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bdfc326614
There's no reason for iprune_mutex being global. Signed-off-by: Adrian Bunk <bunk@stusta.de> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
1423 lines
36 KiB
C
1423 lines
36 KiB
C
/*
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* linux/fs/inode.c
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*
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* (C) 1997 Linus Torvalds
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*/
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#include <linux/config.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/dcache.h>
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#include <linux/init.h>
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#include <linux/quotaops.h>
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#include <linux/slab.h>
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#include <linux/writeback.h>
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#include <linux/module.h>
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#include <linux/backing-dev.h>
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#include <linux/wait.h>
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#include <linux/hash.h>
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#include <linux/swap.h>
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#include <linux/security.h>
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#include <linux/pagemap.h>
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#include <linux/cdev.h>
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#include <linux/bootmem.h>
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#include <linux/inotify.h>
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#include <linux/mount.h>
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/*
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* This is needed for the following functions:
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* - inode_has_buffers
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* - invalidate_inode_buffers
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* - invalidate_bdev
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*
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* FIXME: remove all knowledge of the buffer layer from this file
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*/
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#include <linux/buffer_head.h>
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/*
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* New inode.c implementation.
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*
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* This implementation has the basic premise of trying
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* to be extremely low-overhead and SMP-safe, yet be
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* simple enough to be "obviously correct".
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*
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* Famous last words.
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*/
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/* inode dynamic allocation 1999, Andrea Arcangeli <andrea@suse.de> */
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/* #define INODE_PARANOIA 1 */
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/* #define INODE_DEBUG 1 */
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/*
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* Inode lookup is no longer as critical as it used to be:
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* most of the lookups are going to be through the dcache.
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*/
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#define I_HASHBITS i_hash_shift
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#define I_HASHMASK i_hash_mask
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static unsigned int i_hash_mask;
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static unsigned int i_hash_shift;
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/*
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* Each inode can be on two separate lists. One is
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* the hash list of the inode, used for lookups. The
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* other linked list is the "type" list:
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* "in_use" - valid inode, i_count > 0, i_nlink > 0
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* "dirty" - as "in_use" but also dirty
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* "unused" - valid inode, i_count = 0
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*
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* A "dirty" list is maintained for each super block,
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* allowing for low-overhead inode sync() operations.
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*/
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LIST_HEAD(inode_in_use);
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LIST_HEAD(inode_unused);
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static struct hlist_head *inode_hashtable;
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/*
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* A simple spinlock to protect the list manipulations.
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*
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* NOTE! You also have to own the lock if you change
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* the i_state of an inode while it is in use..
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*/
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DEFINE_SPINLOCK(inode_lock);
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/*
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* iprune_mutex provides exclusion between the kswapd or try_to_free_pages
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* icache shrinking path, and the umount path. Without this exclusion,
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* by the time prune_icache calls iput for the inode whose pages it has
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* been invalidating, or by the time it calls clear_inode & destroy_inode
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* from its final dispose_list, the struct super_block they refer to
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* (for inode->i_sb->s_op) may already have been freed and reused.
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*/
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static DEFINE_MUTEX(iprune_mutex);
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/*
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* Statistics gathering..
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*/
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struct inodes_stat_t inodes_stat;
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static kmem_cache_t * inode_cachep;
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static struct inode *alloc_inode(struct super_block *sb)
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{
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static struct address_space_operations empty_aops;
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static struct inode_operations empty_iops;
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static struct file_operations empty_fops;
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struct inode *inode;
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if (sb->s_op->alloc_inode)
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inode = sb->s_op->alloc_inode(sb);
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else
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inode = (struct inode *) kmem_cache_alloc(inode_cachep, SLAB_KERNEL);
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if (inode) {
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struct address_space * const mapping = &inode->i_data;
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inode->i_sb = sb;
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inode->i_blkbits = sb->s_blocksize_bits;
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inode->i_flags = 0;
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atomic_set(&inode->i_count, 1);
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inode->i_op = &empty_iops;
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inode->i_fop = &empty_fops;
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inode->i_nlink = 1;
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atomic_set(&inode->i_writecount, 0);
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inode->i_size = 0;
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inode->i_blocks = 0;
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inode->i_bytes = 0;
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inode->i_generation = 0;
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#ifdef CONFIG_QUOTA
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memset(&inode->i_dquot, 0, sizeof(inode->i_dquot));
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#endif
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inode->i_pipe = NULL;
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inode->i_bdev = NULL;
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inode->i_cdev = NULL;
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inode->i_rdev = 0;
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inode->i_security = NULL;
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inode->dirtied_when = 0;
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if (security_inode_alloc(inode)) {
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if (inode->i_sb->s_op->destroy_inode)
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inode->i_sb->s_op->destroy_inode(inode);
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else
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kmem_cache_free(inode_cachep, (inode));
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return NULL;
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}
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mapping->a_ops = &empty_aops;
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mapping->host = inode;
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mapping->flags = 0;
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mapping_set_gfp_mask(mapping, GFP_HIGHUSER);
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mapping->assoc_mapping = NULL;
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mapping->backing_dev_info = &default_backing_dev_info;
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/*
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* If the block_device provides a backing_dev_info for client
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* inodes then use that. Otherwise the inode share the bdev's
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* backing_dev_info.
