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-rw-r--r--ANDROID_3.4.5/fs/inode.c1743
1 files changed, 0 insertions, 1743 deletions
diff --git a/ANDROID_3.4.5/fs/inode.c b/ANDROID_3.4.5/fs/inode.c
deleted file mode 100644
index 9f4f5fec..00000000
--- a/ANDROID_3.4.5/fs/inode.c
+++ /dev/null
@@ -1,1743 +0,0 @@
-/*
- * (C) 1997 Linus Torvalds
- * (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation)
- */
-#include <linux/export.h>
-#include <linux/fs.h>
-#include <linux/mm.h>
-#include <linux/backing-dev.h>
-#include <linux/hash.h>
-#include <linux/swap.h>
-#include <linux/security.h>
-#include <linux/cdev.h>
-#include <linux/bootmem.h>
-#include <linux/fsnotify.h>
-#include <linux/mount.h>
-#include <linux/posix_acl.h>
-#include <linux/prefetch.h>
-#include <linux/buffer_head.h> /* for inode_has_buffers */
-#include <linux/ratelimit.h>
-#include "internal.h"
-
-/*
- * Inode locking rules:
- *
- * inode->i_lock protects:
- * inode->i_state, inode->i_hash, __iget()
- * inode->i_sb->s_inode_lru_lock protects:
- * inode->i_sb->s_inode_lru, inode->i_lru
- * inode_sb_list_lock protects:
- * sb->s_inodes, inode->i_sb_list
- * bdi->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->i_sb->s_inode_lru_lock
- *
- * bdi->wb.list_lock
- * inode->i_lock
- *
- * inode_hash_lock
- * inode_sb_list_lock
- * inode->i_lock
- *
- * iunique_lock
- * inode_hash_lock
- */
-
-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);
-
-__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
-
-/*
- * Empty aops. Can be used for the cases where the user does not
- * define any of the address_space operations.
- */
-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 DEFINE_PER_CPU(unsigned int, nr_unused);
-
-static struct kmem_cache *inode_cachep __read_mostly;
-
-static int get_nr_inodes(void)
-{
- 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)
-{
- int i;
- int sum = 0;
- for_each_possible_cpu(i)
- sum += per_cpu(nr_unused, i);
- return sum < 0 ? 0 : sum;
-}
-
-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();
- inodes_stat.nr_unused = get_nr_inodes_unused();
- return proc_dointvec(table, write, buffer, lenp, ppos);
-}
-#endif
-
-/**
- * inode_init_always - perform inode structure intialisation
- * @sb: superblock inode belongs to
- * @inode: inode to initialise
- *
- * These are initializations that need to be done on every inode
- * allocation as the fields are not initialised by slab allocation.
- */
-int inode_init_always(struct super_block *sb, struct inode *inode)
-{
- static const struct inode_operations empty_iops;
- static const struct file_operations empty_fops;
- struct address_space *const mapping = &inode->i_data;
-
- inode->i_sb = sb;
- inode->i_blkbits = sb->s_blocksize_bits;
- inode->i_flags = 0;
- atomic_set(&inode->i_count, 1);
- inode->i_op = &empty_iops;
- inode->i_fop = &empty_fops;
- inode->__i_nlink = 1;
- inode->i_opflags = 0;
- inode->i_uid = 0;
- inode->i_gid = 0;
- atomic_set(&inode->i_writecount, 0);
- inode->i_size = 0;
- inode->i_blocks = 0;
- inode->i_bytes = 0;
- inode->i_generation = 0;
-#ifdef CONFIG_QUOTA
- memset(&inode->i_dquot, 0, sizeof(inode->i_dquot));
-#endif
- inode->i_pipe = NULL;
- inode->i_bdev = NULL;
- inode->i_cdev = NULL;
- inode->i_rdev = 0;
- inode->dirtied_when = 0;
-
- if (security_inode_alloc(inode))
- goto out;
- spin_lock_init(&inode->i_lock);
- lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key);
-
- mutex_init(&inode->i_mutex);
- lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key);
-
- atomic_set(&inode->i_dio_count, 0);
-
- mapping->a_ops = &empty_aops;
- mapping->host = inode;
- mapping->flags = 0;
- mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE);
- mapping->assoc_mapping = NULL;
- mapping->backing_dev_info = &default_backing_dev_info;
- mapping->writeback_index = 0;
-
- /*
- * If the block_device provides a backing_dev_info for client
- * inodes then use that. Otherwise the inode share the bdev's
- * backing_dev_info.
