mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
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1743 lines
45 KiB
C
1743 lines
45 KiB
C
/*
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* (C) 1997 Linus Torvalds
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* (C) 1999 Andrea Arcangeli <andrea@suse.de> (dynamic inode allocation)
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*/
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#include <linux/export.h>
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#include <linux/fs.h>
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#include <linux/mm.h>
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#include <linux/backing-dev.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/cdev.h>
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#include <linux/bootmem.h>
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#include <linux/fsnotify.h>
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#include <linux/mount.h>
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#include <linux/posix_acl.h>
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#include <linux/prefetch.h>
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#include <linux/buffer_head.h> /* for inode_has_buffers */
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#include <linux/ratelimit.h>
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#include "internal.h"
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/*
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* Inode locking rules:
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*
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* inode->i_lock protects:
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* inode->i_state, inode->i_hash, __iget()
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* inode->i_sb->s_inode_lru_lock protects:
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* inode->i_sb->s_inode_lru, inode->i_lru
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* inode_sb_list_lock protects:
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* sb->s_inodes, inode->i_sb_list
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* bdi->wb.list_lock protects:
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* bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list
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* inode_hash_lock protects:
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* inode_hashtable, inode->i_hash
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*
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* Lock ordering:
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*
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* inode_sb_list_lock
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* inode->i_lock
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* inode->i_sb->s_inode_lru_lock
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*
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* bdi->wb.list_lock
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* inode->i_lock
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*
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* inode_hash_lock
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* inode_sb_list_lock
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* inode->i_lock
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*
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* iunique_lock
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* inode_hash_lock
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*/
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static unsigned int i_hash_mask __read_mostly;
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static unsigned int i_hash_shift __read_mostly;
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static struct hlist_head *inode_hashtable __read_mostly;
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static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock);
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__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
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/*
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* Empty aops. Can be used for the cases where the user does not
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* define any of the address_space operations.
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*/
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const struct address_space_operations empty_aops = {
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};
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EXPORT_SYMBOL(empty_aops);
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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 DEFINE_PER_CPU(unsigned int, nr_inodes);
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static DEFINE_PER_CPU(unsigned int, nr_unused);
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static struct kmem_cache *inode_cachep __read_mostly;
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static int get_nr_inodes(void)
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{
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int i;
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int sum = 0;
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for_each_possible_cpu(i)
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sum += per_cpu(nr_inodes, i);
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return sum < 0 ? 0 : sum;
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}
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static inline int get_nr_inodes_unused(void)
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{
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int i;
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int sum = 0;
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for_each_possible_cpu(i)
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sum += per_cpu(nr_unused, i);
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return sum < 0 ? 0 : sum;
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}
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int get_nr_dirty_inodes(void)
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{
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/* not actually dirty inodes, but a wild approximation */
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int nr_dirty = get_nr_inodes() - get_nr_inodes_unused();
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return nr_dirty > 0 ? nr_dirty : 0;
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}
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/*
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* Handle nr_inode sysctl
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*/
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#ifdef CONFIG_SYSCTL
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int proc_nr_inodes(ctl_table *table, int write,
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void __user *buffer, size_t *lenp, loff_t *ppos)
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{
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inodes_stat.nr_inodes = get_nr_inodes();
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inodes_stat.nr_unused = get_nr_inodes_unused();
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return proc_dointvec(table, write, buffer, lenp, ppos);
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}
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#endif
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/**
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* inode_init_always - perform inode structure intialisation
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* @sb: superblock inode belongs to
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* @inode: inode to initialise
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*
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* These are initializations that need to be done on every inode
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* allocation as the fields are not initialised by slab allocation.
