* (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/dcache.h>
-#include <linux/init.h>
-#include <linux/slab.h>
-#include <linux/writeback.h>
-#include <linux/module.h>
#include <linux/backing-dev.h>
-#include <linux/wait.h>
-#include <linux/rwsem.h>
#include <linux/hash.h>
#include <linux/swap.h>
#include <linux/security.h>
-#include <linux/pagemap.h>
#include <linux/cdev.h>
#include <linux/bootmem.h>
#include <linux/fsnotify.h>
#include <linux/mount.h>
-#include <linux/async.h>
#include <linux/posix_acl.h>
#include <linux/prefetch.h>
-#include <linux/ima.h>
-#include <linux/cred.h>
#include <linux/buffer_head.h> /* for inode_has_buffers */
+#include <linux/ratelimit.h>
#include "internal.h"
/*
atomic_set(&inode->i_count, 1);
inode->i_op = &empty_iops;
inode->i_fop = &empty_fops;
- inode->i_nlink = 1;
+ inode->__i_nlink = 1;
inode->i_opflags = 0;
- inode->i_uid = 0;
- inode->i_gid = 0;
+ i_uid_write(inode, 0);
+ i_gid_write(inode, 0);
atomic_set(&inode->i_writecount, 0);
inode->i_size = 0;
inode->i_blocks = 0;
mapping->host = inode;
mapping->flags = 0;
mapping_set_gfp_mask(mapping, GFP_HIGHUSER_MOVABLE);
- mapping->assoc_mapping = NULL;
+ mapping->private_data = NULL;
mapping->backing_dev_info = &default_backing_dev_info;
mapping->writeback_index = 0;
}
inode->i_private = NULL;
inode->i_mapping = mapping;
+ INIT_HLIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */
#ifdef CONFIG_FS_POSIX_ACL
inode->i_acl = inode->i_default_acl = ACL_NOT_CACHED;
#endif
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);
static void i_callback(struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
- INIT_LIST_HEAD(&inode->i_dentry);
kmem_cache_free(inode_cachep, inode);
}
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));
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);
+ mapping->i_mmap = RB_ROOT;
INIT_LIST_HEAD(&mapping->i_mmap_nonlinear);
}
EXPORT_SYMBOL(address_space_init_once);
{
memset(inode, 0, sizeof(*inode));
INIT_HLIST_NODE(&inode->i_hash);
- INIT_LIST_HEAD(&inode->i_dentry);
INIT_LIST_HEAD(&inode->i_devices);
INIT_LIST_HEAD(&inode->i_wb_list);
INIT_LIST_HEAD(&inode->i_lru);
spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
+/*
+ * Add inode to LRU if needed (inode is unused and clean).
+ *
+ * Needs inode->i_lock held.
+ */
+void inode_add_lru(struct inode *inode)
+{
+ if (!(inode->i_state & (I_DIRTY | I_SYNC | I_FREEING | I_WILL_FREE)) &&
+ !atomic_read(&inode->i_count) && inode->i_sb->s_flags & MS_ACTIVE)
+ inode_lru_list_add(inode);
+}
+
+
static void inode_lru_list_del(struct inode *inode)
{
spin_lock(&inode->i_sb->s_inode_lru_lock);
}
EXPORT_SYMBOL(__remove_inode_hash);
-void end_writeback(struct inode *inode)
+void clear_inode(struct inode *inode)
{
might_sleep();
/*
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);
+EXPORT_SYMBOL(clear_inode);
/*
* Free the inode passed in, removing it from the lists it is still connected
inode_sb_list_del(inode);
+ /*
+ * Wait for flusher thread to be done with the inode so that filesystem
+ * does not start destroying it while writeback is still running. Since
+ * the inode has I_FREEING set, flusher thread won't start new work on
+ * the inode. We just have to wait for running writeback to finish.
+ */
+ inode_wait_for_writeback(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);
+ clear_inode(inode);
}
if (S_ISBLK(inode->i_mode) && inode->i_bdev)
bd_forget(inode);
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);
}
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) {
+ hlist_for_each_entry(inode, head, i_hash) {
spin_lock(&inode->i_lock);
if (inode->i_sb != sb) {
spin_unlock(&inode->i_lock);
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) {
+ hlist_for_each_entry(inode, head, i_hash) {
spin_lock(&inode->i_lock);
if (inode->i_ino != ino) {
spin_unlock(&inode->i_lock);
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)) {
+ if (lockdep_match_class(&inode->i_mutex, &type->i_mutex_key)) {
/*
* ensure nobody is actually holding i_mutex
*/
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);
}
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) {
+ hlist_for_each_entry(inode, b, i_hash) {
if (inode->i_ino == ino && inode->i_sb == sb) {
spin_unlock(&inode_hash_lock);
return 0;
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) {
+ hlist_for_each_entry(old, head, i_hash) {
if (old->i_ino != ino)
continue;
if (old->i_sb != sb)
}
break;
}
- if (likely(!node)) {
+ if (likely(!old)) {
spin_lock(&inode->i_lock);
inode->i_state |= I_NEW;
hlist_add_head(&inode->i_hash, head);
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) {
+ hlist_for_each_entry(old, head, i_hash) {
if (old->i_sb != sb)
continue;
if (!test(old, data))
}
break;
}
- if (likely(!node)) {
+ if (likely(!old)) {
spin_lock(&inode->i_lock);
inode->i_state |= I_NEW;
hlist_add_head(&inode->i_hash, head);
}
EXPORT_SYMBOL(generic_delete_inode);
-/*
- * Normal UNIX filesystem behaviour: delete the
- * inode when the usage count drops to zero, and
- * i_nlink is zero.