- */
- if (sb->s_bdev) {
- struct backing_dev_info *bdi;
-
- bdi = sb->s_bdev->bd_inode->i_mapping->backing_dev_info;
- mapping->backing_dev_info = bdi;
- }
- inode->i_private = NULL;
- inode->i_mapping = mapping;
- INIT_LIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */
-#ifdef CONFIG_FS_POSIX_ACL
- inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
-#endif
-
-#ifdef CONFIG_FSNOTIFY
- inode->i_fsnotify_mask = 0;
-#endif
-
- this_cpu_inc(nr_inodes);
-
- return 0;
-out:
- return -ENOMEM;
-}
-EXPORT_SYMBOL(inode_init_always);
-
-static struct inode *alloc_inode(struct super_block *sb)
-{
- struct inode *inode;
-
- if (sb->s_op->alloc_inode)
- inode = sb->s_op->alloc_inode(sb);
- else
- inode = kmem_cache_alloc(inode_cachep, GFP_KERNEL);
-
- if (!inode)
- return NULL;
-
- if (unlikely(inode_init_always(sb, inode))) {
- if (inode->i_sb->s_op->destroy_inode)
- inode->i_sb->s_op->destroy_inode(inode);
- else
- kmem_cache_free(inode_cachep, inode);
- return NULL;
- }
-
- 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));
- security_inode_free(inode);
- fsnotify_inode_delete(inode);
- if (!inode->i_nlink) {
- WARN_ON(atomic_long_read(&inode->i_sb->s_remove_count) == 0);
- atomic_long_dec(&inode->i_sb->s_remove_count);
- }
-
-#ifdef CONFIG_FS_POSIX_ACL
- if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED)
- posix_acl_release(inode->i_acl);
- 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);
-
-static void i_callback(struct rcu_head *head)
-{
- struct inode *inode = container_of(head, struct inode, i_rcu);
- 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
- call_rcu(&inode->i_rcu, i_callback);
-}
-
-/**
- * drop_nlink - directly drop an inode's link count
- * @inode: inode
- *
- * This is a low-level filesystem helper to replace any
- * direct filesystem manipulation of i_nlink. In cases
- * where we are attempting to track writes to the
- * filesystem, a decrement to zero means an imminent
- * write when the file is truncated and actually unlinked
- * on the filesystem.
- */
-void drop_nlink(struct inode *inode)
-{
- WARN_ON(inode->i_nlink == 0);
- inode->__i_nlink--;
- if (!inode->i_nlink)
- atomic_long_inc(&inode->i_sb->s_remove_count);
-}
-EXPORT_SYMBOL(drop_nlink);
-
-/**
- * clear_nlink - directly zero an inode's link count
- * @inode: inode
- *
- * This is a low-level filesystem helper to replace any
- * direct filesystem manipulation of i_nlink. See
- * drop_nlink() for why we care about i_nlink hitting zero.
- */
-void clear_nlink(struct inode *inode)
-{
- if (inode->i_nlink) {
- inode->__i_nlink = 0;
- atomic_long_inc(&inode->i_sb->s_remove_count);
- }
-}
-EXPORT_SYMBOL(clear_nlink);
-
-/**
- * set_nlink - directly set an inode's link count
- * @inode: inode
- * @nlink: new nlink (should be non-zero)
- *
- * This is a low-level filesystem helper to replace any
- * direct filesystem manipulation of i_nlink.
- */
-void set_nlink(struct inode *inode, unsigned int nlink)
-{
- if (!nlink) {
- clear_nlink(inode);
- } else {
- /* Yes, some filesystems do change nlink from zero to one */
- if (inode->i_nlink == 0)
- atomic_long_dec(&inode->i_sb->s_remove_count);
-
- inode->__i_nlink = nlink;
- }
-}
-EXPORT_SYMBOL(set_nlink);
-
-/**
- * inc_nlink - directly increment an inode's link count
- * @inode: inode
- *
- * This is a low-level filesystem helper to replace any
- * direct filesystem manipulation of i_nlink. Currently,
- * it is only here for parity with dec_nlink().
