diff options
author | Dmitry Monakhov <dmonakhov@openvz.org> | 2010-05-16 07:00:00 -0400 |
---|---|---|
committer | Theodore Ts'o <tytso@mit.edu> | 2010-05-16 07:00:00 -0400 |
commit | d17413c08cd2b1dd2bf2cfdbb0f7b736b2b2b15c (patch) | |
tree | af5c4e2e0c7e7d188dd5b8fac61d39ee7984f3c6 /fs/ext4 | |
parent | 21ca087a3891efab4d45488db8febee474d26c68 (diff) |
ext4: clean up inode bitmaps manipulation in ext4_free_inode
- Reorganize locking scheme to batch two atomic operation in to one.
This also allow us to state what healthy group must obey following rule
ext4_free_inodes_count(sb, gdp) == ext4_count_free(inode_bitmap, NUM);
- Fix possible undefined pointer dereference.
- Even if group descriptor stats aren't accessible we have to update
inode bitmaps.
- Move non-group members update out of group_lock.
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
-rw-r--r-- | fs/ext4/ialloc.c | 85 |
1 files changed, 39 insertions, 46 deletions
diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index 57f6eef6ccd6..52618d5a1773 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -240,56 +240,49 @@ void ext4_free_inode(handle_t *handle, struct inode *inode) if (fatal) goto error_return; - /* Ok, now we can actually update the inode bitmaps.. */ - cleared = ext4_clear_bit_atomic(ext4_group_lock_ptr(sb, block_group), - bit, bitmap_bh->b_data); - if (!cleared) - ext4_error(sb, "bit already cleared for inode %lu", ino); - else { - gdp = ext4_get_group_desc(sb, block_group, &bh2); - + fatal = -ESRCH; + gdp = ext4_get_group_desc(sb, block_group, &bh2); + if (gdp) { BUFFER_TRACE(bh2, "get_write_access"); fatal = ext4_journal_get_write_access(handle, bh2); - if (fatal) goto error_return; - - if (gdp) { - ext4_lock_group(sb, block_group); - count = ext4_free_inodes_count(sb, gdp) + 1; - ext4_free_inodes_set(sb, gdp, count); - if (is_directory) { - count = ext4_used_dirs_count(sb, gdp) - 1; - ext4_used_dirs_set(sb, gdp, count); - if (sbi->s_log_groups_per_flex) { - ext4_group_t f; - - f = ext4_flex_group(sbi, block_group); - atomic_dec(&sbi->s_flex_groups[f].used_dirs); - } + } + ext4_lock_group(sb, block_group); + cleared = ext4_clear_bit(bit, bitmap_bh->b_data); + if (fatal || !cleared) { + ext4_unlock_group(sb, block_group); + goto out; + } - } - gdp->bg_checksum = ext4_group_desc_csum(sbi, - block_group, gdp); - ext4_unlock_group(sb, block_group); - percpu_counter_inc(&sbi->s_freeinodes_counter); - if (is_directory) - percpu_counter_dec(&sbi->s_dirs_counter); - - if (sbi->s_log_groups_per_flex) { - ext4_group_t f; - - f = ext4_flex_group(sbi, block_group); - atomic_inc(&sbi->s_flex_groups[f].free_inodes); - } - } - BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata"); - err = ext4_handle_dirty_metadata(handle, NULL, bh2); - if (!fatal) fatal = err; + count = ext4_free_inodes_count(sb, gdp) + 1; + ext4_free_inodes_set(sb, gdp, count); + if (is_directory) { + count = ext4_used_dirs_count(sb, gdp) - 1; + ext4_used_dirs_set(sb, gdp, count); + percpu_counter_dec(&sbi->s_dirs_counter); } - BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata"); - err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); - if (!fatal) - fatal = err; - sb->s_dirt = 1; + gdp->bg_checksum = ext4_group_desc_csum(sbi, block_group, gdp); + ext4_unlock_group(sb, block_group); + + percpu_counter_inc(&sbi->s_freeinodes_counter); + if (sbi->s_log_groups_per_flex) { + ext4_group_t f = ext4_flex_group(sbi, block_group); + + atomic_inc(&sbi->s_flex_groups[f].free_inodes); + if (is_directory) + atomic_dec(&sbi->s_flex_groups[f].used_dirs); + } + BUFFER_TRACE(bh2, "call ext4_handle_dirty_metadata"); + fatal = ext4_handle_dirty_metadata(handle, NULL, bh2); +out: + if (cleared) { + BUFFER_TRACE(bitmap_bh, "call ext4_handle_dirty_metadata"); + err = ext4_handle_dirty_metadata(handle, NULL, bitmap_bh); + if (!fatal) + fatal = err; + sb->s_dirt = 1; + } else + ext4_error(sb, "bit already cleared for inode %lu", ino); + error_return: brelse(bitmap_bh); ext4_std_error(sb, fatal); |