diff options
Diffstat (limited to 'fs/inode.c')
| -rw-r--r-- | fs/inode.c | 1126 |
1 files changed, 647 insertions, 479 deletions
diff --git a/fs/inode.c b/fs/inode.c index 86464332e59..05f4fa52132 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -24,11 +24,45 @@ #include <linux/mount.h> #include <linux/async.h> #include <linux/posix_acl.h> +#include <linux/prefetch.h> +#include <linux/ima.h> +#include <linux/cred.h> +#include "internal.h" + +/* + * inode locking rules. + * + * inode->i_lock protects: + * inode->i_state, inode->i_hash, __iget() + * inode_lru_lock protects: + * inode_lru, inode->i_lru + * inode_sb_list_lock protects: + * sb->s_inodes, inode->i_sb_list + * inode_wb_list_lock protects: + * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list + * inode_hash_lock protects: + * inode_hashtable, inode->i_hash + * + * Lock ordering: + * + * inode_sb_list_lock + * inode->i_lock + * inode_lru_lock + * + * inode_wb_list_lock + * inode->i_lock + * + * inode_hash_lock + * inode_sb_list_lock + * inode->i_lock + * + * iunique_lock + * inode_hash_lock + */ /* * This is needed for the following functions: * - inode_has_buffers - * - invalidate_inode_buffers * - invalidate_bdev * * FIXME: remove all knowledge of the buffer layer from this file @@ -59,6 +93,8 @@ static unsigned int i_hash_mask __read_mostly; static unsigned int i_hash_shift __read_mostly; +static struct hlist_head *inode_hashtable __read_mostly; +static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock); /* * Each inode can be on two separate lists. One is @@ -72,47 +108,72 @@ static unsigned int i_hash_shift __read_mostly; * allowing for low-overhead inode sync() operations. */ -LIST_HEAD(inode_in_use); -LIST_HEAD(inode_unused); -static struct hlist_head *inode_hashtable __read_mostly; +static LIST_HEAD(inode_lru); +static DEFINE_SPINLOCK(inode_lru_lock); + +__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock); +__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock); /* - * A simple spinlock to protect the list manipulations. + * iprune_sem provides exclusion between the icache shrinking and the + * umount path. * - * NOTE! You also have to own the lock if you change - * the i_state of an inode while it is in use.. + * We don't actually need it to protect anything in the umount path, + * but only need to cycle through it to make sure any inode that + * prune_icache took off the LRU list has been fully torn down by the + * time we are past evict_inodes. */ -DEFINE_SPINLOCK(inode_lock); +static DECLARE_RWSEM(iprune_sem); /* - * iprune_sem provides exclusion between the kswapd or try_to_free_pages - * icache shrinking path, and the umount path. Without this exclusion, - * by the time prune_icache calls iput for the inode whose pages it has - * been invalidating, or by the time it calls clear_inode & destroy_inode - * from its final dispose_list, the struct super_block they refer to - * (for inode->i_sb->s_op) may already have been freed and reused. - * - * We make this an rwsem because the fastpath is icache shrinking. In - * some cases a filesystem may be doing a significant amount of work in - * its inode reclaim code, so this should improve parallelism. + * Empty aops. Can be used for the cases where the user does not + * define any of the address_space operations. */ -static DECLARE_RWSEM(iprune_sem); +const struct address_space_operations empty_aops = { +}; +EXPORT_SYMBOL(empty_aops); /* * Statistics gathering.. */ struct inodes_stat_t inodes_stat; +static DEFINE_PER_CPU(unsigned int, nr_inodes); + static struct kmem_cache *inode_cachep __read_mostly; -static void wake_up_inode(struct inode *inode) +static int get_nr_inodes(void) { - /* - * Prevent speculative execution through spin_unlock(&inode_lock); - */ - smp_mb(); - wake_up_bit(&inode->i_state, __I_NEW); + int i; + int sum = 0; + for_each_possible_cpu(i) + sum += per_cpu(nr_inodes, i); + return sum < 0 ? 0 : sum; +} + +static inline int get_nr_inodes_unused(void) +{ + return inodes_stat.nr_unused; +} + +int get_nr_dirty_inodes(void) +{ + /* not actually dirty inodes, but a wild approximation */ + int nr_dirty = get_nr_inodes() - get_nr_inodes_unused(); + return nr_dirty > 0 ? nr_dirty : 0; +} + +/* + * Handle nr_inode sysctl + */ +#ifdef CONFIG_SYSCTL +int proc_nr_inodes(ctl_table *table, int write, + void __user *buffer, size_t *lenp, loff_t *ppos) +{ + inodes_stat.nr_inodes = get_nr_inodes(); + return proc_dointvec(table, write, buffer, lenp, ppos); } +#endif /** * inode_init_always - perform inode structure intialisation @@ -124,7 +185,6 @@ static void wake_up_inode(struct inode *inode) */ int inode_init_always(struct super_block *sb, struct inode *inode) { - static const struct address_space_operations empty_aops; static const struct inode_operations empty_iops; static const struct file_operations empty_fops; struct address_space *const mapping = &inode->i_data; @@ -192,6 +252,8 @@ int inode_init_always(struct super_block *sb, struct inode *inode) inode->i_fsnotify_mask = 0; #endif + this_cpu_inc(nr_inodes); + return 0; out: return -ENOMEM; @@ -221,6 +283,12 @@ static struct inode *alloc_inode(struct super_block *sb) return inode; } +void free_inode_nonrcu(struct inode *inode) +{ + kmem_cache_free(inode_cachep, inode); +} +EXPORT_SYMBOL(free_inode_nonrcu); + void __destroy_inode(struct inode *inode) { BUG_ON(inode_has_buffers(inode)); @@ -232,18 +300,41 @@ void __destroy_inode(struct inode *inode) if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED) posix_acl_release(inode->i_default_acl); #endif + this_cpu_dec(nr_inodes); } EXPORT_SYMBOL(__destroy_inode); -void destroy_inode(struct inode *inode) +static void i_callback(struct rcu_head *head) { + struct inode *inode = container_of(head, struct inode, i_rcu); + INIT_LIST_HEAD(&inode->i_dentry); + kmem_cache_free(inode_cachep, inode); +} + +static void destroy_inode(struct inode *inode) +{ + BUG_ON(!list_empty(&inode->i_lru)); __destroy_inode(inode); if (inode->i_sb->s_op->destroy_inode) inode->i_sb->s_op->destroy_inode(inode); else - kmem_cache_free(inode_cachep, (inode)); + call_rcu(&inode->i_rcu, i_callback); } +void address_space_init_once(struct address_space *mapping) +{ + memset(mapping, 0, sizeof(*mapping)); + INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC); + spin_lock_init(&mapping->tree_lock); + spin_lock_init(&mapping->i_mmap_lock); + INIT_LIST_HEAD(&mapping->private_list); + spin_lock_init(&mapping->private_lock); + INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap); + INIT_LIST_HEAD(&mapping->i_mmap_nonlinear); + mutex_init(&mapping->unmap_mutex); +} +EXPORT_SYMBOL(address_space_init_once); + /* * These are initializations that only need to be done * once, because the fields are idempotent across use @@ -255,13 +346,9 @@ void inode_init_once(struct inode *inode) INIT_HLIST_NODE(&inode->i_hash); INIT_LIST_HEAD(&inode->i_dentry); INIT_LIST_HEAD(&inode->i_devices); - INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); - spin_lock_init(&inode->i_data.tree_lock); - spin_lock_init(&inode->i_data.i_mmap_lock); - INIT_LIST_HEAD(&inode->i_data.private_list); - spin_lock_init(&inode->i_data.private_lock); - INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap); - INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); + INIT_LIST_HEAD(&inode->i_wb_list); + INIT_LIST_HEAD(&inode->i_lru); + address_space_init_once(&inode->i_data); i_size_ordered_init(inode); #ifdef CONFIG_FSNOTIFY INIT_HLIST_HEAD(&inode->i_fsnotify_marks); @@ -277,17 +364,106 @@ static void init_once(void *foo) } /* - * inode_lock must be held + * inode->i_lock must be held */ void __iget(struct inode *inode) { - if (atomic_inc_return(&inode->i_count) != 1) - return; + atomic_inc(&inode->i_count); +} - if (!(inode->i_state & (I_DIRTY|I_SYNC))) - list_move(&inode->i_list, &inode_in_use); - inodes_stat.nr_unused--; +/* + * get additional reference to inode; caller must already hold one. + */ +void ihold(struct inode *inode) +{ + WARN_ON(atomic_inc_return(&inode->i_count) < 2); } +EXPORT_SYMBOL(ihold); + +static void inode_lru_list_add(struct inode *inode) +{ + spin_lock(&inode_lru_lock); + if (list_empty(&inode->i_lru)) { + list_add(&inode->i_lru, &inode_lru); + inodes_stat.nr_unused++; + } + spin_unlock(&inode_lru_lock); +} + +static void inode_lru_list_del(struct inode *inode) +{ + spin_lock(&inode_lru_lock); + if (!list_empty(&inode->i_lru)) { + list_del_init(&inode->i_lru); + inodes_stat.nr_unused--; + } + spin_unlock(&inode_lru_lock); +} + +/** + * inode_sb_list_add - add inode to the superblock list of inodes + * @inode: inode to add + */ +void inode_sb_list_add(struct inode *inode) +{ + spin_lock(&inode_sb_list_lock); + list_add(&inode->i_sb_list, &inode->i_sb->s_inodes); + spin_unlock(&inode_sb_list_lock); +} +EXPORT_SYMBOL_GPL(inode_sb_list_add); + +static inline void inode_sb_list_del(struct inode *inode) +{ + spin_lock(&inode_sb_list_lock); + list_del_init(&inode->i_sb_list); + spin_unlock(&inode_sb_list_lock); +} + +static unsigned long hash(struct super_block *sb, unsigned long hashval) +{ + unsigned long tmp; + + tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / + L1_CACHE_BYTES; + tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); + return tmp & I_HASHMASK; +} + +/** + * __insert_inode_hash - hash an inode + * @inode: unhashed inode + * @hashval: unsigned long value used to locate this object in the + * inode_hashtable. + * + * Add an inode to the inode hash for this superblock. + */ +void __insert_inode_hash(struct inode *inode, unsigned long hashval) +{ + struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval); + + spin_lock(&inode_hash_lock); + spin_lock(&inode->i_lock); + hlist_add_head(&inode->i_hash, b); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); +} +EXPORT_SYMBOL(__insert_inode_hash); + +/** + * remove_inode_hash - remove an inode from the hash + * @inode: inode to unhash + * + * Remove an inode from the superblock. + */ +void remove_inode_hash(struct inode *inode) +{ + spin_lock(&inode_hash_lock); + spin_lock(&inode->i_lock); + hlist_del_init(&inode->i_hash); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); +} +EXPORT_SYMBOL(remove_inode_hash); void end_writeback(struct inode *inode) { @@ -297,14 +473,34 @@ void end_writeback(struct inode *inode) BUG_ON(!(inode->i_state & I_FREEING)); BUG_ON(inode->i_state & I_CLEAR); inode_sync_wait(inode); + /* don't need i_lock here, no concurrent mods to i_state */ inode->i_state = I_FREEING | I_CLEAR; } EXPORT_SYMBOL(end_writeback); +/* + * Free the inode passed in, removing it from the lists it is still connected + * to. We remove any pages still attached to the inode and wait for any IO that + * is still in progress before finally destroying the inode. + * + * An inode must already be marked I_FREEING so that we avoid the inode being + * moved back onto lists if we race with other code that manipulates the lists + * (e.g. writeback_single_inode). The caller is responsible for setting this. + * + * An inode must already be removed from the LRU list before being evicted from + * the cache. This should occur atomically with setting the I_FREEING state + * flag, so no inodes here should ever be on the LRU when being evicted. + */ static void evict(struct inode *inode) { const struct super_operations *op = inode->i_sb->s_op; + BUG_ON(!(inode->i_state & I_FREEING)); + BUG_ON(!list_empty(&inode->i_lru)); + + inode_wb_list_del(inode); + inode_sb_list_del(inode); + if (op->evict_inode) { op->evict_inode(inode); } else { @@ -316,6 +512,15 @@ static void evict(struct inode *inode) bd_forget(inode); if (S_ISCHR(inode->i_mode) && inode->i_cdev) cd_forget(inode); + + remove_inode_hash(inode); + + spin_lock(&inode->i_lock); + wake_up_bit(&inode->i_state, __I_NEW); + BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); + spin_unlock(&inode->i_lock); + + destroy_inode(inode); } /* @@ -327,101 +532,108 @@ static void evict(struct inode *inode) */ static void dispose_list(struct list_head *head) { - int nr_disposed = 0; - while (!list_empty(head)) { struct inode *inode; - inode = list_first_entry(head, struct inode, i_list); - list_del(&inode->i_list); + inode = list_first_entry(head, struct inode, i_lru); + list_del_init(&inode->i_lru); evict(inode); - - spin_lock(&inode_lock); - hlist_del_init(&inode->i_hash); - list_del_init(&inode->i_sb_list); - spin_unlock(&inode_lock); - - wake_up_inode(inode); - destroy_inode(inode); - nr_disposed++; } - spin_lock(&inode_lock); - inodes_stat.nr_inodes -= nr_disposed; - spin_unlock(&inode_lock); } -/* - * Invalidate all inodes for a device. +/** + * evict_inodes - evict all evictable inodes for a superblock + * @sb: superblock to operate on + * + * Make sure that no inodes with zero refcount are retained. This is + * called by superblock shutdown after having MS_ACTIVE flag removed, + * so any inode reaching zero refcount during or after that call will + * be immediately evicted. */ -static int invalidate_list(struct list_head *head, struct list_head *dispose) +void evict_inodes(struct super_block *sb) { - struct list_head *next; - int busy = 0, count = 0; - - next = head->next; - for (;;) { - struct list_head *tmp = next; - struct inode *inode; - - /* - * We can reschedule here without worrying about the list's - * consistency because the per-sb list of inodes must not - * change during umount anymore, and because iprune_sem keeps - * shrink_icache_memory() away. - */ - cond_resched_lock(&inode_lock); + struct inode *inode, *next; + LIST_HEAD(dispose); - next = next->next; - if (tmp == head) - break; - inode = list_entry(tmp, struct inode, i_sb_list); - if (inode->i_state & I_NEW) + spin_lock(&inode_sb_list_lock); + list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { + if (atomic_read(&inode->i_count)) continue; - invalidate_inode_buffers(inode); - if (!atomic_read(&inode->i_count)) { - list_move(&inode->i_list, dispose); - WARN_ON(inode->i_state & I_NEW); - inode->i_state |= I_FREEING; - count++; + + spin_lock(&inode->i_lock); + if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { + spin_unlock(&inode->i_lock); continue; } - busy = 1; + + inode->i_state |= I_FREEING; + inode_lru_list_del(inode); + spin_unlock(&inode->i_lock); + list_add(&inode->i_lru, &dispose); } - /* only unused inodes may be cached with i_count zero */ - inodes_stat.nr_unused -= count; - return busy; + spin_unlock(&inode_sb_list_lock); + + dispose_list(&dispose); + + /* + * Cycle through iprune_sem to make sure any inode that prune_icache + * moved off the list before we took the lock has been fully torn + * down. + */ + down_write(&iprune_sem); + up_write(&iprune_sem); } /** - * invalidate_inodes - discard the inodes on a device - * @sb: superblock + * invalidate_inodes - attempt to free all inodes on a superblock + * @sb: superblock to operate on + * @kill_dirty: flag to guide handling of dirty inodes * - * Discard all of the inodes for a given superblock. If the discard - * fails because there are busy inodes then a non zero value is returned. - * If the discard is successful all the inodes have been discarded. + * Attempts to free all inodes for a given superblock. If there were any + * busy inodes return a non-zero value, else zero. + * If @kill_dirty is set, discard dirty inodes too, otherwise treat + * them as busy. */ -int invalidate_inodes(struct super_block *sb) +int invalidate_inodes(struct super_block *sb, bool kill_dirty) { - int busy; - LIST_HEAD(throw_away); + int busy = 0; + struct inode *inode, *next; + LIST_HEAD(dispose); + + spin_lock(&inode_sb_list_lock); + list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) { + spin_lock(&inode->i_lock); + if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) { + spin_unlock(&inode->i_lock); + continue; + } + if (inode->i_state & I_DIRTY && !kill_dirty) { + spin_unlock(&inode->i_lock); + busy = 1; + continue; + } + if (atomic_read(&inode->i_count)) { + spin_unlock(&inode->i_lock); + busy = 1; + continue; + } - down_write(&iprune_sem); - spin_lock(&inode_lock); - fsnotify_unmount_inodes(&sb->s_inodes); - busy = invalidate_list(&sb->s_inodes, &throw_away); - spin_unlock(&inode_lock); + inode->i_state |= I_FREEING; + inode_lru_list_del(inode); + spin_unlock(&inode->i_lock); + list_add(&inode->i_lru, &dispose); + } + spin_unlock(&inode_sb_list_lock); - dispose_list(&throw_away); - up_write(&iprune_sem); + dispose_list(&dispose); return busy; } -EXPORT_SYMBOL(invalidate_inodes); static int can_unuse(struct inode *inode) { - if (inode->i_state) + if (inode->i_state & ~I_REFERENCED) return 0; if (inode_has_buffers(inode)) return 0; @@ -433,65 +645,99 @@ static int can_unuse(struct inode *inode) } /* - * Scan `goal' inodes on the unused list for freeable ones. They are moved to - * a temporary list and then are freed outside inode_lock by dispose_list(). + * Scan `goal' inodes on the unused list for freeable ones. They are moved to a + * temporary list and then are freed outside inode_lru_lock by dispose_list(). * * Any inodes which are pinned purely because of attached pagecache have their - * pagecache removed. We expect the final iput() on that inode to add it to - * the front of the inode_unused list. So look for it there and if the - * inode is still freeable, proceed. The right inode is found 99.9% of the - * time in testing on a 4-way. + * pagecache removed. If the inode has metadata buffers attached to + * mapping->private_list then try to remove them. * - * If the inode has metadata buffers attached to mapping->private_list then - * try to remove them. + * If the inode has the I_REFERENCED flag set, then it means that it has been + * used recently - the flag is set in iput_final(). When we encounter such an + * inode, clear the flag and move it to the back of the LRU so it gets another + * pass through the LRU before it gets reclaimed. This is necessary because of + * the fact we are doing lazy LRU updates to minimise lock contention so the + * LRU does not have strict ordering. Hence we don't want to reclaim inodes + * with this flag set because they are the inodes that are out of order. */ static void prune_icache(int nr_to_scan) { LIST_HEAD(freeable); - int nr_pruned = 0; int nr_scanned; unsigned long reap = 0; down_read(&iprune_sem); - spin_lock(&inode_lock); + spin_lock(&inode_lru_lock); for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { struct inode *inode; - if (list_empty(&inode_unused)) + if (list_empty(&inode_lru)) break; - inode = list_entry(inode_unused.prev, struct inode, i_list); + inode = list_entry(inode_lru.prev, struct