- */
-void inc_nlink(struct inode *inode)
-{
- if (WARN_ON(inode->i_nlink == 0))
- atomic_long_dec(&inode->i_sb->s_remove_count);
-
- inode->__i_nlink++;
-}
-EXPORT_SYMBOL(inc_nlink);
-
-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);
- mutex_init(&mapping->i_mmap_mutex);
- 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);
-}
-EXPORT_SYMBOL(address_space_init_once);
-
-/*
- * These are initializations that only need to be done
- * once, because the fields are idempotent across use
- * of the inode, so let the slab aware of that.
- */
-void inode_init_once(struct inode *inode)
-{
- memset(inode, 0, sizeof(*inode));
- INIT_HLIST_NODE(&inode->i_hash);
- INIT_LIST_HEAD(&inode->i_devices);
- 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);
-#endif
-}
-EXPORT_SYMBOL(inode_init_once);
-
-static void init_once(void *foo)
-{
- struct inode *inode = (struct inode *) foo;
-
- inode_init_once(inode);
-}
-
-/*
- * inode->i_lock must be held
- */
-void __iget(struct inode *inode)
-{
- atomic_inc(&inode->i_count);
-}
-
-/*
- * 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->i_sb->s_inode_lru_lock);
- if (list_empty(&inode->i_lru)) {
- list_add(&inode->i_lru, &inode->i_sb->s_inode_lru);
- inode->i_sb->s_nr_inodes_unused++;
- this_cpu_inc(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
-}
-
-static void inode_lru_list_del(struct inode *inode)
-{
- spin_lock(&inode->i_sb->s_inode_lru_lock);
- if (!list_empty(&inode->i_lru)) {
- list_del_init(&inode->i_lru);
- inode->i_sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_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)
-{
- if (!list_empty(&inode->i_sb_list)) {
- 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_hash_shift);
- return tmp & i_hash_mask;
-}
-
-/**
- * __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)
-{
- might_sleep();
- /*
- * We have to cycle tree_lock here because reclaim can be still in the
- * process of removing the last page (in __delete_from_page_cache())
- * and we must not free mapping under it.
- */
- spin_lock_irq(&inode->i_data.tree_lock);
- BUG_ON(inode->i_data.nrpages);
- spin_unlock_irq(&inode->i_data.tree_lock);
- BUG_ON(!list_empty(&inode->i_data.private_list));
- 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));
-
- if (!list_empty(&inode->i_wb_list))
- inode_wb_list_del(inode);
-
- inode_sb_list_del(inode);
-
- if (op->evict_inode) {
- op->evict_inode(inode);
- } else {
- if (inode->i_data.nrpages)
- truncate_inode_pages(&inode->i_data, 0);
- end_writeback(inode);
- }
- if (S_ISBLK(inode->i_mode) && inode->i_bdev)
- 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);
-}
-
-/*
- * dispose_list - dispose of the contents of a local list
- * @head: the head of the list to free
- *
- * Dispose-list gets a local list with local inodes in it, so it doesn't
- * need to worry about list corruption and SMP locks.
- */
-static void dispose_list(struct list_head *head)
-{
- while (!list_empty(head)) {
- struct inode *inode;
-
- inode = list_first_entry(head, struct inode, i_lru);
- list_del_init(&inode->i_lru);
-
- evict(inode);
- }
-}
-
-/**
- * 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.
- */
-void evict_inodes(struct super_block *sb)
-{
- 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) {
- if (atomic_read(&inode->i_count))
- continue;
-
- spin_lock(&inode->i_lock);
- if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
- spin_unlock(&inode->i_lock);
- continue;
- }
-
- 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(&dispose);
-}
-
-/**
- * invalidate_inodes - attempt to free all inodes on a superblock
- * @sb: superblock to operate on
- * @kill_dirty: flag to guide handling of dirty inodes
- *
- * 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, bool kill_dirty)
-{
- 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;
- }
-
- 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(&dispose);
-
- return busy;
-}
-
-static int can_unuse(struct inode *inode)
-{
- if (inode->i_state & ~I_REFERENCED)
- return 0;
- if (inode_has_buffers(inode))
- return 0;
- if (atomic_read(&inode->i_count))
- return 0;
- if (inode->i_data.nrpages)
- return 0;
- return 1;
-}
-
-/*
- * Walk the superblock inode LRU for freeable inodes and attempt to free them.
