ext4_ext_check_header(const char *function, struct inode *inode, + struct ext4_extent_header *eh) +{ + const char *error_msg = NULL; + + if (unlikely(eh->eh_magic != EXT4_EXT_MAGIC)) { + error_msg = "invalid magic"; + goto corrupted; + } + if (unlikely(eh->eh_max == 0)) { + error_msg = "invalid eh_max"; + goto corrupted; + } + if (unlikely(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max))) { + error_msg = "invalid eh_entries"; + goto corrupted; + } + return 0; + +corrupted: + ext4_error(inode->i_sb, function, + "bad header in inode #%lu: %s - magic %x, " + "entries %u, max %u, depth %u", + inode->i_ino, error_msg, le16_to_cpu(eh->eh_magic), + le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max), + le16_to_cpu(eh->eh_depth)); + + return -EIO; +} + +static handle_t *ext4_ext_journal_restart(handle_t *handle, int needed) +{ + int err; + + if (handle->h_buffer_credits > needed) + return handle; + if (!ext4_journal_extend(handle, needed)) + return handle; + err = ext4_journal_restart(handle, needed); + + return handle; +} + +/* + * could return: + * - EROFS + * - ENOMEM + */ +static int ext4_ext_get_access(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + if (path->p_bh) { + /* path points to block */ + return ext4_journal_get_write_access(handle, path->p_bh); + } + /* path points to leaf/index in inode body */ + /* we use in-core data, no need to protect them */ + return 0; +} + +/* + * could return: + * - EROFS + * - ENOMEM + * - EIO + */ +static int ext4_ext_dirty(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + int err; + if (path->p_bh) { + /* path points to block */ + err = ext4_journal_dirty_metadata(handle, path->p_bh); + } else { + /* path points to leaf/index in inode body */ + err = ext4_mark_inode_dirty(handle, inode); + } + return err; +} + +static ext4_fsblk_t ext4_ext_find_goal(struct inode *inode, + struct ext4_ext_path *path, + ext4_fsblk_t block) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + ext4_fsblk_t bg_start; + ext4_grpblk_t colour; + int depth; + + if (path) { + struct ext4_extent *ex; + depth = path->p_depth; + + /* try to predict block placement */ + if ((ex = path[depth].p_ext)) + return ext_pblock(ex)+(block-le32_to_cpu(ex->ee_block)); + + /* it looks like index is empty; + * try to find starting block from index itself */ + if (path[depth].p_bh) + return path[depth].p_bh->b_blocknr; + } + + /* OK. use inode's group */ + bg_start = (ei->i_block_group * EXT4_BLOCKS_PER_GROUP(inode->i_sb)) + + le32_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_first_data_block); + colour = (current->pid % 16) * + (EXT4_BLOCKS_PER_GROUP(inode->i_sb) / 16); + return bg_start + colour + block; +} + +static ext4_fsblk_t +ext4_ext_new_block(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *ex, int *err) +{ + ext4_fsblk_t goal, newblock; + + goal = ext4_ext_find_goal(inode, path, le32_to_cpu(ex->ee_block)); + newblock = ext4_new_block(handle, inode, goal, err); + return newblock; +} + +static inline int ext4_ext_space_block(struct inode *inode) +{ + int size; + + size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) + / sizeof(struct ext4_extent); +#ifdef AGRESSIVE_TEST + if (size > 6) + size = 6; +#endif + return size; +} + +static inline int ext4_ext_space_block_idx(struct inode *inode) +{ + int size; + + size = (inode->i_sb->s_blocksize - sizeof(struct ext4_extent_header)) + / sizeof(struct ext4_extent_idx); +#ifdef AGRESSIVE_TEST + if (size > 5) + size = 5; +#endif + return size; +} + +static inline int ext4_ext_space_root(struct inode *inode) +{ + int size; + + size = sizeof(EXT4_I(inode)->i_data); + size -= sizeof(struct ext4_extent_header); + size /= sizeof(struct ext4_extent); +#ifdef AGRESSIVE_TEST + if (size > 3) + size = 3; +#endif + return size; +} + +static inline int ext4_ext_space_root_idx(struct inode *inode) +{ + int size; + + size = sizeof(EXT4_I(inode)->i_data); + size -= sizeof(struct ext4_extent_header); + size /= sizeof(struct ext4_extent_idx); +#ifdef AGRESSIVE_TEST + if (size > 4) + size = 4; +#endif + return size; +} + +#ifdef EXT_DEBUG +static void ext4_ext_show_path(struct inode *inode, struct ext4_ext_path *path) +{ + int k, l = path->p_depth; + + ext_debug("path:"); + for (k = 0; k <= l; k++, path++) { + if (path->p_idx) { + ext_debug(" %d->%llu", le32_to_cpu(path->p_idx->ei_block), + idx_pblock(path->p_idx)); + } else if (path->p_ext) { + ext_debug(" %d:%d:%llu ", + le32_to_cpu(path->p_ext->ee_block), + le16_to_cpu(path->p_ext->ee_len), + ext_pblock(path->p_ext)); + } else + ext_debug(" []"); + } + ext_debug("\n"); +} + +static void ext4_ext_show_leaf(struct inode *inode, struct ext4_ext_path *path) +{ + int depth = ext_depth(inode); + struct ext4_extent_header *eh; + struct ext4_extent *ex; + int i; + + if (!path) + return; + + eh = path[depth].p_hdr; + ex = EXT_FIRST_EXTENT(eh); + + for (i = 0; i < le16_to_cpu(eh->eh_entries); i++, ex++) { + ext_debug("%d:%d:%llu ", le32_to_cpu(ex->ee_block), + le16_to_cpu(ex->ee_len), ext_pblock(ex)); + } + ext_debug("\n"); +} +#else +#define ext4_ext_show_path(inode,path) +#define ext4_ext_show_leaf(inode,path) +#endif + +static void ext4_ext_drop_refs(struct ext4_ext_path *path) +{ + int depth = path->p_depth; + int i; + + for (i = 0; i <= depth; i++, path++) + if (path->p_bh) { + brelse(path->p_bh); + path->p_bh = NULL; + } +} + +/* + * ext4_ext_binsearch_idx: + * binary search for the closest index of the given block + */ +static void +ext4_ext_binsearch_idx(struct inode *inode, struct ext4_ext_path *path, int block) +{ + struct ext4_extent_header *eh = path->p_hdr; + struct ext4_extent_idx *r, *l, *m; + + BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); + BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); + BUG_ON(le16_to_cpu(eh->eh_entries) <= 0); + + ext_debug("binsearch for %d(idx): ", block); + + l = EXT_FIRST_INDEX(eh) + 1; + r = EXT_FIRST_INDEX(eh) + le16_to_cpu(eh->eh_entries) - 1; + while (l <= r) { + m = l + (r - l) / 2; + if (block < le32_to_cpu(m->ei_block)) + r = m - 1; + else + l = m + 1; + ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ei_block, + m, m->ei_block, r, r->ei_block); + } + + path->p_idx = l - 1; + ext_debug(" -> %d->%lld ", le32_to_cpu(path->p_idx->ei_block), + idx_block(path->p_idx)); + +#ifdef CHECK_BINSEARCH + { + struct ext4_extent_idx *chix, *ix; + int k; + + chix = ix = EXT_FIRST_INDEX(eh); + for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ix++) { + if (k != 0 && + le32_to_cpu(ix->ei_block) <= le32_to_cpu(ix[-1].ei_block)) { + printk("k=%d, ix=0x%p, first=0x%p\n", k, + ix, EXT_FIRST_INDEX(eh)); + printk("%u <= %u\n", + le32_to_cpu(ix->ei_block), + le32_to_cpu(ix[-1].ei_block)); + } + BUG_ON(k && le32_to_cpu(ix->ei_block) + <= le32_to_cpu(ix[-1].ei_block)); + if (block < le32_to_cpu(ix->ei_block)) + break; + chix = ix; + } + BUG_ON(chix != path->p_idx); + } +#endif + +} + +/* + * ext4_ext_binsearch: + * binary search for closest extent of the given block + */ +static void +ext4_ext_binsearch(struct inode *inode, struct ext4_ext_path *path, int block) +{ + struct ext4_extent_header *eh = path->p_hdr; + struct ext4_extent *r, *l, *m; + + BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); + BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); + + if (eh->eh_entries == 0) { + /* + * this leaf is empty: + * we get such a leaf in split/add case + */ + return; + } + + ext_debug("binsearch for %d: ", block); + + l = EXT_FIRST_EXTENT(eh) + 1; + r = EXT_FIRST_EXTENT(eh) + le16_to_cpu(eh->eh_entries) - 1; + + while (l <= r) { + m = l + (r - l) / 2; + if (block < le32_to_cpu(m->ee_block)) + r = m - 1; + else + l = m + 1; + ext_debug("%p(%u):%p(%u):%p(%u) ", l, l->ee_block, + m, m->ee_block, r, r->ee_block); + } + + path->p_ext = l - 1; + ext_debug(" -> %d:%llu:%d ", + le32_to_cpu(path->p_ext->ee_block), + ext_pblock(path->p_ext), + le16_to_cpu(path->p_ext->ee_len)); + +#ifdef CHECK_BINSEARCH + { + struct ext4_extent *chex, *ex; + int k; + + chex = ex = EXT_FIRST_EXTENT(eh); + for (k = 0; k < le16_to_cpu(eh->eh_entries); k++, ex++) { + BUG_ON(k && le32_to_cpu(ex->ee_block) + <= le32_to_cpu(ex[-1].ee_block)); + if (block < le32_to_cpu(ex->ee_block)) + break; + chex = ex; + } + BUG_ON(chex != path->p_ext); + } +#endif + +} + +int ext4_ext_tree_init(handle_t *handle, struct inode *inode) +{ + struct ext4_extent_header *eh; + + eh = ext_inode_hdr(inode); + eh->eh_depth = 0; + eh->eh_entries = 0; + eh->eh_magic = EXT4_EXT_MAGIC; + eh->eh_max = cpu_to_le16(ext4_ext_space_root(inode)); + ext4_mark_inode_dirty(handle, inode); + ext4_ext_invalidate_cache(inode); + return 0; +} + +struct ext4_ext_path * +ext4_ext_find_extent(struct inode *inode, int block, struct ext4_ext_path *path) +{ + struct ext4_extent_header *eh; + struct buffer_head *bh; + short int depth, i, ppos = 0, alloc = 0; + + eh = ext_inode_hdr(inode); + BUG_ON(eh == NULL); + if (ext4_ext_check_header(__FUNCTION__, inode, eh)) + return ERR_PTR(-EIO); + + i = depth = ext_depth(inode); + + /* account possible depth increase */ + if (!path) { + path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 2), + GFP_NOFS); + if (!path) + return ERR_PTR(-ENOMEM); + alloc = 1; + } + memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1)); + path[0].p_hdr = eh; + + /* walk through the tree */ + while (i) { + ext_debug("depth %d: num %d, max %d\n", + ppos, le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); + ext4_ext_binsearch_idx(inode, path + ppos, block); + path[ppos].p_block = idx_pblock(path[ppos].p_idx); + path[ppos].p_depth = i; + path[ppos].p_ext = NULL; + + bh = sb_bread(inode->i_sb, path[ppos].p_block); + if (!bh) + goto err; + + eh = ext_block_hdr(bh); + ppos++; + BUG_ON(ppos > depth); + path[ppos].p_bh = bh; + path[ppos].p_hdr = eh; + i--; + + if (ext4_ext_check_header(__FUNCTION__, inode, eh)) + goto err; + } + + path[ppos].p_depth = i; + path[ppos].p_hdr = eh; + path[ppos].p_ext = NULL; + path[ppos].p_idx = NULL; + + if (ext4_ext_check_header(__FUNCTION__, inode, eh)) + goto err; + + /* find extent */ + ext4_ext_binsearch(inode, path + ppos, block); + + ext4_ext_show_path(inode, path); + + return path; + +err: + ext4_ext_drop_refs(path); + if (alloc) + kfree(path); + return ERR_PTR(-EIO); +} + +/* + * ext4_ext_insert_index: + * insert new index [@logical;@ptr] into the block at @curp; + * check where to insert: before @curp or after @curp + */ +static int ext4_ext_insert_index(handle_t *handle, struct inode *inode, + struct ext4_ext_path *curp, + int logical, ext4_fsblk_t ptr) +{ + struct ext4_extent_idx *ix; + int len, err; + + if ((err = ext4_ext_get_access(handle, inode, curp))) + return err; + + BUG_ON(logical == le32_to_cpu(curp->p_idx->ei_block)); + len = EXT_MAX_INDEX(curp->p_hdr) - curp->p_idx; + if (logical > le32_to_cpu(curp->p_idx->ei_block)) { + /* insert after */ + if (curp->p_idx != EXT_LAST_INDEX(curp->p_hdr)) { + len = (len - 1) * sizeof(struct ext4_extent_idx); + len = len < 0 ? 