[PATCH 03/15] configfs_detach_prep(): make sure that wait_mutex won't go away

[Al Viro]

From: Al Viro 

grab a reference to dentry we'd got the sucker from, and return
that dentry via *wait, rather than just returning the address of
->i_mutex.

Signed-off-by: Al Viro 
---
 fs/configfs/dir.c | 17 +
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index ea59c89..48929c4 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -494,7 +494,7 @@ out:
  * If there is an error, the caller will reset the flags via
  * configfs_detach_rollback().
  */
-static int configfs_detach_prep(struct dentry *dentry, struct mutex 
**wait_mutex)
+static int configfs_detach_prep(struct dentry *dentry, struct dentry **wait)
 {
struct configfs_dirent *parent_sd = dentry->d_fsdata;
struct configfs_dirent *sd;
@@ -515,8 +515,8 @@ static int configfs_detach_prep(struct dentry *dentry, 
struct mutex **wait_mutex
if (sd->s_type & CONFIGFS_USET_DEFAULT) {
/* Abort if racing with mkdir() */
if (sd->s_type & CONFIGFS_USET_IN_MKDIR) {
-   if (wait_mutex)
-   *wait_mutex = 
_inode(sd->s_dentry)->i_mutex;
+   if (wait)
+   *wait= dget(sd->s_dentry);
return -EAGAIN;
}
 
@@ -524,7 +524,7 @@ static int configfs_detach_prep(struct dentry *dentry, 
struct mutex **wait_mutex
 * Yup, recursive.  If there's a problem, blame
 * deep nesting of default_groups
 */
-   ret = configfs_detach_prep(sd->s_dentry, wait_mutex);
+   ret = configfs_detach_prep(sd->s_dentry, wait);
if (!ret)
continue;
} else
@@ -1458,7 +1458,7 @@ static int configfs_rmdir(struct inode *dir, struct 
dentry *dentry)
 * the new link is temporarily attached
 */
do {
-   struct mutex *wait_mutex;
+   struct dentry *wait;
 
mutex_lock(_symlink_mutex);
spin_lock(_dirent_lock);
@@ -1469,7 +1469,7 @@ static int configfs_rmdir(struct inode *dir, struct 
dentry *dentry)
 */
ret = sd->s_dependent_count ? -EBUSY : 0;
if (!ret) {
-   ret = configfs_detach_prep(dentry, _mutex);
+   ret = configfs_detach_prep(dentry, );
if (ret)
configfs_detach_rollback(dentry);
}
@@ -1483,8 +1483,9 @@ static int configfs_rmdir(struct inode *dir, struct 
dentry *dentry)
}
 
/* Wait until the racing operation terminates */
-   mutex_lock(wait_mutex);
-   mutex_unlock(wait_mutex);
+   inode_lock(d_inode(wait));
+   inode_unlock(d_inode(wait));
+   dput(wait);
}
} while (ret == -EAGAIN);
 
-- 
2.8.0.rc3

[PATCH 03/15] configfs_detach_prep(): make sure that wait_mutex won't go away

[Al Viro]

From: Al Viro 

grab a reference to dentry we'd got the sucker from, and return
that dentry via *wait, rather than just returning the address of
->i_mutex.

Signed-off-by: Al Viro 
---
 fs/configfs/dir.c | 17 +
 1 file changed, 9 insertions(+), 8 deletions(-)

diff --git a/fs/configfs/dir.c b/fs/configfs/dir.c
index ea59c89..48929c4 100644
--- a/fs/configfs/dir.c
+++ b/fs/configfs/dir.c
@@ -494,7 +494,7 @@ out:
  * If there is an error, the caller will reset the flags via
  * configfs_detach_rollback().
  */
-static int configfs_detach_prep(struct dentry *dentry, struct mutex 
**wait_mutex)
+static int configfs_detach_prep(struct dentry *dentry, struct dentry **wait)
 {
struct configfs_dirent *parent_sd = dentry->d_fsdata;
struct configfs_dirent *sd;
@@ -515,8 +515,8 @@ static int configfs_detach_prep(struct dentry *dentry, 
struct mutex **wait_mutex
if (sd->s_type & CONFIGFS_USET_DEFAULT) {
/* Abort if racing with mkdir() */
if (sd->s_type & CONFIGFS_USET_IN_MKDIR) {
-   if (wait_mutex)
-   *wait_mutex = 
_inode(sd->s_dentry)->i_mutex;
+   if (wait)
+   *wait= dget(sd->s_dentry);
return -EAGAIN;
}
 
@@ -524,7 +524,7 @@ static int configfs_detach_prep(struct dentry *dentry, 
struct mutex **wait_mutex
 * Yup, recursive.  If there's a problem, blame
 * deep nesting of default_groups
 */
-   ret = configfs_detach_prep(sd->s_dentry, wait_mutex);
+   ret = configfs_detach_prep(sd->s_dentry, wait);
if (!ret)
continue;
} else
@@ -1458,7 +1458,7 @@ static int configfs_rmdir(struct inode *dir, struct 
dentry *dentry)
 * the new link is temporarily attached
 */
do {
-   struct mutex *wait_mutex;
+   struct dentry *wait;
 
mutex_lock(_symlink_mutex);
spin_lock(_dirent_lock);
@@ -1469,7 +1469,7 @@ static int configfs_rmdir(struct inode *dir, struct 
dentry *dentry)
 */
ret = sd->s_dependent_count ? -EBUSY : 0;
if (!ret) {
-   ret = configfs_detach_prep(dentry, _mutex);
+   ret = configfs_detach_prep(dentry, );
if (ret)
configfs_detach_rollback(dentry);
}
@@ -1483,8 +1483,9 @@ static int configfs_rmdir(struct inode *dir, struct 
dentry *dentry)
}
 
/* Wait until the racing operation terminates */
-   mutex_lock(wait_mutex);
-   mutex_unlock(wait_mutex);
+   inode_lock(d_inode(wait));
+   inode_unlock(d_inode(wait));
+   dput(wait);
}
} while (ret == -EAGAIN);
 
-- 
2.8.0.rc3