mirror of
https://github.com/team-infusion-developers/android_kernel_samsung_msm8976.git
synced 2024-09-21 03:43:03 +00:00
tmpfs: fix regression hang in fallocate undo
commit 7f556567036cb7f89aabe2f0954b08566b4efb53 upstream. The well-spotted fallocate undo fix is good in most cases, but not when fallocate failed on the very first page. index 0 then passes lend -1 to shmem_undo_range(), and that has two bad effects: (a) that it will undo every fallocation throughout the file, unrestricted by the current range; but more importantly (b) it can cause the undo to hang, because lend -1 is treated as truncation, which makes it keep on retrying until every page has gone, but those already fully instantiated will never go away. Big thank you to xfstests generic/269 which demonstrates this. Fixes: b9b4bb26af01 ("tmpfs: don't undo fallocate past its last page") Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Willy Tarreau <w@1wt.eu>
This commit is contained in:
parent
03b824ddbc
commit
26e8852774
|
@ -1948,9 +1948,11 @@ static long shmem_fallocate(struct file *file, int mode, loff_t offset,
|
||||||
NULL);
|
NULL);
|
||||||
if (error) {
|
if (error) {
|
||||||
/* Remove the !PageUptodate pages we added */
|
/* Remove the !PageUptodate pages we added */
|
||||||
shmem_undo_range(inode,
|
if (index > start) {
|
||||||
(loff_t)start << PAGE_CACHE_SHIFT,
|
shmem_undo_range(inode,
|
||||||
((loff_t)index << PAGE_CACHE_SHIFT) - 1, true);
|
(loff_t)start << PAGE_CACHE_SHIFT,
|
||||||
|
((loff_t)index << PAGE_CACHE_SHIFT) - 1, true);
|
||||||
|
}
|
||||||
goto undone;
|
goto undone;
|
||||||
}
|
}
|
||||||
|
|
||||||
|
|
Loading…
Reference in a new issue