- */
-int generic_drop_inode(struct inode *inode)
-{
- return !inode->i_nlink || inode_unhashed(inode);
-}
-EXPORT_SYMBOL_GPL(generic_drop_inode);
-
/*
* Called when we're dropping the last reference
* to an 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);
+ inode_add_lru(inode);
spin_unlock(&inode->i_lock);
return;
}
return 0;
}
+/*
+ * This does the actual work of updating an inodes time or version. Must have
+ * had called mnt_want_write() before calling this.
+ */
+static int update_time(struct inode *inode, struct timespec *time, int flags)
+{
+ if (inode->i_op->update_time)
+ return inode->i_op->update_time(inode, time, flags);
+
+ if (flags & S_ATIME)
+ inode->i_atime = *time;
+ if (flags & S_VERSION)
+ inode_inc_iversion(inode);
+ if (flags & S_CTIME)
+ inode->i_ctime = *time;
+ if (flags & S_MTIME)
+ inode->i_mtime = *time;
+ mark_inode_dirty_sync(inode);
+ return 0;
+}
+
/**
* touch_atime - update the access time
- * @mnt: mount the inode is accessed on
- * @dentry: dentry accessed
+ * @path: the &struct path to update
*
* Update the accessed time on an inode and mark it for writeback.
* This function automatically handles read only file systems and media,
* as well as the "noatime" flag and inode specific "noatime" markers.
*/
-void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
+void touch_atime(struct path *path)
{
- struct inode *inode = dentry->d_inode;
+ struct vfsmount *mnt = path->mnt;
+ struct inode *inode = path->dentry->d_inode;
struct timespec now;
if (inode->i_flags & S_NOATIME)
if (timespec_equal(&inode->i_atime, &now))
return;
- if (mnt_want_write(mnt))
+ if (!sb_start_write_trylock(inode->i_sb))
return;
- inode->i_atime = now;
- mark_inode_dirty_sync(inode);
- mnt_drop_write(mnt);
+ if (__mnt_want_write(mnt))
+ goto skip_update;
+ /*
+ * File systems can error out when updating inodes if they need to
+ * allocate new space to modify an inode (such is the case for
+ * Btrfs), but since we touch atime while walking down the path we
+ * really don't care if we failed to update the atime of the file,
+ * so just ignore the return value.
+ * We may also fail on filesystems that have the ability to make parts
+ * of the fs read only, e.g. subvolumes in Btrfs.
+ */
+ update_time(inode, &now, S_ATIME);
+ __mnt_drop_write(mnt);
+skip_update:
+ sb_end_write(inode->i_sb);
}
EXPORT_SYMBOL(touch_atime);
+/*
+ * The logic we want is
+ *
+ * if suid or (sgid and xgrp)
+ * remove privs
+ */
+int should_remove_suid(struct dentry *dentry)
+{
+ umode_t mode = dentry->d_inode->i_mode;
+ int kill = 0;
+
+ /* suid always must be killed */
+ if (unlikely(mode & S_ISUID))
+ kill = ATTR_KILL_SUID;
+
+ /*
+ * sgid without any exec bits is just a mandatory locking mark; leave
+ * it alone. If some exec bits are set, it's a real sgid; kill it.
+ */
+ if (unlikely((mode & S_ISGID) && (mode & S_IXGRP)))
+ kill |= ATTR_KILL_SGID;
+
+ if (unlikely(kill && !capable(CAP_FSETID) && S_ISREG(mode)))
+ return kill;
+
+ return 0;
+}
+EXPORT_SYMBOL(should_remove_suid);
+
+static int __remove_suid(struct dentry *dentry, int kill)
+{
+ struct iattr newattrs;
+
+ newattrs.ia_valid = ATTR_FORCE | kill;
+ return notify_change(dentry, &newattrs);
+}
+
+int file_remove_suid(struct file *file)
+{
+ struct dentry *dentry = file->f_path.dentry;
+ struct inode *inode = dentry->d_inode;
+ int killsuid;
+ int killpriv;
+ int error = 0;
+
+ /* Fast path for nothing security related */
+ if (IS_NOSEC(inode))
+ return 0;
+
+ killsuid = should_remove_suid(dentry);
+ killpriv = security_inode_need_killpriv(dentry);
+
+ if (killpriv < 0)
+ return killpriv;
+ if (killpriv)
+ error = security_inode_killpriv(dentry);
+ if (!error && killsuid)
+ error = __remove_suid(dentry, killsuid);
+ if (!error && (inode->i_sb->s_flags & MS_NOSEC))
+ inode->i_flags |= S_NOSEC;
+
+ return error;
+}
+EXPORT_SYMBOL(file_remove_suid);
+
/**
* file_update_time - update mtime and ctime time
* @file: file accessed
* 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.
