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-rw-r--r--fs/inode.c596
1 files changed, 384 insertions, 212 deletions
diff --git a/fs/inode.c b/fs/inode.c
index fb10d86ffad..6eecb7ff0b9 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -2,31 +2,22 @@
* (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 <linux/list_lru.h>
#include "internal.h"
/*
@@ -34,7 +25,7 @@
*
* inode->i_lock protects:
* inode->i_state, inode->i_hash, __iget()
- * inode->i_sb->s_inode_lru_lock protects:
+ * Inode LRU list locks protect:
* inode->i_sb->s_inode_lru, inode->i_lru
* inode_sb_list_lock protects:
* sb->s_inodes, inode->i_sb_list
@@ -47,7 +38,7 @@
*
* inode_sb_list_lock
* inode->i_lock
- * inode->i_sb->s_inode_lru_lock
+ * Inode LRU list locks
*
* bdi->wb.list_lock
* inode->i_lock
@@ -80,33 +71,33 @@ EXPORT_SYMBOL(empty_aops);
*/
struct inodes_stat_t inodes_stat;
-static DEFINE_PER_CPU(unsigned int, nr_inodes);
-static DEFINE_PER_CPU(unsigned int, nr_unused);
+static DEFINE_PER_CPU(unsigned long, nr_inodes);
+static DEFINE_PER_CPU(unsigned long, nr_unused);
static struct kmem_cache *inode_cachep __read_mostly;
-static int get_nr_inodes(void)
+static long get_nr_inodes(void)
{
int i;
- int sum = 0;
+ long 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)
+static inline long get_nr_inodes_unused(void)
{
int i;
- int sum = 0;
+ long sum = 0;
for_each_possible_cpu(i)
sum += per_cpu(nr_unused, i);
return sum < 0 ? 0 : sum;
}
-int get_nr_dirty_inodes(void)
+long get_nr_dirty_inodes(void)
{
/* not actually dirty inodes, but a wild approximation */
- int nr_dirty = get_nr_inodes() - get_nr_inodes_unused();
+ long nr_dirty = get_nr_inodes() - get_nr_inodes_unused();
return nr_dirty > 0 ? nr_dirty : 0;
}
@@ -114,12 +105,12 @@ int get_nr_dirty_inodes(void)
* Handle nr_inode sysctl
*/
#ifdef CONFIG_SYSCTL
-int proc_nr_inodes(ctl_table *table, int write,
+int proc_nr_inodes(struct 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);
+ return proc_doulongvec_minmax(table, write, buffer, lenp, ppos);
}
#endif
@@ -145,8 +136,8 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
inode->i_fop = &empty_fops;
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;
@@ -175,7 +166,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
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;
@@ -192,7 +183,7 @@ int inode_init_always(struct super_block *sb, struct inode *inode)
}
inode->i_private = NULL;
inode->i_mapping = mapping;
- INIT_LIST_HEAD(&inode->i_dentry); /* buggered by rcu freeing */
+ 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
@@ -343,8 +334,10 @@ EXPORT_SYMBOL(set_nlink);
*/
void inc_nlink(struct inode *inode)
{
- if (WARN_ON(inode->i_nlink == 0))
+ if (unlikely(inode->i_nlink == 0)) {
+ WARN_ON(!(inode->i_state & I_LINKABLE));
atomic_long_dec(&inode->i_sb->s_remove_count);
+ }
inode->__i_nlink++;
}
@@ -358,7 +351,7 @@ void address_space_init_once(struct address_space *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);
@@ -409,24 +402,28 @@ 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++;
+ if (list_lru_add(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_inc(nr_unused);
- }
- 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);
- if (!list_empty(&inode->i_lru)) {
- list_del_init(&inode->i_lru);
- inode->i_sb->s_nr_inodes_unused--;
+
+ if (list_lru_del(&inode->i_sb->s_inode_lru, &inode->i_lru))
this_cpu_dec(nr_unused);
- }
- spin_unlock(&inode->i_sb->s_inode_lru_lock);
}
/**
@@ -496,7 +493,7 @@ void __remove_inode_hash(struct inode *inode)
}
EXPORT_SYMBOL(__remove_inode_hash);
-void end_writeback(struct inode *inode)
+void clear_inode(struct inode *inode)
{
might_sleep();
/*
@@ -506,15 +503,15 @@ void end_writeback(struct inode *inode)
*/
spin_lock_irq(&inode->i_data.tree_lock);
BUG_ON(inode->i_data.nrpages);
+ BUG_ON(inode->i_data.nrshadows);
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);
+EXPORT_SYMBOL(clear_inode);
/*
* Free the inode passed in, removing it from the lists it is still connected
@@ -541,12 +538,19 @@ static void evict(struct inode *inode)
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);
+ truncate_inode_pages_final(&inode->i_data);
+ clear_inode(inode);
}
if (S_ISBLK(inode->i_mode) && inode->i_bdev)
bd_forget(inode);
@@ -663,24 +667,8 @@ int invalidate_inodes(struct super_block *sb, bool kill_dirty)
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().
+ * Isolate the inode from the LRU in preparation for freeing it.