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*/
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if (sb->s_bdev) {
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struct backing_dev_info *bdi;
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bdi = sb->s_bdev->bd_inode_backing_dev_info;
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if (!bdi)
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bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
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mapping->backing_dev_info = bdi;
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}
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memset(&inode->u, 0, sizeof(inode->u));
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inode->i_mapping = mapping;
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}
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return inode;
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}
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void destroy_inode(struct inode *inode)
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{
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if (inode_has_buffers(inode))
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BUG();
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security_inode_free(inode);
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if (inode->i_sb->s_op->destroy_inode)
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inode->i_sb->s_op->destroy_inode(inode);
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else
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kmem_cache_free(inode_cachep, (inode));
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}
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/*
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* These are initializations that only need to be done
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* once, because the fields are idempotent across use
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* of the inode, so let the slab aware of that.
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*/
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void inode_init_once(struct inode *inode)
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{
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memset(inode, 0, sizeof(*inode));
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INIT_HLIST_NODE(&inode->i_hash);
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INIT_LIST_HEAD(&inode->i_dentry);
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INIT_LIST_HEAD(&inode->i_devices);
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mutex_init(&inode->i_mutex);
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init_rwsem(&inode->i_alloc_sem);
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INIT_RADIX_TREE(&inode->i_data.page_tree, GFP_ATOMIC);
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rwlock_init(&inode->i_data.tree_lock);
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spin_lock_init(&inode->i_data.i_mmap_lock);
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INIT_LIST_HEAD(&inode->i_data.private_list);
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spin_lock_init(&inode->i_data.private_lock);
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INIT_RAW_PRIO_TREE_ROOT(&inode->i_data.i_mmap);
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INIT_LIST_HEAD(&inode->i_data.i_mmap_nonlinear);
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spin_lock_init(&inode->i_lock);
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i_size_ordered_init(inode);
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#ifdef CONFIG_INOTIFY
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INIT_LIST_HEAD(&inode->inotify_watches);
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mutex_init(&inode->inotify_mutex);
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#endif
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}
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EXPORT_SYMBOL(inode_init_once);
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static void init_once(void * foo, kmem_cache_t * cachep, unsigned long flags)
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{
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struct inode * inode = (struct inode *) foo;
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if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
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SLAB_CTOR_CONSTRUCTOR)
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inode_init_once(inode);
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}
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/*
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* inode_lock must be held
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*/
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void __iget(struct inode * inode)
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{
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if (atomic_read(&inode->i_count)) {
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atomic_inc(&inode->i_count);
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return;
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}
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atomic_inc(&inode->i_count);
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if (!(inode->i_state & (I_DIRTY|I_LOCK)))
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list_move(&inode->i_list, &inode_in_use);
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inodes_stat.nr_unused--;
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}
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/**
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* clear_inode - clear an inode
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* @inode: inode to clear
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*
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* This is called by the filesystem to tell us
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* that the inode is no longer useful. We just
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* terminate it with extreme prejudice.
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*/
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void clear_inode(struct inode *inode)
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{
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might_sleep();
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invalidate_inode_buffers(inode);
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if (inode->i_data.nrpages)
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BUG();
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if (!(inode->i_state & I_FREEING))
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BUG();
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if (inode->i_state & I_CLEAR)
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BUG();
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wait_on_inode(inode);
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DQUOT_DROP(inode);
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if (inode->i_sb && inode->i_sb->s_op->clear_inode)
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inode->i_sb->s_op->clear_inode(inode);
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if (inode->i_bdev)
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bd_forget(inode);
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if (inode->i_cdev)
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cd_forget(inode);
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inode->i_state = I_CLEAR;
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}
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EXPORT_SYMBOL(clear_inode);
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/*
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* dispose_list - dispose of the contents of a local list
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* @head: the head of the list to free
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*
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* Dispose-list gets a local list with local inodes in it, so it doesn't
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* need to worry about list corruption and SMP locks.
