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| author | Miklos Szeredi <mszeredi@suse.cz> | 2014-09-24 17:09:11 +0200 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2014-11-03 10:46:27 +0000 |
| commit | ad0f3236b95c392787cb8555aea5ee1c4d84f01e (patch) | |
| tree | ee84311fbbb19a5b9fbed60b1562b77da52f8395 /fs/direct-io.c | |
| parent | 88157ce345bf86dc8bb3038683c8a619146bc66e (diff) | |
| download | linux-stable-ad0f3236b95c392787cb8555aea5ee1c4d84f01e.tar.gz linux-stable-ad0f3236b95c392787cb8555aea5ee1c4d84f01e.tar.bz2 linux-stable-ad0f3236b95c392787cb8555aea5ee1c4d84f01e.zip | |
fuse: honour max_read and max_write in direct_io mode
commit 2c80929c4c4d54e568b07ab85877d5fd38f4b02f upstream.
The third argument of fuse_get_user_pages() "nbytesp" refers to the number of
bytes a caller asked to pack into fuse request. This value may be lesser
than capacity of fuse request or iov_iter. So fuse_get_user_pages() must
ensure that *nbytesp won't grow.
Now, when helper iov_iter_get_pages() performs all hard work of extracting
pages from iov_iter, it can be done by passing properly calculated
"maxsize" to the helper.
The other caller of iov_iter_get_pages() (dio_refill_pages()) doesn't need
this capability, so pass LONG_MAX as the maxsize argument here.
Fixes: c9c37e2e6378 ("fuse: switch to iov_iter_get_pages()")
Reported-by: Werner Baumann <werner.baumann@onlinehome.de>
Tested-by: Maxim Patlasov <mpatlasov@parallels.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'fs/direct-io.c')
| -rw-r--r-- | fs/direct-io.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c index c3116404ab49..e181b6b2e297 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -158,7 +158,7 @@ static inline int dio_refill_pages(struct dio *dio, struct dio_submit *sdio) { ssize_t ret; - ret = iov_iter_get_pages(sdio->iter, dio->pages, DIO_PAGES, + ret = iov_iter_get_pages(sdio->iter, dio->pages, LONG_MAX, DIO_PAGES, &sdio->from); if (ret < 0 && sdio->blocks_available && (dio->rw & WRITE)) { |