+ * timestamps are handled by the server. This can return an error for
+ * file systems who need to allocate space in order to update an inode.
*/
-void file_update_time(struct file *file)
+int file_update_time(struct file *file)
{
- struct inode *inode = file->f_path.dentry->d_inode;
+ struct inode *inode = file_inode(file);
struct timespec now;
- enum { S_MTIME = 1, S_CTIME = 2, S_VERSION = 4 } sync_it = 0;
+ int sync_it = 0;
+ int ret;
/* First try to exhaust all avenues to not sync */
if (IS_NOCMTIME(inode))
- return;
+ return 0;
now = current_fs_time(inode->i_sb);
if (!timespec_equal(&inode->i_mtime, &now))
sync_it |= S_VERSION;
if (!sync_it)
- return;
+ return 0;
/* Finally allowed to write? Takes lock. */
- if (mnt_want_write_file(file))
- return;
+ if (__mnt_want_write_file(file))
+ return 0;
- /* 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->f_path.mnt);
+ ret = update_time(inode, &now, sync_it);
+ __mnt_drop_write_file(file);
+
+ return ret;
}
EXPORT_SYMBOL(file_update_time);
*/
void __init inode_init_early(void)
{
- int loop;
+ unsigned int loop;
/* If hashes are distributed across NUMA nodes, defer
* hash allocation until vmalloc space is available.
HASH_EARLY,
&i_hash_shift,
&i_hash_mask,
+ 0,
0);
- for (loop = 0; loop < (1 << i_hash_shift); loop++)
+ for (loop = 0; loop < (1U << i_hash_shift); loop++)
INIT_HLIST_HEAD(&inode_hashtable[loop]);
}
void __init inode_init(void)
{
- int loop;
+ unsigned int loop;
/* inode slab cache */
inode_cachep = kmem_cache_create("inode_cache",
0,
&i_hash_shift,
&i_hash_mask,
+ 0,
0);
- for (loop = 0; loop < (1 << i_hash_shift); loop++)
+ for (loop = 0; loop < (1U << i_hash_shift); loop++)
INIT_HLIST_HEAD(&inode_hashtable[loop]);
}
* @mode: mode of the new inode
*/
void inode_init_owner(struct inode *inode, const struct inode *dir,
- mode_t mode)
+ umode_t mode)
{
inode->i_uid = current_fsuid();
if (dir && dir->i_mode & S_ISGID) {
*/
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)
+ if (uid_eq(current_fsuid(), inode->i_uid))
return true;
- if (ns_capable(ns, CAP_FOWNER))
+ if (inode_capable(inode, CAP_FOWNER))
return true;
return false;
}
EXPORT_SYMBOL(inode_owner_or_capable);
+
+/*
+ * Direct i/o helper functions
+ */
+static void __inode_dio_wait(struct inode *inode)
+{
+ wait_queue_head_t *wq = bit_waitqueue(&inode->i_state, __I_DIO_WAKEUP);
+ DEFINE_WAIT_BIT(q, &inode->i_state, __I_DIO_WAKEUP);
+
+ do {
+ prepare_to_wait(wq, &q.wait, TASK_UNINTERRUPTIBLE);
+ if (atomic_read(&inode->i_dio_count))
+ schedule();
+ } while (atomic_read(&inode->i_dio_count));
+ finish_wait(wq, &q.wait);
+}
+
+/**
+ * inode_dio_wait - wait for outstanding DIO requests to finish
+ * @inode: inode to wait for
+ *
+ * Waits for all pending direct I/O requests to finish so that we can
+ * proceed with a truncate or equivalent operation.
+ *
+ * Must be called under a lock that serializes taking new references
+ * to i_dio_count, usually by inode->i_mutex.
+ */
+void inode_dio_wait(struct inode *inode)
+{
+ if (atomic_read(&inode->i_dio_count))
+ __inode_dio_wait(inode);
+}
+EXPORT_SYMBOL(inode_dio_wait);
+
+/*
+ * inode_dio_done - signal finish of a direct I/O requests
+ * @inode: inode the direct I/O happens on
+ *
+ * This is called once we've finished processing a direct I/O request,
+ * and is used to wake up callers waiting for direct I/O to be quiesced.
+ */
+void inode_dio_done(struct inode *inode)
+{
+ if (atomic_dec_and_test(&inode->i_dio_count))
+ wake_up_bit(&inode->i_state, __I_DIO_WAKEUP);
+}
+EXPORT_SYMBOL(inode_dio_done);
Code Review / linux-3.10.git / blobdiff