fuse: allocate ff->release_args only if release is needed

[ Upstream commit e26ee4efbc79610b20e7abe9d96c87f33dacc1ff ]

This removed the need to pass isdir argument to fuse_put_file().

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Stable-dep-of: 26e5c67deb2e ("fuse: fix livelock in synchronous file put from fuseblk workers")
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 0dbacdd7bb0d8a6f5c3b747ce0e6750d8e0fc2fc..e54d70a42519bfe01faa5e1c6c6bbfddaf650ebb 100644 (file)
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -584,7 +584,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
                goto out_err;
 
        err = -ENOMEM;
-       ff = fuse_file_alloc(fm);
+       ff = fuse_file_alloc(fm, true);
        if (!ff)
                goto out_put_forget_req;
 

diff --git a/fs/fuse/file.c b/fs/fuse/file.c
index db5ba56a837a82b93d0031fffdc7b4bc54dd2243..627ad8fadbec029ecceec4499e7f459509940316 100644 (file)
--- a/fs/fuse/file.c
+++ b/fs/fuse/file.c
@@ -54,7 +54,7 @@ struct fuse_release_args {
        struct inode *inode;
 };
 
-struct fuse_file *fuse_file_alloc(struct fuse_mount *fm)
+struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release)
 {
        struct fuse_file *ff;
 
@@ -63,11 +63,13 @@ struct fuse_file *fuse_file_alloc(struct fuse_mount *fm)
                return NULL;
 
        ff->fm = fm;
-       ff->release_args = kzalloc(sizeof(*ff->release_args),
-                                  GFP_KERNEL_ACCOUNT);
-       if (!ff->release_args) {
-               kfree(ff);
-               return NULL;
+       if (release) {
+               ff->release_args = kzalloc(sizeof(*ff->release_args),
+                                          GFP_KERNEL_ACCOUNT);
+               if (!ff->release_args) {
+                       kfree(ff);
+                       return NULL;
+               }
        }
 
        INIT_LIST_HEAD(&ff->write_entry);
@@ -103,14 +105,14 @@ static void fuse_release_end(struct fuse_mount *fm, struct fuse_args *args,
        kfree(ra);
 }
 
-static void fuse_file_put(struct fuse_file *ff, bool sync, bool isdir)
+static void fuse_file_put(struct fuse_file *ff, bool sync)
 {
        if (refcount_dec_and_test(&ff->count)) {
-               struct fuse_args *args = &ff->release_args->args;
+               struct fuse_release_args *ra = ff->release_args;
+               struct fuse_args *args = (ra ? &ra->args : NULL);
 
-               if (isdir ? ff->fm->fc->no_opendir : ff->fm->fc->no_open) {
-                       /* Do nothing when client does not implement 'open' */
-                       fuse_release_end(ff->fm, args, 0);
+               if (!args) {
+                       /* Do nothing when server does not implement 'open' */
                } else if (sync) {
                        fuse_simple_request(ff->fm, args);
                        fuse_release_end(ff->fm, args, 0);
@@ -130,15 +132,16 @@ struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
        struct fuse_conn *fc = fm->fc;
        struct fuse_file *ff;
        int opcode = isdir ? FUSE_OPENDIR : FUSE_OPEN;
+       bool open = isdir ? !fc->no_opendir : !fc->no_open;
 
-       ff = fuse_file_alloc(fm);
+       ff = fuse_file_alloc(fm, open);
        if (!ff)
                return ERR_PTR(-ENOMEM);
 
        ff->fh = 0;
        /* Default for no-open */
        ff->open_flags = FOPEN_KEEP_CACHE | (isdir ? FOPEN_CACHE_DIR : 0);
-       if (isdir ? !fc->no_opendir : !fc->no_open) {
+       if (open) {
                struct fuse_open_out outarg;
                int err;
 
@@ -146,11 +149,13 @@ struct fuse_file *fuse_file_open(struct fuse_mount *fm, u64 nodeid,
                if (!err) {
                        ff->fh = outarg.fh;
                        ff->open_flags = outarg.open_flags;
-
                } else if (err != -ENOSYS) {
                        fuse_file_free(ff);
                        return ERR_PTR(err);
                } else {
+                       /* No release needed */
+                       kfree(ff->release_args);
+                       ff->release_args = NULL;
                        if (isdir)
                                fc->no_opendir = 1;
                        else
@@ -272,7 +277,7 @@ out_inode_unlock:
 }
 
 static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
-                                unsigned int flags, int opcode)
+                                unsigned int flags, int opcode, bool sync)
 {
        struct fuse_conn *fc = ff->fm->fc;
        struct fuse_release_args *ra = ff->release_args;
@@ -290,6 +295,9 @@ static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
 
        wake_up_interruptible_all(&ff->poll_wait);
 