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*/
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static void dispose_list(struct list_head *head)
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{
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int nr_disposed = 0;
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while (!list_empty(head)) {
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struct inode *inode;
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inode = list_entry(head->next, struct inode, i_list);
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list_del(&inode->i_list);
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if (inode->i_data.nrpages)
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truncate_inode_pages(&inode->i_data, 0);
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clear_inode(inode);
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spin_lock(&inode_lock);
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hlist_del_init(&inode->i_hash);
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list_del_init(&inode->i_sb_list);
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spin_unlock(&inode_lock);
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wake_up_inode(inode);
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destroy_inode(inode);
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nr_disposed++;
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}
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spin_lock(&inode_lock);
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inodes_stat.nr_inodes -= nr_disposed;
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spin_unlock(&inode_lock);
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}
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/*
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* Invalidate all inodes for a device.
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*/
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static int invalidate_list(struct list_head *head, struct list_head *dispose)
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{
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struct list_head *next;
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int busy = 0, count = 0;
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next = head->next;
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for (;;) {
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struct list_head * tmp = next;
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struct inode * inode;
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/*
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* We can reschedule here without worrying about the list's
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* consistency because the per-sb list of inodes must not
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* change during umount anymore, and because iprune_mutex keeps
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* shrink_icache_memory() away.
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*/
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cond_resched_lock(&inode_lock);
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next = next->next;
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if (tmp == head)
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break;
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inode = list_entry(tmp, struct inode, i_sb_list);
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invalidate_inode_buffers(inode);
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if (!atomic_read(&inode->i_count)) {
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list_move(&inode->i_list, dispose);
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inode->i_state |= I_FREEING;
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count++;
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continue;
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}
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busy = 1;
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}
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/* only unused inodes may be cached with i_count zero */
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inodes_stat.nr_unused -= count;
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return busy;
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}
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/**
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* invalidate_inodes - discard the inodes on a device
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* @sb: superblock
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*
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* Discard all of the inodes for a given superblock. If the discard
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* fails because there are busy inodes then a non zero value is returned.
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* If the discard is successful all the inodes have been discarded.
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*/
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int invalidate_inodes(struct super_block * sb)
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{
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int busy;
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LIST_HEAD(throw_away);
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mutex_lock(&iprune_mutex);
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spin_lock(&inode_lock);
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inotify_unmount_inodes(&sb->s_inodes);
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busy = invalidate_list(&sb->s_inodes, &throw_away);
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spin_unlock(&inode_lock);
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dispose_list(&throw_away);
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mutex_unlock(&iprune_mutex);
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return busy;
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}
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EXPORT_SYMBOL(invalidate_inodes);
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int __invalidate_device(struct block_device *bdev)
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{
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struct super_block *sb = get_super(bdev);
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int res = 0;
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if (sb) {
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/*
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* no need to lock the super, get_super holds the
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* read mutex so the filesystem cannot go away
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* under us (->put_super runs with the write lock
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* hold).
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*/
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shrink_dcache_sb(sb);
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res = invalidate_inodes(sb);
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drop_super(sb);
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}
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invalidate_bdev(bdev, 0);
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return res;
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}
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EXPORT_SYMBOL(__invalidate_device);
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static int can_unuse(struct inode *inode)
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{
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if (inode->i_state)
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return 0;
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if (inode_has_buffers(inode))
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return 0;
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if (atomic_read(&inode->i_count))
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return 0;
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if (inode->i_data.nrpages)
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return 0;
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return 1;
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}
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/*
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* Scan `goal' inodes on the unused list for freeable ones. They are moved to
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* a temporary list and then are freed outside inode_lock by dispose_list().
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*
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* Any inodes which are pinned purely because of attached pagecache have their
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* pagecache removed. We expect the final iput() on that inode to add it to
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* the front of the inode_unused list. So look for it there and if the
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* inode is still freeable, proceed. The right inode is found 99.9% of the
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* time in testing on a 4-way.
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*
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* If the inode has metadata buffers attached to mapping->private_list then
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* try to remove them.
