X-Git-Url: http://git.rot13.org/?a=blobdiff_plain;f=fs%2Fsysfs%2Finode.c;h=1be853706e9991b0b4f270479acde63f5cff527a;hb=608e266a2d4e62c1b98c1c573064b6afe8c06a58;hp=ccb7d722c55897a6105e93457b923e5b1b741c0d;hpb=2f774456e4b9bc3d4fb3522b2482c7acfa2df197;p=powerpc.git diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index ccb7d722c5..1be853706e 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -13,6 +13,7 @@ #include #include #include +#include #include #include "sysfs.h" @@ -132,166 +133,185 @@ static inline void set_inode_attr(struct inode * inode, struct iattr * iattr) */ static struct lock_class_key sysfs_inode_imutex_key; -struct inode * sysfs_new_inode(mode_t mode, struct sysfs_dirent * sd) +void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode) { - struct inode * inode = new_inode(sysfs_sb); - if (inode) { - 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 - * get them for the new inode from persistent copy - * in sysfs_dirent - */ - set_inode_attr(inode, sd->s_iattr); - } else - set_default_inode_attr(inode, mode); - } - return inode; -} - -int sysfs_create(struct dentry * dentry, int mode, int (*init)(struct inode *)) -{ - int error = 0; - struct inode * inode = NULL; - if (dentry) { - if (!dentry->d_inode) { - struct sysfs_dirent * sd = dentry->d_fsdata; - if ((inode = sysfs_new_inode(mode, sd))) { - if (dentry->d_parent && dentry->d_parent->d_inode) { - struct inode *p_inode = dentry->d_parent->d_inode; - p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; - } - goto Proceed; - } - else - error = -ENOMEM; - } else - error = -EEXIST; - } else - error = -ENOENT; - goto Done; - - Proceed: - if (init) - error = init(inode); - if (!error) { - d_instantiate(dentry, inode); - if (S_ISDIR(mode)) - dget(dentry); /* pin only directory dentry in core */ + 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; + inode->i_ino = sd->s_ino; + lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key); + + if (sd->s_iattr) { + /* sysfs_dirent has non-default attributes + * get them for the new inode from persistent copy + * in sysfs_dirent + */ + set_inode_attr(inode, sd->s_iattr); } else - iput(inode); - Done: - return error; + set_default_inode_attr(inode, sd->s_mode); } -/* - * Get the name for corresponding element represented by the given sysfs_dirent +/** + * sysfs_get_inode - get inode for sysfs_dirent + * @sd: sysfs_dirent to allocate inode for + * + * Get inode for @sd. If such inode doesn't exist, a new inode + * is allocated and basics are initialized. New inode is + * returned locked. + * + * LOCKING: + * Kernel thread context (may sleep). + * + * RETURNS: + * Pointer to allocated inode on success, NULL on failure. */ -const unsigned char * sysfs_get_name(struct sysfs_dirent *sd) +struct inode * sysfs_get_inode(struct sysfs_dirent *sd) { - struct attribute * attr; - struct bin_attribute * bin_attr; - struct sysfs_symlink * sl; - - BUG_ON(!sd || !sd->s_element); - - switch (sd->s_type) { - case SYSFS_DIR: - /* Always have a dentry so use that */ - return sd->s_dentry->d_name.name; - - case SYSFS_KOBJ_ATTR: - attr = sd->s_element; - return attr->name; + struct inode *inode; - case SYSFS_KOBJ_BIN_ATTR: - bin_attr = sd->s_element; - return bin_attr->attr.name; + inode = iget_locked(sysfs_sb, sd->s_ino); + if (inode && (inode->i_state & I_NEW)) + sysfs_init_inode(sd, inode); - case SYSFS_KOBJ_LINK: - sl = sd->s_element; - return sl->link_name; - } - return NULL; + return inode; } -static inline void orphan_all_buffers(struct inode *node) +/** + * sysfs_instantiate - instantiate dentry + * @dentry: dentry to be instantiated + * @inode: inode associated with @sd + * + * Unlock @inode if locked and instantiate @dentry with @inode. + * + * LOCKING: + * None. + */ +void sysfs_instantiate(struct dentry *dentry, struct inode *inode) { - struct sysfs_buffer_collection *set = node->i_private; - struct sysfs_buffer *buf; + BUG_ON(!dentry || dentry->d_inode); + + if (inode->i_state & I_NEW) { + unlock_new_inode(inode); - mutex_lock_nested(&node->i_mutex, I_MUTEX_CHILD); - if (node->i_private) { - list_for_each_entry(buf, &set->associates, associates) - buf->orphaned = 1; + if (dentry->d_parent && dentry->d_parent->d_inode) { + struct inode *p_inode = dentry->d_parent->d_inode; + p_inode->i_mtime = p_inode->i_ctime = CURRENT_TIME; + } } - mutex_unlock(&node->i_mutex); -} + d_instantiate(dentry, inode); +} -/* - * Unhashes the dentry corresponding to given sysfs_dirent - * Called with parent inode's i_mutex held. +/** + * sysfs_drop_dentry - drop dentry for the specified sysfs_dirent + * @sd: target sysfs_dirent + * + * Drop dentry for @sd. @sd must have been unlinked from its + * parent on entry to this function such that it can't be looked + * up anymore. + * + * @sd->s_dentry which is protected with sysfs_lock points to the + * currently associated dentry but we're not holding a reference + * to it and racing with dput(). Grab dcache_lock and verify + * dentry before dropping it. If @sd->s_dentry is NULL or dput() + * beats us, no need to bother. */ -void sysfs_drop_dentry(struct sysfs_dirent * sd, struct dentry * parent) +void sysfs_drop_dentry(struct sysfs_dirent *sd) { - struct dentry * dentry = sd->s_dentry; + struct dentry *dentry = NULL; + struct timespec curtime; struct inode *inode; - if (dentry) { - spin_lock(&dcache_lock); + /* We're not holding a reference to ->s_dentry dentry but the + * field will stay valid as long as sysfs_lock is held. + */ + spin_lock(&sysfs_lock); + spin_lock(&dcache_lock); + + /* drop dentry if it's there and dput() didn't kill it yet */ + if (sd->s_dentry && sd->s_dentry->d_inode) { + dentry = dget_locked(sd->s_dentry); spin_lock(&dentry->d_lock); - if (!(d_unhashed(dentry) && dentry->d_inode)) { - inode = dentry->d_inode; - spin_lock(&inode->i_lock); - __iget(inode); - spin_unlock(&inode->i_lock); - dget_locked(dentry); - __d_drop(dentry); - spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); - simple_unlink(parent->d_inode, dentry); - orphan_all_buffers(inode); - iput(inode); - } else { - spin_unlock(&dentry->d_lock); - spin_unlock(&dcache_lock); - } + __d_drop(dentry); + spin_unlock(&dentry->d_lock); + } + + spin_unlock(&dcache_lock); + spin_unlock(&sysfs_lock); + + dput(dentry); + /* XXX: unpin if directory, this will go away soon */ + if (sysfs_type(sd) == SYSFS_DIR) + dput(dentry); + + /* adjust nlink and update timestamp */ + curtime = CURRENT_TIME; + + inode = ilookup(sysfs_sb, sd->s_ino); + if (inode) { + mutex_lock(&inode->i_mutex); + + inode->i_ctime = curtime; + drop_nlink(inode); + if (sysfs_type(sd) == SYSFS_DIR) + drop_nlink(inode); + + mutex_unlock(&inode->i_mutex); + iput(inode); + } + + /* adjust nlink and udpate timestamp of the parent */ + inode = ilookup(sysfs_sb, sd->s_parent->s_ino); + if (inode) { + mutex_lock(&inode->i_mutex); + + inode->i_ctime = inode->i_mtime = curtime; + if (sysfs_type(sd) == SYSFS_DIR) + drop_nlink(inode); + + mutex_unlock(&inode->i_mutex); + iput(inode); } } -int sysfs_hash_and_remove(struct dentry * dir, const char * name) +int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name) { - struct sysfs_dirent * sd; - struct sysfs_dirent * parent_sd; + struct dentry *dir; + struct sysfs_dirent **pos, *sd; int found = 0; - if (!dir) + if (!dir_sd) return -ENOENT; + dir = dir_sd->s_dentry; + if (dir->d_inode == NULL) /* no inode means this hasn't been made visible yet */ return -ENOENT; - parent_sd = dir->d_fsdata; mutex_lock_nested(&dir->d_inode->i_mutex, I_MUTEX_PARENT); - list_for_each_entry(sd, &parent_sd->s_children, s_sibling) { - if (!sd->s_element) + for (pos = &dir_sd->s_children; *pos; pos = &(*pos)->s_sibling) { + sd = *pos; + + if (!sysfs_type(sd)) continue; - if (!strcmp(sysfs_get_name(sd), name)) { - list_del_init(&sd->s_sibling); - sysfs_drop_dentry(sd, dir); - sysfs_put(sd); + if (!strcmp(sd->s_name, name)) { + sd->s_flags |= SYSFS_FLAG_REMOVED; + *pos = sd->s_sibling; + sd->s_sibling = NULL; found = 1; break; } } mutex_unlock(&dir->d_inode->i_mutex); - return found ? 0 : -ENOENT; + if (!found) + return -ENOENT; + + sysfs_drop_dentry(sd); + sysfs_deactivate(sd); + sysfs_put(sd); + + return 0; }