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

Pull fuse bugfixes from Miklos Szeredi:
 "This contains two more fixes by Maxim for writeback/truncate races and
  fixes for RCU walk in fuse_dentry_revalidate()"

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: no RCU mode in fuse_access()
  fuse: readdirplus: fix RCU walk
  fuse: don't check_submounts_and_drop() in RCU walk
  fuse: fix fallocate vs. ftruncate race
  fuse: wait for writeback in fuse_file_fallocate()

3 files changed, 32 insertions, 13 deletions

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 62b43b577bfc..b7989f2ab4c4 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -182,6 +182,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
         struct inode *inode;
         struct dentry *parent;
         struct fuse_conn *fc;
+        struct fuse_inode *fi;
         int ret;
 
         inode = ACCESS_ONCE(entry->d_inode);
@@ -228,7 +229,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
                 if (!err && !outarg.nodeid)
                         err = -ENOENT;
                 if (!err) {
-                        struct fuse_inode *fi = get_fuse_inode(inode);
+                        fi = get_fuse_inode(inode);
                         if (outarg.nodeid != get_node_id(inode)) {
                                 fuse_queue_forget(fc, forget, outarg.nodeid, 1);
                                 goto invalid;
@@ -246,8 +247,11 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
                                        attr_version);
                 fuse_change_entry_timeout(entry, &outarg);
         } else if (inode) {
-                fc = get_fuse_conn(inode);
-                if (fc->readdirplus_auto) {
+                fi = get_fuse_inode(inode);
+                if (flags & LOOKUP_RCU) {
+                        if (test_bit(FUSE_I_INIT_RDPLUS, &fi->state))
+                                return -ECHILD;
+                } else if (test_and_clear_bit(FUSE_I_INIT_RDPLUS, &fi->state)) {
                         parent = dget_parent(entry);
                         fuse_advise_use_readdirplus(parent->d_inode);
                         dput(parent);
@@ -259,7 +263,8 @@ out:
 
 invalid:
         ret = 0;
-        if (check_submounts_and_drop(entry) != 0)
+
+        if (!(flags & LOOKUP_RCU) && check_submounts_and_drop(entry) != 0)
                 ret = 1;
         goto out;
 }
@@ -1063,6 +1068,8 @@ static int fuse_access(struct inode *inode, int mask)
         struct fuse_access_in inarg;
         int err;
 
+        BUG_ON(mask & MAY_NOT_BLOCK);
+
         if (fc->no_access)
                 return 0;
 
@@ -1150,9 +1157,6 @@ static int fuse_permission(struct inode *inode, int mask)
                    noticed immediately, only after the attribute
                    timeout has expired */
         } else if (mask & (MAY_ACCESS | MAY_CHDIR)) {
-                if (mask & MAY_NOT_BLOCK)
-                        return -ECHILD;
-
                 err = fuse_access(inode, mask);
         } else if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) {
                 if (!(inode->i_mode & S_IXUGO)) {
@@ -1291,6 +1295,8 @@ static int fuse_direntplus_link(struct file *file,
         }
 
 found:
+        if (fc->readdirplus_auto)
+                set_bit(FUSE_I_INIT_RDPLUS, &get_fuse_inode(inode)->state);
         fuse_change_entry_timeout(dentry, o);
 
         err = 0;
diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index d409deafc67b..4598345ab87d 100644
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -2467,6 +2467,7 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
 {
         struct fuse_file *ff = file->private_data;
         struct inode *inode = file->f_inode;
+        struct fuse_inode *fi = get_fuse_inode(inode);
         struct fuse_conn *fc = ff->fc;
         struct fuse_req *req;
         struct fuse_fallocate_in inarg = {
@@ -2484,10 +2485,20 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
 
         if (lock_inode) {
                 mutex_lock(&inode->i_mutex);
-                if (mode & FALLOC_FL_PUNCH_HOLE)
-                        fuse_set_nowrite(inode);
+                if (mode & FALLOC_FL_PUNCH_HOLE) {
+                        loff_t endbyte = offset + length - 1;
+                        err = filemap_write_and_wait_range(inode->i_mapping,
+                                                           offset, endbyte);
+                        if (err)
+                                goto out;
+
+                        fuse_sync_writes(inode);
+                }
         }
 
+        if (!(mode & FALLOC_FL_KEEP_SIZE))
+                set_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+
         req = fuse_get_req_nopages(fc);
         if (IS_ERR(req)) {
                 err = PTR_ERR(req);
@@ -2520,11 +2531,11 @@ static long fuse_file_fallocate(struct file *file, int mode, loff_t offset,
         fuse_invalidate_attr(inode);
 
 out:
-        if (lock_inode) {
-                if (mode & FALLOC_FL_PUNCH_HOLE)
-                        fuse_release_nowrite(inode);
+        if (!(mode & FALLOC_FL_KEEP_SIZE))
+                clear_bit(FUSE_I_SIZE_UNSTABLE, &fi->state);
+
+        if (lock_inode)
                 mutex_unlock(&inode->i_mutex);
-        }
 
         return err;
 }
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 5ced199b50bb..5b9e6f3b6aef 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -115,6 +115,8 @@ struct fuse_inode {
 enum {
         /** Advise readdirplus  */
         FUSE_I_ADVISE_RDPLUS,
+        /** Initialized with readdirplus */
+        FUSE_I_INIT_RDPLUS,
         /** An operation changing file size is in progress  */
         FUSE_I_SIZE_UNSTABLE,
 };