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*/
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static void prune_icache(int nr_to_scan)
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{
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LIST_HEAD(freeable);
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int nr_pruned = 0;
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int nr_scanned;
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unsigned long reap = 0;
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mutex_lock(&iprune_mutex);
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spin_lock(&inode_lock);
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for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) {
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struct inode *inode;
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if (list_empty(&inode_unused))
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break;
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inode = list_entry(inode_unused.prev, struct inode, i_list);
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if (inode->i_state || atomic_read(&inode->i_count)) {
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list_move(&inode->i_list, &inode_unused);
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continue;
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}
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if (inode_has_buffers(inode) || inode->i_data.nrpages) {
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__iget(inode);
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spin_unlock(&inode_lock);
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if (remove_inode_buffers(inode))
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reap += invalidate_inode_pages(&inode->i_data);
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iput(inode);
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spin_lock(&inode_lock);
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if (inode != list_entry(inode_unused.next,
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struct inode, i_list))
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continue; /* wrong inode or list_empty */
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if (!can_unuse(inode))
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continue;
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}
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list_move(&inode->i_list, &freeable);
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inode->i_state |= I_FREEING;
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nr_pruned++;
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}
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inodes_stat.nr_unused -= nr_pruned;
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spin_unlock(&inode_lock);
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dispose_list(&freeable);
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mutex_unlock(&iprune_mutex);
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if (current_is_kswapd())
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mod_page_state(kswapd_inodesteal, reap);
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else
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mod_page_state(pginodesteal, reap);
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}
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/*
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* shrink_icache_memory() will attempt to reclaim some unused inodes. Here,
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* "unused" means that no dentries are referring to the inodes: the files are
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* not open and the dcache references to those inodes have already been
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* reclaimed.
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*
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* This function is passed the number of inodes to scan, and it returns the
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* total number of remaining possibly-reclaimable inodes.
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*/
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static int shrink_icache_memory(int nr, gfp_t gfp_mask)
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{
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if (nr) {
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/*
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* Nasty deadlock avoidance. We may hold various FS locks,
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* and we don't want to recurse into the FS that called us
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* in clear_inode() and friends..
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*/
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if (!(gfp_mask & __GFP_FS))
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return -1;
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prune_icache(nr);
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}
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return (inodes_stat.nr_unused / 100) * sysctl_vfs_cache_pressure;
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}
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|
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static void __wait_on_freeing_inode(struct inode *inode);
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/*
|
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* Called with the inode lock held.
|
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* NOTE: we are not increasing the inode-refcount, you must call __iget()
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* by hand after calling find_inode now! This simplifies iunique and won't
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* add any additional branch in the common code.
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*/
|
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static struct inode * find_inode(struct super_block * sb, struct hlist_head *head, int (*test)(struct inode *, void *), void *data)
|
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{
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struct hlist_node *node;
|
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struct inode * inode = NULL;
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|
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repeat:
|
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hlist_for_each (node, head) {
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inode = hlist_entry(node, struct inode, i_hash);
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if (inode->i_sb != sb)
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continue;
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if (!test(inode, data))
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continue;
|
|
if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
|
|
__wait_on_freeing_inode(inode);
|
|
goto repeat;
|
|
}
|
|
break;
|
|
}
|
|
return node ? inode : NULL;
|
|
}
|
|
|
|
/*
|
|
* find_inode_fast is the fast path version of find_inode, see the comment at
|
|
* iget_locked for details.
|
|
*/
|
|
static struct inode * find_inode_fast(struct super_block * sb, struct hlist_head *head, unsigned long ino)
|
|
{
|
|
struct hlist_node *node;
|
|
struct inode * inode = NULL;
|
|
|
|
repeat:
|
|
hlist_for_each (node, head) {
|
|
inode = hlist_entry(node, struct inode, i_hash);
|
|
if (inode->i_ino != ino)
|
|
continue;
|
|
if (inode->i_sb != sb)
|
|
continue;
|
|
if (inode->i_state & (I_FREEING|I_CLEAR|I_WILL_FREE)) {
|
|
__wait_on_freeing_inode(inode);
|
|
goto repeat;
|
|
}
|
|
break;
|
|
}
|
|
return node ? inode : NULL;
|
|
}
|
|
|
|
/**
|
|
* new_inode - obtain an inode
|
|
* @sb: superblock
|
|
*
|
|
* Allocates a new inode for given superblock.