+       if (!ra)
+               return;
+
        ra->inarg.fh = ff->fh;
        ra->inarg.flags = flags;
        ra->args.in_numargs = 1;
@@ -299,6 +307,13 @@ static void fuse_prepare_release(struct fuse_inode *fi, struct fuse_file *ff,
        ra->args.nodeid = ff->nodeid;
        ra->args.force = true;
        ra->args.nocreds = true;
+
+       /*
+        * Hold inode until release is finished.
+        * From fuse_sync_release() the refcount is 1 and everything's
+        * synchronous, so we are fine with not doing igrab() here.
+        */
+       ra->inode = sync ? NULL : igrab(&fi->inode);
 }
 
 void fuse_file_release(struct inode *inode, struct fuse_file *ff,
@@ -308,14 +323,12 @@ void fuse_file_release(struct inode *inode, struct fuse_file *ff,
        struct fuse_release_args *ra = ff->release_args;
        int opcode = isdir ? FUSE_RELEASEDIR : FUSE_RELEASE;
 
-       fuse_prepare_release(fi, ff, open_flags, opcode);
+       fuse_prepare_release(fi, ff, open_flags, opcode, false);
 
-       if (ff->flock) {
+       if (ra && ff->flock) {
                ra->inarg.release_flags |= FUSE_RELEASE_FLOCK_UNLOCK;
                ra->inarg.lock_owner = fuse_lock_owner_id(ff->fm->fc, id);
        }
-       /* Hold inode until release is finished */
-       ra->inode = igrab(inode);
 
        /*
         * Normally this will send the RELEASE request, however if
@@ -326,7 +339,7 @@ void fuse_file_release(struct inode *inode, struct fuse_file *ff,
         * synchronous RELEASE is allowed (and desirable) in this case
         * because the server can be trusted not to screw up.
         */
-       fuse_file_put(ff, ff->fm->fc->destroy, isdir);
+       fuse_file_put(ff, ff->fm->fc->destroy);
 }
 
 void fuse_release_common(struct file *file, bool isdir)
@@ -361,12 +374,8 @@ void fuse_sync_release(struct fuse_inode *fi, struct fuse_file *ff,
                       unsigned int flags)
 {
        WARN_ON(refcount_read(&ff->count) > 1);
-       fuse_prepare_release(fi, ff, flags, FUSE_RELEASE);
-       /*
-        * iput(NULL) is a no-op and since the refcount is 1 and everything's
-        * synchronous, we are fine with not doing igrab() here"
-        */
-       fuse_file_put(ff, true, false);
+       fuse_prepare_release(fi, ff, flags, FUSE_RELEASE, true);
+       fuse_file_put(ff, true);
 }
 EXPORT_SYMBOL_GPL(fuse_sync_release);
 
@@ -923,7 +932,7 @@ static void fuse_readpages_end(struct fuse_mount *fm, struct fuse_args *args,
                put_page(page);
        }
        if (ia->ff)
-               fuse_file_put(ia->ff, false, false);
+               fuse_file_put(ia->ff, false);
 
        fuse_io_free(ia);
 }
@@ -1670,7 +1679,7 @@ static void fuse_writepage_free(struct fuse_writepage_args *wpa)
                __free_page(ap->pages[i]);
 
        if (wpa->ia.ff)
-               fuse_file_put(wpa->ia.ff, false, false);
+               fuse_file_put(wpa->ia.ff, false);
 
        kfree(ap->pages);
        kfree(wpa);
@@ -1918,7 +1927,7 @@ int fuse_write_inode(struct inode *inode, struct writeback_control *wbc)
        ff = __fuse_write_file_get(fi);
        err = fuse_flush_times(inode, ff);
        if (ff)
-               fuse_file_put(ff, false, false);
+               fuse_file_put(ff, false);
 
        return err;
 }
@@ -2316,7 +2325,7 @@ static int fuse_writepages(struct address_space *mapping,
                fuse_writepages_send(&data);
        }
        if (data.ff)
-               fuse_file_put(data.ff, false, false);
+               fuse_file_put(data.ff, false);
 
        kfree(data.orig_pages);
 out:

diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 6c3ec70c1b70d8c845e72c72e75fd382ed078b42..d280ef6e346b40a357bab9a5d0ee2590ca51fc36 100644 (file)
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -1022,7 +1022,7 @@ void fuse_read_args_fill(struct fuse_io_args *ia, struct file *file, loff_t pos,
  */
 int fuse_open_common(struct inode *inode, struct file *file, bool isdir);
 
-struct fuse_file *fuse_file_alloc(struct fuse_mount *fm);
+struct fuse_file *fuse_file_alloc(struct fuse_mount *fm, bool release);
 void fuse_file_free(struct fuse_file *ff);
 void fuse_finish_open(struct inode *inode, struct file *file);