tree bc11ca9a8bc1f1ebdc70e59bb28e8e328346f7bb
parent 3c8fad1829cc33e903500b41d989fa50ab196378
author Nick Piggin <nickpiggin@yahoo.com.au> 1115334945 -0700
committer Linus Torvalds <torvalds@ppc970.osdl.org> 1115336200 -0700

[PATCH] fix race in __block_prepare_write

Fix a race where __block_prepare_write can leak out an in-flight read
against a bh if get_block returns an error.  This can lead to the page
becoming unlocked while the buffer is locked and the read still in flight.
__mpage_writepage BUGs on this condition.

BUG sighted on a 2-way Itanium2 system with 16K PAGE_SIZE running

	fsstress -v -d $DIR/tmp -n 1000 -p 1000 -l 2

where $DIR is a new ext2 filesystem with 4K blocks that is quite
small (causing get_block to fail often with -ENOSPC).

Signed-off-by: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>