|
|
*/
|
|
struct inode *new_inode(struct super_block *sb)
|
|
{
|
|
static unsigned long last_ino;
|
|
struct inode * inode;
|
|
|
|
spin_lock_prefetch(&inode_lock);
|
|
|
|
inode = alloc_inode(sb);
|
|
if (inode) {
|
|
spin_lock(&inode_lock);
|
|
inodes_stat.nr_inodes++;
|
|
list_add(&inode->i_list, &inode_in_use);
|
|
list_add(&inode->i_sb_list, &sb->s_inodes);
|
|
inode->i_ino = ++last_ino;
|
|
inode->i_state = 0;
|
|
spin_unlock(&inode_lock);
|
|
}
|
|
return inode;
|
|
}
|
|
|
|
EXPORT_SYMBOL(new_inode);
|
|
|
|
void unlock_new_inode(struct inode *inode)
|
|
{
|
|
/*
|
|
* This is special! We do not need the spinlock
|
|
* when clearing I_LOCK, 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_LOCK).
|
|
*/
|
|
inode->i_state &= ~(I_LOCK|I_NEW);
|
|
wake_up_inode(inode);
|
|
}
|
|
|
|
EXPORT_SYMBOL(unlock_new_inode);
|
|
|
|
/*
|
|
* This is called without the inode lock held.. Be careful.
|
|
*
|
|
* We no longer cache the sb_flags in i_flags - see fs.h
|
|
* -- rmk@arm.uk.linux.org
|
|
*/
|
|
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 * inode;
|
|
|
|
inode = alloc_inode(sb);
|
|
if (inode) {
|
|
struct inode * old;
|
|
|
|
spin_lock(&inode_lock);
|
|
/* We released the lock, so.. */
|
|
old = find_inode(sb, head, test, data);
|
|
if (!old) {
|
|
if (set(inode, data))
|
|
goto set_failed;
|
|
|
|
inodes_stat.nr_inodes++;
|
|
list_add(&inode->i_list, &inode_in_use);
|
|
list_add(&inode->i_sb_list, &sb->s_inodes);
|
|
hlist_add_head(&inode->i_hash, head);
|
|
inode->i_state = I_LOCK|I_NEW;
|
|
spin_unlock(&inode_lock);
|
|
|
|
/* Return the locked inode with I_NEW set, the
|
|
* caller is responsible for filling in the contents
|
|
*/
|
|
return inode;
|
|
}
|
|
|
|
/*
|
|
* Uhhuh, somebody else created the same inode under
|
|
* us. Use the old inode instead of the one we just
|
|
* allocated.
|
|
*/
|
|
__iget(old);
|
|
spin_unlock(&inode_lock);
|
|
destroy_inode(inode);
|
|
inode = old;
|
|
wait_on_inode(inode);
|
|
}
|
|
return inode;
|
|
|
|
set_failed:
|
|
spin_unlock(&inode_lock);
|
|
destroy_inode(inode);
|
|
return NULL;
|
|
}
|
|
|
|
/*
|
|
* get_new_inode_fast is the fast path version of get_new_inode, see the
|
|
* comment at iget_locked for details.
|
|
*/
|
|
static struct inode * get_new_inode_fast(struct super_block *sb, struct hlist_head *head, unsigned long ino)
|
|
{
|
|
struct inode * inode;
|
|
|
|
inode = alloc_inode(sb);
|
|
if (inode) {
|
|
struct inode * old;
|
|
|
|
spin_lock(&inode_lock);
|
|
/* We released the lock, so.. */
|
|
old = find_inode_fast(sb, head, ino);
|
|
if (!old) {
|
|
inode->i_ino = ino;
|
|
inodes_stat.nr_inodes++;
|
|
list_add(&inode->i_list, &inode_in_use);
|
|
list_add(&inode->i_sb_list, &sb->s_inodes);
|
|
hlist_add_head(&inode->i_hash, head);
|
|
inode->i_state = I_LOCK|I_NEW;
|
|
spin_unlock(&inode_lock);
|
|
|
|
/* Return the locked inode with I_NEW set, the
|
|
* caller is responsible for filling in the contents
|
|
*/
|
|
return inode;
|
|
}
|
|
|
|
/*
|
|
* Uhhuh, somebody else created the same inode under
|
|
* us. Use the old inode instead of the one we just
|
|
* allocated.