- * This is called from the superblock shrinker function with a number of inodes
- * to trim from the LRU. Inodes to be freed are moved to a temporary list and
- * then are freed outside inode_lock by dispose_list().
- *
- * Any inodes which are pinned purely because of attached pagecache have their
- * pagecache removed. 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.
- */
-void prune_icache_sb(struct super_block *sb, int nr_to_scan)
-{
- LIST_HEAD(freeable);
- int nr_scanned;
- unsigned long reap = 0;
-
- spin_lock(&sb->s_inode_lru_lock);
- for (nr_scanned = nr_to_scan; nr_scanned >= 0; nr_scanned--) {
- struct inode *inode;
-
- if (list_empty(&sb->s_inode_lru))
- break;
-
- inode = list_entry(sb->s_inode_lru.prev, struct inode, i_lru);
-
- /*
- * we are inverting the sb->s_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_tail(&inode->i_lru, &sb->s_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);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- continue;
- }
-
- /* recently referenced inodes get one more pass */
- if (inode->i_state & I_REFERENCED) {
- inode->i_state &= ~I_REFERENCED;
- list_move(&inode->i_lru, &sb->s_inode_lru);
- spin_unlock(&inode->i_lock);
- continue;
- }
- if (inode_has_buffers(inode) || inode->i_data.nrpages) {
- __iget(inode);
- spin_unlock(&inode->i_lock);
- spin_unlock(&sb->s_inode_lru_lock);
- if (remove_inode_buffers(inode))
- reap += invalidate_mapping_pages(&inode->i_data,
- 0, -1);
- iput(inode);
- spin_lock(&sb->s_inode_lru_lock);
-
- if (inode != list_entry(sb->s_inode_lru.next,
- struct inode, i_lru))
- continue; /* wrong inode or list_empty */
- /* avoid lock inversions with trylock */
- if (!spin_trylock(&inode->i_lock))
- continue;
- if (!can_unuse(inode)) {
- spin_unlock(&inode->i_lock);
- continue;
- }
- }
- WARN_ON(inode->i_state & I_NEW);
- inode->i_state |= I_FREEING;
- spin_unlock(&inode->i_lock);
-
- list_move(&inode->i_lru, &freeable);
- sb->s_nr_inodes_unused--;
- this_cpu_dec(nr_unused);
- }
- if (current_is_kswapd())
- __count_vm_events(KSWAPD_INODESTEAL, reap);
- else
- __count_vm_events(PGINODESTEAL, reap);
- spin_unlock(&sb->s_inode_lru_lock);
- if (current->reclaim_state)
- current->reclaim_state->reclaimed_slab += reap;
-
- dispose_list(&freeable);
-}
-
-static void __wait_on_freeing_inode(struct inode *inode);
-/*
- * Called with the inode lock held.
- */
-static struct inode *find_inode(struct super_block *sb,
- struct hlist_head *head,
- int (*test)(struct inode *, void *),
- void *data)
-{
- struct hlist_node *node;
- struct inode *inode = NULL;
-
-repeat:
- hlist_for_each_entry(inode, node, head, i_hash) {
- spin_lock(&inode->i_lock);
- if (inode->i_sb != sb) {
- spin_unlock(&inode->i_lock);
- continue;
- }
- 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;
- }
- __iget(inode);
- spin_unlock(&inode->i_lock);
- return inode;
- }
- return 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_entry(inode, node, head, i_hash) {
- spin_lock(&inode->i_lock);
- if (inode->i_ino != ino) {
- spin_unlock(&inode->i_lock);
- continue;
- }
- 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;
- }
- __iget(inode);
- spin_unlock(&inode->i_lock);
- return inode;
- }
- return NULL;
-}
-
-/*
- * 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.
- *
- * 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.
- */
-#define LAST_INO_BATCH 1024
-static DEFINE_PER_CPU(unsigned int, last_ino);
-
-unsigned int get_next_ino(void)
-{
- unsigned int *p = &get_cpu_var(last_ino);
- unsigned int res = *p;
-
-#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(get_next_ino);
-
-/**
- * new_inode_pseudo - obtain an inode
- * @sb: superblock
- *
- * Allocates a new inode for given superblock.
