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

c4bc705e · Linus Torvalds <[email protected]> · 2013-02-21 09:03:54 -08:00

Pull fuse updates from Miklos Szeredi:
 "The biggest part of this pull request is a patch series from Maxim
  Patlasov to optimize scatter-gather direct IO.  There's also the
  addition of a "readdirplus" API, poll events and various fixes and
  cleanups.

  There's a one line change outside of fuse to mm/filemap.c which makes
  the argument of iov_iter_single_seg_count() const, required by Maxim's
  patches."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (22 commits)
  fuse: allow control of adaptive readdirplus use
  Synchronize fuse header with one used in library
  fuse: send poll events
  fuse: don't WARN when nlink is zero
  fuse: avoid out-of-scope stack access
  fuse: bump version for READDIRPLUS
  FUSE: Adapt readdirplus to application usage patterns
  Do not use RCU for current process credentials
  fuse: cleanup fuse_direct_io()
  fuse: optimize __fuse_direct_io()
  fuse: optimize fuse_get_user_pages()
  fuse: pass iov[] to fuse_get_user_pages()
  mm: minor cleanup of iov_iter_single_seg_count()
  fuse: use req->page_descs[] for argpages cases
  fuse: add per-page descriptor <offset, length> to fuse_req
  fuse: rework fuse_do_ioctl()
  fuse: rework fuse_perform_write()
  fuse: rework fuse_readpages()
  fuse: rework fuse_retrieve()
  fuse: categorize fuse_get_req()
  ...

Commit: c4bc705e45d91f900f7ec2e23a458280b084ae91
Parents: 2608e3d0 · 634734b6

Merge commit. Changes below are compared with the first parent: 2608e3d0.

Changes

9 files changed · +609 −180

File	Status	Add	Del	Content
fs/fuse/cuse.c	modified	+7	−3	View file
fs/fuse/dev.c	modified	+96	−32	View file
fs/fuse/dir.c	modified	+221	−38	View file
fs/fuse/file.c	modified	+154	−84	View file
fs/fuse/fuse_i.h	modified	+61	−13	View file
fs/fuse/inode.c	modified	+11	−5	View file
include/linux/fs.h	modified	+1	−1	View file
include/uapi/linux/fuse.h	modified	+57	−3	View file
mm/filemap.c	modified	+1	−1	View file

Only the first 600 diff lines are shown. Download the complete patch.

fs/fuse/cuse.c

View file

diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index e397b67..6f96a8d 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -91,19 +91,22 @@ static ssize_t cuse_read(struct file *file, char __user *buf, size_t count,
 			 loff_t *ppos)
 {
 	loff_t pos = 0;
+	struct iovec iov = { .iov_base = buf, .iov_len = count };
 
-	return fuse_direct_io(file, buf, count, &pos, 0);
+	return fuse_direct_io(file, &iov, 1, count, &pos, 0);
 }
 
 static ssize_t cuse_write(struct file *file, const char __user *buf,
 			  size_t count, loff_t *ppos)
 {
 	loff_t pos = 0;
+	struct iovec iov = { .iov_base = (void __user *)buf, .iov_len = count };
+
 	/*
 	 * No locking or generic_write_checks(), the server is
 	 * responsible for locking and sanity checks.
 	 */
-	return fuse_direct_io(file, buf, count, &pos, 1);
+	return fuse_direct_io(file, &iov, 1, count, &pos, 1);
 }
 
 static int cuse_open(struct inode *inode, struct file *file)
@@ -419,7 +422,7 @@ static int cuse_send_init(struct cuse_conn *cc)
 
 	BUILD_BUG_ON(CUSE_INIT_INFO_MAX > PAGE_SIZE);
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req(fc, 1);
 	if (IS_ERR(req)) {
 		rc = PTR_ERR(req);
 		goto err;
@@ -449,6 +452,7 @@ static int cuse_send_init(struct cuse_conn *cc)
 	req->out.argvar = 1;
 	req->out.argpages = 1;
 	req->pages[0] = page;
+	req->page_descs[0].length = req->out.args[1].size;
 	req->num_pages = 1;
 	req->end = cuse_process_init_reply;
 	fuse_request_send_background(fc, req);

fs/fuse/dev.c

View file

diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index e83351a..e9bdec0 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -34,34 +34,67 @@ static struct fuse_conn *fuse_get_conn(struct file *file)
 	return file->private_data;
 }
 