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*/
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int inode_init_always(struct super_block *sb, struct inode *inode)
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{
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static const struct inode_operations empty_iops;
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static const struct file_operations empty_fops;
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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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inode->i_opflags = 0;
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inode->i_uid = 0;
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inode->i_gid = 0;
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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->dirtied_when = 0;
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if (security_inode_alloc(inode))
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goto out;
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spin_lock_init(&inode->i_lock);
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lockdep_set_class(&inode->i_lock, &sb->s_type->i_lock_key);
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mutex_init(&inode->i_mutex);
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lockdep_set_class(&inode->i_mutex, &sb->s_type->i_mutex_key);
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atomic_set(&inode->i_dio_count, 0);
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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_MOVABLE);
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mapping->assoc_mapping = NULL;
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mapping->backing_dev_info = &default_backing_dev_info;
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mapping->writeback_index = 0;
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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->i_mapping->backing_dev_info;
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mapping->backing_dev_info = bdi;
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}
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inode->i_private = NULL;
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inode->i_mapping = mapping;
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INIT_LIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */
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#ifdef CONFIG_FS_POSIX_ACL
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inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
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#endif
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#ifdef CONFIG_FSNOTIFY
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inode->i_fsnotify_mask = 0;
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#endif
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this_cpu_inc(nr_inodes);
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return 0;
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out:
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return -ENOMEM;
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}
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EXPORT_SYMBOL(inode_init_always);
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static struct inode *alloc_inode(struct super_block *sb)
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{
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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 = kmem_cache_alloc(inode_cachep, GFP_KERNEL);
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if (!inode)
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return NULL;
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if (unlikely(inode_init_always(sb, 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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return inode;
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}
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void free_inode_nonrcu(struct inode *inode)
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{
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kmem_cache_free(inode_cachep, inode);
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}
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EXPORT_SYMBOL(free_inode_nonrcu);
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void __destroy_inode(struct inode *inode)
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{
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BUG_ON(inode_has_buffers(inode));
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security_inode_free(inode);
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fsnotify_inode_delete(inode);
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if (!inode->i_nlink) {
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WARN_ON(atomic_long_read(&inode->i_sb->s_remove_count) == 0);
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atomic_long_dec(&inode->i_sb->s_remove_count);
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}
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#ifdef CONFIG_FS_POSIX_ACL
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if (inode->i_acl && inode->i_acl != ACL_NOT_CACHED)
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posix_acl_release(inode->i_acl);
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if (inode->i_default_acl && inode->i_default_acl != ACL_NOT_CACHED)
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posix_acl_release(inode->i_default_acl);
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#endif
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this_cpu_dec(nr_inodes);
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}
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EXPORT_SYMBOL(__destroy_inode);
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static void i_callback(struct rcu_head *head)
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{
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struct inode *inode = container_of(head, struct inode, i_rcu);
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kmem_cache_free(inode_cachep, inode);
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}
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static void destroy_inode(struct inode *inode)
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{
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BUG_ON(!list_empty(&inode->i_lru));
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__destroy_inode(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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call_rcu(&inode->i_rcu, i_callback);
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}
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/**
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* drop_nlink - directly drop an inode's link count
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* @inode: inode
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*
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* This is a low-level filesystem helper to replace any
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* direct filesystem manipulation of i_nlink. In cases
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* where we are attempting to track writes to the
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* filesystem, a decrement to zero means an imminent
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* write when the file is truncated and actually unlinked
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* on the filesystem.
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*/
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void drop_nlink(struct inode *inode)
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{
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WARN_ON(inode->i_nlink == 0);
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inode->__i_nlink--;
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if (!inode->i_nlink)
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atomic_long_inc(&inode->i_sb->s_remove_count);
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}
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EXPORT_SYMBOL(drop_nlink);
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/**
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* clear_nlink - directly zero an inode's link count
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* @inode: inode
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*
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* This is a low-level filesystem helper to replace any
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* direct filesystem manipulation of i_nlink. See
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* drop_nlink() for why we care about i_nlink hitting zero.
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*/
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void clear_nlink(struct inode *inode)
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{
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if (inode->i_nlink) {
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inode->__i_nlink = 0;
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atomic_long_inc(&inode->i_sb->s_remove_count);
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}
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}
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EXPORT_SYMBOL(clear_nlink);
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/**
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* set_nlink - directly set an inode's link count
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* @inode: inode
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* @nlink: new nlink (should be non-zero)
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*
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* This is a low-level filesystem helper to replace any
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* direct filesystem manipulation of i_nlink.
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*/
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void set_nlink(struct inode *inode, unsigned int nlink)
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{
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if (!nlink) {
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clear_nlink(inode);
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} else {
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/* Yes, some filesystems do change nlink from zero to one */
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if (inode->i_nlink == 0)
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atomic_long_dec(&inode->i_sb->s_remove_count);
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inode->__i_nlink = nlink;
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}
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}
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EXPORT_SYMBOL(set_nlink);
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/**
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* inc_nlink - directly increment an inode's link count
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* @inode: inode
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*
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* This is a low-level filesystem helper to replace any
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* direct filesystem manipulation of i_nlink. Currently,
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* it is only here for parity with dec_nlink().
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*/
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void inc_nlink(struct inode *inode)
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{
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if (WARN_ON(inode->i_nlink == 0))
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atomic_long_dec(&inode->i_sb->s_remove_count);
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inode->__i_nlink++;
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}
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EXPORT_SYMBOL(inc_nlink);
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void address_space_init_once(struct address_space *mapping)
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{
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memset(mapping, 0, sizeof(*mapping));
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INIT_RADIX_TREE(&mapping->page_tree, GFP_ATOMIC);
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spin_lock_init(&mapping->tree_lock);
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mutex_init(&mapping->i_mmap_mutex);
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INIT_LIST_HEAD(&mapping->private_list);
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spin_lock_init(&mapping->private_lock);
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INIT_RAW_PRIO_TREE_ROOT(&mapping->i_mmap);
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INIT_LIST_HEAD(&mapping->i_mmap_nonlinear);
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}
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EXPORT_SYMBOL(address_space_init_once);
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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_devices);
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INIT_LIST_HEAD(&inode->i_wb_list);
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INIT_LIST_HEAD(&inode->i_lru);
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address_space_init_once(&inode->i_data);
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i_size_ordered_init(inode);
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#ifdef CONFIG_FSNOTIFY
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INIT_HLIST_HEAD(&inode->i_fsnotify_marks);
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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)
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{
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struct inode *inode = (struct inode *) foo;
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inode_init_once(inode);
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}
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/*
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* inode->i_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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atomic_inc(&inode->i_count);
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}
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/*
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* get additional reference to inode; caller must already hold one.
