[PATCH 07/15] sysfs: sysfs_chmod_file handle multiple superblocks

Subsystems: driver core, kobjects, debugfs and sysfs, filesystems (vfs and infrastructure), the rest · Maintainers: Greg Kroah-Hartman, "Rafael J. Wysocki", Danilo Krummrich, Johan Hovold, Alexander Viro, Christian Brauner, Linus Torvalds

STALE6642d

3 messages, 3 authors, 2008-08-20 · open the first message on its own page

[PATCH 07/15] sysfs: sysfs_chmod_file handle multiple superblocks

From: Eric W. Biederman <hidden>
Date: 2008-07-04 01:22:34

Teach sysfs_chmod_file how to handle multiple sysfs superblocks.
Since we only have one inode per sd the only thing we have to deal
with is multiple dentries for sending fs notifications.  This might
dup the inode notifications oh well.

Signed-off-by: Eric W. Biederman <redacted>
---
 fs/sysfs/file.c |   39 +++++++++++++++++++++++++--------------
 1 files changed, 25 insertions(+), 14 deletions(-)
diff --git a/fs/sysfs/file.c b/fs/sysfs/file.c
index 1304b3a..5955ae9 100644
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -574,8 +574,8 @@ EXPORT_SYMBOL_GPL(sysfs_add_file_to_group);
 int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
 {
 	struct sysfs_dirent *victim_sd = NULL;
-	struct dentry *victim = NULL;
-	struct inode * inode;
+	struct super_block *sb;
+	struct inode * inode = NULL;
 	struct iattr newattrs;
 	int rc;
 
@@ -584,31 +584,42 @@ int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
 	if (!victim_sd)
 		goto out;
 
-	mutex_lock(&sysfs_rename_mutex);
-	victim = sysfs_get_dentry(sysfs_sb, victim_sd);
-	mutex_unlock(&sysfs_rename_mutex);
-	if (IS_ERR(victim)) {
-		rc = PTR_ERR(victim);
-		victim = NULL;
-		goto out;
-	}
-
-	inode = victim->d_inode;
+	rc = -ENOENT;
+	mutex_lock(&sysfs_mutex);
+	inode = sysfs_get_inode(victim_sd);
+	mutex_unlock(&sysfs_mutex);
+	if (!inode)
+ 		goto out;
 
+	mutex_lock(&sysfs_rename_mutex);
+	sysfs_grab_supers();
 	mutex_lock(&inode->i_mutex);
 
 	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
 	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
 	newattrs.ia_ctime = current_fs_time(inode->i_sb);
 	rc = sysfs_sd_setattr(victim_sd, inode, &newattrs);
+	if (rc)
+		goto out_unlock;
+
+	list_for_each_entry(sb, &sysfs_fs_type.fs_supers, s_instances) {
+		/* Ignore it when the dentry does not exist on the
+		 * target superblock.
+		 */
+		struct dentry *	victim = sysfs_get_dentry(sb, victim_sd);
+		if (IS_ERR(victim))
+			continue;
 
-	if (rc == 0) {
 		fsnotify_change(victim, newattrs.ia_valid);
+		dput(victim);
 	}
 
+ out_unlock:
 	mutex_unlock(&inode->i_mutex);
+	sysfs_release_supers();
+	mutex_unlock(&sysfs_rename_mutex);
  out:
-	dput(victim);
+	iput(inode);
 	sysfs_put(victim_sd);
 	return rc;
 }
-- 
1.5.3.rc6.17.g1911

Re: [PATCH 07/15] sysfs: sysfs_chmod_file handle multiple superblocks

From: Tejun Heo <hidden>
Date: 2008-07-04 06:45:47

Eric W. Biederman wrote:
Teach sysfs_chmod_file how to handle multiple sysfs superblocks.
Since we only have one inode per sd the only thing we have to deal
with is multiple dentries for sending fs notifications.  This might
dup the inode notifications oh well.

