From e5d9a0df07484d6d191756878c974e4307fb24ce Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 30 Apr 2008 00:54:44 -0700 Subject: [PATCH] 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/file.c | 7 ++++--- fs/fuse/inode.c | 3 ++- 2 files changed, 6 insertions(+), 4 deletions(-) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index a02418c89d..2d3649e425 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -966,14 +966,15 @@ static ssize_t fuse_direct_io(struct file *file, const char __user *buf, 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); diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c index 7d01c68852..0cef5ea319 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -584,6 +584,7 @@ static void process_init_reply(struct fuse_conn *fc, struct fuse_req *req) fc->bdi.ra_pages = min(fc->bdi.ra_pages, ra_pages); fc->minor = arg->minor; fc->max_write = arg->minor < 5 ? 4096 : arg->max_write; + fc->max_write = min_t(unsigned, 4096, fc->max_write); fc->conn_init = 1; } fuse_put_request(fc, req); @@ -658,7 +659,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) fc->flags = d.flags; fc->user_id = d.user_id; fc->group_id = d.group_id; - fc->max_read = d.max_read; + fc->max_read = min_t(unsigned, 4096, d.max_read); /* Used by get_root_inode() */ sb->s_fs_info = fc; -- 2.39.5