*
* Any inodes which are pinned purely because of attached pagecache have their
* pagecache removed. If the inode has metadata buffers attached to
@@ -694,89 +682,82 @@ static int can_unuse(struct inode *inode)
* 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)
+static enum lru_status
+inode_lru_isolate(struct list_head *item, spinlock_t *lru_lock, void *arg)
{
- LIST_HEAD(freeable);
- int nr_scanned;
- unsigned long reap = 0;
+ struct list_head *freeable = arg;
+ struct inode *inode = container_of(item, struct inode, i_lru);
- spin_lock(&sb->s_inode_lru_lock);
- for (nr_scanned = nr_to_scan; nr_scanned >= 0; nr_scanned--) {
- struct inode *inode;
+ /*
+ * we are inverting the lru lock/inode->i_lock here, so use a trylock.
+ * If we fail to get the lock, just skip it.
+ */
+ if (!spin_trylock(&inode->i_lock))
+ return LRU_SKIP;
- if (list_empty(&sb->s_inode_lru))
- break;
+ /*
+ * 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);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+ }
- inode = list_entry(sb->s_inode_lru.prev, struct inode, i_lru);
+ /* recently referenced inodes get one more pass */
+ if (inode->i_state & I_REFERENCED) {
+ inode->i_state &= ~I_REFERENCED;
+ spin_unlock(&inode->i_lock);
+ return LRU_ROTATE;
+ }
- /*
- * 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;
+ if (inode_has_buffers(inode) || inode->i_data.nrpages) {
+ __iget(inode);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(lru_lock);
+ if (remove_inode_buffers(inode)) {
+ unsigned long reap;
+ reap = invalidate_mapping_pages(&inode->i_data, 0, -1);
+ if (current_is_kswapd())
+ __count_vm_events(KSWAPD_INODESTEAL, reap);
+ else
+ __count_vm_events(PGINODESTEAL, reap);
+ if (current->reclaim_state)
+ current->reclaim_state->reclaimed_slab += reap;
}
+ iput(inode);
+ spin_lock(lru_lock);
+ return LRU_RETRY;
+ }
- /*
- * 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;
- }
+ WARN_ON(inode->i_state & I_NEW);
+ inode->i_state |= I_FREEING;
+ list_move(&inode->i_lru, freeable);
+ spin_unlock(&inode->i_lock);
- /* 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);
+ this_cpu_dec(nr_unused);
+ return LRU_REMOVED;
+}
- 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;
+/*
+ * 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().
+ */
+long prune_icache_sb(struct super_block *sb, unsigned long nr_to_scan,
+ int nid)
+{
+ LIST_HEAD(freeable);
+ long freed;
+ freed = list_lru_walk_node(&sb->s_inode_lru, nid, inode_lru_isolate,
+ &freeable, &nr_to_scan);
dispose_list(&freeable);
+ return freed;
}
static void __wait_on_freeing_inode(struct inode *inode);
@@ -788,20 +769,15 @@ static struct inode *find_inode(struct super_block *sb,
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);
+ hlist_for_each_entry(inode, head, i_hash) {
+ if (inode->i_sb != sb)
continue;
- }
- if (!test(inode, data)) {
- spin_unlock(&inode->i_lock);
+ if (!test(inode, data))
continue;
- }
+ spin_lock(&inode->i_lock);
if (inode->i_state & (I_FREEING|I_WILL_FREE)) {
__wait_on_freeing_inode(inode);
goto repeat;
@@ -820,20 +796,15 @@ repeat:
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);
+ hlist_for_each_entry(inode, head, i_hash) {
+ if (inode->i_ino != ino)
continue;
- }
- if (inode->i_sb != sb) {
- spin_unlock(&inode->i_lock);
+ if (inode->i_sb != sb)
continue;
- }
+ spin_lock(&inode->i_lock);
if (inode->i_state & (I_FREEING|I_WILL_FREE)) {
__wait_on_freeing_inode(inode);
goto repeat;
@@ -938,8 +909,7 @@ void lockdep_annotate_inode_mutex_key(struct inode *inode)
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
*/
@@ -966,12 +936,48 @@ void unlock_new_inode(struct inode *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);
/**
+ * lock_two_nondirectories - take two i_mutexes on non-directory objects
+ *
+ * Lock any non-NULL argument that is not a directory.
+ * Zero, one or two objects may be locked by this function.