- * Inode wont be chained in superblock s_inodes list
- * This means :
- * - fs can't be unmount
- * - quotas, fsnotify, writeback can't work
- */
-struct inode *new_inode_pseudo(struct super_block *sb)
-{
- struct inode *inode = alloc_inode(sb);
-
- if (inode) {
- spin_lock(&inode->i_lock);
- inode->i_state = 0;
- spin_unlock(&inode->i_lock);
- INIT_LIST_HEAD(&inode->i_sb_list);
- }
- return inode;
-}
-
-/**
- * new_inode - obtain an inode
- * @sb: superblock
- *
- * Allocates a new inode for given superblock. The default gfp_mask
- * for allocations related to inode->i_mapping is GFP_HIGHUSER_MOVABLE.
- * If HIGHMEM pages are unsuitable or it is known that pages allocated
- * for the page cache are not reclaimable or migratable,
- * mapping_set_gfp_mask() must be called with suitable flags on the
- * newly created inode's mapping
- *
- */
-struct inode *new_inode(struct super_block *sb)
-{
- struct inode *inode;
-
- spin_lock_prefetch(&inode_sb_list_lock);
-
- inode = new_inode_pseudo(sb);
- if (inode)
- inode_sb_list_add(inode);
- return inode;
-}
-EXPORT_SYMBOL(new_inode);
-
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-void lockdep_annotate_inode_mutex_key(struct inode *inode)
-{
- 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 */
- if (lockdep_match_class(&inode->i_mutex, &type->i_mutex_key)) {
- /*
- * ensure nobody is actually holding i_mutex
- */
- mutex_destroy(&inode->i_mutex);
- mutex_init(&inode->i_mutex);
- lockdep_set_class(&inode->i_mutex,
- &type->i_mutex_dir_key);
- }
- }
-}
-EXPORT_SYMBOL(lockdep_annotate_inode_mutex_key);
-#endif
-
-/**
- * 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)
-{
- lockdep_annotate_inode_mutex_key(inode);
- spin_lock(&inode->i_lock);
- WARN_ON(!(inode->i_state & I_NEW));
- inode->i_state &= ~I_NEW;
- smp_mb();
- wake_up_bit(&inode->i_state, __I_NEW);
- spin_unlock(&inode->i_lock);
-}
-EXPORT_SYMBOL(unlock_new_inode);
-
-/**
- * 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().
- *
- * Note both @test and @set are called with the inode_hash_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;
-
- 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_hash_lock);
- /* We released the lock, so.. */
- old = find_inode(sb, head, test, data);
- if (!old) {
- if (set(inode, data))
- goto set_failed;
-
- spin_lock(&inode->i_lock);
- inode->i_state = I_NEW;
- 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
- */
- return inode;
- }
-
- /*
- * Uhhuh, somebody else created the same inode under
- * us. Use the old inode instead of the one we just
- * allocated.
- */
- spin_unlock(&inode_hash_lock);
- destroy_inode(inode);
- inode = old;
- wait_on_inode(inode);
- }
- return inode;
-
-set_failed:
- spin_unlock(&inode_hash_lock);
- destroy_inode(inode);
- return NULL;
-}
-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
- *
- * 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().
- */
-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_hash_lock);
- /* We released the lock, so.. */
- old = find_inode_fast(sb, head, ino);
- if (!old) {
- inode->i_ino = ino;
- spin_lock(&inode->i_lock);
- inode->i_state = I_NEW;
- 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
- */
- return inode;
- }
-
- /*
- * Uhhuh, somebody else created the same inode under
- * us. Use the old inode instead of the one we just
- * allocated.
- */
- 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
- * @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)
-{
- /*
- * 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 DEFINE_SPINLOCK(iunique_lock);
- static unsigned int counter;
- ino_t res;
-
- spin_lock(&iunique_lock);
- do {
- if (counter <= max_reserved)
- counter = max_reserved + 1;
- res = counter++;
- } while (!test_inode_iunique(sb, res));
- spin_unlock(&iunique_lock);
-
- return res;
-}
-EXPORT_SYMBOL(iunique);
-
-struct inode *igrab(struct inode *inode)
-{
- spin_lock(&inode->i_lock);
- if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) {
- __iget(inode);
- 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;
- }
- return inode;
-}
-EXPORT_SYMBOL(igrab);
-
-/**
- * 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
- *
- * 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: 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.
