Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse

Pull fuse update from Miklos Szeredi:
 "This contains a fix for a potential use-after-module-unload bug
  noticed by Al and caching improvements for read-only fuse filesystems
  by Andrew Gallagher"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: support clients that don't implement 'open'
  fuse: don't invalidate attrs when not using atime
  fuse: fix SetPageUptodate() condition in STORE
  fuse: fix pipe_buf_operations

7 files changed, 74 insertions, 63 deletions

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index ef74ad5fd362..0a648bb455ae 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -1296,22 +1296,6 @@ static ssize_t fuse_dev_read(struct kiocb *iocb, const struct iovec *iov,
         return fuse_dev_do_read(fc, file, &cs, iov_length(iov, nr_segs));
 }
 
-static int fuse_dev_pipe_buf_steal(struct pipe_inode_info *pipe,
-                                   struct pipe_buffer *buf)
-{
-        return 1;
-}
-
-static const struct pipe_buf_operations fuse_dev_pipe_buf_ops = {
-        .can_merge = 0,
-        .map = generic_pipe_buf_map,
-        .unmap = generic_pipe_buf_unmap,
-        .confirm = generic_pipe_buf_confirm,
-        .release = generic_pipe_buf_release,
-        .steal = fuse_dev_pipe_buf_steal,
-        .get = generic_pipe_buf_get,
-};
-
 static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
                                     struct pipe_inode_info *pipe,
                                     size_t len, unsigned int flags)
@@ -1358,7 +1342,11 @@ static ssize_t fuse_dev_splice_read(struct file *in, loff_t *ppos,
                 buf->page = bufs[page_nr].page;
                 buf->offset = bufs[page_nr].offset;
                 buf->len = bufs[page_nr].len;
-                buf->ops = &fuse_dev_pipe_buf_ops;
+                /*
+                 * Need to be careful about this.  Having buf->ops in module
+                 * code can Oops if the buffer persists after module unload.
+                 */
+                buf->ops = &nosteal_pipe_buf_ops;
 
                 pipe->nrbufs++;
                 page_nr++;
@@ -1599,7 +1587,8 @@ static int fuse_notify_store(struct fuse_conn *fc, unsigned int size,
 
                 this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
                 err = fuse_copy_page(cs, &page, offset, this_num, 0);
-                if (!err && offset == 0 && (num != 0 || file_size == end))
+                if (!err && offset == 0 &&
+                    (this_num == PAGE_CACHE_SIZE || file_size == end))
                         SetPageUptodate(page);
                 unlock_page(page);
                 page_cache_release(page);
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index c3eb2c46c8f1..1d1292c581c3 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -112,6 +112,16 @@ void fuse_invalidate_attr(struct inode *inode)
         get_fuse_inode(inode)->i_time = 0;
 }
 
+/**
+ * Mark the attributes as stale due to an atime change.  Avoid the invalidate if
+ * atime is not used.
+ */
+void fuse_invalidate_atime(struct inode *inode)
+{
+        if (!IS_RDONLY(inode))
+                fuse_invalidate_attr(inode);
+}
+
 /*
  * Just mark the entry as stale, so that a next attempt to look it up
  * will result in a new lookup call to userspace
@@ -1371,7 +1381,7 @@ static int fuse_readdir(struct file *file, struct dir_context *ctx)
         }
 
         __free_page(page);
-        fuse_invalidate_attr(inode); /* atime changed */
+        fuse_invalidate_atime(inode);
         return err;
 }
 
@@ -1404,7 +1414,7 @@ static char *read_link(struct dentry *dentry)
                 link[req->out.args[0].size] = '\0';
  out:
         fuse_put_request(fc, req);
-        fuse_invalidate_attr(inode); /* atime changed */
+        fuse_invalidate_atime(inode);
         return link;
 }
 
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index 7e70506297bc..74f6ca500504 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -127,7 +127,15 @@ static void fuse_file_put(struct fuse_file *ff, bool sync)
         if (atomic_dec_and_test(&ff->count)) {
                 struct fuse_req *req = ff->reserved_req;
 
-                if (sync) {
+                if (ff->fc->no_open) {
+                        /*
+                         * Drop the release request when client does not
+                         * implement 'open'
+                         */
+                        req->background = 0;
+                        path_put(&req->misc.release.path);
+                        fuse_put_request(ff->fc, req);
+                } else if (sync) {
                         req->background = 0;
                         fuse_request_send(ff->fc, req);
                         path_put(&req->misc.release.path);
@@ -144,27 +152,36 @@ static void fuse_file_put(struct fuse_file *ff, bool sync)
 int fuse_do_open(struct fuse_conn *fc, u64 nodeid, struct file *file,
                  bool isdir)
 {
-        struct fuse_open_out outarg;
         struct fuse_file *ff;
-        int err;
         int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
 
         ff = fuse_file_alloc(fc);
         if (!ff)
                 return -ENOMEM;
 
-        err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
-        if (err) {
-                fuse_file_free(ff);
-                return err;
+        ff->fh = 0;
+        ff->open_flags = FOPEN_KEEP_CACHE; /* Default for no-open */
+        if (!fc->no_open || isdir) {
+                struct fuse_open_out outarg;
+                int err;
+
+                err = fuse_send_open(fc, nodeid, file, opcode, &outarg);
+                if (!err) {
+                        ff->fh = outarg.fh;
+                        ff->open_flags = outarg.open_flags;
+
+                } else if (err != -ENOSYS || isdir) {
+                        fuse_file_free(ff);
+                        return err;
+                } else {
+                        fc->no_open = 1;
+                }
         }
 
         if (isdir)
-                outarg.open_flags &= ~FOPEN_DIRECT_IO;
+                ff->open_flags &= ~FOPEN_DIRECT_IO;
 
