X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=fs%2Finode.c;h=79a986f5a160d16f9721998490287ebdc36757c5;hb=d8b3d7077d08311552643a220f21ce0d30130f59;hp=8c983e9a5f47a8ee38193c8f302f99410df09530;hpb=207e0a826fdee4bfe853681aef2175a739c11286;p=linux-2.6.git diff --git a/fs/inode.c b/fs/inode.c index 8c983e9a5..79a986f5a 100644 --- a/fs/inode.c +++ b/fs/inode.c @@ -21,6 +21,8 @@ #include #include #include +#include +#include /* * This is needed for the following functions: @@ -54,8 +56,8 @@ #define I_HASHBITS i_hash_shift #define I_HASHMASK i_hash_mask -static unsigned int i_hash_mask; -static unsigned int i_hash_shift; +static unsigned int i_hash_mask __read_mostly; +static unsigned int i_hash_shift __read_mostly; /* * Each inode can be on two separate lists. One is @@ -71,7 +73,7 @@ static unsigned int i_hash_shift; LIST_HEAD(inode_in_use); LIST_HEAD(inode_unused); -static struct hlist_head *inode_hashtable; +static struct hlist_head *inode_hashtable __read_mostly; /* * A simple spinlock to protect the list manipulations. @@ -82,27 +84,27 @@ static struct hlist_head *inode_hashtable; DEFINE_SPINLOCK(inode_lock); /* - * iprune_sem provides exclusion between the kswapd or try_to_free_pages + * iprune_mutex 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. */ -DECLARE_MUTEX(iprune_sem); +static DEFINE_MUTEX(iprune_mutex); /* * Statistics gathering.. */ struct inodes_stat_t inodes_stat; -static kmem_cache_t * inode_cachep; +static kmem_cache_t * inode_cachep __read_mostly; static struct inode *alloc_inode(struct super_block *sb) { static struct address_space_operations empty_aops; static struct inode_operations empty_iops; - static struct file_operations empty_fops; + static const struct file_operations empty_fops; struct inode *inode; if (sb->s_op->alloc_inode) @@ -173,8 +175,7 @@ static struct inode *alloc_inode(struct super_block *sb) void destroy_inode(struct inode *inode) { - if (inode_has_buffers(inode)) - BUG(); + BUG_ON(inode_has_buffers(inode)); security_inode_free(inode); if (inode->i_sb->s_op->destroy_inode) inode->i_sb->s_op->destroy_inode(inode); @@ -194,7 +195,7 @@ 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); - sema_init(&inode->i_sem, 1); + mutex_init(&inode->i_mutex); init_rwsem(&inode->i_alloc_sem); INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC); rwlock_init(&inode->i_data.tree_lock); @@ -205,6 +206,10 @@ void inode_init_once(struct inode *inode) INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear); spin_lock_init(&inode->i_lock); i_size_ordered_init(inode); +#ifdef CONFIG_INOTIFY + INIT_LIST_HEAD(&inode->inotify_watches); + mutex_init(&inode->inotify_mutex); +#endif } EXPORT_SYMBOL(inode_init_once); @@ -248,12 +253,9 @@ void clear_inode(struct inode *inode) might_sleep(); invalidate_inode_buffers(inode); - if (inode->i_data.nrpages) - BUG(); - if (!(inode->i_state & I_FREEING)) - BUG(); - if (inode->i_state & I_CLEAR) - BUG(); + BUG_ON(inode->i_data.nrpages); + BUG_ON(!(inode->i_state & I_FREEING)); + BUG_ON(inode->i_state & I_CLEAR); wait_on_inode(inode); DQUOT_DROP(inode); if (inode->i_sb && inode->i_sb->s_op->clear_inode) @@ -287,6 +289,13 @@ static void dispose_list(struct list_head *head) if (inode->i_data.nrpages) truncate_inode_pages(&inode->i_data, 0); clear_inode(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++; } @@ -311,7 +320,7 @@ static int invalidate_list(struct list_head *head, struct list_head *dispose) /* * 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 + * change during umount anymore, and because iprune_mutex keeps * shrink_icache_memory() away. */ cond_resched_lock(&inode_lock); @@ -322,8 +331,6 @@ static int invalidate_list(struct list_head *head, struct list_head *dispose) inode = list_entry(tmp, struct inode, i_sb_list); invalidate_inode_buffers(inode); if (!atomic_read(&inode->i_count)) { - hlist_del_init(&inode->i_hash); - list_del(&inode->i_sb_list); list_move(&inode->i_list, dispose); inode->i_state |= I_FREEING; count++; @@ -349,13 +356,14 @@ int invalidate_inodes(struct super_block * sb) int busy; LIST_HEAD(throw_away); - down(&iprune_sem); + mutex_lock(&iprune_mutex); spin_lock(&inode_lock); + inotify_unmount_inodes(&sb->s_inodes); busy = invalidate_list(&sb->s_inodes, &throw_away); spin_unlock(&inode_lock); dispose_list(&throw_away); - up(&iprune_sem); + mutex_unlock(&iprune_mutex); return busy; } @@ -370,7 +378,7 @@ int __invalidate_device(struct block_device *bdev) if (sb) { /* * no need to lock the super, get_super holds the - * read semaphore so the filesystem cannot go away + * read mutex so the filesystem cannot go away * under us (->put_super runs with the write lock * hold). */ @@ -416,7 +424,7 @@ static void prune_icache(int nr_to_scan) int nr_scanned; unsigned long reap = 0; - down(&iprune_sem); + mutex_lock(&iprune_mutex); spin_lock(&inode_lock); for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) { struct inode *inode; @@ -444,8 +452,6 @@ static void prune_icache(int nr_to_scan) if (!can_unuse(inode)) continue; } - hlist_del_init(&inode->i_hash); - list_del_init(&inode->i_sb_list); list_move(&inode->i_list, &freeable); inode->i_state |= I_FREEING; nr_pruned++; @@ -454,7 +460,7 @@ static void prune_icache(int nr_to_scan) spin_unlock(&inode_lock); dispose_list(&freeable); - up(&iprune_sem); + mutex_unlock(&iprune_mutex); if (current_is_kswapd()) mod_page_state(kswapd_inodesteal, reap); @@ -471,7 +477,7 @@ static void prune_icache(int nr_to_scan) * This function is passed the number of inodes to scan, and it returns the * total number of remaining possibly-reclaimable inodes. */ -static int shrink_icache_memory(int nr, unsigned int gfp_mask) +static int shrink_icache_memory(int nr, gfp_t gfp_mask) { if (nr) { /* @@ -505,7 +511,7 @@ repeat: continue; if (!test(inode, data)) continue; - if (inode->i_state & (I_FREEING|I_CLEAR)) { + if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { __wait_on_freeing_inode(inode); goto repeat; } @@ -530,7 +536,7 @@ repeat: continue; if (inode->i_sb != sb) continue; - if (inode->i_state & (I_FREEING|I_CLEAR)) { + if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) { __wait_on_freeing_inode(inode); goto repeat; } @@ -732,7 +738,7 @@ EXPORT_SYMBOL(iunique); struct inode *igrab(struct inode *inode) { spin_lock(&inode_lock); - if (!(inode->i_state & I_FREEING)) + if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) __iget(inode); else /* @@ -753,6 +759,7 @@ EXPORT_SYMBOL(igrab); * @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 @@ -765,9 +772,9 @@ EXPORT_SYMBOL(igrab); * * Note, @test is called with the inode_lock held, so can't sleep. */ -static inline struct inode *ifind(struct super_block *sb, +static struct inode *ifind(struct super_block *sb, struct hlist_head *head, int (*test)(struct inode *, void *), - void *data) + void *data, const int wait) { struct inode *inode; @@ -776,7 +783,8 @@ static inline struct inode *ifind(struct super_block *sb, if (inode) { __iget(inode); spin_unlock(&inode_lock); - wait_on_inode(inode); + if (likely(wait)) + wait_on_inode(inode); return inode; } spin_unlock(&inode_lock); @@ -798,7 +806,7 @@ static inline struct inode *ifind(struct super_block *sb, * * Otherwise NULL is returned. */ -static inline struct inode *ifind_fast(struct super_block *sb, +static struct inode *ifind_fast(struct super_block *sb, struct hlist_head *head, unsigned long ino) { struct inode *inode; @@ -816,7 +824,7 @@ static inline struct inode *ifind_fast(struct super_block *sb, } /** - * ilookup5 - search for an inode in the inode cache + * 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 @@ -828,7 +836,38 @@ static inline struct inode *ifind_fast(struct super_block *sb, * identification of an inode. * * If the inode is in the cache, the inode is returned with an incremented - * reference count. + * 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. + * + * Otherwise NULL is