|
|
*/
|
|
__iget(old);
|
|
spin_unlock(&inode_lock);
|
|
destroy_inode(inode);
|
|
inode = old;
|
|
wait_on_inode(inode);
|
|
}
|
|
return inode;
|
|
}
|
|
|
|
static inline 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;
|
|
}
|
|
|
|
/**
|
|
* iunique - get a unique inode number
|
|
* @sb: superblock
|
|
* @max_reserved: highest reserved inode number
|
|
*
|
|
* Obtain an inode number that is unique on the system for a given
|
|
* superblock. This is used by file systems that have no natural
|
|
* permanent inode numbering system. An inode number is returned that
|
|
* is higher than the reserved limit but unique.
|
|
*
|
|
* BUGS:
|
|
* With a large number of inodes live on the file system this function
|
|
* currently becomes quite slow.
|
|
*/
|
|
ino_t iunique(struct super_block *sb, ino_t max_reserved)
|
|
{
|
|
static ino_t counter;
|
|
struct inode *inode;
|
|
struct hlist_head * head;
|
|
ino_t res;
|
|
spin_lock(&inode_lock);
|
|
retry:
|
|
if (counter > max_reserved) {
|
|
head = inode_hashtable + hash(sb,counter);
|
|
res = counter++;
|
|
inode = find_inode_fast(sb, head, res);
|
|
if (!inode) {
|
|
spin_unlock(&inode_lock);
|
|
return res;
|
|
}
|
|
} else {
|
|
counter = max_reserved + 1;
|
|
}
|
|
goto retry;
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL(iunique);
|
|
|
|
struct inode *igrab(struct inode *inode)
|
|
{
|
|
spin_lock(&inode_lock);
|
|
if (!(inode->i_state & (I_FREEING|I_WILL_FREE)))
|
|
__iget(inode);
|
|
else
|
|
/*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*
|
|
* 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.
|
|
*
|
|
* Note, @test is called with the inode_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);
|
|
|
|
return ifind(sb, head, test, data, 1);
|
|
}
|
|
|
|
EXPORT_SYMBOL(ilookup5);
|
|
|
|
/**
|
|
* ilookup - search for an inode in the inode cache
|
|
* @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.
|
|
*/
|
|
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
|
|
*
|
|
* This is iget() without the read_inode() portion of get_new_inode().
|
|
*
|
|
* 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
|
|
*
|
|
* This is iget() without the read_inode() portion of get_new_inode_fast().
|
|
*
|
|
* 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;
|
|
|
|
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);
|
|
}
|
|
|
|
EXPORT_SYMBOL(iget_locked);
|
|
|
|
/**
|
|
* __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);
|
|
|
|
/*
|
|
* Tell the filesystem that this inode is no longer of any interest and should
|
|
* be completely destroyed.
|
|
*
|
|
* We leave the inode in the inode hash table until *after* the filesystem's
|
|
* ->delete_inode completes. This ensures that an iget (such as nfsd might
|
|
* instigate) will always find up-to-date information either in the hash or on
|
|
* disk.
|
|
*
|
|
* I_FREEING is set so that no-one will take a new reference to the inode while
|
|
* it is being deleted.
|
|
*/
|
|
void generic_delete_inode(struct inode *inode)
|
|
{
|
|
struct super_operations *op = inode->i_sb->s_op;
|
|
|
|
list_del_init(&inode->i_list);
|
|
list_del_init(&inode->i_sb_list);
|
|
inode->i_state|=I_FREEING;
|
|
inodes_stat.nr_inodes--;
|
|
spin_unlock(&inode_lock);
|
|
|
|
security_inode_delete(inode);
|
|
|
|
if (op->delete_inode) {
|
|
void (*delete)(struct inode *) = op->delete_inode;
|
|
if (!is_bad_inode(inode))
|
|
DQUOT_INIT(inode);
|
|
/* Filesystems implementing their own
|
|
* s_op->delete_inode are required to call
|
|
* truncate_inode_pages and clear_inode()
|
|
* internally */
|
|
delete(inode);
|
|
} 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();
|
|
destroy_inode(inode);
|
|
}
|
|
|
|
EXPORT_SYMBOL(generic_delete_inode);
|
|
|
|
static void generic_forget_inode(struct inode *inode)
|
|
{
|
|
struct super_block *sb = inode->i_sb;
|
|
|
|
if (!hlist_unhashed(&inode->i_hash)) {
|
|
if (!(inode->i_state & (I_DIRTY|I_LOCK)))
|
|
list_move(&inode->i_list, &inode_unused);
|
|
inodes_stat.nr_unused++;
|
|
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;
|
|
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);
|
|
}
|
|
|
|
/*
|
|
* Normal UNIX filesystem behaviour: delete the
|
|
* inode when the usage count drops to zero, and
|
|
* i_nlink is zero.