+ *
+ * @inode1: first inode to lock
+ * @inode2: second inode to lock
+ */
+void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
+{
+ if (inode1 > inode2)
+ swap(inode1, inode2);
+
+ if (inode1 && !S_ISDIR(inode1->i_mode))
+ mutex_lock(&inode1->i_mutex);
+ if (inode2 && !S_ISDIR(inode2->i_mode) && inode2 != inode1)
+ mutex_lock_nested(&inode2->i_mutex, I_MUTEX_NONDIR2);
+}
+EXPORT_SYMBOL(lock_two_nondirectories);
+
+/**
+ * unlock_two_nondirectories - release locks from lock_two_nondirectories()
+ * @inode1: first inode to unlock
+ * @inode2: second inode to unlock
+ */
+void unlock_two_nondirectories(struct inode *inode1, struct inode *inode2)
+{
+ if (inode1 && !S_ISDIR(inode1->i_mode))
+ mutex_unlock(&inode1->i_mutex);
+ if (inode2 && !S_ISDIR(inode2->i_mode) && inode2 != inode1)
+ mutex_unlock(&inode2->i_mutex);
+}
+EXPORT_SYMBOL(unlock_two_nondirectories);
+
+/**
* iget5_locked - obtain an inode from a mounted file system
* @sb: super block of file system
* @hashval: hash value (usually inode number) to get
@@ -1122,11 +1128,10 @@ EXPORT_SYMBOL(iget_locked);
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;
@@ -1281,10 +1286,9 @@ int insert_inode_locked(struct inode *inode)
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)
@@ -1296,7 +1300,7 @@ int insert_inode_locked(struct inode *inode)
}
break;
}
- if (likely(!node)) {
+ if (likely(!old)) {
spin_lock(&inode->i_lock);
inode->i_state |= I_NEW;
hlist_add_head(&inode->i_hash, head);
@@ -1324,11 +1328,10 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval,
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))
@@ -1340,7 +1343,7 @@ int insert_inode_locked4(struct inode *inode, unsigned long hashval,
}
break;
}
- if (likely(!node)) {
+ if (likely(!old)) {
spin_lock(&inode->i_lock);
inode->i_state |= I_NEW;
hlist_add_head(&inode->i_hash, head);
@@ -1369,17 +1372,6 @@ int generic_delete_inode(struct inode *inode)
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.
*
@@ -1404,8 +1396,7 @@ static void iput_final(struct 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);
+ inode_add_lru(inode);
spin_unlock(&inode->i_lock);
return;
}
@@ -1501,18 +1492,39 @@ static int relatime_need_update(struct vfsmount *mnt, struct inode *inode,
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(const 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)
@@ -1535,15 +1547,96 @@ void touch_atime(struct vfsmount *mnt, struct dentry *dentry)
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;
+ /*
+ * Note we call this on write, so notify_change will not
+ * encounter any conflicting delegations:
+ */
+ return notify_change(dentry, &newattrs, NULL);
+}
+
+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
@@ -1553,18 +1646,20 @@ EXPORT_SYMBOL(touch_atime);
* 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))
@@ -1577,21 +1672,16 @@ void file_update_time(struct file *file)
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(file);
+ ret = update_time(inode, &now, sync_it);
+ __mnt_drop_write_file(file);
+
+ return ret;
}
EXPORT_SYMBOL(file_update_time);
@@ -1651,7 +1741,7 @@ __setup("ihash_entries=", set_ihash_entries);
*/
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.
@@ -1667,15 +1757,16 @@ void __init inode_init_early(void)
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",
@@ -1697,9 +1788,10 @@ void __init inode_init(void)
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]);
}
@@ -1713,7 +1805,7 @@ void init_special_inode(struct inode *inode, umode_t mode, dev_t rdev)
inode->i_fop = &def_blk_fops;
inode->i_rdev = rdev;
} else if (S_ISFIFO(mode))
- inode->i_fop = &def_fifo_fops;
+ inode->i_fop = &pipefifo_fops;
else if (S_ISSOCK(mode))
inode->i_fop = &bad_sock_fops;
else
@@ -1747,17 +1839,97 @@ 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.
+ * Return true if current either has CAP_FOWNER in a namespace with the
+ * inode owner uid mapped, or owns the file.
*/
bool inode_owner_or_capable(const struct inode *inode)
{
- struct user_namespace *ns = inode_userns(inode);
+ struct user_namespace *ns;
- 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))
+
+ ns = current_user_ns();
+ if (ns_capable(ns, CAP_FOWNER) && kuid_has_mapping(ns, inode->i_uid))
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);
+
+/*
+ * inode_set_flags - atomically set some inode flags
+ *
+ * Note: the caller should be holding i_mutex, or else be sure that
+ * they have exclusive access to the inode structure (i.e., while the
+ * inode is being instantiated). The reason for the cmpxchg() loop
+ * --- which wouldn't be necessary if all code paths which modify
+ * i_flags actually followed this rule, is that there is at least one
+ * code path which doesn't today --- for example,
+ * __generic_file_aio_write() calls file_remove_suid() without holding
+ * i_mutex --- so we use cmpxchg() out of an abundance of caution.
+ *
+ * In the long run, i_mutex is overkill, and we should probably look
+ * at using the i_lock spinlock to protect i_flags, and then make sure
+ * it is so documented in include/linux/fs.h and that all code follows
+ * the locking convention!!
+ */
+void inode_set_flags(struct inode *inode, unsigned int flags,
+ unsigned int mask)
+{
+ unsigned int old_flags, new_flags;
+
+ WARN_ON_ONCE(flags & ~mask);
+ do {
+ old_flags = ACCESS_ONCE(inode->i_flags);
+ new_flags = (old_flags & ~mask) | flags;
+ } while (unlikely(cmpxchg(&inode->i_flags, old_flags,
+ new_flags) != old_flags));
+}
+EXPORT_SYMBOL(inode_set_flags);