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*/
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void ihold(struct inode *inode)
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{
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WARN_ON(atomic_inc_return(&inode->i_count) < 2);
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}
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EXPORT_SYMBOL(ihold);
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static void inode_lru_list_add(struct inode *inode)
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{
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spin_lock(&inode->i_sb->s_inode_lru_lock);
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if (list_empty(&inode->i_lru)) {
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list_add(&inode->i_lru, &inode->i_sb->s_inode_lru);
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inode->i_sb->s_nr_inodes_unused++;
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this_cpu_inc(nr_unused);
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}
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spin_unlock(&inode->i_sb->s_inode_lru_lock);
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}
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static void inode_lru_list_del(struct inode *inode)
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{
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spin_lock(&inode->i_sb->s_inode_lru_lock);
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if (!list_empty(&inode->i_lru)) {
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list_del_init(&inode->i_lru);
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inode->i_sb->s_nr_inodes_unused--;
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this_cpu_dec(nr_unused);
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}
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spin_unlock(&inode->i_sb->s_inode_lru_lock);
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}
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/**
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* inode_sb_list_add - add inode to the superblock list of inodes
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* @inode: inode to add
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*/
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void inode_sb_list_add(struct inode *inode)
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{
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spin_lock(&inode_sb_list_lock);
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list_add(&inode->i_sb_list, &inode->i_sb->s_inodes);
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spin_unlock(&inode_sb_list_lock);
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}
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EXPORT_SYMBOL_GPL(inode_sb_list_add);
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static inline void inode_sb_list_del(struct inode *inode)
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{
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if (!list_empty(&inode->i_sb_list)) {
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spin_lock(&inode_sb_list_lock);
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list_del_init(&inode->i_sb_list);
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spin_unlock(&inode_sb_list_lock);
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}
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}
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static unsigned long hash(struct super_block *sb, unsigned long hashval)
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{
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unsigned long tmp;
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tmp = (hashval * (unsigned long)sb) ^ (GOLDEN_RATIO_PRIME + hashval) /
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L1_CACHE_BYTES;
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tmp = tmp ^ ((tmp ^ GOLDEN_RATIO_PRIME) >> i_hash_shift);
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return tmp & i_hash_mask;
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}
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/**
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* __insert_inode_hash - hash an inode
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* @inode: unhashed inode
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* @hashval: unsigned long value used to locate this object in the
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* inode_hashtable.
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*
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* Add an inode to the inode hash for this superblock.
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*/
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void __insert_inode_hash(struct inode *inode, unsigned long hashval)
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{
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struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval);
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spin_lock(&inode_hash_lock);
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spin_lock(&inode->i_lock);
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hlist_add_head(&inode->i_hash, b);
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spin_unlock(&inode->i_lock);
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spin_unlock(&inode_hash_lock);
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}
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EXPORT_SYMBOL(__insert_inode_hash);
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|
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/**
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* __remove_inode_hash - remove an inode from the hash
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* @inode: inode to unhash
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*
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* Remove an inode from the superblock.
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*/
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void __remove_inode_hash(struct inode *inode)
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{
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spin_lock(&inode_hash_lock);
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spin_lock(&inode->i_lock);
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hlist_del_init(&inode->i_hash);
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spin_unlock(&inode->i_lock);
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spin_unlock(&inode_hash_lock);
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}
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EXPORT_SYMBOL(__remove_inode_hash);
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|
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void end_writeback(struct inode *inode)
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{
|
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might_sleep();
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/*
|
|
* We have to cycle tree_lock here because reclaim can be still in the
|
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* process of removing the last page (in __delete_from_page_cache())
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* and we must not free mapping under it.
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|
*/
|
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spin_lock_irq(&inode->i_data.tree_lock);
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BUG_ON(inode->i_data.nrpages);
|
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spin_unlock_irq(&inode->i_data.tree_lock);
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BUG_ON(!list_empty(&inode->i_data.private_list));
|
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BUG_ON(!(inode->i_state & I_FREEING));
|
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BUG_ON(inode->i_state & I_CLEAR);
|
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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);
|