|
|
*/
|
|
void generic_drop_inode(struct inode *inode)
|
|
{
|
|
if (!inode->i_nlink)
|
|
generic_delete_inode(inode);
|
|
else
|
|
generic_forget_inode(inode);
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(generic_drop_inode);
|
|
|
|
/*
|
|
* Called when we're dropping the last reference
|
|
* to an inode.
|
|
*
|
|
* Call the FS "drop()" function, defaulting to
|
|
* the legacy UNIX filesystem behaviour..
|
|
*
|
|
* NOTE! NOTE! NOTE! We're called with the inode lock
|
|
* held, and the drop function is supposed to release
|
|
* the lock!
|
|
*/
|
|
static inline void iput_final(struct inode *inode)
|
|
{
|
|
struct super_operations *op = inode->i_sb->s_op;
|
|
void (*drop)(struct inode *) = generic_drop_inode;
|
|
|
|
if (op && op->drop_inode)
|
|
drop = op->drop_inode;
|
|
drop(inode);
|
|
}
|
|
|
|
/**
|
|
* iput - put an inode
|
|
* @inode: inode to put
|
|
*
|
|
* Puts an inode, dropping its usage count. If the inode use count hits
|
|
* zero, the inode is then freed and may also be destroyed.
|
|
*
|
|
* Consequently, iput() can sleep.
|
|
*/
|
|
void iput(struct inode *inode)
|
|
{
|
|
if (inode) {
|
|
struct super_operations *op = inode->i_sb->s_op;
|
|
|
|
BUG_ON(inode->i_state == I_CLEAR);
|
|
|
|
if (op && op->put_inode)
|
|
op->put_inode(inode);
|
|
|
|
if (atomic_dec_and_lock(&inode->i_count, &inode_lock))
|
|
iput_final(inode);
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL(iput);
|
|
|
|
/**
|
|
* bmap - find a block number in a file
|
|
* @inode: inode of file
|
|
* @block: block to find
|
|
*
|
|
* Returns the block number on the device holding the inode that
|
|
* is the disk block number for the block of the file requested.
|
|
* That is, asked for block 4 of inode 1 the function will return the
|
|
* disk block relative to the disk start that holds that block of the
|
|
* file.
|
|
*/
|
|
sector_t bmap(struct inode * inode, sector_t block)
|
|
{
|
|
sector_t res = 0;
|
|
if (inode->i_mapping->a_ops->bmap)
|
|
res = inode->i_mapping->a_ops->bmap(inode->i_mapping, block);
|
|
return res;
|
|
}
|
|
|
|
EXPORT_SYMBOL(bmap);
|
|
|
|
/**
|
|
* 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 touch_atime(struct vfsmount *mnt, struct dentry *dentry)
|
|
{
|
|
struct inode *inode = dentry->d_inode;
|
|
struct timespec now;
|
|
|
|
if (IS_RDONLY(inode))
|
|
return;
|
|
|
|
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;
|
|
|
|
/*
|
|
* 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);
|
|
}
|
|
}
|
|
|
|
EXPORT_SYMBOL(touch_atime);
|
|
|
|
/**
|
|
* file_update_time - update mtime and ctime time
|
|
* @file: file accessed
|
|
*
|
|
* 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 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))
|
|
return;
|
|
|
|
now = current_fs_time(inode->i_sb);
|
|
if (!timespec_equal(&inode->i_mtime, &now))
|
|
sync_it = 1;
|
|
inode->i_mtime = 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(file_update_time);
|
|
|
|
int inode_needs_sync(struct inode *inode)
|
|
{
|
|
if (IS_SYNC(inode))
|
|
return 1;
|
|
if (S_ISDIR(inode->i_mode) && IS_DIRSYNC(inode))
|
|
return 1;
|
|
return 0;
|
|
}
|
|
|
|
EXPORT_SYMBOL(inode_needs_sync);
|
|
|
|
/*
|
|
* Quota functions that want to walk the inode lists..
