All of lore.kernel.org
 help / color / mirror / Atom feed
From: Jan Kara <jack@suse.cz>
To: Jens Axboe <axboe@kernel.dk>
Cc: <linux-block@vger.kernel.org>,
	Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>,
	Jan Kara <jack@suse.cz>
Subject: [PATCH 08/15] loop: Push loop_ctl_mutex down to loop_get_status()
Date: Wed, 10 Oct 2018 12:04:08 +0200	[thread overview]
Message-ID: <20181010100415.26525-9-jack@suse.cz> (raw)
In-Reply-To: <20181010100415.26525-1-jack@suse.cz>

Push loop_ctl_mutex down to loop_get_status() to avoid the unusual
convention that the function gets called with loop_ctl_mutex held and
releases it.

Signed-off-by: Jan Kara <jack@suse.cz>
---
 drivers/block/loop.c | 37 ++++++++++---------------------------
 1 file changed, 10 insertions(+), 27 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index be41d5dcecd2..cb4eeff91238 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -1233,6 +1233,9 @@ loop_get_status(struct loop_device *lo, struct loop_info64 *info)
 	struct kstat stat;
 	int ret;
 
+	ret = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
+	if (ret)
+		return ret;
 	if (lo->lo_state != Lo_bound) {
 		mutex_unlock(&loop_ctl_mutex);
 		return -ENXIO;
@@ -1347,10 +1350,8 @@ loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) {
 	struct loop_info64 info64;
 	int err;
 
-	if (!arg) {
-		mutex_unlock(&loop_ctl_mutex);
+	if (!arg)
 		return -EINVAL;
-	}
 	err = loop_get_status(lo, &info64);
 	if (!err)
 		err = loop_info64_to_old(&info64, &info);
@@ -1365,10 +1366,8 @@ loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) {
 	struct loop_info64 info64;
 	int err;
 
-	if (!arg) {
-		mutex_unlock(&loop_ctl_mutex);
+	if (!arg)
 		return -EINVAL;
-	}
 	err = loop_get_status(lo, &info64);
 	if (!err && copy_to_user(arg, &info64, sizeof(info64)))
 		err = -EFAULT;
@@ -1478,12 +1477,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
 		}
 		break;
 	case LOOP_GET_STATUS:
-		err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
-		if (err)
-			return err;
-		err = loop_get_status_old(lo, (struct loop_info __user *) arg);
-		/* loop_get_status() unlocks loop_ctl_mutex */
-		break;
+		return loop_get_status_old(lo, (struct loop_info __user *) arg);
 	case LOOP_SET_STATUS64:
 		err = -EPERM;
 		if ((mode & FMODE_WRITE) || capable(CAP_SYS_ADMIN)) {
@@ -1496,12 +1490,7 @@ static int lo_ioctl(struct block_device *bdev, fmode_t mode,
 		}
 		break;
 	case LOOP_GET_STATUS64:
-		err = mutex_lock_killable_nested(&loop_ctl_mutex, 1);
-		if (err)
-			return err;
-		err = loop_get_status64(lo, (struct loop_info64 __user *) arg);
-		/* loop_get_status() unlocks loop_ctl_mutex */
-		break;
+		return loop_get_status64(lo, (struct loop_info64 __user *) arg);
 	case LOOP_SET_CAPACITY:
 	case LOOP_SET_DIRECT_IO:
 	case LOOP_SET_BLOCK_SIZE:
@@ -1626,10 +1615,8 @@ loop_get_status_compat(struct loop_device *lo,
 	struct loop_info64 info64;
 	int err;
 
-	if (!arg) {
-		mutex_unlock(&loop_ctl_mutex);
+	if (!arg)
 		return -EINVAL;
-	}
 	err = loop_get_status(lo, &info64);
 	if (!err)
 		err = loop_info64_to_compat(&info64, arg);
@@ -1652,12 +1639,8 @@ static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode,
 		}
 		break;
 	case LOOP_GET_STATUS:
-		err = mutex_lock_killable(&loop_ctl_mutex);
-		if (!err) {
-			err = loop_get_status_compat(lo,
-						     (struct compat_loop_info __user *)arg);
-			/* loop_get_status() unlocks loop_ctl_mutex */
-		}
+		err = loop_get_status_compat(lo,
+				     (struct compat_loop_info __user *)arg);
 		break;
 	case LOOP_SET_CAPACITY:
 	case LOOP_CLR_FD:
-- 
2.16.4

  parent reply	other threads:[~2018-10-10 10:04 UTC|newest]

Thread overview: 24+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-10-10 10:04 [PATCH 0/15 v2] loop: Fix oops and possible deadlocks Jan Kara
2018-10-10 10:04 ` [PATCH 01/15] block/loop: Don't grab "struct file" for vfs_getattr() operation Jan Kara
2018-10-10 10:04 ` [PATCH 02/15] block/loop: Use global lock for ioctl() operation Jan Kara
2018-10-10 10:04 ` [PATCH 03/15] loop: Fold __loop_release into loop_release Jan Kara
2018-10-10 10:04 ` [PATCH 04/15] loop: Get rid of loop_index_mutex Jan Kara
2018-10-10 10:04 ` [PATCH 05/15] loop: Push lo_ctl_mutex down into individual ioctls Jan Kara
2018-10-10 10:04 ` [PATCH 06/15] loop: Split setting of lo_state from loop_clr_fd Jan Kara
2018-10-10 10:04 ` [PATCH 07/15] loop: Push loop_ctl_mutex down into loop_clr_fd() Jan Kara
2018-10-10 10:04 ` Jan Kara [this message]
2018-10-10 10:04 ` [PATCH 09/15] loop: Push loop_ctl_mutex down to loop_set_status() Jan Kara
2018-10-10 10:04 ` [PATCH 10/15] loop: Push loop_ctl_mutex down to loop_set_fd() Jan Kara
2018-10-10 10:04 ` [PATCH 11/15] loop: Push loop_ctl_mutex down to loop_change_fd() Jan Kara
2018-10-10 10:04 ` [PATCH 12/15] loop: Move special partition reread handling in loop_clr_fd() Jan Kara
2018-10-10 10:04 ` [PATCH 13/15] loop: Move loop_reread_partitions() out of loop_ctl_mutex Jan Kara
2018-10-10 10:04 ` [PATCH 14/15] loop: Fix deadlock when calling blkdev_reread_part() Jan Kara
2018-10-10 10:04 ` [PATCH 15/15] loop: Avoid circular locking dependency between loop_ctl_mutex and bd_mutex Jan Kara
2018-10-10 10:19 ` [PATCH 0/15 v2] loop: Fix oops and possible deadlocks Tetsuo Handa
2018-10-10 11:42   ` Johannes Thumshirn
2018-10-10 12:28     ` Jan Kara
2018-10-10 12:43       ` Johannes Thumshirn
2018-10-16 11:36       ` Jan Kara
2018-10-16 12:04         ` Johannes Thumshirn
2018-10-16 18:16         ` Omar Sandoval
2018-10-17  9:47           ` Jan Kara

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=20181010100415.26525-9-jack@suse.cz \
    --to=jack@suse.cz \
    --cc=axboe@kernel.dk \
    --cc=linux-block@vger.kernel.org \
    --cc=penguin-kernel@i-love.sakura.ne.jp \
    /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 an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.