diff options
Diffstat (limited to 'fs/ext4/extents_status.c')
| -rw-r--r-- | fs/ext4/extents_status.c | 187 |
1 files changed, 187 insertions, 0 deletions
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 8530fbd3012d..194785ce890a 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c @@ -142,6 +142,7 @@ */ static struct kmem_cache *ext4_es_cachep; +static struct kmem_cache *ext4_pending_cachep; static int __es_insert_extent(struct inode *inode, struct extent_status *newes); static int __es_remove_extent(struct inode *inode, ext4_lblk_t lblk, @@ -1365,3 +1366,189 @@ static int es_reclaim_extents(struct ext4_inode_info *ei, int *nr_to_scan) ei->i_es_tree.cache_es = NULL; return nr_shrunk; } + +#ifdef ES_DEBUG__ +static void ext4_print_pending_tree(struct inode *inode) +{ + struct ext4_pending_tree *tree; + struct rb_node *node; + struct pending_reservation *pr; + + printk(KERN_DEBUG "pending reservations for inode %lu:", inode->i_ino); + tree = &EXT4_I(inode)->i_pending_tree; + node = rb_first(&tree->root); + while (node) { + pr = rb_entry(node, struct pending_reservation, rb_node); + printk(KERN_DEBUG " %u", pr->lclu); + node = rb_next(node); + } + printk(KERN_DEBUG "\n"); +} +#else +#define ext4_print_pending_tree(inode) +#endif + +int __init ext4_init_pending(void) +{ + ext4_pending_cachep = kmem_cache_create("ext4_pending_reservation", + sizeof(struct pending_reservation), + 0, (SLAB_RECLAIM_ACCOUNT), NULL); + if (ext4_pending_cachep == NULL) + return -ENOMEM; + return 0; +} + +void ext4_exit_pending(void) +{ + kmem_cache_destroy(ext4_pending_cachep); +} + +void ext4_init_pending_tree(struct ext4_pending_tree *tree) +{ + tree->root = RB_ROOT; +} + +/* + * __get_pending - retrieve a pointer to a pending reservation + * + * @inode - file containing the pending cluster reservation + * @lclu - logical cluster of interest + * + * Returns a pointer to a pending reservation if it's a member of + * the set, and NULL if not. Must be called holding i_es_lock. + */ +static struct pending_reservation *__get_pending(struct inode *inode, + ext4_lblk_t lclu) +{ + struct ext4_pending_tree *tree; + struct rb_node *node; + struct pending_reservation *pr = NULL; + + tree = &EXT4_I(inode)->i_pending_tree; + node = (&tree->root)->rb_node; + + while (node) { + pr = rb_entry(node, struct pending_reservation, rb_node); + if (lclu < pr->lclu) + node = node->rb_left; + else if (lclu > pr->lclu) + node = node->rb_right; + else if (lclu == pr->lclu) + return pr; + } + return NULL; +} + +/* + * __insert_pending - adds a pending cluster reservation to the set of + * pending reservations + * + * @inode - file containing the cluster + * @lblk - logical block in the cluster to be added + * + * Returns 0 on successful insertion and -ENOMEM on failure. If the + * pending reservation is already in the set, returns successfully. + */ +static int __insert_pending(struct inode *inode, ext4_lblk_t lblk) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct ext4_pending_tree *tree = &EXT4_I(inode)->i_pending_tree; + struct rb_node **p = &tree->root.rb_node; + struct rb_node *parent = NULL; + struct pending_reservation *pr; + ext4_lblk_t lclu; + int ret = 0; + + lclu = EXT4_B2C(sbi, lblk); + /* search to find parent for insertion */ + while (*p) { + parent = *p; + pr = rb_entry(parent, struct pending_reservation, rb_node); + + if (lclu < pr->lclu) { + p = &(*p)->rb_left; + } else if (lclu > pr->lclu) { + p = &(*p)->rb_right; + } else { + /* pending reservation already inserted */ + goto out; + } + } + + pr = kmem_cache_alloc(ext4_pending_cachep, GFP_ATOMIC); + if (pr == NULL) { + ret = -ENOMEM; + goto out; + } + pr->lclu = lclu; + + rb_link_node(&pr->rb_node, parent, p); + rb_insert_color(&pr->rb_node, &tree->root); + +out: + return ret; +} + +/* + * __remove_pending - removes a pending cluster reservation from the set + * of pending reservations + * + * @inode - file containing the cluster + * @lblk - logical block in the pending cluster reservation to be removed + * + * Returns successfully if pending reservation is not a member of the set. + */ +static void __remove_pending(struct inode *inode, ext4_lblk_t lblk) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct pending_reservation *pr; + struct ext4_pending_tree *tree; + + pr = __get_pending(inode, EXT4_B2C(sbi, lblk)); + if (pr != NULL) { + tree = &EXT4_I(inode)->i_pending_tree; + rb_erase(&pr->rb_node, &tree->root); + kmem_cache_free(ext4_pending_cachep, pr); + } +} + +/* + * ext4_remove_pending - removes a pending cluster reservation from the set + * of pending reservations + * + * @inode - file containing the cluster + * @lblk - logical block in the pending cluster reservation to be removed + * + * Locking for external use of __remove_pending. + */ +void ext4_remove_pending(struct inode *inode, ext4_lblk_t lblk) +{ + struct ext4_inode_info *ei = EXT4_I(inode); + + write_lock(&ei->i_es_lock); + __remove_pending(inode, lblk); + write_unlock(&ei->i_es_lock); +} + +/* + * ext4_is_pending - determine whether a cluster has a pending reservation + * on it + * + * @inode - file containing the cluster + * @lblk - logical block in the cluster + * + * Returns true if there's a pending reservation for the cluster in the + * set of pending reservations, and false if not. + */ +bool ext4_is_pending(struct inode *inode, ext4_lblk_t lblk) +{ + struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb); + struct ext4_inode_info *ei = EXT4_I(inode); + bool ret; + + read_lock(&ei->i_es_lock); + ret = (bool)(__get_pending(inode, EXT4_B2C(sbi, lblk)) != NULL); + read_unlock(&ei->i_es_lock); + + return ret; +} |