From 1d3d752b471d2a3a1d5e4fe177e5e7d52abb4e4c Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Fri, 6 Jan 2006 00:19:40 -0800 Subject: [PATCH] [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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/fuse/dev.c | 26 ++++++++++++++++---------- fs/fuse/dir.c | 14 +------------- fs/fuse/fuse_i.h | 9 ++++++--- fs/fuse/inode.c | 2 +- include/linux/fuse.h | 8 ++------ 5 files changed, 26 insertions(+), 33 deletions(-) diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c index e5bc3f8eebd0..1afdffdf80db 100644 --- a/fs/fuse/dev.c +++ b/fs/fuse/dev.c @@ -617,6 +617,7 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov, struct fuse_copy_state cs; unsigned reqsize; + restart: spin_lock(&fuse_lock); fc = file->private_data; err = -EPERM; @@ -632,20 +633,25 @@ static ssize_t fuse_dev_readv(struct file *file, const struct iovec *iov, 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 9a6075de961f..f156392d019e 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -236,10 +236,6 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry, int mode, 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 @@ static int fuse_symlink(struct inode *dir, struct dentry *entry, { 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 @@ static int fuse_setxattr(struct dentry *entry, const char *name, 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 2d4835e54c90..17fd368559cd 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_out { 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 3b928a02af04..3580b9e12345 100644 --- a/fs/fuse/inode.c +++ b/fs/fuse/inode.c @@ -485,7 +485,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent) 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); diff --git a/include/linux/fuse.h b/include/linux/fuse.h index 9d5177c356cc..8f64cc2205b0 100644 --- a/include/linux/fuse.h +++ b/include/linux/fuse.h @@ -108,12 +108,8 @@ enum fuse_opcode { FUSE_CREATE = 35 }; -/* Conservative buffer size for the client */ -#define FUSE_MAX_IN 8192 - -#define FUSE_NAME_MAX 1024 -#define FUSE_SYMLINK_MAX 4096 -#define FUSE_XATTR_SIZE_MAX 4096 +/* The read buffer is required to be at least 8k, but may be much larger */ +#define FUSE_MIN_READ_BUFFER 8192 struct fuse_entry_out { __u64 nodeid; /* Inode ID */ -- 2.20.1