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| author | Miklos Szeredi <mszeredi@suse.cz> | 2014-09-24 19:09:11 +0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-09-27 05:16:51 +0400 |
| commit | 2c80929c4c4d54e568b07ab85877d5fd38f4b02f (patch) | |
| tree | a43d1f9a9706d519a46c1b772b69c8996319961c /fs | |
| parent | b928095b0a7cff7fb9fcf4c706348ceb8ab2c295 (diff) | |
| download | linux-2c80929c4c4d54e568b07ab85877d5fd38f4b02f.tar.xz | |
fuse: honour max_read and max_write in direct_io mode
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>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/direct-io.c | 2 | ||||
| -rw-r--r-- | fs/fuse/file.c | 1 |
2 files changed, 2 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)) { diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 912061ac4baf..caa8d95b24e8 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1305,6 +1305,7 @@ static int fuse_get_user_pages(struct fuse_req *req, struct iov_iter *ii, size_t start; ssize_t ret = iov_iter_get_pages(ii, &req->pages[req->num_pages], + *nbytesp - nbytes, req->max_pages - req->num_pages, &start); if (ret < 0) |