0 : len; + ext_debug("insert new index %d after: %d. " + "move %d from 0x%p to 0x%p\n", + logical, ptr, len, + (curp->p_idx + 1), (curp->p_idx + 2)); + memmove(curp->p_idx + 2, curp->p_idx + 1, len); + } + ix = curp->p_idx + 1; + } else { + /* insert before */ + len = len * sizeof(struct ext4_extent_idx); + len = len < 0 ? 0 : len; + ext_debug("insert new index %d before: %d. " + "move %d from 0x%p to 0x%p\n", + logical, ptr, len, + curp->p_idx, (curp->p_idx + 1)); + memmove(curp->p_idx + 1, curp->p_idx, len); + ix = curp->p_idx; + } + + ix->ei_block = cpu_to_le32(logical); + ext4_idx_store_pblock(ix, ptr); + curp->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(curp->p_hdr->eh_entries)+1); + + BUG_ON(le16_to_cpu(curp->p_hdr->eh_entries) + > le16_to_cpu(curp->p_hdr->eh_max)); + BUG_ON(ix > EXT_LAST_INDEX(curp->p_hdr)); + + err = ext4_ext_dirty(handle, inode, curp); + ext4_std_error(inode->i_sb, err); + + return err; +} + +/* + * ext4_ext_split: + * inserts new subtree into the path, using free index entry + * at depth @at: + * - allocates all needed blocks (new leaf and all intermediate index blocks) + * - makes decision where to split + * - moves remaining extents and index entries (right to the split point) + * into the newly allocated blocks + * - initializes subtree + */ +static int ext4_ext_split(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *newext, int at) +{ + struct buffer_head *bh = NULL; + int depth = ext_depth(inode); + struct ext4_extent_header *neh; + struct ext4_extent_idx *fidx; + struct ext4_extent *ex; + int i = at, k, m, a; + ext4_fsblk_t newblock, oldblock; + __le32 border; + ext4_fsblk_t *ablocks = NULL; /* array of allocated blocks */ + int err = 0; + + /* make decision: where to split? */ + /* FIXME: now decision is simplest: at current extent */ + + /* if current leaf will be split, then we should use + * border from split point */ + BUG_ON(path[depth].p_ext > EXT_MAX_EXTENT(path[depth].p_hdr)); + if (path[depth].p_ext != EXT_MAX_EXTENT(path[depth].p_hdr)) { + border = path[depth].p_ext[1].ee_block; + ext_debug("leaf will be split." + " next leaf starts at %d\n", + le32_to_cpu(border)); + } else { + border = newext->ee_block; + ext_debug("leaf will be added." + " next leaf starts at %d\n", + le32_to_cpu(border)); + } + + /* + * If error occurs, then we break processing + * and mark filesystem read-only. index won't + * be inserted and tree will be in consistent + * state. Next mount will repair buffers too. + */ + + /* + * Get array to track all allocated blocks. + * We need this to handle errors and free blocks + * upon them. + */ + ablocks = kmalloc(sizeof(ext4_fsblk_t) * depth, GFP_NOFS); + if (!ablocks) + return -ENOMEM; + memset(ablocks, 0, sizeof(ext4_fsblk_t) * depth); + + /* allocate all needed blocks */ + ext_debug("allocate %d blocks for indexes/leaf\n", depth - at); + for (a = 0; a < depth - at; a++) { + newblock = ext4_ext_new_block(handle, inode, path, newext, &err); + if (newblock == 0) + goto cleanup; + ablocks[a] = newblock; + } + + /* initialize new leaf */ + newblock = ablocks[--a]; + BUG_ON(newblock == 0); + bh = sb_getblk(inode->i_sb, newblock); + if (!bh) { + err = -EIO; + goto cleanup; + } + lock_buffer(bh); + + if ((err = ext4_journal_get_create_access(handle, bh))) + goto cleanup; + + neh = ext_block_hdr(bh); + neh->eh_entries = 0; + neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); + neh->eh_magic = EXT4_EXT_MAGIC; + neh->eh_depth = 0; + ex = EXT_FIRST_EXTENT(neh); + + /* move remainder of path[depth] to the new leaf */ + BUG_ON(path[depth].p_hdr->eh_entries != path[depth].p_hdr->eh_max); + /* start copy from next extent */ + /* TODO: we could do it by single memmove */ + m = 0; + path[depth].p_ext++; + while (path[depth].p_ext <= + EXT_MAX_EXTENT(path[depth].p_hdr)) { + ext_debug("move %d:%llu:%d in new leaf %llu\n", + le32_to_cpu(path[depth].p_ext->ee_block), + ext_pblock(path[depth].p_ext), + le16_to_cpu(path[depth].p_ext->ee_len), + newblock); + /*memmove(ex++, path[depth].p_ext++, + sizeof(struct ext4_extent)); + neh->eh_entries++;*/ + path[depth].p_ext++; + m++; + } + if (m) { + memmove(ex, path[depth].p_ext-m, sizeof(struct ext4_extent)*m); + neh->eh_entries = cpu_to_le16(le16_to_cpu(neh->eh_entries)+m); + } + + set_buffer_uptodate(bh); + unlock_buffer(bh); + + if ((err = ext4_journal_dirty_metadata(handle, bh))) + goto cleanup; + brelse(bh); + bh = NULL; + + /* correct old leaf */ + if (m) { + if ((err = ext4_ext_get_access(handle, inode, path + depth))) + goto cleanup; + path[depth].p_hdr->eh_entries = + cpu_to_le16(le16_to_cpu(path[depth].p_hdr->eh_entries)-m); + if ((err = ext4_ext_dirty(handle, inode, path + depth))) + goto cleanup; + + } + + /* create intermediate indexes */ + k = depth - at - 1; + BUG_ON(k < 0); + if (k) + ext_debug("create %d intermediate indices\n", k); + /* insert new index into current index block */ + /* current depth stored in i var */ + i = depth - 1; + while (k--) { + oldblock = newblock; + newblock = ablocks[--a]; + bh = sb_getblk(inode->i_sb, (ext4_fsblk_t)newblock); + if (!bh) { + err = -EIO; + goto cleanup; + } + lock_buffer(bh); + + if ((err = ext4_journal_get_create_access(handle, bh))) + goto cleanup; + + neh = ext_block_hdr(bh); + neh->eh_entries = cpu_to_le16(1); + neh->eh_magic = EXT4_EXT_MAGIC; + neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); + neh->eh_depth = cpu_to_le16(depth - i); + fidx = EXT_FIRST_INDEX(neh); + fidx->ei_block = border; + ext4_idx_store_pblock(fidx, oldblock); + + ext_debug("int.index at %d (block %llu): %lu -> %llu\n", i, + newblock, (unsigned long) le32_to_cpu(border), + oldblock); + /* copy indexes */ + m = 0; + path[i].p_idx++; + + ext_debug("cur 0x%p, last 0x%p\n", path[i].p_idx, + EXT_MAX_INDEX(path[i].p_hdr)); + BUG_ON(EXT_MAX_INDEX(path[i].p_hdr) != + EXT_LAST_INDEX(path[i].p_hdr)); + while (path[i].p_idx <= EXT_MAX_INDEX(path[i].p_hdr)) { + ext_debug("%d: move %d:%d in new index %llu\n", i, + le32_to_cpu(path[i].p_idx->ei_block), + idx_pblock(path[i].p_idx), + newblock); + /*memmove(++fidx, path[i].p_idx++, + sizeof(struct ext4_extent_idx)); + neh->eh_entries++; + BUG_ON(neh->eh_entries > neh->eh_max);*/ + path[i].p_idx++; + m++; + } + if (m) { + memmove(++fidx, path[i].p_idx - m, + sizeof(struct ext4_extent_idx) * m); + neh->eh_entries = + cpu_to_le16(le16_to_cpu(neh->eh_entries) + m); + } + set_buffer_uptodate(bh); + unlock_buffer(bh); + + if ((err = ext4_journal_dirty_metadata(handle, bh))) + goto cleanup; + brelse(bh); + bh = NULL; + + /* correct old index */ + if (m) { + err = ext4_ext_get_access(handle, inode, path + i); + if (err) + goto cleanup; + path[i].p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path[i].p_hdr->eh_entries)-m); + err = ext4_ext_dirty(handle, inode, path + i); + if (err) + goto cleanup; + } + + i--; + } + + /* insert new index */ + if (err) + goto cleanup; + + err = ext4_ext_insert_index(handle, inode, path + at, + le32_to_cpu(border), newblock); + +cleanup: + if (bh) { + if (buffer_locked(bh)) + unlock_buffer(bh); + brelse(bh); + } + + if (err) { + /* free all allocated blocks in error case */ + for (i = 0; i < depth; i++) { + if (!ablocks[i]) + continue; + ext4_free_blocks(handle, inode, ablocks[i], 1); + } + } + kfree(ablocks); + + return err; +} + +/* + * ext4_ext_grow_indepth: + * implements tree growing procedure: + * - allocates new block + * - moves top-level data (index block or leaf) into the new block + * - initializes new top-level, creating index that points to the + * just created block + */ +static int ext4_ext_grow_indepth(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *newext) +{ + struct ext4_ext_path *curp = path; + struct ext4_extent_header *neh; + struct ext4_extent_idx *fidx; + struct buffer_head *bh; + ext4_fsblk_t newblock; + int err = 0; + + newblock = ext4_ext_new_block(handle, inode, path, newext, &err); + if (newblock == 0) + return err; + + bh = sb_getblk(inode->i_sb, newblock); + if (!bh) { + err = -EIO; + ext4_std_error(inode->i_sb, err); + return err; + } + lock_buffer(bh); + + if ((err = ext4_journal_get_create_access(handle, bh))) { + unlock_buffer(bh); + goto out; + } + + /* move top-level index/leaf into new block */ + memmove(bh->b_data, curp->p_hdr, sizeof(EXT4_I(inode)->i_data)); + + /* set size of new block */ + neh = ext_block_hdr(bh); + /* old root could have indexes or leaves + * so calculate e_max right way */ + if (ext_depth(inode)) + neh->eh_max = cpu_to_le16(ext4_ext_space_block_idx(inode)); + else + neh->eh_max = cpu_to_le16(ext4_ext_space_block(inode)); + neh->eh_magic = EXT4_EXT_MAGIC; + set_buffer_uptodate(bh); + unlock_buffer(bh); + + if ((err = ext4_journal_dirty_metadata(handle, bh))) + goto out; + + /* create index in new top-level index: num,max,pointer */ + if ((err = ext4_ext_get_access(handle, inode, curp))) + goto out; + + curp->p_hdr->eh_magic = EXT4_EXT_MAGIC; + curp->p_hdr->eh_max = cpu_to_le16(ext4_ext_space_root_idx(inode)); + curp->p_hdr->eh_entries = cpu_to_le16(1); + curp->p_idx = EXT_FIRST_INDEX(curp->p_hdr); + /* FIXME: it works, but actually path[0] can be index */ + curp->p_idx->ei_block = EXT_FIRST_EXTENT(path[0].p_hdr)->ee_block; + ext4_idx_store_pblock(curp->p_idx, newblock); + + neh = ext_inode_hdr(inode); + fidx = EXT_FIRST_INDEX(neh); + ext_debug("new root: num %d(%d), lblock %d, ptr %llu\n", + le16_to_cpu(neh->eh_entries), le16_to_cpu(neh->eh_max), + le32_to_cpu(fidx->ei_block), idx_pblock(fidx)); + + neh->eh_depth = cpu_to_le16(path->p_depth + 1); + err = ext4_ext_dirty(handle, inode, curp); +out: + brelse(bh); + + return err; +} + +/* + * ext4_ext_create_new_leaf: + * finds empty index and adds new leaf. + * if no free index is found, then it requests in-depth growing. + */ +static int ext4_ext_create_new_leaf(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *newext) +{ + struct ext4_ext_path *curp; + int depth, i, err = 0; + +repeat: + i = depth = ext_depth(inode); + + /* walk up to the tree and look for free index entry */ + curp = path + depth; + while (i > 0 && !EXT_HAS_FREE_INDEX(curp)) { + i--; + curp--; + } + + /* we use already allocated block for index block, + * so subsequent data blocks should be contiguous */ + if (EXT_HAS_FREE_INDEX(curp)) { + /* if we found index with free entry, then use that + * entry: create all needed subtree and add new leaf */ + err = ext4_ext_split(handle, inode, path, newext, i); + + /* refill path */ + ext4_ext_drop_refs(path); + path = ext4_ext_find_extent(inode, + le32_to_cpu(newext->ee_block), + path); + if (IS_ERR(path)) + err = PTR_ERR(path); + } else { + /* tree is full, time to grow in depth */ + err = ext4_ext_grow_indepth(handle, inode, path, newext); + if (err) + goto out; + + /* refill path */ + ext4_ext_drop_refs(path); + path = ext4_ext_find_extent(inode, + le32_to_cpu(newext->ee_block), + path); + if (IS_ERR(path)) { + err = PTR_ERR(path); + goto out; + } + + /* + * only first (depth 0 -> 1) produces free space; + * in all other cases we have to split the grown tree + */ + depth = ext_depth(inode); + if (path[depth].p_hdr->eh_entries == path[depth].p_hdr->eh_max) { + /* now we need to split */ + goto repeat; + } + } + +out: + return err; +} + +/* + * ext4_ext_next_allocated_block: + * returns allocated block in subsequent extent or EXT_MAX_BLOCK. + * NOTE: it considers block number from index entry as + * allocated block. Thus, index entries have to be consistent + * with leaves. + */ +static unsigned long +ext4_ext_next_allocated_block(struct ext4_ext_path *path) +{ + int depth; + + BUG_ON(path == NULL); + depth = path->p_depth; + + if (depth == 0 && path->p_ext == NULL) + return EXT_MAX_BLOCK; + + while (depth >= 0) { + if (depth == path->p_depth) { + /* leaf */ + if (path[depth].p_ext != + EXT_LAST_EXTENT(path[depth].p_hdr)) + return le32_to_cpu(path[depth].p_ext[1].ee_block); + } else { + /* index */ + if (path[depth].p_idx != + EXT_LAST_INDEX(path[depth].p_hdr)) + return le32_to_cpu(path[depth].p_idx[1].ei_block); + } + depth--; + } + + return EXT_MAX_BLOCK; +} + +/* + * ext4_ext_next_leaf_block: + * returns first allocated block from next leaf or EXT_MAX_BLOCK + */ +static unsigned ext4_ext_next_leaf_block(struct inode *inode, + struct ext4_ext_path *path) +{ + int depth; + + BUG_ON(path == NULL); + depth = path->p_depth; + + /* zero-tree has no leaf blocks at all */ + if (depth == 0) + return EXT_MAX_BLOCK; + + /* go to index block */ + depth--; + + while (depth >= 0) { + if (path[depth].p_idx != + EXT_LAST_INDEX(path[depth].p_hdr)) + return le32_to_cpu(path[depth].p_idx[1].ei_block); + depth--; + } + + return EXT_MAX_BLOCK; +} + +/* + * ext4_ext_correct_indexes: + * if leaf gets modified and modified extent is first in the leaf, + * then we have to correct all indexes above. + * TODO: do we need to correct tree in all cases? + */ +int ext4_ext_correct_indexes(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + struct ext4_extent_header *eh; + int depth = ext_depth(inode); + struct ext4_extent *ex; + __le32 border; + int k, err = 0; + + eh = path[depth].p_hdr; + ex = path[depth].p_ext; + BUG_ON(ex == NULL); + BUG_ON(eh == NULL); + + if (depth == 0) { + /* there is no tree at all */ + return 0; + } + + if (ex != EXT_FIRST_EXTENT(eh)) { + /* we correct tree if first leaf got modified only */ + return 0; + } + + /* + * TODO: we need correction if border is smaller than current one + */ + k = depth - 1; + border = path[depth].p_ext->ee_block; + if ((err = ext4_ext_get_access(handle, inode, path + k))) + return err; + path[k].p_idx->ei_block = border; + if ((err = ext4_ext_dirty(handle, inode, path + k))) + return err; + + while (k--) { + /* change all left-side indexes */ + if (path[k+1].p_idx != EXT_FIRST_INDEX(path[k+1].p_hdr)) + break; + if ((err = ext4_ext_get_access(handle, inode, path + k))) + break; + path[k].p_idx->ei_block = border; + if ((err = ext4_ext_dirty(handle, inode, path + k))) + break; + } + + return err; +} + +static int inline +ext4_can_extents_be_merged(struct inode *inode, struct ext4_extent *ex1, + struct ext4_extent *ex2) +{ + if (le32_to_cpu(ex1->ee_block) + le16_to_cpu(ex1->ee_len) + != le32_to_cpu(ex2->ee_block)) + return 0; + + /* + * To allow future support for preallocated extents to be added + * as an RO_COMPAT feature, refuse to merge to extents if + * this can result in the top bit of ee_len being set. + */ + if (le16_to_cpu(ex1->ee_len) + le16_to_cpu(ex2->ee_len) > EXT_MAX_LEN) + return 0; +#ifdef AGRESSIVE_TEST + if (le16_to_cpu(ex1->ee_len) >= 4) + return 0; +#endif + + if (ext_pblock(ex1) + le16_to_cpu(ex1->ee_len) == ext_pblock(ex2)) + return 1; + return 0; +} + +/* + * ext4_ext_insert_extent: + * tries to merge requsted extent into the existing extent or + * inserts requested extent as new one into the tree, + * creating new leaf in the no-space case. + */ +int ext4_ext_insert_extent(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, + struct ext4_extent *newext) +{ + struct ext4_extent_header * eh; + struct ext4_extent *ex, *fex; + struct ext4_extent *nearex; /* nearest extent */ + struct ext4_ext_path *npath = NULL; + int depth, len, err, next; + + BUG_ON(newext->ee_len == 0); + depth = ext_depth(inode); + ex = path[depth].p_ext; + BUG_ON(path[depth].p_hdr == NULL); + + /* try to insert block into found extent and return */ + if (ex && ext4_can_extents_be_merged(inode, ex, newext)) { + ext_debug("append %d block to %d:%d (from %llu)\n", + le16_to_cpu(newext->ee_len), + le32_to_cpu(ex->ee_block), + le16_to_cpu(ex->ee_len), ext_pblock(ex)); + if ((err = ext4_ext_get_access(handle, inode, path + depth))) + return err; + ex->ee_len = cpu_to_le16(le16_to_cpu(ex->ee_len) + + le16_to_cpu(newext->ee_len)); + eh = path[depth].p_hdr; + nearex = ex; + goto merge; + } + +repeat: + depth = ext_depth(inode); + eh = path[depth].p_hdr; + if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) + goto has_space; + + /* probably next leaf has space for us? */ + fex = EXT_LAST_EXTENT(eh); + next = ext4_ext_next_leaf_block(inode, path); + if (le32_to_cpu(newext->ee_block) > le32_to_cpu(fex->ee_block) + && next != EXT_MAX_BLOCK) { + ext_debug("next leaf block - %d\n", next); + BUG_ON(npath != NULL); + npath = ext4_ext_find_extent(inode, next, NULL); + if (IS_ERR(npath)) + return