This patch modifies sysfs_move_dir to perform all of it's
operations under the sysfs_mutex. By looking for conflicts
using sysfs_find_dirent we accidentally moving something
onto a name that already exists but just not in the dcache
right now.
Two s_dentry usages are killed.
And it has probably become unnecessary to grab i_mutex at
all but I'm not brave enough to do that just yet.
Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
fs/sysfs/dir.c | 24 +++++++++++++-----------
1 files changed, 13 insertions(+), 11 deletions(-)
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c
index 8e614d3..ed2e6f3 100644
--- a/fs/sysfs/dir.c
+++ b/fs/sysfs/dir.c
@@ -897,7 +897,7 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
error = PTR_ERR(old_dentry);
goto out_dput;
}
- old_parent = sd->s_parent->s_dentry;
+ old_parent = old_dentry->d_parent;
new_parent = sysfs_get_dentry(new_parent_sd);
if (IS_ERR(new_parent)) {
@@ -915,29 +915,31 @@ again:
mutex_unlock(&old_parent->d_inode->i_mutex);
goto again;
}
+ mutex_lock(&sysfs_mutex);
- new_dentry = lookup_one_len(kobj->name, new_parent, strlen(kobj->name));
- if (IS_ERR(new_dentry)) {
- error = PTR_ERR(new_dentry);
+ error = -EEXIST;
+ if (sysfs_find_dirent(new_parent_sd, kobj->name))
goto out_unlock;
- } else
- error = 0;
+
+ error = -ENOMEM;
+ new_dentry = d_alloc_name(new_parent, kobj->name);
+ if (!new_dentry)
+ goto out_unlock;
+
+ error = 0;
d_add(new_dentry, NULL);
- d_move(sd->s_dentry, new_dentry);
+ d_move(old_dentry, new_dentry);
dput(new_dentry);
/* Remove from old parent's list and insert into new parent's list. */
- mutex_lock(&sysfs_mutex);
-
sysfs_unlink_sibling(sd);
sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
sd->s_parent = new_parent_sd;
sysfs_link_sibling(sd);
- mutex_unlock(&sysfs_mutex);
-
out_unlock:
+ mutex_unlock(&sysfs_mutex);
mutex_unlock(&new_parent->d_inode->i_mutex);
mutex_unlock(&old_parent->d_inode->i_mutex);
out_dput:
--
1.5.1.1.181.g2de0
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