diff options
Diffstat (limited to 'fs/ext4/ext4.h')
| -rw-r--r-- | fs/ext4/ext4.h | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h index d0f15ef56de..02ec44bf38e 100644 --- a/fs/ext4/ext4.h +++ b/fs/ext4/ext4.h @@ -1228,6 +1228,18 @@ struct ext4_group_info *ext4_get_group_info(struct super_block *sb, return grp_info[indexv][indexh]; } +/* + * Reading s_groups_count requires using smp_rmb() afterwards. See + * the locking protocol documented in the comments of ext4_group_add() + * in resize.c + */ +static inline ext4_group_t ext4_get_groups_count(struct super_block *sb) +{ + ext4_group_t ngroups = EXT4_SB(sb)->s_groups_count; + + smp_rmb(); + return ngroups; +} static inline ext4_group_t ext4_flex_group(struct ext4_sb_info *sbi, ext4_group_t block_group) |