From: Shyam Prasad N <nspmangalore@gmail.com>
To: smfrench@gmail.com, bharathsm.hsk@gmail.com, pc@cjr.nz,
tom@talpey.com, linux-cifs@vger.kernel.org
Cc: Shyam Prasad N <sprasad@microsoft.com>
Subject: [PATCH 05/11] cifs: lock chan_lock outside match_session
Date: Fri, 10 Mar 2023 15:32:04 +0000 [thread overview]
Message-ID: <20230310153211.10982-5-sprasad@microsoft.com> (raw)
In-Reply-To: <20230310153211.10982-1-sprasad@microsoft.com>
Coverity had rightly indicated a possible deadlock
due to chan_lock being done inside match_session.
All callers of match_* functions should pick up the
necessary locks and call them.
Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
---
fs/cifs/connect.c | 13 +++++++------
1 file changed, 7 insertions(+), 6 deletions(-)
diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index 4ea1e51c3fa5..fb9d9994df09 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -1735,7 +1735,7 @@ cifs_get_tcp_session(struct smb3_fs_context *ctx,
return ERR_PTR(rc);
}
-/* this function must be called with ses_lock held */
+/* this function must be called with ses_lock and chan_lock held */
static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
{
if (ctx->sectype != Unspecified &&
@@ -1746,12 +1746,8 @@ static int match_session(struct cifs_ses *ses, struct smb3_fs_context *ctx)
* If an existing session is limited to less channels than
* requested, it should not be reused
*/
- spin_lock(&ses->chan_lock);
- if (ses->chan_max < ctx->max_channels) {
- spin_unlock(&ses->chan_lock);
+ if (ses->chan_max < ctx->max_channels)
return 0;
- }
- spin_unlock(&ses->chan_lock);
switch (ses->sectype) {
case Kerberos:
@@ -1879,10 +1875,13 @@ cifs_find_smb_ses(struct TCP_Server_Info *server, struct smb3_fs_context *ctx)
spin_unlock(&ses->ses_lock);
continue;
}
+ spin_lock(&ses->chan_lock);
if (!match_session(ses, ctx)) {
+ spin_unlock(&ses->chan_lock);
spin_unlock(&ses->ses_lock);
continue;
}
+ spin_unlock(&ses->chan_lock);
spin_unlock(&ses->ses_lock);
++ses->ses_count;
@@ -2706,6 +2705,7 @@ cifs_match_super(struct super_block *sb, void *data)
spin_lock(&tcp_srv->srv_lock);
spin_lock(&ses->ses_lock);
+ spin_lock(&ses->chan_lock);
spin_lock(&tcon->tc_lock);
if (!match_server(tcp_srv, ctx, dfs_super_cmp) ||
!match_session(ses, ctx) ||
@@ -2718,6 +2718,7 @@ cifs_match_super(struct super_block *sb, void *data)
rc = compare_mount_options(sb, mnt_data);
out:
spin_unlock(&tcon->tc_lock);
+ spin_unlock(&ses->chan_lock);
spin_unlock(&ses->ses_lock);
spin_unlock(&tcp_srv->srv_lock);
--
2.34.1
next prev parent reply other threads:[~2023-03-10 15:45 UTC|newest]
Thread overview: 31+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-10 15:32 [PATCH 01/11] cifs: fix tcon status change after tree connect Shyam Prasad N
2023-03-10 15:32 ` [PATCH 02/11] cifs: generate signkey for the channel that's reconnecting Shyam Prasad N
2023-03-10 15:32 ` [PATCH 03/11] cifs: avoid race conditions with parallel reconnects Shyam Prasad N
2023-03-10 15:32 ` [PATCH 04/11] cifs: serialize channel reconnects Shyam Prasad N
2023-03-10 22:40 ` Steve French
2023-03-10 15:32 ` Shyam Prasad N [this message]
2023-03-10 15:32 ` [PATCH 06/11] cifs: fix sockaddr comparison in iface_cmp Shyam Prasad N
2023-03-11 4:51 ` kernel test robot
2023-03-10 15:32 ` [PATCH 07/11] cifs: do not poll server interfaces too regularly Shyam Prasad N
2023-03-10 15:32 ` [PATCH 08/11] cifs: distribute channels across interfaces based on speed Shyam Prasad N
2024-02-27 11:16 ` Jan Čermák
2024-02-27 16:17 ` Shyam Prasad N
2024-02-28 9:22 ` Jan Čermák
2024-03-05 14:56 ` Shyam Prasad N
2024-03-06 15:43 ` Paulo Alcantara
2024-03-11 10:01 ` Jan Čermák
2024-03-11 11:14 ` Shyam Prasad N
2024-03-12 14:20 ` Jan Čermák
2024-03-13 10:45 ` Shyam Prasad N
2024-03-26 14:10 ` Jan Čermák
2023-03-10 15:32 ` [PATCH 09/11] cifs: account for primary channel in the interface list Shyam Prasad N
2023-03-13 5:27 ` kernel test robot
2023-03-10 15:32 ` [PATCH 10/11] cifs: handle when server stops supporting multichannel Shyam Prasad N
2023-03-13 6:09 ` kernel test robot
2023-03-10 15:32 ` [PATCH 11/11] cifs: empty interface list when server doesn't support query interfaces Shyam Prasad N
2023-03-14 22:19 ` [PATCH 01/11] cifs: fix tcon status change after tree connect Paulo Alcantara
2023-03-16 10:57 ` Shyam Prasad N
2023-03-16 20:59 ` Paulo Alcantara
2023-03-17 10:48 ` Shyam Prasad N
2023-03-17 12:35 ` Paulo Alcantara
2023-03-17 18:25 ` Steve French
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20230310153211.10982-5-sprasad@microsoft.com \
--to=nspmangalore@gmail.com \
--cc=bharathsm.hsk@gmail.com \
--cc=linux-cifs@vger.kernel.org \
--cc=pc@cjr.nz \
--cc=smfrench@gmail.com \
--cc=sprasad@microsoft.com \
--cc=tom@talpey.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).