From: Sasha Levin <sashal@kernel.org>
To: stable@vger.kernel.org
Cc: Amir Goldstein <amir73il@gmail.com>,
Miklos Szeredi <mszeredi@redhat.com>,
Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.15.y 1/2] fuse: allocate ff->release_args only if release is needed
Date: Mon, 20 Oct 2025 12:02:55 -0400 [thread overview]
Message-ID: <20251020160256.1828701-1-sashal@kernel.org> (raw)
In-Reply-To: <2025101629-privacy-morally-5172@gregkh>
From: Amir Goldstein <amir73il@gmail.com>
[ 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>
---
fs/fuse/dir.c | 2 +-
fs/fuse/file.c | 69 +++++++++++++++++++++++++++---------------------
fs/fuse/fuse_i.h | 2 +-
3 files changed, 41 insertions(+), 32 deletions(-)
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 1b8bf81d6c16b..43d311ff246bb 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -491,7 +491,7 @@ 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 bb4c5d1848cb7..d940bebe623e8 100644
--- 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
@@ -274,7 +279,7 @@ int fuse_open_common(struct inode *inode, struct file *file, bool isdir)
}
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;
@@ -292,6 +297,9 @@ 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;
@@ -301,6 +309,13 @@ 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,
@@ -310,14 +325,12 @@ 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
@@ -328,7 +341,7 @@ 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)
@@ -360,12 +373,8 @@ 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);
@@ -918,7 +927,7 @@ 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);
}
@@ -1625,7 +1634,7 @@ 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);
@@ -1874,7 +1883,7 @@ 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;
}
@@ -2263,7 +2272,7 @@ 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 ac655c7a15db2..7688122c1976a 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -996,7 +996,7 @@ 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);
--
2.51.0
next prev parent reply other threads:[~2025-10-20 16:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-16 12:36 FAILED: patch "[PATCH] fuse: fix livelock in synchronous file put from fuseblk" failed to apply to 5.15-stable tree gregkh
2025-10-20 16:02 ` Sasha Levin [this message]
2025-10-20 16:02 ` [PATCH 5.15.y 2/2] fuse: fix livelock in synchronous file put from fuseblk workers Sasha Levin
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