-        ff->fh = outarg.fh;
         ff->nodeid = nodeid;
-        ff->open_flags = outarg.open_flags;
         file->private_data = fuse_file_get(ff);
 
         return 0;
@@ -687,7 +704,7 @@ static int fuse_readpage(struct file *file, struct page *page)
                 SetPageUptodate(page);
         }
 
-        fuse_invalidate_attr(inode); /* atime changed */
+        fuse_invalidate_atime(inode);
  out:
         unlock_page(page);
         return err;
@@ -716,7 +733,7 @@ static void fuse_readpages_end(struct fuse_conn *fc, struct fuse_req *req)
                         fuse_read_update_size(inode, pos,
                                               req->misc.read.attr_ver);
                 }
-                fuse_invalidate_attr(inode); /* atime changed */
+                fuse_invalidate_atime(inode);
         }
 
         for (i = 0; i < req->num_pages; i++) {
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 7d2730912667..2da5db2c8bdb 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -485,6 +485,9 @@ struct fuse_conn {
          * and hence races in setting them will not cause malfunction
          */
 
+        /** Is open/release not implemented by fs? */
+        unsigned no_open:1;
+
         /** Is fsync not implemented by fs? */
         unsigned no_fsync:1;
 
@@ -788,6 +791,8 @@ void fuse_invalidate_attr(struct inode *inode);
 
 void fuse_invalidate_entry_cache(struct dentry *entry);
 
+void fuse_invalidate_atime(struct inode *inode);
+
 /**
  * Acquire reference to fuse_conn
  */
diff --git a/fs/splice.c b/fs/splice.c
index 46a08f772d7d..12028fa41def 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -555,6 +555,24 @@ static const struct pipe_buf_operations default_pipe_buf_ops = {
         .get = generic_pipe_buf_get,
 };
 
+static int generic_pipe_buf_nosteal(struct pipe_inode_info *pipe,
+                                    struct pipe_buffer *buf)
+{
+        return 1;
+}
+
+/* Pipe buffer operations for a socket and similar. */
+const struct pipe_buf_operations nosteal_pipe_buf_ops = {
+        .can_merge = 0,
+        .map = generic_pipe_buf_map,
+        .unmap = generic_pipe_buf_unmap,
+        .confirm = generic_pipe_buf_confirm,
+        .release = generic_pipe_buf_release,
+        .steal = generic_pipe_buf_nosteal,
+        .get = generic_pipe_buf_get,
+};
+EXPORT_SYMBOL(nosteal_pipe_buf_ops);
+
 static ssize_t kernel_readv(struct file *file, const struct iovec *vec,
                             unsigned long vlen, loff_t offset)
 {
diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h
index b8809fef61f5..ab5752692113 100644
--- a/include/linux/pipe_fs_i.h
+++ b/include/linux/pipe_fs_i.h
@@ -157,6 +157,8 @@ int generic_pipe_buf_confirm(struct pipe_inode_info *, struct pipe_buffer *);
 int generic_pipe_buf_steal(struct pipe_inode_info *, struct pipe_buffer *);
 void generic_pipe_buf_release(struct pipe_inode_info *, struct pipe_buffer *);
 
+extern const struct pipe_buf_operations nosteal_pipe_buf_ops;
+
 /* for F_SETPIPE_SZ and F_GETPIPE_SZ */
 long pipe_fcntl(struct file *, unsigned int, unsigned long arg);
 struct pipe_inode_info *get_pipe_info(struct file *file);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 06e72d3cdf60..0b5149c5bc4a 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -74,36 +74,6 @@
 struct kmem_cache *skbuff_head_cache __read_mostly;
 static struct kmem_cache *skbuff_fclone_cache __read_mostly;
 
-static void sock_pipe_buf_release(struct pipe_inode_info *pipe,
-                                  struct pipe_buffer *buf)
-{
-        put_page(buf->page);
-}
-
-static void sock_pipe_buf_get(struct pipe_inode_info *pipe,
-                                struct pipe_buffer *buf)
-{
-        get_page(buf->page);
-}
-
-static int sock_pipe_buf_steal(struct pipe_inode_info *pipe,
-                               struct pipe_buffer *buf)
-{
-        return 1;
-}
-
-
-/* Pipe buffer operations for a socket. */
-static const struct pipe_buf_operations sock_pipe_buf_ops = {
-        .can_merge = 0,
-        .map = generic_pipe_buf_map,
-        .unmap = generic_pipe_buf_unmap,
-        .confirm = generic_pipe_buf_confirm,
-        .release = sock_pipe_buf_release,
-        .steal = sock_pipe_buf_steal,
-        .get = sock_pipe_buf_get,
-};
-
 /**
  *      skb_panic - private function for out-of-line support
  *      @skb:   buffer
@@ -1830,7 +1800,7 @@ int skb_splice_bits(struct sk_buff *skb, unsigned int offset,
                 .partial = partial,
                 .nr_pages_max = MAX_SKB_FRAGS,
                 .flags = flags,
-                .ops = &sock_pipe_buf_ops,
+                .ops = &nosteal_pipe_buf_ops,
                 .spd_release = sock_spd_release,
         };
         struct sk_buff *frag_iter;