- *
- * 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;
-
- spin_lock(&inode_hash_lock);
- inode = find_inode(sb, head, test, data);
- spin_unlock(&inode_hash_lock);
-
- return inode;
-}
-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
- *
- * 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.
- *
- * 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_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 inode *inode = ilookup5_nowait(sb, hashval, test, data);
-
- if (inode)
- wait_on_inode(inode);
- return inode;
-}
-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
- *
- * 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);
- 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;
-}
-EXPORT_SYMBOL(ilookup);
-
-int insert_inode_locked(struct inode *inode)
-{
- struct super_block *sb = inode->i_sb;
- ino_t ino = inode->i_ino;
- struct hlist_head *head = inode_hashtable + hash(sb, ino);
-
- while (1) {
- struct hlist_node *node;
- struct inode *old = NULL;
- 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;
- 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->i_lock);
- spin_unlock(&inode_hash_lock);
- return 0;
- }
- __iget(old);
- spin_unlock(&old->i_lock);
- spin_unlock(&inode_hash_lock);
- wait_on_inode(old);
- if (unlikely(!inode_unhashed(old))) {
- iput(old);
- return -EBUSY;
- }
- iput(old);
- }
-}
-EXPORT_SYMBOL(insert_inode_locked);
-
-int insert_inode_locked4(struct inode *inode, unsigned long hashval,
- int (*test)(struct inode *, void *), void *data)
-{
- struct super_block *sb = inode->i_sb;
- struct hlist_head *head = inode_hashtable + hash(sb, hashval);
-
- while (1) {
- struct hlist_node *node;
- struct inode *old = NULL;
-
- 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;
- 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->i_lock);
- spin_unlock(&inode_hash_lock);
- return 0;
- }
- __iget(old);
- spin_unlock(&old->i_lock);
- spin_unlock(&inode_hash_lock);
- wait_on_inode(old);
- if (unlikely(!inode_unhashed(old))) {
- iput(old);
- return -EBUSY;
- }
- iput(old);
- }
-}
-EXPORT_SYMBOL(insert_inode_locked4);
-
-
-int generic_delete_inode(struct inode *inode)
-{
- return 1;
-}
-EXPORT_SYMBOL(generic_delete_inode);
-
-/*
- * Called when we're dropping the last reference
- * to an inode.
- *
- * Call the FS "drop_inode()" function, defaulting to
- * the legacy UNIX filesystem behaviour. If it tells
- * us to evict inode, do so. Otherwise, retain inode
- * in cache if fs is alive, sync and evict if fs is
- * shutting down.
- */
-static void iput_final(struct inode *inode)
-{
- struct super_block *sb = inode->i_sb;
- const struct super_operations *op = inode->i_sb->s_op;
- int drop;
-
- WARN_ON(inode->i_state & I_NEW);
-
- if (op->drop_inode)
- drop = op->drop_inode(inode);
- else
- drop = generic_drop_inode(inode);
-
- if (!drop && (sb->s_flags & MS_ACTIVE)) {
- inode->i_state |= I_REFERENCED;
- if (!(inode->i_state & (I_DIRTY|I_SYNC)))
- inode_lru_list_add(inode);
- spin_unlock(&inode->i_lock);
- return;
- }
-
- if (!drop) {
- inode->i_state |= I_WILL_FREE;
- spin_unlock(&inode->i_lock);
- write_inode_now(inode, 1);
- spin_lock(&inode->i_lock);
- WARN_ON(inode->i_state & I_NEW);
- inode->i_state &= ~I_WILL_FREE;
- }
-
- inode->i_state |= I_FREEING;
- if (!list_empty(&inode->i_lru))
- inode_lru_list_del(inode);
- spin_unlock(&inode->i_lock);
-
- evict(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) {
- BUG_ON(inode->i_state & I_CLEAR);
-
- if (atomic_dec_and_lock(&inode->i_count, &inode->i_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);
-
-/*
- * With relative atime, only update atime if the previous atime is
- * earlier than either the ctime or mtime or if at least a day has
- * passed since the last atime update.
