From a34eb503742fd25155fd6cff6163daacead9fbc3 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Fri, 26 Jul 2013 15:15:46 -0400 Subject: [PATCH] ext4: make sure group number is bumped after a inode allocation race When we try to allocate an inode, and there is a race between two CPU's trying to grab the same inode, _and_ this inode is the last free inode in the block group, make sure the group number is bumped before we continue searching the rest of the block groups. Otherwise, we end up searching the current block group twice, and we end up skipping searching the last block group. So in the unlikely situation where almost all of the inodes are allocated, it's possible that we will return ENOSPC even though there might be free inodes in that last block group. Signed-off-by: "Theodore Ts'o" Cc: stable@vger.kernel.org --- fs/ext4/ialloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) diff --git a/fs/ext4/ialloc.c b/fs/ext4/ialloc.c index f03598c6ffd3..8bf5999875ee 100644 --- a/fs/ext4/ialloc.c +++ b/fs/ext4/ialloc.c @@ -734,11 +734,8 @@ repeat_in_this_group: ino = ext4_find_next_zero_bit((unsigned long *) inode_bitmap_bh->b_data, EXT4_INODES_PER_GROUP(sb), ino); - if (ino >= EXT4_INODES_PER_GROUP(sb)) { - if (++group == ngroups) - group = 0; - continue; - } + if (ino >= EXT4_INODES_PER_GROUP(sb)) + goto next_group; if (group == 0 && (ino+1) < EXT4_FIRST_INO(sb)) { ext4_error(sb, "reserved inode found cleared - " "inode=%lu", ino + 1); @@ -769,6 +766,9 @@ repeat_in_this_group: goto got; /* we grabbed the inode! */ if (ino < EXT4_INODES_PER_GROUP(sb)) goto repeat_in_this_group; +next_group: + if (++group == ngroups) + group = 0; } err = -ENOSPC; goto out; -- 2.39.5