inode, i_lru); + + /* + * we are inverting the inode_lru_lock/inode->i_lock here, + * so use a trylock. If we fail to get the lock, just move the + * inode to the back of the list so we don't spin on it. + */ + if (!spin_trylock(&inode->i_lock)) { + list_move(&inode->i_lru, &inode_lru); + continue; + } + + /* + * Referenced or dirty inodes are still in use. Give them + * another pass through the LRU as we canot reclaim them now. + */ + if (atomic_read(&inode->i_count) || + (inode->i_state & ~I_REFERENCED)) { + list_del_init(&inode->i_lru); + spin_unlock(&inode->i_lock); + inodes_stat.nr_unused--; + continue; + } - if (inode->i_state || atomic_read(&inode->i_count)) { - list_move(&inode->i_list, &inode_unused); + /* recently referenced inodes get one more pass */ + if (inode->i_state & I_REFERENCED) { + inode->i_state &= ~I_REFERENCED; + list_move(&inode->i_lru, &inode_lru); + spin_unlock(&inode->i_lock); continue; } if (inode_has_buffers(inode) || inode->i_data.nrpages) { __iget(inode); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_lru_lock); if (remove_inode_buffers(inode)) reap += invalidate_mapping_pages(&inode->i_data, 0, -1); iput(inode); - spin_lock(&inode_lock); + spin_lock(&inode_lru_lock); - if (inode != list_entry(inode_unused.next, - struct inode, i_list)) + if (inode != list_entry(inode_lru.next, + struct inode, i_lru)) continue; /* wrong inode or list_empty */ - if (!can_unuse(inode)) + /* avoid lock inversions with trylock */ + if (!spin_trylock(&inode->i_lock)) continue; + if (!can_unuse(inode)) { + spin_unlock(&inode->i_lock); + continue; + } } - list_move(&inode->i_list, &freeable); WARN_ON(inode->i_state & I_NEW); inode->i_state |= I_FREEING; - nr_pruned++; + spin_unlock(&inode->i_lock); + + list_move(&inode->i_lru, &freeable); + inodes_stat.nr_unused--; } - inodes_stat.nr_unused -= nr_pruned; if (current_is_kswapd()) __count_vm_events(KSWAPD_INODESTEAL, reap); else __count_vm_events(PGINODESTEAL, reap); - spin_unlock(&inode_lock); + spin_unlock(&inode_lru_lock); dispose_list(&freeable); up_read(&iprune_sem); @@ -518,7 +764,7 @@ static int shrink_icache_memory(struct shrinker *shrink, int nr, gfp_t gfp_mask) return -1; prune_icache(nr); } - return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure; + return (get_nr_inodes_unused() / 100) * sysctl_vfs_cache_pressure; } static struct shrinker icache_shrinker = { @@ -529,9 +775,6 @@ static struct shrinker icache_shrinker = { static void __wait_on_freeing_inode(struct inode *inode); /* * Called with the inode lock held. - * NOTE: we are not increasing the inode-refcount, you must call __iget() - * by hand after calling find_inode now! This simplifies iunique and won't - * add any additional branch in the common code. */ static struct inode *find_inode(struct super_block *sb, struct hlist_head *head, @@ -543,17 +786,24 @@ static struct inode *find_inode(struct super_block *sb, repeat: hlist_for_each_entry(inode, node, head, i_hash) { - if (inode->i_sb != sb) + spin_lock(&inode->i_lock); + if (inode->i_sb != sb) { + spin_unlock(&inode->i_lock); continue; - if (!test(inode, data)) + } + if (!test(inode, data)) { + spin_unlock(&inode->i_lock); continue; + } if (inode->i_state & (I_FREEING|I_WILL_FREE)) { __wait_on_freeing_inode(inode); goto repeat; } - break; + __iget(inode); + spin_unlock(&inode->i_lock); + return inode; } - return node ? inode : NULL; + return NULL; } /* @@ -568,61 +818,63 @@ static struct inode *find_inode_fast(struct super_block *sb, repeat: hlist_for_each_entry(inode, node, head, i_hash) { - if (inode->i_ino != ino) + spin_lock(&inode->i_lock); + if (inode->i_ino != ino) { + spin_unlock(&inode->i_lock); continue; - if (inode->i_sb != sb) + } + if (inode->i_sb != sb) { + spin_unlock(&inode->i_lock); continue; + } if (inode->i_state & (I_FREEING|I_WILL_FREE)) { __wait_on_freeing_inode(inode); goto repeat; } - break; + __iget(inode); + spin_unlock(&inode->i_lock); + return inode; } - return node ? inode : NULL; -} - -static unsigned long hash(struct super_block *sb, unsigned long hashval) -{ - unsigned long tmp; - - tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) / - L1_CACHE_BYTES; - tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> I_HASHBITS); - return tmp & I_HASHMASK; -} - -static inline void -__inode_add_to_lists(struct super_block *sb, struct hlist_head *head, - struct inode *inode) -{ - inodes_stat.nr_inodes++; - list_add(&inode->i_list, &inode_in_use); - list_add(&inode->i_sb_list, &sb->s_inodes); - if (head) - hlist_add_head(&inode->i_hash, head); + return NULL; } -/** - * inode_add_to_lists - add a new inode to relevant lists - * @sb: superblock inode belongs to - * @inode: inode to mark in use +/* + * Each cpu owns a range of LAST_INO_BATCH numbers. + * 'shared_last_ino' is dirtied only once out of LAST_INO_BATCH allocations, + * to renew the exhausted range. * - * When an inode is allocated it needs to be accounted for, added to the in use - * list, the owning superblock and the inode hash. This needs to be done under - * the inode_lock, so export a function to do this rather than the inode lock - * itself. We calculate the hash list to add to here so it is all internal - * which requires the caller to have already set up the inode number in the - * inode to add. + * This does not significantly increase overflow rate because every CPU can + * consume at most LAST_INO_BATCH-1 unused inode numbers. So there is + * NR_CPUS*(LAST_INO_BATCH-1) wastage. At 4096 and 1024, this is ~0.1% of the + * 2^32 range, and is a worst-case. Even a 50% wastage would only increase + * overflow rate by 2x, which does not seem too significant. + * + * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW + * error if st_ino won't fit in target struct field. Use 32bit counter + * here to attempt to avoid that. */ -void inode_add_to_lists(struct super_block *sb, struct inode *inode) +#define LAST_INO_BATCH 1024 +static DEFINE_PER_CPU(unsigned int, last_ino); + +unsigned int get_next_ino(void) { - struct hlist_head *head = inode_hashtable + hash(sb, inode->i_ino); + unsigned int *p = &get_cpu_var(last_ino); + unsigned int res = *p; - spin_lock(&inode_lock); - __inode_add_to_lists(sb, head, inode); - spin_unlock(&inode_lock); +#ifdef