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| author | Nicolas Pitre <nico@cam.org> | 2009-09-05 00:25:37 -0400 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2009-09-05 13:41:08 -0700 |
| commit | 9de6886ec6e37f45807266a702bb7621498395ad (patch) | |
| tree | 39402a2d467a856d0f956015a7ad0772719bf1b6 | |
| parent | ac7ac9f2b9bfd9b68a1571d27e4c8bebb4788914 (diff) | |
| download | linux-9de6886ec6e37f45807266a702bb7621498395ad.tar.gz linux-9de6886ec6e37f45807266a702bb7621498395ad.tar.bz2 linux-9de6886ec6e37f45807266a702bb7621498395ad.zip | |
ext2: fix unbalanced kmap()/kunmap()
In ext2_rename(), dir_page is acquired through ext2_dotdot(). It is
then released through ext2_set_link() but only if old_dir != new_dir.
Failing that, the pkmap reference count is never decremented and the
page remains pinned forever. Repeat that a couple times with highmem
pages and all pkmap slots get exhausted, and every further kmap() calls
end up stalling on the pkmap_map_wait queue at which point the whole
system comes to a halt.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Acked-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
| -rw-r--r-- | fs/ext2/namei.c | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c index e1dedb0f7873..78d9b925fc94 100644 --- a/fs/ext2/namei.c +++ b/fs/ext2/namei.c @@ -362,6 +362,10 @@ static int ext2_rename (struct inode * old_dir, struct dentry * old_dentry, if (dir_de) { if (old_dir != new_dir) ext2_set_link(old_inode, dir_de, dir_page, new_dir, 0); + else { + kunmap(dir_page); + page_cache_release(dir_page); + } inode_dec_link_count(old_dir); } return 0; |