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| author | Maxim Patlasov <MPatlasov@parallels.com> | 2013-09-13 19:20:16 +0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-10-13 16:08:32 -0700 |
| commit | 9abd30b435085cf2d897a77d657a4b6b8a56fd2c (patch) | |
| tree | 2bcfd27e40bfe19c5cf01e3b4ea581a6045e6859 /fs/ocfs2 | |
| parent | eb12ca30f11b89eab811b23562e976c1c954c7f3 (diff) | |
fuse: fix fallocate vs. ftruncate race
commit 0ab08f576b9e6a6b689fc6b4e632079b978e619b upstream.
A former patch introducing FUSE_I_SIZE_UNSTABLE flag provided detailed
description of races between ftruncate and anyone who can extend i_size:
> 1. As in the previous scenario fuse_dentry_revalidate() discovered that i_size
> changed (due to our own fuse_do_setattr()) and is going to call
> truncate_pagecache() for some 'new_size' it believes valid right now. But by
> the time that particular truncate_pagecache() is called ...
> 2. fuse_do_setattr() returns (either having called truncate_pagecache() or
> not -- it doesn't matter).
> 3. The file is extended either by write(2) or ftruncate(2) or fallocate(2).
> 4. mmap-ed write makes a page in the extended region dirty.
This patch adds necessary bits to fuse_file_fallocate() to protect from that
race.
Signed-off-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/ocfs2')
0 files changed, 0 insertions, 0 deletions