returned. + * + * Note, @test is called with the inode_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); + + return ifind(sb, head, test, data, 0); +} + +EXPORT_SYMBOL(ilookup5_nowait); + +/** + * ilookup5 - 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. + * + * If the inode is in the cache, the inode lock is waited upon and the inode is + * returned with an incremented reference count. * * Otherwise NULL is returned. * @@ -839,7 +878,7 @@ struct inode *ilookup5(struct super_block *sb, unsigned long hashval, { struct hlist_head *head = inode_hashtable + hash(sb, hashval); - return ifind(sb, head, test, data); + return ifind(sb, head, test, data, 1); } EXPORT_SYMBOL(ilookup5); @@ -896,7 +935,7 @@ struct inode *iget5_locked(struct super_block *sb, unsigned long hashval, struct hlist_head *head = inode_hashtable + hash(sb, hashval); struct inode *inode; - inode = ifind(sb, head, test, data); + inode = ifind(sb, head, test, data, 1); if (inode) return inode; /* @@ -997,25 +1036,26 @@ void generic_delete_inode(struct inode *inode) inodes_stat.nr_inodes--; spin_unlock(&inode_lock); - if (inode->i_data.nrpages) - truncate_inode_pages(&inode->i_data, 0); - security_inode_delete(inode); if (op->delete_inode) { void (*delete)(struct inode *) = op->delete_inode; if (!is_bad_inode(inode)) DQUOT_INIT(inode); - /* s_op->delete_inode internally recalls clear_inode() */ + /* Filesystems implementing their own + * s_op->delete_inode are required to call + * truncate_inode_pages and clear_inode() + * internally */ delete(inode); - } else + } else { + truncate_inode_pages(&inode->i_data, 0); clear_inode(inode); + } spin_lock(&inode_lock); hlist_del_init(&inode->i_hash); spin_unlock(&inode_lock); wake_up_inode(inode); - if (inode->i_state != I_CLEAR) - BUG(); + BUG_ON(inode->i_state != I_CLEAR); destroy_inode(inode); } @@ -1029,22 +1069,27 @@ static void generic_forget_inode(struct inode *inode) if (!(inode->i_state & (I_DIRTY|I_LOCK))) list_move(&inode->i_list, &inode_unused); inodes_stat.nr_unused++; - spin_unlock(&inode_lock); - if (!sb || (sb->s_flags & MS_ACTIVE)) + if (!sb || (sb->s_flags & MS_ACTIVE)) { + spin_unlock(&inode_lock); return; + } + inode->i_state |= I_WILL_FREE; + spin_unlock(&inode_lock); write_inode_now(inode, 1); spin_lock(&inode_lock); + 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); - inode->i_state|=I_FREEING; + inode->i_state |= I_FREEING; inodes_stat.nr_inodes--; spin_unlock(&inode_lock); if (inode->i_data.nrpages) truncate_inode_pages(&inode->i_data, 0); clear_inode(inode); + wake_up_inode(inode); destroy_inode(inode); } @@ -1053,7 +1098,7 @@ static void generic_forget_inode(struct inode *inode) * inode when the usage count drops to zero, and * i_nlink is zero. */ -static void generic_drop_inode(struct inode *inode) +void generic_drop_inode(struct inode *inode) { if (!inode->i_nlink) generic_delete_inode(inode); @@ -1061,6 +1106,8 @@ static void generic_drop_inode(struct inode *inode) generic_forget_inode(inode); } +EXPORT_SYMBOL_GPL(generic_drop_inode); + /* * Called when we're dropping the last reference * to an inode. @@ -1130,53 +1177,65 @@ sector_t bmap(struct inode * inode, sector_t block) EXPORT_SYMBOL(bmap); /** - * update_atime - update the access time - * @inode: inode accessed + * touch_atime - update the access time + * @mnt: mount the inode is accessed on + * @dentry: dentry accessed * * Update the accessed time on an inode and mark it for writeback. * This function automatically handles read only file systems and media, * as well as the "noatime" flag and inode specific "noatime" markers. */ -void update_atime(struct inode *inode) +void touch_atime(struct vfsmount *mnt, struct dentry *dentry) { + struct inode *inode = dentry->d_inode; struct timespec now; - if (IS_NOATIME(inode)) + if (IS_RDONLY(inode)) return; - if (IS_NODIRATIME(inode) && S_ISDIR(inode->i_mode)) + + if ((inode->i_flags & S_NOATIME) || + (inode->i_sb->s_flags & MS_NOATIME) || + ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))) return; - if (IS_RDONLY(inode)) + + /* + * We may have a NULL vfsmount when coming from NFSD + */ + if (mnt && + ((mnt->mnt_flags & MNT_NOATIME) || + ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode)))) return; now = current_fs_time(inode->i_sb); if (!timespec_equal(&inode->i_atime, &now)) { inode->i_atime = now; mark_inode_dirty_sync(inode); - } else { - if (!timespec_equal(&inode->i_atime, &now)) - inode->i_atime = now; } } -EXPORT_SYMBOL(update_atime); +EXPORT_SYMBOL(touch_atime); /** - * inode_update_time - update mtime and ctime time - * @inode: inode accessed - * @ctime_too: update ctime too + * file_update_time - update mtime and ctime time + * @file: file accessed * - * Update the mtime time on an inode and mark it for writeback. - * When ctime_too is specified update the ctime too. + * Update the mtime and ctime members of an inode and mark the inode + * for writeback. Note that this function is meant exclusively for + * usage in the file write path of filesystems, and filesystems may + * choose to explicitly ignore update via this function with the + * S_NOCTIME inode flag, e.g. for network filesystem where these + * timestamps are handled by the server. */ -void inode_update_time(struct inode *inode, struct vfsmount *mnt, int ctime_too) +void file_update_time(struct file *file) { + struct inode *inode = file->f_dentry->d_inode; struct timespec now; int sync_it = 0; if (IS_NOCMTIME(inode)) return; - if (IS_RDONLY(inode) || MNT_IS_RDONLY(mnt)) + if (IS_RDONLY(inode)) return; now = current_fs_time(inode->i_sb); @@ -1184,16 +1243,15 @@ void inode_update_time(struct inode *inode, struct vfsmount *mnt, int ctime_too) sync_it = 1; inode->i_mtime = now; - if (ctime_too) { - if (!timespec_equal(&inode->i_ctime, &now)) - sync_it = 1; - inode->i_ctime = now; - } + if (!timespec_equal(&inode->i_ctime, &now)) + sync_it = 1; + inode->i_ctime = now; + if (sync_it) mark_inode_dirty_sync(inode); } -EXPORT_SYMBOL(inode_update_time); +EXPORT_SYMBOL(file_update_time); int inode_needs_sync(struct inode *inode) { @@ -1243,29 +1301,21 @@ int inode_wait(void *word) } /* - * If we try to find an inode in the inode hash while it is being deleted, we - * have to wait until the filesystem completes its deletion before reporting - * that it isn't found. This is because iget will immediately call - * ->read_inode, and we want to be sure that evidence of the deletion is found - * by ->read_inode. + * If we try to find an inode in the inode hash while it is being + * deleted, we have to wait until the filesystem completes its + * deletion before reporting that it isn't found. This function waits + * until the deletion _might_ have completed. Callers are responsible + * to recheck inode state. + * + * It doesn't matter if I_LOCK 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. */ static void __wait_on_freeing_inode(struct inode *inode) { wait_queue_head_t *wq; DEFINE_WAIT_BIT(wait, &inode->i_state, __I_LOCK); - - /* - * I_FREEING and I_CLEAR are cleared in process context under - * inode_lock, so we have to give the tasks who would clear them - * a chance to run and acquire inode_lock. - */ - if (!(inode->i_state & I_LOCK)) { - spin_unlock(&inode_lock); - yield(); - spin_lock(&inode_lock); - return; - } wq = bit_waitqueue(&inode->i_state, __I_LOCK); prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE); spin_unlock(&inode_lock); @@ -1325,8 +1375,13 @@ void __init inode_init(unsigned long mempages) int loop; /* inode slab cache */ - inode_cachep = kmem_cache_create("inode_cache", sizeof(struct inode), - 0, SLAB_RECLAIM_ACCOUNT|SLAB_PANIC, init_once, NULL); + inode_cachep = kmem_cache_create("inode_cache", + sizeof(struct inode), + 0, + (SLAB_RECLAIM_ACCOUNT|SLAB_PANIC| + SLAB_MEM_SPREAD), + init_once, + NULL); set_shrinker(DEFAULT_SEEKS, shrink_icache_memory); /* Hash may have been set up in inode_init_early */