-static void fuse_request_init(struct fuse_req *req)
+static void fuse_request_init(struct fuse_req *req, struct page **pages,
+			      struct fuse_page_desc *page_descs,
+			      unsigned npages)
 {
 	memset(req, 0, sizeof(*req));
+	memset(pages, 0, sizeof(*pages) * npages);
+	memset(page_descs, 0, sizeof(*page_descs) * npages);
 	INIT_LIST_HEAD(&req->list);
 	INIT_LIST_HEAD(&req->intr_entry);
 	init_waitqueue_head(&req->waitq);
 	atomic_set(&req->count, 1);
+	req->pages = pages;
+	req->page_descs = page_descs;
+	req->max_pages = npages;
 }
 
-struct fuse_req *fuse_request_alloc(void)
+static struct fuse_req *__fuse_request_alloc(unsigned npages, gfp_t flags)
 {
-	struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_KERNEL);
-	if (req)
-		fuse_request_init(req);
+	struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, flags);
+	if (req) {
+		struct page **pages;
+		struct fuse_page_desc *page_descs;
+
+		if (npages <= FUSE_REQ_INLINE_PAGES) {
+			pages = req->inline_pages;
+			page_descs = req->inline_page_descs;
+		} else {
+			pages = kmalloc(sizeof(struct page *) * npages, flags);
+			page_descs = kmalloc(sizeof(struct fuse_page_desc) *
+					     npages, flags);
+		}
+
+		if (!pages || !page_descs) {
+			kfree(pages);
+			kfree(page_descs);
+			kmem_cache_free(fuse_req_cachep, req);
+			return NULL;
+		}
+
+		fuse_request_init(req, pages, page_descs, npages);
+	}
 	return req;
 }
+
+struct fuse_req *fuse_request_alloc(unsigned npages)
+{
+	return __fuse_request_alloc(npages, GFP_KERNEL);
+}
 EXPORT_SYMBOL_GPL(fuse_request_alloc);
 
-struct fuse_req *fuse_request_alloc_nofs(void)
+struct fuse_req *fuse_request_alloc_nofs(unsigned npages)
 {
-	struct fuse_req *req = kmem_cache_alloc(fuse_req_cachep, GFP_NOFS);
-	if (req)
-		fuse_request_init(req);
-	return req;
+	return __fuse_request_alloc(npages, GFP_NOFS);
 }
 
 void fuse_request_free(struct fuse_req *req)
 {
+	if (req->pages != req->inline_pages) {
+		kfree(req->pages);
+		kfree(req->page_descs);
+	}
 	kmem_cache_free(fuse_req_cachep, req);
 }
 
@@ -97,7 +130,7 @@ static void fuse_req_init_context(struct fuse_req *req)
 	req->in.h.pid = current->pid;
 }
 
-struct fuse_req *fuse_get_req(struct fuse_conn *fc)
+struct fuse_req *fuse_get_req(struct fuse_conn *fc, unsigned npages)
 {
 	struct fuse_req *req;
 	sigset_t oldset;
@@ -116,7 +149,7 @@ struct fuse_req *fuse_get_req(struct fuse_conn *fc)
 	if (!fc->connected)
 		goto out;
 
-	req = fuse_request_alloc();
+	req = fuse_request_alloc(npages);
 	err = -ENOMEM;
 	if (!req)
 		goto out;
@@ -165,7 +198,7 @@ static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
 	struct fuse_file *ff = file->private_data;
 
 	spin_lock(&fc->lock);
-	fuse_request_init(req);
+	fuse_request_init(req, req->pages, req->page_descs, req->max_pages);
 	BUG_ON(ff->reserved_req);
 	ff->reserved_req = req;
 	wake_up_all(&fc->reserved_req_waitq);
@@ -186,13 +219,14 @@ static void put_reserved_req(struct fuse_conn *fc, struct fuse_req *req)
  * filesystem should not have it's own file open.  If deadlock is
  * intentional, it can still be broken by "aborting" the filesystem.
  */
-struct fuse_req *fuse_get_req_nofail(struct fuse_conn *fc, struct file *file)
+struct fuse_req *fuse_get_req_nofail_nopages(struct fuse_conn *fc,
+					     struct file *file)
 {
 	struct fuse_req *req;
 
 	atomic_inc(&fc->num_waiting);
 	wait_event(fc->blocked_waitq, !fc->blocked);
-	req = fuse_request_alloc();
+	req = fuse_request_alloc(0);
 	if (!req)
 		req = get_reserved_req(fc, file);
 
