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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-23 20:42:19 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2020-02-23 20:42:19 +0300 |
| commit | a3163ca03f9913ba2c2fb6a06305f3dca98adfd1 (patch) | |
| tree | 64a91a3b12056688c929a8d11a09fda96aabab95 /fs/ext4/balloc.c | |
| parent | c6188dff33fba320826e87e387ae6efffab0525d (diff) | |
| parent | 9db176bceb5c5df4990486709da386edadc6bd1d (diff) | |
| download | linux-a3163ca03f9913ba2c2fb6a06305f3dca98adfd1.tar.xz | |
Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
"More miscellaneous ext4 bug fixes (all stable fodder)"
* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
ext4: fix mount failure with quota configured as module
jbd2: fix ocfs2 corrupt when clearing block group bits
ext4: fix race between writepages and enabling EXT4_EXTENTS_FL
ext4: rename s_journal_flag_rwsem to s_writepages_rwsem
ext4: fix potential race between s_flex_groups online resizing and access
ext4: fix potential race between s_group_info online resizing and access
ext4: fix potential race between online resizing and write operations
ext4: add cond_resched() to __ext4_find_entry()
ext4: fix a data race in EXT4_I(inode)->i_disksize
Diffstat (limited to 'fs/ext4/balloc.c')
| -rw-r--r-- | fs/ext4/balloc.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c index 5f993a411251..8fd0b3cdab4c 100644 --- a/fs/ext4/balloc.c +++ b/fs/ext4/balloc.c @@ -270,6 +270,7 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb, ext4_group_t ngroups = ext4_get_groups_count(sb); struct ext4_group_desc *desc; struct ext4_sb_info *sbi = EXT4_SB(sb); + struct buffer_head *bh_p; if (block_group >= ngroups) { ext4_error(sb, "block_group >= groups_count - block_group = %u," @@ -280,7 +281,14 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb, 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]) { + bh_p = sbi_array_rcu_deref(sbi, s_group_desc, group_desc); + /* + * sbi_array_rcu_deref returns with rcu unlocked, this is ok since + * the pointer being dereferenced won't be dereferenced again. By + * looking at the usage in add_new_gdb() the value isn't modified, + * just the pointer, and so it remains valid. + */ + if (!bh_p) { ext4_error(sb, "Group descriptor not loaded - " "block_group = %u, group_desc = %u, desc = %u", block_group, group_desc, offset); @@ -288,10 +296,10 @@ struct ext4_group_desc * ext4_get_group_desc(struct super_block *sb, } desc = (struct ext4_group_desc *)( - (__u8 *)sbi->s_group_desc[group_desc]->b_data + + (__u8 *)bh_p->b_data + offset * EXT4_DESC_SIZE(sb)); if (bh) - *bh = sbi->s_group_desc[group_desc]; + *bh = bh_p; return desc; } |