- */
-static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
- struct timespec now)
-{
-
- if (!(mnt->mnt_flags & MNT_RELATIME))
- return 1;
- /*
- * Is mtime younger than atime? If yes, update atime:
- */
- if (timespec_compare(&inode->i_mtime, &inode->i_atime) >= 0)
- return 1;
- /*
- * Is ctime younger than atime? If yes, update atime:
- */
- if (timespec_compare(&inode->i_ctime, &inode->i_atime) >= 0)
- return 1;
-
- /*
- * Is the previous atime value older than a day? If yes,
- * update atime:
- */
- if ((long)(now.tv_sec - inode->i_atime.tv_sec) >= 24*60*60)
- return 1;
- /*
- * Good, we can skip the atime update:
- */
- return 0;
-}
-
-/**
- * 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 path *path)
-{
- struct vfsmount *mnt = path->mnt;
- struct inode *inode = path->dentry->d_inode;
- struct timespec now;
-
- if (inode->i_flags & S_NOATIME)
- return;
- if (IS_NOATIME(inode))
- return;
- if ((inode->i_sb->s_flags & MS_NODIRATIME) && S_ISDIR(inode->i_mode))
- return;
-
- if (mnt->mnt_flags & MNT_NOATIME)
- return;
- if ((mnt->mnt_flags & MNT_NODIRATIME) && S_ISDIR(inode->i_mode))
- return;
-
- now = current_fs_time(inode->i_sb);
-
- if (!relatime_need_update(mnt, inode, now))
- return;
-
- if (timespec_equal(&inode->i_atime, &now))
- return;
-
- if (mnt_want_write(mnt))
- return;
-
- inode->i_atime = now;
- mark_inode_dirty_sync(inode);
- mnt_drop_write(mnt);
-}
-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_NOCMTIME 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_path.dentry->d_inode;
- struct timespec now;
- enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0;
-
- /* First try to exhaust all avenues to not sync */
- if (IS_NOCMTIME(inode))
- return;
-
- now = current_fs_time(inode->i_sb);
- if (!timespec_equal(&inode->i_mtime, &now))
- sync_it = S_MTIME;
-
- if (!timespec_equal(&inode->i_ctime, &now))
- sync_it |= S_CTIME;
-
- if (IS_I_VERSION(inode))
- sync_it |= S_VERSION;
-
- if (!sync_it)
- return;
-
- /* Finally allowed to write? Takes lock. */
- if (mnt_want_write_file(file))
- return;
-
- /* Only change inode inside the lock region */
- if (sync_it & S_VERSION)
- inode_inc_iversion(inode);
- if (sync_it & S_CTIME)
- inode->i_ctime = now;
- if (sync_it & S_MTIME)
- inode->i_mtime = now;
- mark_inode_dirty_sync(inode);
- mnt_drop_write_file(file);
-}
-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);
-
-int inode_wait(void *word)
-{
- schedule();
- return 0;
-}
-EXPORT_SYMBOL(inode_wait);
-
-/*
- * 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_NEW is not set initially, a call to
- * 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)
-{
- wait_queue_head_t *wq;
- 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->i_lock);
- spin_unlock(&inode_hash_lock);
- schedule();
- finish_wait(wq, &wait.wait);
- spin_lock(&inode_hash_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)
-{
- unsigned 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 < (1U << i_hash_shift); loop++)
- INIT_HLIST_HEAD(&inode_hashtable[loop]);
-}
-
-void __init inode_init(void)
-{
- unsigned 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);
-
- /* 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 < (1U << 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) for"
- " inode %s:%lu\n", mode, inode->i_sb->s_id,
- inode->i_ino);
-}
-EXPORT_SYMBOL(init_special_inode);
-
-/**
- * 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
- */
-void inode_init_owner(struct inode *inode, const struct inode *dir,
- umode_t mode)
-{
- inode->i_uid = current_fsuid();
- if (dir && dir->i_mode & S_ISGID) {
- inode->i_gid = dir->i_gid;
- if (S_ISDIR(mode))
- mode |= S_ISGID;
- } else
- inode->i_gid = current_fsgid();
- 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);
generated by cgit (git 2.34.1) at 2025-01-08 22:08:19 +0000