[PATCH] fuse: clean up request size limit checking
Change the way a too large request is handled. Until now in this case the
device read returned -EINVAL and the operation returned -EIO.
Make it more flexibible by not returning -EINVAL from the read, but restarting
it instead.
Also remove the fixed limit on setxattr data and let the filesystem provide as
large a read buffer as it needs to handle the extended attribute data.
The symbolic link length is already checked by VFS to be less than PATH_MAX,
so the extra check against FUSE_SYMLINK_MAX is not needed.
The check in fuse_create_open() against FUSE_NAME_MAX is not needed, since the
dentry has already been looked up, and hence the name already checked.
Signed-off-by: Miklos Szeredi <miklos@szeredi.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index e5bc3f8..1afdffd 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -617,6 +617,7 @@
struct fuse_copy_state cs;
unsigned reqsize;
+ restart:
spin_lock(&fuse_lock);
fc = file->private_data;
err = -EPERM;
@@ -632,20 +633,25 @@
req = list_entry(fc->pending.next, struct fuse_req, list);
list_del_init(&req->list);
- spin_unlock(&fuse_lock);
in = &req->in;
- reqsize = req->in.h.len;
- fuse_copy_init(&cs, 1, req, iov, nr_segs);
- err = -EINVAL;
- if (iov_length(iov, nr_segs) >= reqsize) {
- err = fuse_copy_one(&cs, &in->h, sizeof(in->h));
- if (!err)
- err = fuse_copy_args(&cs, in->numargs, in->argpages,
- (struct fuse_arg *) in->args, 0);
+ reqsize = in->h.len;
+ /* If request is too large, reply with an error and restart the read */
+ if (iov_length(iov, nr_segs) < reqsize) {
+ req->out.h.error = -EIO;
+ /* SETXATTR is special, since it may contain too large data */
+ if (in->h.opcode == FUSE_SETXATTR)
+ req->out.h.error = -E2BIG;
+ request_end(fc, req);
+ goto restart;
}
+ spin_unlock(&fuse_lock);
+ fuse_copy_init(&cs, 1, req, iov, nr_segs);
+ err = fuse_copy_one(&cs, &in->h, sizeof(in->h));
+ if (!err)
+ err = fuse_copy_args(&cs, in->numargs, in->argpages,
+ (struct fuse_arg *) in->args, 0);
fuse_copy_finish(&cs);
-
spin_lock(&fuse_lock);
req->locked = 0;
if (!err && req->interrupted)
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 9a6075d..f156392 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -236,10 +236,6 @@
if (fc->no_create)
goto out;
- err = -ENAMETOOLONG;
- if (entry->d_name.len > FUSE_NAME_MAX)
- goto out;
-
err = -EINTR;
req = fuse_get_request(fc);
if (!req)
@@ -413,12 +409,7 @@
{
struct fuse_conn *fc = get_fuse_conn(dir);
unsigned len = strlen(link) + 1;
- struct fuse_req *req;
-
- if (len > FUSE_SYMLINK_MAX)
- return -ENAMETOOLONG;
-
- req = fuse_get_request(fc);
+ struct fuse_req *req = fuse_get_request(fc);
if (!req)
return -EINTR;
@@ -988,9 +979,6 @@
struct fuse_setxattr_in inarg;
int err;
- if (size > FUSE_XATTR_SIZE_MAX)
- return -E2BIG;
-
if (fc->no_setxattr)
return -EOPNOTSUPP;
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 2d4835e..17fd368 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -21,6 +21,12 @@
/** If more requests are outstanding, then the operation will block */
#define FUSE_MAX_OUTSTANDING 10
+/** Maximum size of data in a write request */
+#define FUSE_MAX_WRITE 4096
+
+/** It could be as large as PATH_MAX, but would that have any uses? */
+#define FUSE_NAME_MAX 1024
+
/** If the FUSE_DEFAULT_PERMISSIONS flag is given, the filesystem
module will check permissions based on the file mode. Otherwise no
permission checking is done in the kernel */
@@ -108,9 +114,6 @@
struct fuse_arg args[3];
};
-struct fuse_req;
-struct fuse_conn;
-
/**
* A request to the client
*/
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 3b928a0..3580b9e 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -485,7 +485,7 @@
fc->max_read = d.max_read;
if (fc->max_read / PAGE_CACHE_SIZE < fc->bdi.ra_pages)
fc->bdi.ra_pages = fc->max_read / PAGE_CACHE_SIZE;
- fc->max_write = FUSE_MAX_IN / 2;
+ fc->max_write = FUSE_MAX_WRITE;
err = -ENOMEM;
root = get_root_inode(sb, d.rootmode);