CONFIG_SMP + if (unlikely((res & (LAST_INO_BATCH-1)) == 0)) { + static atomic_t shared_last_ino; + int next = atomic_add_return(LAST_INO_BATCH, &shared_last_ino); + + res = next - LAST_INO_BATCH; + } +#endif + + *p = ++res; + put_cpu_var(last_ino); + return res; } -EXPORT_SYMBOL_GPL(inode_add_to_lists); +EXPORT_SYMBOL(get_next_ino); /** * new_inode - obtain an inode @@ -638,32 +890,32 @@ EXPORT_SYMBOL_GPL(inode_add_to_lists); */ struct inode *new_inode(struct super_block *sb) { - /* - * On a 32bit, non LFS stat() call, glibc will generate an EOVERFLOW - * error if st_ino won't fit in target struct field. Use 32bit counter - * here to attempt to avoid that. - */ - static unsigned int last_ino; struct inode *inode; - spin_lock_prefetch(&inode_lock); + spin_lock_prefetch(&inode_sb_list_lock); inode = alloc_inode(sb); if (inode) { - spin_lock(&inode_lock); - __inode_add_to_lists(sb, NULL, inode); - inode->i_ino = ++last_ino; + spin_lock(&inode->i_lock); inode->i_state = 0; - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + inode_sb_list_add(inode); } return inode; } EXPORT_SYMBOL(new_inode); +/** + * unlock_new_inode - clear the I_NEW state and wake up any waiters + * @inode: new inode to unlock + * + * Called when the inode is fully initialised to clear the new state of the + * inode and wake up anyone waiting for the inode to finish initialisation. + */ void unlock_new_inode(struct inode *inode) { #ifdef CONFIG_DEBUG_LOCK_ALLOC - if (inode->i_mode & S_IFDIR) { + if (S_ISDIR(inode->i_mode)) { struct file_system_type *type = inode->i_sb->s_type; /* Set new key only if filesystem hasn't already changed it */ @@ -679,50 +931,67 @@ void unlock_new_inode(struct inode *inode) } } #endif - /* - * This is special! We do not need the spinlock when clearing I_NEW, - * because we're guaranteed that nobody else tries to do anything about - * the state of the inode when it is locked, as we just created it (so - * there can be no old holders that haven't tested I_NEW). - * However we must emit the memory barrier so that other CPUs reliably - * see the clearing of I_NEW after the other inode initialisation has - * completed. - */ - smp_mb(); + spin_lock(&inode->i_lock); WARN_ON(!(inode->i_state & I_NEW)); inode->i_state &= ~I_NEW; - wake_up_inode(inode); + wake_up_bit(&inode->i_state, __I_NEW); + spin_unlock(&inode->i_lock); } EXPORT_SYMBOL(unlock_new_inode); -/* - * This is called without the inode lock held.. Be careful. +/** + * iget5_locked - obtain an inode from a mounted file system + * @sb: super block of file system + * @hashval: hash value (usually inode number) to get + * @test: callback used for comparisons between inodes + * @set: callback used to initialize a new struct inode + * @data: opaque data pointer to pass to @test and @set + * + * Search for the inode specified by @hashval and @data in the inode cache, + * and if present it is return it with an increased reference count. This is + * a generalized version of iget_locked() for file systems where the inode + * number is not sufficient for unique identification of an inode. + * + * If the inode is not in cache, allocate a new inode and return it locked, + * hashed, and with the I_NEW flag set. The file system gets to fill it in + * before unlocking it via unlock_new_inode(). * - * We no longer cache the sb_flags in i_flags - see fs.h - * -- rmk@arm.uk.linux.org + * Note both @test and @set are called with the inode_hash_lock held, so can't + * sleep. */ -static struct inode *get_new_inode(struct super_block *sb, - struct hlist_head *head, - int (*test)(struct inode *, void *), - int (*set)(struct inode *, void *), - void *data) +struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, + int (*test)(struct inode *, void *), + int (*set)(struct inode *, void *), void *data) { + struct hlist_head *head = inode_hashtable + hash(sb, hashval); struct inode *inode; + spin_lock(&inode_hash_lock); + inode = find_inode(sb, head, test, data); + spin_unlock(&inode_hash_lock); + + if (inode) { + wait_on_inode(inode); + return inode; + } + inode = alloc_inode(sb); if (inode) { struct inode *old; - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); /* We released the lock, so.. */ old = find_inode(sb, head, test, data); if (!old) { if (set(inode, data)) goto set_failed; - __inode_add_to_lists(sb, head, inode); + spin_lock(&inode->i_lock); inode->i_state = I_NEW; - spin_unlock(&inode_lock); + hlist_add_head(&inode->i_hash, head); + spin_unlock(&inode->i_lock); + inode_sb_list_add(inode); + spin_unlock(&inode_hash_lock); /* Return the locked inode with I_NEW set, the * caller is responsible for filling in the contents @@ -735,8 +1004,7 @@ static struct inode *get_new_inode(struct super_block *sb, * us. Use the old inode instead of the one we just * allocated. */ - __iget(old); - spin_unlock(&inode_lock); + spin_unlock(&inode_hash_lock); destroy_inode(inode); inode = old; wait_on_inode(inode); @@ -744,32 +1012,53 @@ static struct inode *get_new_inode(struct super_block *sb, return inode; set_failed: - spin_unlock(&inode_lock); + spin_unlock(&inode_hash_lock); destroy_inode(inode); return NULL; } +EXPORT_SYMBOL(iget5_locked); -/* - * get_new_inode_fast is the fast path version of get_new_inode, see the - * comment at iget_locked for details. +/** + * iget_locked - obtain an inode from a mounted file system + * @sb: super block of file system + * @ino: inode number to get + * + * Search for the inode specified by @ino in the inode cache and if present + * return it with an increased reference count. This is for file systems + * where the inode number is sufficient for unique identification of an inode. + * + * If the inode is not in cache, allocate a new inode and return it locked, + * hashed, and with the I_NEW flag set. The file system gets to fill it in + * before unlocking it via unlock_new_inode(). */ -static struct inode *get_new_inode_fast(struct super_block *sb, - struct hlist_head *head, unsigned long ino) +struct inode *iget_locked(struct super_block *sb, unsigned long ino) { + struct hlist_head *head = inode_hashtable + hash(sb, ino); struct inode *inode; + spin_lock(&inode_hash_lock); + inode = find_inode_fast(sb, head, ino); + spin_unlock(&inode_hash_lock); + if (inode) { + wait_on_inode(inode); + return inode; + } + inode = alloc_inode(sb); if (inode) { struct inode *old; - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); /* We released the lock, so.. */ old = find_inode_fast(sb, head, ino); if (!old) { inode->i_ino = ino; - __inode_add_to_lists(sb, head, inode); + spin_lock(&inode->i_lock); inode->i_state = I_NEW; - spin_unlock(&inode_lock); + hlist_add_head(&inode->i_hash, head); + spin_unlock(&inode->i_lock); + inode_sb_list_add(inode); + spin_unlock(&inode_hash_lock); /* Return the locked inode with I_NEW set, the * caller is responsible for filling in the contents @@ -782,14 +1071,39 @@ static struct inode *get_new_inode_fast(struct super_block *sb, * us. Use the old inode instead of the one we just * allocated. */ - __iget(old); - spin_unlock(&inode_lock); + spin_unlock(&inode_hash_lock); destroy_inode(inode); inode = old; wait_on_inode(inode); } return inode; } +EXPORT_SYMBOL(iget_locked); + +/* + * search the inode cache for a matching inode number. + * If we find one, then the inode number we are trying to + * allocate is not unique and so we should not use it. + * + * Returns 1 if the inode number is unique, 0 if it is not. + */ +static int test_inode_iunique(struct super_block *sb, unsigned long ino) +{ + struct hlist_head *b = inode_hashtable + hash(sb, ino); + struct hlist_node *node; + struct inode *inode; + + spin_lock(&inode_hash_lock); + hlist_for_each_entry(inode, node, b, i_hash) { + if (inode->i_ino == ino && inode->i_sb == sb) { + spin_unlock(&inode_hash_lock); + return 0; + } + } + spin_unlock(&inode_hash_lock); + + return 1; +} /** * iunique - get a unique inode number @@ -812,20 +1126,17 @@ ino_t iunique(struct super_block *sb, ino_t max_reserved) * error if st_ino won't fit in target struct field. Use 32bit counter * here to attempt to avoid that. */ + static DEFINE_SPINLOCK(iunique_lock); static unsigned int counter; - struct inode *inode; - struct hlist_head *head; ino_t res; - spin_lock(&inode_lock); + spin_lock(&iunique_lock); do { if (counter <= max_reserved) counter = max_reserved + 1; res = counter++; - head = inode_hashtable + hash(sb, res); - inode = find_inode_fast(sb, head, res); - } while (inode != NULL); - spin_unlock(&inode_lock); + } while (!test_inode_iunique(sb, res)); + spin_unlock(&iunique_lock); return res; } @@ -833,118 +1144,50 @@ EXPORT_SYMBOL(iunique); struct inode *igrab(struct inode *inode) { - spin_lock(&inode_lock); - if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) + spin_lock(&inode->i_lock); + if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) { __iget(inode); - else + spin_unlock(&inode->i_lock); + } else { + spin_unlock(&inode->i_lock); /* * Handle the case where s_op->clear_inode is not been * called yet, and somebody is calling igrab * while the inode is getting freed. */ inode = NULL; - spin_unlock(&inode_lock); + } return inode; } EXPORT_SYMBOL(igrab); /** - * ifind - internal function, you want ilookup5() or iget5(). - * @sb: super block of file system to search - * @head: the head of the list to search - * @test: callback used for comparisons between inodes - * @data: opaque data pointer to pass to @test - * @wait: if true wait for the inode to be unlocked, if false do not - * - * ifind() searches for the inode specified by @data in the inode - * cache. This is a generalized version of ifind_fast() for file systems where - * the inode number is not sufficient for unique identification of an inode. - * - * If the inode is in the cache, the inode is returned with an incremented - * reference count. - * - * Otherwise NULL is returned. - * - * Note, @test is called with the inode_lock held, so can't sleep. - */ -static struct inode *ifind(struct super_block *sb, - struct hlist_head *head, int (*test)(struct inode *, void *), - void *data, const int wait) -{ - struct inode *inode; - - spin_lock(&inode_lock); - inode = find_inode(sb, head, test, data); - if (inode) { - __iget(inode); - spin_unlock(&inode_lock); - if (likely(wait)) - wait_on_inode(inode); - return inode; - } - spin_unlock(&inode_lock); - return NULL; -} - -/** - * ifind_fast - internal function, you want ilookup() or iget(). - * @sb: super block of file system to search - * @head: head of the list to search - * @ino: inode number to search for - * - * ifind_fast() searches for the inode @ino in the inode cache. This is for - * file systems where the inode number is sufficient for unique identification - * of an inode. - * - * If the inode is in the cache, the inode is returned with an incremented - * reference count. - * - * Otherwise NULL is returned. - */ -static struct inode *ifind_fast(struct super_block *sb, - struct hlist_head *head, unsigned long ino) -{ - struct inode *inode; - - spin_lock(&inode_lock); - inode = find_inode_fast(sb, head, ino); - if (inode) { - __iget(inode); - spin_unlock(&inode_lock); - wait_on_inode(inode); - return inode; - } - spin_unlock(&inode_lock); - return NULL; -} - -/** * ilookup5_nowait - search for an inode in the inode cache * @sb: super block of file system to search * @hashval: hash value (usually inode number) to search for * @test: callback used for comparisons between inodes * @data: opaque data pointer to pass to @test * - * ilookup5() uses ifind() to search for the inode specified by @hashval and - * @data in the inode cache. This is a generalized version of ilookup() for - * file systems where the inode number is not sufficient for unique - * identification of an inode. - * + * Search for the inode specified by @hashval and @data in the inode cache. * If the inode is in the cache, the inode is returned with an incremented - * reference count. Note, the inode lock is not waited upon so you have to be - * very careful what you do with the returned inode. You probably should be - * using ilookup5() instead. + * reference count. * - * Otherwise NULL is returned. + * Note: I_NEW is not waited upon so you have to be very careful what you do + * with the returned inode. You probably should be using ilookup5() instead. * - * Note, @test is called with the