diff options
Diffstat (limited to 'fs/sysfs')
| -rw-r--r-- | fs/sysfs/dir.c | 158 | ||||
| -rw-r--r-- | fs/sysfs/inode.c | 12 | ||||
| -rw-r--r-- | fs/sysfs/sysfs.h | 1 |
3 files changed, 32 insertions, 139 deletions
diff --git a/fs/sysfs/dir.c b/fs/sysfs/dir.c index f3af45e47eaa..97954c69ff0e 100644 --- a/fs/sysfs/dir.c +++ b/fs/sysfs/dir.c @@ -25,7 +25,6 @@ #include "sysfs.h" DEFINE_MUTEX(sysfs_mutex); -DEFINE_MUTEX(sysfs_rename_mutex); DEFINE_SPINLOCK(sysfs_assoc_lock); static DEFINE_SPINLOCK(sysfs_ino_lock); @@ -85,46 +84,6 @@ static void sysfs_unlink_sibling(struct sysfs_dirent *sd) } /** - * sysfs_get_dentry - get dentry for the given sysfs_dirent - * @sd: sysfs_dirent of interest - * - * Get dentry for @sd. Dentry is looked up if currently not - * present. This function descends from the root looking up - * dentry for each step. - * - * LOCKING: - * mutex_lock(sysfs_rename_mutex) - * - * RETURNS: - * Pointer to found dentry on success, ERR_PTR() value on error. - */ -struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd) -{ - struct dentry *dentry = dget(sysfs_sb->s_root); - - while (dentry->d_fsdata != sd) { - struct sysfs_dirent *cur; - struct dentry *parent; - - /* find the first ancestor which hasn't been looked up */ - cur = sd; - while (cur->s_parent != dentry->d_fsdata) - cur = cur->s_parent; - - /* look it up */ - parent = dentry; - mutex_lock(&parent->d_inode->i_mutex); - dentry = lookup_one_noperm(cur->s_name, parent); - mutex_unlock(&parent->d_inode->i_mutex); - dput(parent); - - if (IS_ERR(dentry)) - break; - } - return dentry; -} - -/** * sysfs_get_active - get an active reference to sysfs_dirent * @sd: sysfs_dirent to get an active reference to * @@ -315,6 +274,14 @@ static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) if (sd->s_flags & SYSFS_FLAG_REMOVED) goto out_bad; + /* The sysfs dirent has been moved? */ + if (dentry->d_parent->d_fsdata != sd->s_parent) + goto out_bad; + + /* The sysfs dirent has been renamed */ + if (strcmp(dentry->d_name.name, sd->s_name) != 0) + goto out_bad; + mutex_unlock(&sysfs_mutex); out_valid: return 1; @@ -322,6 +289,12 @@ out_bad: /* Remove the dentry from the dcache hashes. * If this is a deleted dentry we use d_drop instead of d_delete * so sysfs doesn't need to cope with negative dentries. + * + * If this is a dentry that has simply been renamed we + * use d_drop to remove it from the dcache lookup on its + * old parent. If this dentry persists later when a lookup + * is performed at its new name the dentry will be readded + * to the dcache hashes. */ is_dir = (sysfs_type(sd) == SYSFS_DIR); mutex_unlock(&sysfs_mutex); @@ -705,10 +678,15 @@ static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry, } /* instantiate and hash dentry */ - dentry->d_op = &sysfs_dentry_ops; - dentry->d_fsdata = sysfs_get(sd); - d_instantiate(dentry, inode); - d_rehash(dentry); + ret = d_find_alias(inode); + if (!ret) { + dentry->d_op = &sysfs_dentry_ops; + dentry->d_fsdata = sysfs_get(sd); + d_add(dentry, inode); + } else { + d_move(ret, dentry); + iput(inode); + } out_unlock: mutex_unlock(&sysfs_mutex); @@ -785,62 +763,32 @@ void sysfs_remove_dir(struct kobject * kobj) int sysfs_rename_dir(struct kobject * kobj, const char *new_name) { struct sysfs_dirent *sd = kobj->sd; - struct dentry *parent = NULL; - struct dentry *old_dentry = NULL, *new_dentry = NULL; const char *dup_name = NULL; int error; - mutex_lock(&sysfs_rename_mutex); + mutex_lock(&sysfs_mutex); error = 0; if (strcmp(sd->s_name, new_name) == 0) goto out; /* nothing to rename */ - /* get the original dentry */ - old_dentry = sysfs_get_dentry(sd); - if (IS_ERR(old_dentry)) { - error = PTR_ERR(old_dentry); - old_dentry = NULL; - goto out; - } - - parent = old_dentry->d_parent; - - /* lock parent and get dentry for new name */ - mutex_lock(&parent->d_inode->i_mutex); - mutex_lock(&sysfs_mutex); - error = -EEXIST; if (sysfs_find_dirent(sd->s_parent, new_name)) - goto out_unlock; - - error = -ENOMEM; - new_dentry = d_alloc_name(parent, new_name); - if (!new_dentry) - goto out_unlock; + goto out; /* rename sysfs_dirent */ error = -ENOMEM; new_name = dup_name = kstrdup(new_name, GFP_KERNEL); if (!new_name) - goto out_unlock; + goto out; dup_name = sd->s_name; sd->s_name = new_name; - /* rename */ - d_add(new_dentry, NULL); - d_move(old_dentry, new_dentry); - error = 0; - out_unlock: + out: mutex_unlock(&sysfs_mutex); - mutex_unlock(&parent->d_inode->i_mutex); kfree(dup_name); - dput(old_dentry); - dput(new_dentry); - out: - mutex_unlock(&sysfs_rename_mutex); return error; } @@ -848,12 +796,11 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) { struct sysfs_dirent *sd = kobj->sd; struct sysfs_dirent *new_parent_sd; - struct dentry *old_parent, *new_parent = NULL; - struct dentry *old_dentry = NULL, *new_dentry = NULL; int error; - mutex_lock(&sysfs_rename_mutex); BUG_ON(!sd->s_parent); + + mutex_lock(&sysfs_mutex); new_parent_sd = (new_parent_kobj && new_parent_kobj->sd) ? new_parent_kobj->sd : &sysfs_root; @@ -861,61 +808,20 @@ int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj) if (sd->s_parent == new_parent_sd) goto out; /* nothing to move */ - /* get dentries */ - old_dentry = sysfs_get_dentry(sd); - if (IS_ERR(old_dentry)) { - error = PTR_ERR(old_dentry); - old_dentry = NULL; - goto out; - } - old_parent = old_dentry->d_parent; - - new_parent = sysfs_get_dentry(new_parent_sd); - if (IS_ERR(new_parent)) { - error = PTR_ERR(new_parent); - new_parent = NULL; - goto out; - } - -again: - mutex_lock(&old_parent->d_inode->i_mutex); - if (!mutex_trylock(&new_parent->d_inode->i_mutex)) { - mutex_unlock(&old_parent->d_inode->i_mutex); - goto again; - } - mutex_lock(&sysfs_mutex); - error = -EEXIST; if (sysfs_find_dirent(new_parent_sd, sd->s_name)) - goto out_unlock; - - error = -ENOMEM; - new_dentry = d_alloc_name(new_parent, sd->s_name); - if (!new_dentry) - goto out_unlock; - - error = 0; - d_add(new_dentry, NULL); - d_move(old_dentry, new_dentry); + goto out; /* Remove from old parent's list and insert into new parent's list. */ sysfs_unlink_sibling(sd); sysfs_get(new_parent_sd); - drop_nlink(old_parent->d_inode); sysfs_put(sd->s_parent); sd->s_parent = new_parent_sd; - inc_nlink(new_parent->d_inode); sysfs_link_sibling(sd); - out_unlock: + error = 0; +out: mutex_unlock(&sysfs_mutex); - mutex_unlock(&new_parent->d_inode->i_mutex); - mutex_unlock(&old_parent->d_inode->i_mutex); - out: - dput(new_parent); - dput(old_dentry); - dput(new_dentry); - mutex_unlock(&sysfs_rename_mutex); return error; } diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index 1ffd5559926f..9f783d4e4b51 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -205,17 +205,6 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr) inode->i_ctime = iattr->ia_ctime; } - -/* - * sysfs has a different i_mutex lock order behavior for i_mutex than other - * filesystems; sysfs i_mutex is called in many places with subsystem locks - * held. At the same time, many of the VFS locking rules do not apply to - * sysfs at all (cross directory rename for example). To untangle this mess - * (which gives false positives in lockdep), we're giving sysfs inodes their - * own class for i_mutex. - */ -static struct lock_class_key sysfs_inode_imutex_key; - static int sysfs_count_nlink(struct sysfs_dirent *sd) { struct sysfs_dirent *child; @@ -268,7 +257,6 @@ static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) inode->i_mapping->a_ops = &sysfs_aops; inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info; inode->i_op = &sysfs_inode_operations; - lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key); set_default_inode_attr(inode, sd->s_mode); sysfs_refresh_inode(sd, inode); diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index 90b35012abb2..98a15bf1efe1 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -103,7 +103,6 @@ extern struct kmem_cache *sysfs_dir_cachep; * dir.c */ extern struct mutex sysfs_mutex; -extern struct mutex sysfs_rename_mutex; extern spinlock_t sysfs_assoc_lock; extern const struct file_operations sysfs_dir_operations; |