PTR_ERR(npath); + BUG_ON(npath->p_depth != path->p_depth); + eh = npath[depth].p_hdr; + if (le16_to_cpu(eh->eh_entries) < le16_to_cpu(eh->eh_max)) { + ext_debug("next leaf isnt full(%d)\n", + le16_to_cpu(eh->eh_entries)); + path = npath; + goto repeat; + } + ext_debug("next leaf has no free space(%d,%d)\n", + le16_to_cpu(eh->eh_entries), le16_to_cpu(eh->eh_max)); + } + + /* + * There is no free space in the found leaf. + * We're gonna add a new leaf in the tree. + */ + err = ext4_ext_create_new_leaf(handle, inode, path, newext); + if (err) + goto cleanup; + depth = ext_depth(inode); + eh = path[depth].p_hdr; + +has_space: + nearex = path[depth].p_ext; + + if ((err = ext4_ext_get_access(handle, inode, path + depth))) + goto cleanup; + + if (!nearex) { + /* there is no extent in this leaf, create first one */ + ext_debug("first extent in the leaf: %d:%llu:%d\n", + le32_to_cpu(newext->ee_block), + ext_pblock(newext), + le16_to_cpu(newext->ee_len)); + path[depth].p_ext = EXT_FIRST_EXTENT(eh); + } else if (le32_to_cpu(newext->ee_block) + > le32_to_cpu(nearex->ee_block)) { +/* BUG_ON(newext->ee_block == nearex->ee_block); */ + if (nearex != EXT_LAST_EXTENT(eh)) { + len = EXT_MAX_EXTENT(eh) - nearex; + len = (len - 1) * sizeof(struct ext4_extent); + len = len < 0 ? 0 : len; + ext_debug("insert %d:%llu:%d after: nearest 0x%p, " + "move %d from 0x%p to 0x%p\n", + le32_to_cpu(newext->ee_block), + ext_pblock(newext), + le16_to_cpu(newext->ee_len), + nearex, len, nearex + 1, nearex + 2); + memmove(nearex + 2, nearex + 1, len); + } + path[depth].p_ext = nearex + 1; + } else { + BUG_ON(newext->ee_block == nearex->ee_block); + len = (EXT_MAX_EXTENT(eh) - nearex) * sizeof(struct ext4_extent); + len = len < 0 ? 0 : len; + ext_debug("insert %d:%llu:%d before: nearest 0x%p, " + "move %d from 0x%p to 0x%p\n", + le32_to_cpu(newext->ee_block), + ext_pblock(newext), + le16_to_cpu(newext->ee_len), + nearex, len, nearex + 1, nearex + 2); + memmove(nearex + 1, nearex, len); + path[depth].p_ext = nearex; + } + + eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)+1); + nearex = path[depth].p_ext; + nearex->ee_block = newext->ee_block; + nearex->ee_start = newext->ee_start; + nearex->ee_start_hi = newext->ee_start_hi; + nearex->ee_len = newext->ee_len; + +merge: + /* try to merge extents to the right */ + while (nearex < EXT_LAST_EXTENT(eh)) { + if (!ext4_can_extents_be_merged(inode, nearex, nearex + 1)) + break; + /* merge with next extent! */ + nearex->ee_len = cpu_to_le16(le16_to_cpu(nearex->ee_len) + + le16_to_cpu(nearex[1].ee_len)); + if (nearex + 1 < EXT_LAST_EXTENT(eh)) { + len = (EXT_LAST_EXTENT(eh) - nearex - 1) + * sizeof(struct ext4_extent); + memmove(nearex + 1, nearex + 2, len); + } + eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); + BUG_ON(eh->eh_entries == 0); + } + + /* try to merge extents to the left */ + + /* time to correct all indexes above */ + err = ext4_ext_correct_indexes(handle, inode, path); + if (err) + goto cleanup; + + err = ext4_ext_dirty(handle, inode, path + depth); + +cleanup: + if (npath) { + ext4_ext_drop_refs(npath); + kfree(npath); + } + ext4_ext_tree_changed(inode); + ext4_ext_invalidate_cache(inode); + return err; +} + +int ext4_ext_walk_space(struct inode *inode, unsigned long block, + unsigned long num, ext_prepare_callback func, + void *cbdata) +{ + struct ext4_ext_path *path = NULL; + struct ext4_ext_cache cbex; + struct ext4_extent *ex; + unsigned long next, start = 0, end = 0; + unsigned long last = block + num; + int depth, exists, err = 0; + + BUG_ON(func == NULL); + BUG_ON(inode == NULL); + + while (block < last && block != EXT_MAX_BLOCK) { + num = last - block; + /* find extent for this block */ + path = ext4_ext_find_extent(inode, block, path); + if (IS_ERR(path)) { + err = PTR_ERR(path); + path = NULL; + break; + } + + depth = ext_depth(inode); + BUG_ON(path[depth].p_hdr == NULL); + ex = path[depth].p_ext; + next = ext4_ext_next_allocated_block(path); + + exists = 0; + if (!ex) { + /* there is no extent yet, so try to allocate + * all requested space */ + start = block; + end = block + num; + } else if (le32_to_cpu(ex->ee_block) > block) { + /* need to allocate space before found extent */ + start = block; + end = le32_to_cpu(ex->ee_block); + if (block + num < end) + end = block + num; + } else if (block >= + le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len)) { + /* need to allocate space after found extent */ + start = block; + end = block + num; + if (end >= next) + end = next; + } else if (block >= le32_to_cpu(ex->ee_block)) { + /* + * some part of requested space is covered + * by found extent + */ + start = block; + end = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len); + if (block + num < end) + end = block + num; + exists = 1; + } else { + BUG(); + } + BUG_ON(end <= start); + + if (!exists) { + cbex.ec_block = start; + cbex.ec_len = end - start; + cbex.ec_start = 0; + cbex.ec_type = EXT4_EXT_CACHE_GAP; + } else { + cbex.ec_block = le32_to_cpu(ex->ee_block); + cbex.ec_len = le16_to_cpu(ex->ee_len); + cbex.ec_start = ext_pblock(ex); + cbex.ec_type = EXT4_EXT_CACHE_EXTENT; + } + + BUG_ON(cbex.ec_len == 0); + err = func(inode, path, &cbex, cbdata); + ext4_ext_drop_refs(path); + + if (err < 0) + break; + if (err == EXT_REPEAT) + continue; + else if (err == EXT_BREAK) { + err = 0; + break; + } + + if (ext_depth(inode) != depth) { + /* depth was changed. we have to realloc path */ + kfree(path); + path = NULL; + } + + block = cbex.ec_block + cbex.ec_len; + } + + if (path) { + ext4_ext_drop_refs(path); + kfree(path); + } + + return err; +} + +static inline void +ext4_ext_put_in_cache(struct inode *inode, __u32 block, + __u32 len, __u32 start, int type) +{ + struct ext4_ext_cache *cex; + BUG_ON(len == 0); + cex = &EXT4_I(inode)->i_cached_extent; + cex->ec_type = type; + cex->ec_block = block; + cex->ec_len = len; + cex->ec_start = start; +} + +/* + * ext4_ext_put_gap_in_cache: + * calculate boundaries of the gap that the requested block fits into + * and cache this gap + */ +static inline void +ext4_ext_put_gap_in_cache(struct inode *inode, struct ext4_ext_path *path, + unsigned long block) +{ + int depth = ext_depth(inode); + unsigned long lblock, len; + struct ext4_extent *ex; + + ex = path[depth].p_ext; + if (ex == NULL) { + /* there is no extent yet, so gap is [0;-] */ + lblock = 0; + len = EXT_MAX_BLOCK; + ext_debug("cache gap(whole file):"); + } else if (block < le32_to_cpu(ex->ee_block)) { + lblock = block; + len = le32_to_cpu(ex->ee_block) - block; + ext_debug("cache gap(before): %lu [%lu:%lu]", + (unsigned long) block, + (unsigned long) le32_to_cpu(ex->ee_block), + (unsigned long) le16_to_cpu(ex->ee_len)); + } else if (block >= le32_to_cpu(ex->ee_block) + + le16_to_cpu(ex->ee_len)) { + lblock = le32_to_cpu(ex->ee_block) + + le16_to_cpu(ex->ee_len); + len = ext4_ext_next_allocated_block(path); + ext_debug("cache gap(after): [%lu:%lu] %lu", + (unsigned long) le32_to_cpu(ex->ee_block), + (unsigned long) le16_to_cpu(ex->ee_len), + (unsigned long) block); + BUG_ON(len == lblock); + len = len - lblock; + } else { + lblock = len = 0; + BUG(); + } + + ext_debug(" -> %lu:%lu\n", (unsigned long) lblock, len); + ext4_ext_put_in_cache(inode, lblock, len, 0, EXT4_EXT_CACHE_GAP); +} + +static inline int +ext4_ext_in_cache(struct inode *inode, unsigned long block, + struct ext4_extent *ex) +{ + struct ext4_ext_cache *cex; + + cex = &EXT4_I(inode)->i_cached_extent; + + /* has cache valid data? */ + if (cex->ec_type == EXT4_EXT_CACHE_NO) + return EXT4_EXT_CACHE_NO; + + BUG_ON(cex->ec_type != EXT4_EXT_CACHE_GAP && + cex->ec_type != EXT4_EXT_CACHE_EXTENT); + if (block >= cex->ec_block && block < cex->ec_block + cex->ec_len) { + ex->ee_block = cpu_to_le32(cex->ec_block); + ext4_ext_store_pblock(ex, cex->ec_start); + ex->ee_len = cpu_to_le16(cex->ec_len); + ext_debug("%lu cached by %lu:%lu:%llu\n", + (unsigned long) block, + (unsigned long) cex->ec_block, + (unsigned long) cex->ec_len, + cex->ec_start); + return cex->ec_type; + } + + /* not in cache */ + return EXT4_EXT_CACHE_NO; +} + +/* + * ext4_ext_rm_idx: + * removes index from the index block. + * It's used in truncate case only, thus all requests are for + * last index in the block only. + */ +int ext4_ext_rm_idx(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path) +{ + struct buffer_head *bh; + int err; + ext4_fsblk_t leaf; + + /* free index block */ + path--; + leaf = idx_pblock(path->p_idx); + BUG_ON(path->p_hdr->eh_entries == 0); + if ((err = ext4_ext_get_access(handle, inode, path))) + return err; + path->p_hdr->eh_entries = cpu_to_le16(le16_to_cpu(path->p_hdr->eh_entries)-1); + if ((err = ext4_ext_dirty(handle, inode, path))) + return err; + ext_debug("index is empty, remove it, free block %llu\n", leaf); + bh = sb_find_get_block(inode->i_sb, leaf); + ext4_forget(handle, 1, inode, bh, leaf); + ext4_free_blocks(handle, inode, leaf, 1); + return err; +} + +/* + * ext4_ext_calc_credits_for_insert: + * This routine returns max. credits that the extent tree can consume. + * It should be OK for low-performance paths like ->writepage() + * To allow many writing processes to fit into a single transaction, + * the caller should calculate credits under truncate_mutex and + * pass the actual path. + */ +int inline ext4_ext_calc_credits_for_insert(struct inode *inode, + struct ext4_ext_path *path) +{ + int depth, needed; + + if (path) { + /* probably there is space in leaf? */ + depth = ext_depth(inode); + if (le16_to_cpu(path[depth].p_hdr->eh_entries) + < le16_to_cpu(path[depth].p_hdr->eh_max)) + return 1; + } + + /* + * given 32-bit logical block (4294967296 blocks), max. tree + * can be 4 levels in depth -- 4 * 340^4 == 53453440000. + * Let's also add one more level for imbalance. + */ + depth = 5; + + /* allocation of new data block(s) */ + needed = 2; + + /* + * tree can be full, so it would need to grow in depth: + * allocation + old root + new root + */ + needed += 2 + 1 + 1; + + /* + * Index split can happen, we would need: + * allocate intermediate indexes (bitmap + group) + * + change two blocks at each level, but root (already included) + */ + needed = (depth * 2) + (depth * 2); + + /* any allocation modifies superblock */ + needed += 1; + + return needed; +} + +static int ext4_remove_blocks(handle_t *handle, struct inode *inode, + struct ext4_extent *ex, + unsigned long from, unsigned long to) +{ + struct buffer_head *bh; + int i; + +#ifdef EXTENTS_STATS + { + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + unsigned short ee_len = le16_to_cpu(ex->ee_len); + spin_lock(&sbi->s_ext_stats_lock); + sbi->s_ext_blocks += ee_len; + sbi->s_ext_extents++; + if (ee_len < sbi->s_ext_min) + sbi->s_ext_min = ee_len; + if (ee_len > sbi->s_ext_max) + sbi->s_ext_max = ee_len; + if (ext_depth(inode) > sbi->s_depth_max) + sbi->s_depth_max = ext_depth(inode); + spin_unlock(&sbi->s_ext_stats_lock); + } +#endif + if (from >= le32_to_cpu(ex->ee_block) + && to == le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) { + /* tail removal */ + unsigned long num; + ext4_fsblk_t start; + num = le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - from; + start = ext_pblock(ex) + le16_to_cpu(ex->ee_len) - num; + ext_debug("free last %lu blocks starting %llu\n", num, start); + for (i = 0; i < num; i++) { + bh = sb_find_get_block(inode->i_sb, start + i); + ext4_forget(handle, 0, inode, bh, start + i); + } + ext4_free_blocks(handle, inode, start, num); + } else if (from == le32_to_cpu(ex->ee_block) + && to <= le32_to_cpu(ex->ee_block) + le16_to_cpu(ex->ee_len) - 1) { + printk("strange request: removal %lu-%lu from %u:%u\n", + from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len)); + } else { + printk("strange request: removal(2) %lu-%lu from %u:%u\n", + from, to, le32_to_cpu(ex->ee_block), le16_to_cpu(ex->ee_len)); + } + return 0; +} + +static int +ext4_ext_rm_leaf(handle_t *handle, struct inode *inode, + struct ext4_ext_path *path, unsigned long start) +{ + int err = 0, correct_index = 0; + int depth = ext_depth(inode), credits; + struct ext4_extent_header *eh; + unsigned a, b, block, num; + unsigned long ex_ee_block; + unsigned short ex_ee_len; + struct ext4_extent *ex; + + ext_debug("truncate since %lu in leaf\n", start); + if (!path[depth].p_hdr) + path[depth].p_hdr = ext_block_hdr(path[depth].p_bh); + eh = path[depth].p_hdr; + BUG_ON(eh == NULL); + BUG_ON(le16_to_cpu(eh->eh_entries) > le16_to_cpu(eh->eh_max)); + BUG_ON(eh->eh_magic != EXT4_EXT_MAGIC); + + /* find where to start removing */ + ex = EXT_LAST_EXTENT(eh); + + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = le16_to_cpu(ex->ee_len); + + while (ex >= EXT_FIRST_EXTENT(eh) && + ex_ee_block + ex_ee_len > start) { + ext_debug("remove ext %lu:%u\n", ex_ee_block, ex_ee_len); + path[depth].p_ext = ex; + + a = ex_ee_block > start ? ex_ee_block : start; + b = ex_ee_block + ex_ee_len - 1 < EXT_MAX_BLOCK ? + ex_ee_block + ex_ee_len - 1 : EXT_MAX_BLOCK; + + ext_debug(" border %u:%u\n", a, b); + + if (a != ex_ee_block && b != ex_ee_block + ex_ee_len - 1) { + block = 0; + num = 0; + BUG(); + } else if (a != ex_ee_block) { + /* remove tail of the extent */ + block = ex_ee_block; + num = a - block; + } else if (b != ex_ee_block + ex_ee_len - 1) { + /* remove head of the extent */ + block = a; + num = b - a; + /* there is no "make a hole" API yet */ + BUG(); + } else { + /* remove whole extent: excellent! */ + block = ex_ee_block; + num = 0; + BUG_ON(a != ex_ee_block); + BUG_ON(b != ex_ee_block + ex_ee_len - 1); + } + + /* at present, extent can't cross block group: */ + /* leaf + bitmap + group desc + sb + inode */ + credits = 5; + if (ex == EXT_FIRST_EXTENT(eh)) { + correct_index = 1; + credits += (ext_depth(inode)) + 1; + } +#ifdef CONFIG_QUOTA + credits += 2 * EXT4_QUOTA_TRANS_BLOCKS(inode->i_sb); +#endif + + handle = ext4_ext_journal_restart(handle, credits); + if (IS_ERR(handle)) { + err = PTR_ERR(handle); + goto out; + } + + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out; + + err = ext4_remove_blocks(handle, inode, ex, a, b); + if (err) + goto out; + + if (num == 0) { + /* this extent is removed; mark slot entirely unused */ + ext4_ext_store_pblock(ex, 0); + eh->eh_entries = cpu_to_le16(le16_to_cpu(eh->eh_entries)-1); + } + + ex->ee_block = cpu_to_le32(block); + ex->ee_len = cpu_to_le16(num); + + err = ext4_ext_dirty(handle, inode, path + depth); + if (err) + goto out; + + ext_debug("new extent: %u:%u:%llu\n", block, num, + ext_pblock(ex)); + ex--; + ex_ee_block = le32_to_cpu(ex->ee_block); + ex_ee_len = le16_to_cpu(ex->ee_len); + } + + if (correct_index && eh->eh_entries) + err = ext4_ext_correct_indexes(handle, inode, path); + + /* if this leaf is free, then we should + * remove it from index block above */ + if (err == 0 && eh->eh_entries == 0 && path[depth].p_bh != NULL) + err = ext4_ext_rm_idx(handle, inode, path + depth); + +out: + return err; +} + +/* + * ext4_ext_more_to_rm: + * returns 1 if current index has to be freed (even partial) + */ +static int inline +ext4_ext_more_to_rm(struct ext4_ext_path *path) +{ + BUG_ON(path->p_idx == NULL); + + if (path->p_idx < EXT_FIRST_INDEX(path->p_hdr)) + return 0; + + /* + * if truncate on deeper level happened, it wasn't partial, + * so we have to consider current index for truncation + */ + if (le16_to_cpu(path->p_hdr->eh_entries) == path->p_block) + return 0; + return 1; +} + +int ext4_ext_remove_space(struct inode *inode, unsigned long start) +{ + struct super_block *sb = inode->i_sb; + int depth = ext_depth(inode); + struct ext4_ext_path *path; + handle_t *handle; + int i = 0, err = 0; + + ext_debug("truncate since %lu\n", start); + + /* probably first extent we're gonna free will be last in block */ + handle = ext4_journal_start(inode, depth + 1); + if (IS_ERR(handle)) + return PTR_ERR(handle); + + ext4_ext_invalidate_cache(inode); + + /* + * We start scanning from right side, freeing all the blocks + * after i_size and walking into the tree depth-wise. + */ + path = kmalloc(sizeof(struct ext4_ext_path) * (depth + 1), GFP_KERNEL); + if (path == NULL) { + ext4_journal_stop(handle); + return -ENOMEM; + } + memset(path, 0, sizeof(struct ext4_ext_path) * (depth + 1)); + path[0].p_hdr = ext_inode_hdr(inode); + if (ext4_ext_check_header(__FUNCTION__, inode, path[0].p_hdr)) { + err = -EIO; + goto out; + } + path[0].p_depth = dep