inode_lock held, so can't sleep. + * Note2: @test is called with the inode_hash_lock held, so can't sleep. */ struct inode *ilookup5_nowait(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), void *data) { struct hlist_head *head = inode_hashtable + hash(sb, hashval); + struct inode *inode; - return ifind(sb, head, test, data, 0); + spin_lock(&inode_hash_lock); + inode = find_inode(sb, head, test, data); + spin_unlock(&inode_hash_lock); + + return inode; } EXPORT_SYMBOL(ilookup5_nowait); @@ -955,24 +1198,24 @@ EXPORT_SYMBOL(ilookup5_nowait); * @test: callback used for comparisons between inodes * @data: opaque data pointer to pass to @test * - * ilookup5() uses ifind() to search for the inode specified by @hashval and - * @data in the inode cache. This is a generalized version of ilookup() for - * file systems where the inode number is not sufficient for unique - * identification of an inode. - * - * If the inode is in the cache, the inode lock is waited upon and the inode is + * Search for the inode specified by @hashval and @data in the inode cache, + * and if the inode is in the cache, return the inode with an incremented + * reference count. Waits on I_NEW before returning the inode. * returned with an incremented reference count. * - * Otherwise NULL is returned. + * This is a generalized version of ilookup() for file systems where the + * inode number is not sufficient for unique identification of an inode. * - * Note, @test is called with the inode_lock held, so can't sleep. + * Note: @test is called with the inode_hash_lock held, so can't sleep. */ struct inode *ilookup5(struct super_block *sb, unsigned long hashval, int (*test)(struct inode *, void *), void *data) { - struct hlist_head *head = inode_hashtable + hash(sb, hashval); + struct inode *inode = ilookup5_nowait(sb, hashval, test, data); - return ifind(sb, head, test, data, 1); + if (inode) + wait_on_inode(inode); + return inode; } EXPORT_SYMBOL(ilookup5); @@ -981,91 +1224,23 @@ EXPORT_SYMBOL(ilookup5); * @sb: super block of file system to search * @ino: inode number to search for * - * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache. - * This is for file systems where the inode number is sufficient for unique - * identification of an inode. - * - * If the inode is in the cache, the inode is returned with an incremented - * reference count. - * - * Otherwise NULL is returned. + * Search for the inode @ino in the inode cache, and if the inode is in the + * cache, the inode is returned with an incremented reference count. */ struct inode *ilookup(struct super_block *sb, unsigned long ino) { struct hlist_head *head = inode_hashtable + hash(sb, ino); - - return ifind_fast(sb, head, ino); -} -EXPORT_SYMBOL(ilookup); - -/** - * iget5_locked - obtain an inode from a mounted file system - * @sb: super block of file system - * @hashval: hash value (usually inode number) to get - * @test: callback used for comparisons between inodes - * @set: callback used to initialize a new struct inode - * @data: opaque data pointer to pass to @test and @set - * - * iget5_locked() uses ifind() to search for the inode specified by @hashval - * and @data in the inode cache and if present it is returned with an increased - * reference count. This is a generalized version of iget_locked() for file - * systems where the inode number is not sufficient for unique identification - * of an inode. - * - * If the inode is not in cache, get_new_inode() is called to allocate a new - * inode and this is returned locked, hashed, and with the I_NEW flag set. The - * file system gets to fill it in before unlocking it via unlock_new_inode(). - * - * Note both @test and @set are called with the inode_lock held, so can't sleep. - */ -struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, - int (*test)(struct inode *, void *), - int (*set)(struct inode *, void *), void *data) -{ - struct hlist_head *head = inode_hashtable + hash(sb, hashval); struct inode *inode; - inode = ifind(sb, head, test, data, 1); - if (inode) - return inode; - /* - * get_new_inode() will do the right thing, re-trying the search - * in case it had to block at any point. - */ - return get_new_inode(sb, head, test, set, data); -} -EXPORT_SYMBOL(iget5_locked); - -/** - * iget_locked - obtain an inode from a mounted file system - * @sb: super block of file system - * @ino: inode number to get - * - * iget_locked() uses ifind_fast() to search for the inode specified by @ino in - * the inode cache and if present it is returned with an increased reference - * count. This is for file systems where the inode number is sufficient for - * unique identification of an inode. - * - * If the inode is not in cache, get_new_inode_fast() is called to allocate a - * new inode and this is returned locked, hashed, and with the I_NEW flag set. - * The file system gets to fill it in before unlocking it via - * unlock_new_inode(). - */ -struct inode *iget_locked(struct super_block *sb, unsigned long ino) -{ - struct hlist_head *head = inode_hashtable + hash(sb, ino); - struct inode *inode; + spin_lock(&inode_hash_lock); + inode = find_inode_fast(sb, head, ino); + spin_unlock(&inode_hash_lock); - inode = ifind_fast(sb, head, ino); if (inode) - return inode; - /* - * get_new_inode_fast() will do the right thing, re-trying the search - * in case it had to block at any point. - */ - return get_new_inode_fast(sb, head, ino); + wait_on_inode(inode); + return inode; } -EXPORT_SYMBOL(iget_locked); +EXPORT_SYMBOL(ilookup); int insert_inode_locked(struct inode *inode) { @@ -1073,29 +1248,35 @@ int insert_inode_locked(struct inode *inode) ino_t ino = inode->i_ino; struct hlist_head *head = inode_hashtable + hash(sb, ino); - inode->i_state |= I_NEW; while (1) { struct hlist_node *node; struct inode *old = NULL; - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); hlist_for_each_entry(old, node, head, i_hash) { if (old->i_ino != ino) continue; if (old->i_sb != sb) continue; - if (old->i_state & (I_FREEING|I_WILL_FREE)) + spin_lock(&old->i_lock); + if (old->i_state & (I_FREEING|I_WILL_FREE)) { + spin_unlock(&old->i_lock); continue; + } break; } if (likely(!node)) { + spin_lock(&inode->i_lock); + inode->i_state |= I_NEW; hlist_add_head(&inode->i_hash, head); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); return 0; } __iget(old); - spin_unlock(&inode_lock); + spin_unlock(&old->i_lock); + spin_unlock(&inode_hash_lock); wait_on_inode(old); - if (unlikely(!hlist_unhashed(&old->i_hash))) { + if (unlikely(!inode_unhashed(old))) { iput(old); return -EBUSY; } @@ -1110,31 +1291,36 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval, struct super_block *sb = inode->i_sb; struct hlist_head *head = inode_hashtable + hash(sb, hashval); - inode->i_state |= I_NEW; - while (1) { struct hlist_node *node; struct inode *old = NULL; - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); hlist_for_each_entry(old, node, head, i_hash) { if (old->i_sb != sb) continue; if (!test(old, data)) continue; - if (old->i_state & (I_FREEING|I_WILL_FREE)) + spin_lock(&old->i_lock); + if (old->i_state & (I_FREEING|I_WILL_FREE)) { + spin_unlock(&old->i_lock); continue; + } break; } if (likely(!node)) { + spin_lock(&inode->i_lock); + inode->i_state |= I_NEW; hlist_add_head(&inode->i_hash, head); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); return 0; } __iget(old); - spin_unlock(&inode_lock); + spin_unlock(&old->i_lock); + spin_unlock(&inode_hash_lock); wait_on_inode(old); - if (unlikely(!hlist_unhashed(&old->i_hash))) { + if (unlikely(!inode_unhashed(old))) { iput(old); return -EBUSY; } @@ -1143,36 +1329,6 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval, } EXPORT_SYMBOL(insert_inode_locked4); -/** - * __insert_inode_hash - hash an inode - * @inode: unhashed inode - * @hashval: unsigned long value used to locate this object in the - * inode_hashtable. - * - * Add an inode to the inode hash for this superblock. - */ -void __insert_inode_hash(struct inode *inode, unsigned long hashval) -{ - struct hlist_head *head = inode_hashtable + hash(inode->i_sb, hashval); - spin_lock(&inode_lock); - hlist_add_head(&inode->i_hash, head); - spin_unlock(&inode_lock); -} -EXPORT_SYMBOL(__insert_inode_hash); - -/** - * remove_inode_hash - remove an inode from the hash - * @inode: inode to unhash - * - * Remove an inode from the superblock. - */ -void remove_inode_hash(struct inode *inode) -{ - spin_lock(&inode_lock); - hlist_del_init(&inode->i_hash); - spin_unlock(&inode_lock); -} -EXPORT_SYMBOL(remove_inode_hash); int generic_delete_inode(struct inode *inode) { @@ -1187,7 +1343,7 @@ EXPORT_SYMBOL(generic_delete_inode); */ int generic_drop_inode(struct inode *inode) { - return !inode->i_nlink || hlist_unhashed(&inode->i_hash); + return !inode->i_nlink || inode_unhashed(inode); } EXPORT_SYMBOL_GPL(generic_drop_inode); @@ -1207,42 +1363,35 @@ static void iput_final(struct inode *inode) const struct super_operations *op = inode->i_sb->s_op; int drop; + WARN_ON(inode->i_state & I_NEW); + if (op && op->drop_inode) drop = op->drop_inode(inode); else drop = generic_drop_inode(inode); - if (!drop) { + if (!drop && (sb->s_flags & MS_ACTIVE)) { + inode->i_state |= I_REFERENCED; if (!(inode->i_state & (I_DIRTY|I_SYNC))) - list_move(&inode->i_list, &inode_unused); - inodes_stat.nr_unused++; - if (sb->s_flags & MS_ACTIVE) { - spin_unlock(&inode_lock); - return; - } - WARN_ON(inode->i_state & I_NEW); + inode_lru_list_add(inode); + spin_unlock(&inode->i_lock); + return; + } + + if (!drop) { inode->i_state |= I_WILL_FREE; - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); write_inode_now(inode, 1); - spin_lock(&inode_lock); + spin_lock(&inode->i_lock); WARN_ON(inode->i_state & I_NEW); inode->i_state &= ~I_WILL_FREE; - inodes_stat.nr_unused--; - hlist_del_init(&inode->i_hash); } - list_del_init(&inode->i_list); - list_del_init(&inode->i_sb_list); - WARN_ON(inode->i_state & I_NEW); + inode->i_state |= I_FREEING; - inodes_stat.nr_inodes--; - spin_unlock(&inode_lock); + inode_lru_list_del(inode); + spin_unlock(&inode->i_lock); + evict(inode); - spin_lock(&inode_lock); - hlist_del_init(&inode->i_hash); - spin_unlock(&inode_lock); - wake_up_inode(inode); - BUG_ON(inode->i_state != (I_FREEING | I_CLEAR)); - destroy_inode(inode); } /** @@ -1259,7 +1408,7 @@ void iput(struct inode *inode) if (inode) { BUG_ON(inode->i_state & I_CLEAR); - if (atomic_dec_and_lock(&inode->i_count, &inode_lock)) + if (atomic_dec_and_lock(&inode->i_count, &inode->i_lock)) iput_final(inode); } } @@ -1438,9 +1587,8 @@ EXPORT_SYMBOL(inode_wait); * to recheck inode state. * * It doesn't matter if I_NEW is not set initially, a call to - * wake_up_inode() after removing from the hash list will DTRT. - * - * This is called with inode_lock held. + * wake_up_bit(&inode->i_state, __I_NEW) after removing from the hash list + * will DTRT. */ static void __wait_on_freeing_inode(struct inode *inode) { @@ -1448,10 +1596,11 @@ static void __wait_on_freeing_inode(struct inode *inode) DEFINE_WAIT_BIT(wait, &inode->i_state, __I_NEW); wq = bit_waitqueue(&inode->i_state, __I_NEW); prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); - spin_unlock(&inode_lock); + spin_unlock(&inode->i_lock); + spin_unlock(&inode_hash_lock); schedule(); finish_wait(wq, &wait.wait); - spin_lock(&inode_lock); + spin_lock(&inode_hash_lock); } static __initdata unsigned long ihash_entries; @@ -1543,7 +1692,7 @@ void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev) EXPORT_SYMBOL(init_special_inode); /** - * Init uid,gid,mode for new inode according to posix standards + * inode_init_owner - Init uid,gid,mode for new inode according to posix standards * @inode: New inode * @dir: Directory inode * @mode: mode of the new inode @@ -1561,3 +1710,22 @@ void inode_init_owner(struct inode *inode, const struct inode *dir, inode->i_mode = mode; } EXPORT_SYMBOL(inode_init_owner); + +/** + * inode_owner_or_capable - check current task permissions to inode + * @inode: inode being checked + * + * Return true if current either has CAP_FOWNER to the inode, or + * owns the file. + */ +bool inode_owner_or_capable(const struct inode *inode) +{ + struct user_namespace *ns = inode_userns(inode); + + if (current_user_ns() == ns && current_fsuid() == inode->i_uid) + return true; + if (ns_capable(ns, CAP_FOWNER)) + return true; + return false; +} +EXPORT_SYMBOL(inode_owner_or_capable); |