diff options
| author |   Jan Kara <jack@suse.cz> | 2017-02-08 14:30:53 -0800 |
|---|---|---|
| committer |   Linus Torvalds <torvalds@linux-foundation.org> | 2017-02-08 15:41:43 -0800 |
| commit | 0911d0041c22922228ca52a977d7b0b0159fee4b (patch) | |
| tree | ecd0e2bd3ec2f1e934409a43dd3b0798860c7d8b /include/linux/buffer_head.h | |
| parent | kernel/ucount.c: mark user_header with kmemleak_ignore() (diff) | |
| download | linux-dev-0911d0041c22922228ca52a977d7b0b0159fee4b.tar.xz linux-dev-0911d0041c22922228ca52a977d7b0b0159fee4b.zip | |
mm: avoid returning VM_FAULT_RETRY from ->page_mkwrite handlers
Some ->page_mkwrite handlers may return VM_FAULT_RETRY as its return
code (GFS2 or Lustre can definitely do this). However VM_FAULT_RETRY
from ->page_mkwrite is completely unhandled by the mm code and results
in locking and writeably mapping the page which definitely is not what
the caller wanted.
Fix Lustre and block_page_mkwrite_ret() used by other filesystems
(notably GFS2) to return VM_FAULT_NOPAGE instead which results in
bailing out from the fault code, the CPU then retries the access, and we
fault again effectively doing what the handler wanted.
Link: http://lkml.kernel.org/r/20170203150729.15863-1-jack@suse.cz
Signed-off-by: Jan Kara <jack@suse.cz>
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Jinshan Xiong <jinshan.xiong@intel.com>
Cc: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/buffer_head.h')
| -rw-r--r-- | include/linux/buffer_head.h | 4 |
1 files changed, 1 insertions, 3 deletions
diff --git a/include/linux/buffer_head.h b/include/linux/buffer_head.h index d67ab83823ad..79591c3660cc 100644 --- a/include/linux/buffer_head.h +++ b/include/linux/buffer_head.h @@ -243,12 +243,10 @@ static inline int block_page_mkwrite_return(int err) { if (err == 0) return VM_FAULT_LOCKED; - if (err == -EFAULT) + if (err == -EFAULT || err == -EAGAIN) return VM_FAULT_NOPAGE; if (err == -ENOMEM) return VM_FAULT_OOM; - if (err == -EAGAIN) - return VM_FAULT_RETRY; /* -ENOSPC, -EDQUOT, -EIO ... */ return VM_FAULT_SIGBUS; } |