@@ -406,9 +440,8 @@ __acquires(fc->lock)
 	}
 }
 
-void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
+static void __fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
 {
-	req->isreply = 1;
 	spin_lock(&fc->lock);
 	if (!fc->connected)
 		req->out.h.error = -ENOTCONN;
@@ -425,6 +458,12 @@ void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
 	}
 	spin_unlock(&fc->lock);
 }
+
+void fuse_request_send(struct fuse_conn *fc, struct fuse_req *req)
+{
+	req->isreply = 1;
+	__fuse_request_send(fc, req);
+}
 EXPORT_SYMBOL_GPL(fuse_request_send);
 
 static void fuse_request_send_nowait_locked(struct fuse_conn *fc,
@@ -491,6 +530,27 @@ void fuse_request_send_background_locked(struct fuse_conn *fc,
 	fuse_request_send_nowait_locked(fc, req);
 }
 
+void fuse_force_forget(struct file *file, u64 nodeid)
+{
+	struct inode *inode = file->f_path.dentry->d_inode;
+	struct fuse_conn *fc = get_fuse_conn(inode);
+	struct fuse_req *req;
+	struct fuse_forget_in inarg;
+
+	memset(&inarg, 0, sizeof(inarg));
+	inarg.nlookup = 1;
+	req = fuse_get_req_nofail_nopages(fc, file);
+	req->in.h.opcode = FUSE_FORGET;
+	req->in.h.nodeid = nodeid;
+	req->in.numargs = 1;
+	req->in.args[0].size = sizeof(inarg);
+	req->in.args[0].value = &inarg;
+	req->isreply = 0;
+	__fuse_request_send(fc, req);
+	/* ignore errors */
+	fuse_put_request(fc, req);
+}
+
 /*
  * Lock the request.  Up to the next unlock_request() there mustn't be
  * anything that could cause a page-fault.  If the request was already
@@ -850,11 +910,11 @@ static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
 {
 	unsigned i;
 	struct fuse_req *req = cs->req;
-	unsigned offset = req->page_offset;
-	unsigned count = min(nbytes, (unsigned) PAGE_SIZE - offset);
 
 	for (i = 0; i < req->num_pages && (nbytes || zeroing); i++) {
 		int err;
+		unsigned offset = req->page_descs[i].offset;
+		unsigned count = min(nbytes, req->page_descs[i].length);
 
 		err = fuse_copy_page(cs, &req->pages[i], offset, count,
 				     zeroing);
@@ -862,8 +922,6 @@ static int fuse_copy_pages(struct fuse_copy_state *cs, unsigned nbytes,
 			return err;
 
 		nbytes -= count;
-		count = min(nbytes, (unsigned) PAGE_SIZE);
-		offset = 0;
 	}
 	return 0;
 }
@@ -1536,29 +1594,34 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
 	unsigned int num;
 	unsigned int offset;
 	size_t total_len = 0;
+	int num_pages;
+
+	offset = outarg->offset & ~PAGE_CACHE_MASK;
+	file_size = i_size_read(inode);
+
+	num = outarg->size;
+	if (outarg->offset > file_size)
+		num = 0;
+	else if (outarg->offset + num > file_size)
+		num = file_size - outarg->offset;
+
+	num_pages = (num + offset + PAGE_SIZE - 1) >> PAGE_SHIFT;
+	num_pages = min(num_pages, FUSE_MAX_PAGES_PER_REQ);
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req(fc, num_pages);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
-	offset = outarg->offset & ~PAGE_CACHE_MASK;
-
 	req->in.h.opcode = FUSE_NOTIFY_REPLY;
 	req->in.h.nodeid = outarg->nodeid;
 	req->in.numargs = 2;
 	req->in.argpages = 1;
-	req->page_offset = offset;
+	req->page_descs[0].offset = offset;
 	req->end = fuse_retrieve_end;
 
 	index = outarg->offset >> PAGE_CACHE_SHIFT;
-	file_size = i_size_read(inode);
-	num = outarg->size;
-	if (outarg->offset > file_size)
-		num = 0;
-	else if (outarg->offset + num > file_size)
-		num = file_size - outarg->offset;
 
-	while (num && req->num_pages < FUSE_MAX_PAGES_PER_REQ) {
+	while (num && req->num_pages < num_pages) {
 		struct page *page;
 		unsigned int this_num;
 
@@ -1568,6 +1631,7 @@ static int fuse_retrieve(struct fuse_conn *fc, struct inode *inode,
 
 		this_num = min_t(unsigned, num, PAGE_CACHE_SIZE - offset);
 		req->pages[req->num_pages] = page;
+		req->page_descs[req->num_pages].length = this_num;
 		req->num_pages++;
 
 		offset = 0;

fs/fuse/dir.c

View file

diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index b7c09f9..8506522 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -14,6 +14,29 @@
 #include <linux/namei.h>
 #include <linux/slab.h>
 
