diff options
author | Vladimir V. Saveliev <vs@namesys.com> | 2006-06-27 02:53:57 -0700 |
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committer | Linus Torvalds <torvalds@g5.osdl.org> | 2006-06-27 17:32:39 -0700 |
commit | 6527c2bdf1f833cc18e8f42bd97973d583e4aa83 (patch) | |
tree | 737055ae276cdfa75e7b3e55a3ebdd1f88105606 /sound/i2c | |
parent | 1c0f16e5cdff59f3b132a1b0c0d44a941f8813d2 (diff) |
[PATCH] generic_file_buffered_write(): deadlock on vectored write
generic_file_buffered_write() prefaults in user pages in order to avoid
deadlock on copying from the same page as write goes to.
However, it looks like there is a problem when write is vectored:
fault_in_pages_readable brings in current segment or its part (maxlen).
OTOH, filemap_copy_from_user_iovec is called to copy number of bytes
(bytes) which may exceed current segment, so filemap_copy_from_user_iovec
switches to the next segment which is not brought in yet. Pagefault is
generated. That causes the deadlock if pagefault is for the same page
write goes to: page being written is locked and not uptodate, pagefault
will deadlock trying to lock locked page.
[akpm@osdl.org: somewhat rewritten]
Cc: Neil Brown <neilb@suse.de>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Diffstat (limited to 'sound/i2c')
0 files changed, 0 insertions, 0 deletions