Signed-off-by: Eric W. Biederman <redacted>
Great, Acked-by: Tejun Heo [off-list ref]

-- 
tejun

patch sysfs-sysfs_chmod_file-handle-multiple-superblocks.patch added to gregkh-2.6 tree

From: gregkh@suse.de
Date: 2008-08-20 02:22:31

This is a note to let you know that I've just added the patch titled

    Subject: sysfs: sysfs_chmod_file handle multiple superblocks

to my gregkh-2.6 tree.  Its filename is

    sysfs-sysfs_chmod_file-handle-multiple-superblocks.patch

This tree can be found at 
    http://www.kernel.org/pub/linux/kernel/people/gregkh/gregkh-2.6/patches/

From ebiederm@xmission.com Thu Jul  3 18:21:56 2008
From: Eric W. Biederman <redacted>
Date: Thu, 03 Jul 2008 18:13:05 -0700
Subject: sysfs: sysfs_chmod_file handle multiple superblocks
To: Greg Kroah-Hartman <gregkh@suse.de>, Andrew Morton <akpm@linux-foundation.org>
Cc: Tejun Heo <redacted>, Daniel Lezcano <redacted>, <redacted>, Al Viro <redacted>, Linux Containers <redacted>, Benjamin Thery <redacted>, <redacted>
Message-ID: [off-list ref]


From: Eric W. Biederman <redacted>

Teach sysfs_chmod_file how to handle multiple sysfs superblocks.
Since we only have one inode per sd the only thing we have to deal
with is multiple dentries for sending fs notifications.  This might
dup the inode notifications oh well.

Signed-off-by: Eric W. Biederman <redacted>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
 fs/sysfs/file.c |   39 +++++++++++++++++++++++++--------------
 1 file changed, 25 insertions(+), 14 deletions(-)
--- a/fs/sysfs/file.c
+++ b/fs/sysfs/file.c
@@ -578,8 +578,8 @@ EXPORT_SYMBOL_GPL(sysfs_add_file_to_grou
 int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
 {
 	struct sysfs_dirent *victim_sd = NULL;
-	struct dentry *victim = NULL;
-	struct inode * inode;
+	struct super_block *sb;
+	struct inode * inode = NULL;
 	struct iattr newattrs;
 	int rc;
 
@@ -588,31 +588,42 @@ int sysfs_chmod_file(struct kobject *kob
 	if (!victim_sd)
 		goto out;
 
-	mutex_lock(&sysfs_rename_mutex);
-	victim = sysfs_get_dentry(sysfs_sb, victim_sd);
-	mutex_unlock(&sysfs_rename_mutex);
-	if (IS_ERR(victim)) {
-		rc = PTR_ERR(victim);
-		victim = NULL;
-		goto out;
-	}
-
-	inode = victim->d_inode;
+	rc = -ENOENT;
+	mutex_lock(&sysfs_mutex);
+	inode = sysfs_get_inode(victim_sd);
+	mutex_unlock(&sysfs_mutex);
+	if (!inode)
+ 		goto out;
 
+	mutex_lock(&sysfs_rename_mutex);
+	sysfs_grab_supers();
 	mutex_lock(&inode->i_mutex);
 
 	newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
 	newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
 	newattrs.ia_ctime = current_fs_time(inode->i_sb);
 	rc = sysfs_sd_setattr(victim_sd, inode, &newattrs);
+	if (rc)
+		goto out_unlock;
+
+	list_for_each_entry(sb, &sysfs_fs_type.fs_supers, s_instances) {
+		/* Ignore it when the dentry does not exist on the
+		 * target superblock.
+		 */
+		struct dentry *	victim = sysfs_get_dentry(sb, victim_sd);
+		if (IS_ERR(victim))
+			continue;
 
-	if (rc == 0) {
 		fsnotify_change(victim, newattrs.ia_valid);
+		dput(victim);
 	}
 
+ out_unlock:
 	mutex_unlock(&inode->i_mutex);
+	sysfs_release_supers();
+	mutex_unlock(&sysfs_rename_mutex);
  out:
-	dput(victim);
+	iput(inode);
 	sysfs_put(victim_sd);
 	return rc;
 }

Patches currently in gregkh-2.6 which might be from ebiederm@xmission.com are

driver-core/kobject-fix-kobject_rename-and-config_sysfs.patch
driver-core/kobject-cleanup-kobject_rename-and-config_sysfs.patch
driver-core/sysfs-implement-__sysfs_get_dentry.patch
driver-core/sysfs-introduce-sysfs_sd_setattr-and-fix-sysfs_chmod.patch
driver-core/sysfs-sysfs_get_dentry-add-a-sb-parameter.patch
driver-core/sysfs-rename-support-multiple-superblocks.patch
driver-core/sysfs-support-for-preventing-unmounts.patch
driver-core/sysfs-sysfs_chmod_file-handle-multiple-superblocks.patch
Keyboard shortcuts
hback out one level
jnext message in thread
kprevious message in thread
ldrill in
Escclose help / fold thread tree
?toggle this help