+static bool fuse_use_readdirplus(struct inode *dir, struct file *filp)
+{
+	struct fuse_conn *fc = get_fuse_conn(dir);
+	struct fuse_inode *fi = get_fuse_inode(dir);
+
+	if (!fc->do_readdirplus)
+		return false;
+	if (!fc->readdirplus_auto)
+		return true;
+	if (test_and_clear_bit(FUSE_I_ADVISE_RDPLUS, &fi->state))
+		return true;
+	if (filp->f_pos == 0)
+		return true;
+	return false;
+}
+
+static void fuse_advise_use_readdirplus(struct inode *dir)
+{
+	struct fuse_inode *fi = get_fuse_inode(dir);
+
+	set_bit(FUSE_I_ADVISE_RDPLUS, &fi->state);
+}
+
 #if BITS_PER_LONG >= 64
 static inline void fuse_dentry_settime(struct dentry *entry, u64 time)
 {
@@ -178,7 +201,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 			return -ECHILD;
 
 		fc = get_fuse_conn(inode);
-		req = fuse_get_req(fc);
+		req = fuse_get_req_nopages(fc);
 		if (IS_ERR(req))
 			return 0;
 
@@ -219,6 +242,7 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 				       attr_version);
 		fuse_change_entry_timeout(entry, &outarg);
 	}
+	fuse_advise_use_readdirplus(inode);
 	return 1;
 }
 
@@ -271,7 +295,7 @@ int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 	if (name->len > FUSE_NAME_MAX)
 		goto out;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	err = PTR_ERR(req);
 	if (IS_ERR(req))
 		goto out;
@@ -355,6 +379,7 @@ static struct dentry *fuse_lookup(struct inode *dir, struct dentry *entry,
 	else
 		fuse_invalidate_entry_cache(entry);
 
+	fuse_advise_use_readdirplus(dir);
 	return newent;
 
  out_iput:
@@ -391,7 +416,7 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 	if (!forget)
 		goto out_err;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	err = PTR_ERR(req);
 	if (IS_ERR(req))
 		goto out_put_forget_req;
@@ -592,7 +617,7 @@ static int fuse_mknod(struct inode *dir, struct dentry *entry, umode_t mode,
 {
 	struct fuse_mknod_in inarg;
 	struct fuse_conn *fc = get_fuse_conn(dir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -623,7 +648,7 @@ static int fuse_mkdir(struct inode *dir, struct dentry *entry, umode_t mode)
 {
 	struct fuse_mkdir_in inarg;
 	struct fuse_conn *fc = get_fuse_conn(dir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -647,7 +672,7 @@ 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 = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -664,7 +689,7 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry)
 {
 	int err;
 	struct fuse_conn *fc = get_fuse_conn(dir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -682,7 +707,14 @@ static int fuse_unlink(struct inode *dir, struct dentry *entry)
 
 		spin_lock(&fc->lock);
 		fi->attr_version = ++fc->attr_version;
-		drop_nlink(inode);
+		/*
+		 * If i_nlink == 0 then unlink doesn't make sense, yet this can
+		 * happen if userspace filesystem is careless.  It would be
+		 * difficult to enforce correct nlink usage so just ignore this
+		 * condition here
+		 */
+		if (inode->i_nlink > 0)
+			drop_nlink(inode);
 		spin_unlock(&fc->lock);
 		fuse_invalidate_attr(inode);
 		fuse_invalidate_attr(dir);
@@ -696,7 +728,7 @@ static int fuse_rmdir(struct inode *dir, struct dentry *entry)
 {
 	int err;
 	struct fuse_conn *fc = get_fuse_conn(dir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -723,7 +755,7 @@ static int fuse_rename(struct inode *olddir, struct dentry *oldent,
 	int err;
 	struct fuse_rename_in inarg;
 	struct fuse_conn *fc = get_fuse_conn(olddir);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 
 	if (IS_ERR(req))
 		return PTR_ERR(req);
@@ -776,7 +808,7 @@ static int fuse_link(struct dentry *entry, struct inode *newdir,
 	struct fuse_link_in inarg;
 	struct inode *inode = entry->d_inode;
 	struct fuse_conn *fc = get_fuse_conn(inode);
-	struct fuse_req *req = fuse_get_req(fc);
+	struct fuse_req *req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -848,7 +880,7 @@ static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
 	struct fuse_req *req;
 	u64 attr_version;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -985,7 +1017,7 @@ int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
 
