fuse: fix max i/o size calculation
Fix a bug that Werner Baumann reported: fuse can send a bigger write request
than the maximum specified. This only affected direct_io operation.
In addition set a sane minimum for the max_read and max_write tunables, so I/O
always makes some progress.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index a02418c..2d3649e 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -966,14 +966,15 @@
while (count) {
size_t nres;
- size_t nbytes = min(count, nmax);
- int err = fuse_get_user_pages(req, buf, nbytes, !write);
+ size_t nbytes_limit = min(count, nmax);
+ size_t nbytes;
+ int err = fuse_get_user_pages(req, buf, nbytes_limit, !write);
if (err) {
res = err;
break;
}
nbytes = (req->num_pages << PAGE_SHIFT) - req->page_offset;
- nbytes = min(count, nbytes);
+ nbytes = min(nbytes_limit, nbytes);
if (write)
nres = fuse_send_write(req, file, inode, pos, nbytes,
current->files);