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From: Al Viro <viro@zeniv.linux.org.uk>
To: Denis Kirjanov <kda@linux-powerpc.org>
Cc: Christoph Hellwig <hch@infradead.org>,
	linux-kernel@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>,
	linux-fsdevel@vger.kernel.org
Subject: [PATCH 3/8] unix_bind(): separate BSD and abstract cases
Date: Fri, 19 Feb 2021 04:21:10 +0000	[thread overview]
Message-ID: <YC88tqCkBEKoLrjW@zeniv-ca.linux.org.uk> (raw)
In-Reply-To: <YC86WeSTkYZqRlJY@zeniv-ca.linux.org.uk>

We do get some duplication that way, but it's minor compared to
parts that are different.  What we get is an ability to change
locking in BSD case without making failure exits very hard to
follow.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
---
 net/unix/af_unix.c | 52 ++++++++++++++++++++++++++++++++--------------------
 1 file changed, 32 insertions(+), 20 deletions(-)

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 451d81f405c0..11e18b0efbc6 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1023,7 +1023,6 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	int err;
 	unsigned int hash;
 	struct unix_address *addr;
-	struct path path = { };
 
 	err = -EINVAL;
 	if (addr_len < offsetofend(struct sockaddr_un, sun_family) ||
@@ -1050,6 +1049,7 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 	refcount_set(&addr->refcnt, 1);
 
 	if (sun_path[0]) {
+		struct path path = { };
 		umode_t mode = S_IFSOCK |
 		       (SOCK_INODE(sock)->i_mode & ~current_umask());
 		err = unix_mknod(sun_path, mode, &path);
@@ -1058,40 +1058,52 @@ static int unix_bind(struct socket *sock, struct sockaddr *uaddr, int addr_len)
 				err = -EADDRINUSE;
 			goto out_addr;
 		}
-	}
 
-	err = mutex_lock_interruptible(&u->bindlock);
-	if (err)
-		goto out_put;
+		err = mutex_lock_interruptible(&u->bindlock);
+		if (err) {
+			path_put(&path);
+			goto out_addr;
+		}
 
-	err = -EINVAL;
-	if (u->addr)
-		goto out_up;
+		err = -EINVAL;
+		if (u->addr) {
+			mutex_unlock(&u->bindlock);
+			path_put(&path);
+			goto out_addr;
+		}
 
-	if (sun_path[0]) {
 		addr->hash = UNIX_HASH_SIZE;
 		hash = d_backing_inode(path.dentry)->i_ino & (UNIX_HASH_SIZE - 1);
 		spin_lock(&unix_table_lock);
 		u->path = path;
+		__unix_set_addr(sk, addr, hash);
+		mutex_unlock(&u->bindlock);
+		addr = NULL;
+		err = 0;
 	} else {
+		err = mutex_lock_interruptible(&u->bindlock);
+		if (err)
+			goto out_addr;
+
+		err = -EINVAL;
+		if (u->addr) {
+			mutex_unlock(&u->bindlock);
+			goto out_addr;
+		}
+
 		spin_lock(&unix_table_lock);
 		err = -EADDRINUSE;
 		if (__unix_find_socket_byname(net, sunaddr, addr_len,
 					      sk->sk_type, hash)) {
 			spin_unlock(&unix_table_lock);
-			goto out_up;
+			mutex_unlock(&u->bindlock);
+			goto out_addr;
 		}
-		hash = addr->hash;
+		__unix_set_addr(sk, addr, addr->hash);
+		mutex_unlock(&u->bindlock);
+		addr = NULL;
+		err = 0;
 	}
-
-	__unix_set_addr(sk, addr, hash);
-	addr = NULL;
-	err = 0;
-out_up:
-	mutex_unlock(&u->bindlock);
-out_put:
-	if (err)
-		path_put(&path);
 out_addr:
 	if (addr)
 		unix_release_addr(addr);
-- 
2.11.0


  parent reply	other threads:[~2021-02-19  4:22 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <20210125154937.26479-1-kda@linux-powerpc.org>
     [not found] ` <20210127175742.GA1744861@infradead.org>
     [not found]   ` <CAOJe8K0MC-TCURE2Gpci1SLnLXCbUkE7q6SS0fznzBA+Pf-B8Q@mail.gmail.com>
     [not found]     ` <20210129082524.GA2282796@infradead.org>
     [not found]       ` <CAOJe8K0iG91tm8YBRmE_rdMMMbc4iRsMGYNxJk0p9vEedNHEkg@mail.gmail.com>
     [not found]         ` <20210129131855.GA2346744@infradead.org>
2021-02-14 18:17           ` [PATCH] fs: export kern_path_locked Al Viro
2021-02-16 14:31             ` Denis Kirjanov
2021-02-16 18:00               ` Al Viro
2021-02-19  4:11                 ` Al Viro
2021-02-19  4:19                   ` [PATCH 1/8] af_unix: take address assignment/hash insertion into a new helper Al Viro
2021-02-20 19:12                     ` Cong Wang
2021-02-20 19:32                       ` Al Viro
2021-02-20 20:31                         ` Cong Wang
2021-02-20 21:08                           ` Al Viro
2021-02-22 19:06                             ` [PATCHSET] making unix_bind() undo mknod on failure Al Viro
2021-02-22 19:12                               ` [PATCH 1/8] af_unix: take address assignment/hash insertion into a new helper Al Viro
2021-02-22 19:12                                 ` [PATCH 2/8] unix_bind(): allocate addr earlier Al Viro
2021-02-22 19:12                                 ` [PATCH 3/8] unix_bind(): separate BSD and abstract cases Al Viro
2021-02-22 19:12                                 ` [PATCH 4/8] unix_bind(): take BSD and abstract address cases into new helpers Al Viro
2021-02-22 19:12                                 ` [PATCH 5/8] fold unix_mknod() into unix_bind_bsd() Al Viro
2021-02-22 19:12                                 ` [PATCH 6/8] unix_bind_bsd(): move done_path_create() call after dealing with ->bindlock Al Viro
2021-02-22 19:12                                 ` [PATCH 7/8] unix_bind_bsd(): unlink if we fail after successful mknod Al Viro
2021-02-22 19:12                                 ` [PATCH 8/8] __unix_find_socket_byname(): don't pass hash and type separately Al Viro
2021-02-22 19:12                               ` [PATCHSET] making unix_bind() undo mknod on failure Al Viro
2021-02-22 19:24                                 ` Al Viro
2021-02-24  0:40                               ` Jakub Kicinski
2021-02-19  4:20                   ` [PATCH 2/8] unix_bind(): allocate addr earlier Al Viro
2021-02-19  4:21                   ` Al Viro [this message]
2021-02-19  4:21                   ` [PATCH 4/8] unix_bind(): take BSD and abstract address cases into new helpers Al Viro
2021-02-19  4:22                   ` [PATCH 5/8] fold unix_mknod() into unix_bind_bsd() Al Viro
2021-02-19  4:22                   ` [PATCH 6/8] unix_bind_bsd(): move done_path_create() call after dealing with ->bindlock Al Viro
2021-02-19  4:23                   ` [PATCH 7/8] unix_bind_bsd(): unlink if we fail after successful mknod Al Viro
2021-02-19  4:23                   ` [PATCH 8/8] __unix_find_socket_byname(): don't pass hash and type separately Al Viro

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