 /*
  * Calling into a user-controlled filesystem gives the filesystem
- * daemon ptrace-like capabilities over the requester process.  This
+ * daemon ptrace-like capabilities over the current process.  This
  * means, that the filesystem daemon is able to record the exact
  * filesystem operations performed, and can also control the behavior
  * of the requester process in otherwise impossible ways.  For example
@@ -996,27 +1028,23 @@ int fuse_reverse_inval_entry(struct super_block *sb, u64 parent_nodeid,
  * for which the owner of the mount has ptrace privilege.  This
  * excludes processes started by other users, suid or sgid processes.
  */
-int fuse_allow_task(struct fuse_conn *fc, struct task_struct *task)
+int fuse_allow_current_process(struct fuse_conn *fc)
 {
 	const struct cred *cred;
-	int ret;
 
 	if (fc->flags & FUSE_ALLOW_OTHER)
 		return 1;
 
-	rcu_read_lock();
-	ret = 0;
-	cred = __task_cred(task);
+	cred = current_cred();
 	if (uid_eq(cred->euid, fc->user_id) &&
 	    uid_eq(cred->suid, fc->user_id) &&
 	    uid_eq(cred->uid,  fc->user_id) &&
 	    gid_eq(cred->egid, fc->group_id) &&
 	    gid_eq(cred->sgid, fc->group_id) &&
 	    gid_eq(cred->gid,  fc->group_id))
-		ret = 1;
-	rcu_read_unlock();
+		return 1;
 
-	return ret;
+	return 0;
 }
 
 static int fuse_access(struct inode *inode, int mask)
@@ -1029,7 +1057,7 @@ static int fuse_access(struct inode *inode, int mask)
 	if (fc->no_access)
 		return 0;
 
-	req = fuse_get_req(fc);
+	req = fuse_get_req_nopages(fc);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
 
@@ -1077,7 +1105,7 @@ static int fuse_permission(struct inode *inode, int mask)
 	bool refreshed = false;
 	int err = 0;
 
-	if (!fuse_allow_task(fc, current))
+	if (!fuse_allow_current_process(fc))
 		return -EACCES;
 
 	/*
@@ -1155,19 +1183,157 @@ static int parse_dirfile(char *buf, size_t nbytes, struct file *file,
 	return 0;
 }
 
-static int fuse_readdir(struct file *file, void *dstbuf, filldir_t filldir)
+static int fuse_direntplus_link(struct file *file,
+				struct fuse_direntplus *direntplus,
+				u64 attr_version)
 {
 	int err;
+	struct fuse_entry_out *o = &direntplus->entry_out;
+	struct fuse_dirent *dirent = &direntplus->dirent;
+	struct dentry *parent = file->f_path.dentry;
+	struct qstr name = QSTR_INIT(dirent->name, dirent->namelen);
+	struct dentry *dentry;
+	struct dentry *alias;
+	struct inode *dir = parent->d_inode;
+	struct fuse_conn *fc;
+	struct inode *inode;
+
+	if (!o->nodeid) {
+		/*
+		 * Unlike in the case of fuse_lookup, zero nodeid does not mean
+		 * ENOENT. Instead, it only means the userspace filesystem did
+		 * not want to return attributes/handle for this entry.
+		 *
+		 * So do nothing.
+		 */
+		return 0;
+	}
+
+	if (name.name[0] == '.') {
+		/*
+		 * We could potentially refresh the attributes of the directory
+		 * and its parent?
+		 */
+		if (name.len == 1)
+			return 0;
+		if (name.name[1] == '.' && name.len == 2)
+			return 0;
+	}
+	fc = get_fuse_conn(dir);
+
+	name.hash = full_name_hash(name.name, name.len);
+	dentry = d_lookup(parent, &name);
+	if (dentry && dentry->d_inode) {
+		inode = dentry->d_inode;
+		if (get_node_id(inode) == o->nodeid) {
+			struct fuse_inode *fi;
+			fi = get_fuse_inode(inode);
+			spin_lock(&fc->lock);
+			fi->nlookup++;
+			spin_unlock(&fc->lock);
+
+			/*
+			 * The other branch to 'found' comes via fuse_iget()
+			 * which bumps nlookup inside
+			 */
+			goto found;
+		}
+		err = d_invalidate(dentry);
+		if (err)
+			goto out;
+		dput(dentry);
+		dentry = NULL;
+	}
+
+	dentry = d_alloc(parent, &name);
+	err = -ENOMEM;
+	if (!dentry)
+		goto out;
+
+	inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
+			  &o->attr, entry_attr_timeout(o), attr_version);
+	if (!inode)

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fs/fuse/file.c

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fs/fuse/fuse_i.h

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fs/fuse/inode.c

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include/linux/fs.h

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include/uapi/linux/fuse.h

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mm/filemap.c

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