diff options
Diffstat (limited to 'fs/sysfs/inode.c')
| -rw-r--r-- | fs/sysfs/inode.c | 26 |
1 files changed, 21 insertions, 5 deletions
diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index f0b347bd12c..e79e38d52c0 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -12,11 +12,12 @@ #include <linux/namei.h> #include <linux/backing-dev.h> #include <linux/capability.h> +#include <linux/errno.h> #include "sysfs.h" extern struct super_block * sysfs_sb; -static struct address_space_operations sysfs_aops = { +static const struct address_space_operations sysfs_aops = { .readpage = simple_readpage, .prepare_write = simple_prepare_write, .commit_write = simple_commit_write @@ -109,15 +110,26 @@ 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; + struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd) { struct inode * inode = new_inode(sysfs_sb); if (inode) { - inode->i_blksize = PAGE_CACHE_SIZE; inode->i_blocks = 0; 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); if (sd->s_iattr) { /* sysfs_dirent has non-default attributes @@ -222,17 +234,18 @@ void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent) } } -void sysfs_hash_and_remove(struct dentry * dir, const char * name) +int sysfs_hash_and_remove(struct dentry * dir, const char * name) { struct sysfs_dirent * sd; struct sysfs_dirent * parent_sd; + int found = 0; if (!dir) - return; + return -ENOENT; if (dir->d_inode == NULL) /* no inode means this hasn't been made visible yet */ - return; + return -ENOENT; parent_sd = dir->d_fsdata; mutex_lock(&dir->d_inode->i_mutex); @@ -243,8 +256,11 @@ void sysfs_hash_and_remove(struct dentry * dir, const char * name) list_del_init(&sd->s_sibling); sysfs_drop_dentry(sd, dir); sysfs_put(sd); + found = 1; break; } } mutex_unlock(&dir->d_inode->i_mutex); + + return found ? 0 : -ENOENT; } |