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05 April 2024, 19:05:47 UTC
Revision 0911d0041c22922228ca52a977d7b0b0159fee4b authored by Jan Kara on 08 February 2017, 22:30:53 UTC, committed by Linus Torvalds on 08 February 2017, 23:41:43 UTC 
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>
1 parent ed5bd7d
History
Tip revision: 0911d0041c22922228ca52a977d7b0b0159fee4b authored by Jan Kara on 08 February 2017, 22:30:53 UTC
mm: avoid returning VM_FAULT_RETRY from ->page_mkwrite handlers
Tip revision: 0911d00
File Mode Size
.gitignore -rw-r--r-- 151 bytes
Kconfig -rw-r--r-- 7.5 KB
Makefile -rw-r--r-- 2.0 KB
gen_init_cpio.c -rw-r--r-- 12.7 KB
initramfs_data.S -rw-r--r-- 1.3 KB
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