|
|
*/
|
|
#ifdef CONFIG_QUOTA
|
|
|
|
/* Function back in dquot.c */
|
|
int remove_inode_dquot_ref(struct inode *, int, struct list_head *);
|
|
|
|
void remove_dquot_ref(struct super_block *sb, int type,
|
|
struct list_head *tofree_head)
|
|
{
|
|
struct inode *inode;
|
|
|
|
if (!sb->dq_op)
|
|
return; /* nothing to do */
|
|
spin_lock(&inode_lock); /* This lock is for inodes code */
|
|
|
|
/*
|
|
* We don't have to lock against quota code - test IS_QUOTAINIT is
|
|
* just for speedup...
|
|
*/
|
|
list_for_each_entry(inode, &sb->s_inodes, i_sb_list)
|
|
if (!IS_NOQUOTA(inode))
|
|
remove_inode_dquot_ref(inode, type, tofree_head);
|
|
|
|
spin_unlock(&inode_lock);
|
|
}
|
|
|
|
#endif
|
|
|
|
int inode_wait(void *word)
|
|
{
|
|
schedule();
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* 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);
|
|
wq = bit_waitqueue(&inode->i_state, __I_LOCK);
|
|
prepare_to_wait(wq, &wait.wait, TASK_UNINTERRUPTIBLE);
|
|
spin_unlock(&inode_lock);
|
|
schedule();
|
|
finish_wait(wq, &wait.wait);
|
|
spin_lock(&inode_lock);
|
|
}
|
|
|
|
void wake_up_inode(struct inode *inode)
|
|
{
|
|
/*
|
|
* Prevent speculative execution through spin_unlock(&inode_lock);
|
|
*/
|
|
smp_mb();
|
|
wake_up_bit(&inode->i_state, __I_LOCK);
|
|
}
|
|
|
|
static __initdata unsigned long ihash_entries;
|
|
static int __init set_ihash_entries(char *str)
|
|
{
|
|
if (!str)
|
|
return 0;
|
|
ihash_entries = simple_strtoul(str, &str, 0);
|
|
return 1;
|
|
}
|
|
__setup("ihash_entries=", set_ihash_entries);
|
|
|
|
/*
|
|
* Initialize the waitqueues and inode hash table.
|
|
*/
|
|
void __init inode_init_early(void)
|
|
{
|
|
int loop;
|
|
|
|
/* If hashes are distributed across NUMA nodes, defer
|
|
* hash allocation until vmalloc space is available.
|
|
*/
|
|
if (hashdist)
|
|
return;
|
|
|
|
inode_hashtable =
|
|
alloc_large_system_hash("Inode-cache",
|
|
sizeof(struct hlist_head),
|
|
ihash_entries,
|
|
14,
|
|
HASH_EARLY,
|
|
&i_hash_shift,
|
|
&i_hash_mask,
|
|
0);
|
|
|
|
for (loop = 0; loop < (1 << i_hash_shift); loop++)
|
|
INIT_HLIST_HEAD(&inode_hashtable[loop]);
|
|
}
|
|
|
|
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|
|
|
SLAB_MEM_SPREAD),
|
|
init_once,
|
|
NULL);
|
|
set_shrinker(DEFAULT_SEEKS, shrink_icache_memory);
|
|
|
|
/* Hash may have been set up in inode_init_early */
|
|
if (!hashdist)
|
|
return;
|
|
|
|
inode_hashtable =
|
|
alloc_large_system_hash("Inode-cache",
|
|
sizeof(struct hlist_head),
|
|
ihash_entries,
|
|
14,
|
|
0,
|
|
&i_hash_shift,
|
|
&i_hash_mask,
|
|
0);
|
|
|
|
for (loop = 0; loop < (1 << i_hash_shift); loop++)
|
|
INIT_HLIST_HEAD(&inode_hashtable[loop]);
|
|
}
|
|
|
|
void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev)
|
|
{
|
|
inode->i_mode = mode;
|
|
if (S_ISCHR(mode)) {
|
|
inode->i_fop = &def_chr_fops;
|
|
inode->i_rdev = rdev;
|
|
} else if (S_ISBLK(mode)) {
|
|
inode->i_fop = &def_blk_fops;
|
|
inode->i_rdev = rdev;
|
|
} else if (S_ISFIFO(mode))
|
|
inode->i_fop = &def_fifo_fops;
|
|
else if (S_ISSOCK(mode))
|
|
inode->i_fop = &bad_sock_fops;
|
|
else
|
|
printk(KERN_DEBUG "init_special_inode: bogus i_mode (%o)\n",
|
|
mode);
|
|
}
|
|
EXPORT_SYMBOL(init_special_inode);
|