Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
fs: simplify iget & friends
fs: pull inode->i_lock up out of writeback_single_inode
fs: rename inode_lock to inode_hash_lock
fs: move i_wb_list out from under inode_lock
fs: move i_sb_list out from under inode_lock
fs: remove inode_lock from iput_final and prune_icache
fs: Lock the inode LRU list separately
fs: factor inode disposal
fs: protect inode->i_state with inode->i_lock
autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
autofs4 - remove autofs4_lock
autofs4 - fix d_manage() return on rcu-walk
autofs4 - fix autofs4_expire_indirect() traversal
autofs4 - fix dentry leak in autofs4_expire_direct()
autofs4 - reinstate last used update on access
vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index 2e994ef..61b31ac 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -128,7 +128,7 @@
destroy_inode:
dirty_inode: (must not sleep)
write_inode:
-drop_inode: !!!inode_lock!!!
+drop_inode: !!!inode->i_lock!!!
evict_inode:
put_super: write
write_super: read
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 0c986c9..6e29954 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -298,11 +298,14 @@
remaining links or not. Caller does *not* evict the pagecache or inode-associated
metadata buffers; getting rid of those is responsibility of method, as it had
been for ->delete_inode().
- ->drop_inode() returns int now; it's called on final iput() with inode_lock
-held and it returns true if filesystems wants the inode to be dropped. As before,
-generic_drop_inode() is still the default and it's been updated appropriately.
-generic_delete_inode() is also alive and it consists simply of return 1. Note that
-all actual eviction work is done by caller after ->drop_inode() returns.
+
+ ->drop_inode() returns int now; it's called on final iput() with
+inode->i_lock held and it returns true if filesystems wants the inode to be
+dropped. As before, generic_drop_inode() is still the default and it's been
+updated appropriately. generic_delete_inode() is also alive and it consists
+simply of return 1. Note that all actual eviction work is done by caller after
+->drop_inode() returns.
+
clear_inode() is gone; use end_writeback() instead. As before, it must
be called exactly once on each call of ->evict_inode() (as it used to be for
each call of ->delete_inode()). Unlike before, if you are using inode-associated
@@ -397,6 +400,9 @@
--
[mandatory]
+
+--
+[mandatory]
->get_sb() is gone. Switch to use of ->mount(). Typically it's just
a matter of switching from calling get_sb_... to mount_... and changing the
function type. If you were doing it manually, just switch from setting ->mnt_root
diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt
index 306f0ae..80815ed 100644
--- a/Documentation/filesystems/vfs.txt
+++ b/Documentation/filesystems/vfs.txt
@@ -254,7 +254,7 @@
should be synchronous or not, not all filesystems check this flag.
drop_inode: called when the last access to the inode is dropped,
- with the inode_lock spinlock held.
+ with the inode->i_lock spinlock held.
This method should be either NULL (normal UNIX filesystem
semantics) or "generic_delete_inode" (for filesystems that do not
diff --git a/fs/autofs4/autofs_i.h b/fs/autofs4/autofs_i.h
index 54f9237..475f9c5 100644
--- a/fs/autofs4/autofs_i.h
+++ b/fs/autofs4/autofs_i.h
@@ -61,8 +61,6 @@
current->pid, __func__, ##args); \
} while (0)
-extern spinlock_t autofs4_lock;
-
/* Unified info structure. This is pointed to by both the dentry and
inode structures. Each file in the filesystem has an instance of this
structure. It holds a reference to the dentry, so dentries are never
diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c
index 1442da4..509fe1e 100644
--- a/fs/autofs4/dev-ioctl.c
+++ b/fs/autofs4/dev-ioctl.c
@@ -372,6 +372,10 @@
return -EBUSY;
} else {
struct file *pipe = fget(pipefd);
+ if (!pipe) {
+ err = -EBADF;
+ goto out;
+ }
if (!pipe->f_op || !pipe->f_op->write) {
err = -EPIPE;
fput(pipe);
diff --git a/fs/autofs4/expire.c b/fs/autofs4/expire.c
index f43100b..450f529 100644
--- a/fs/autofs4/expire.c
+++ b/fs/autofs4/expire.c
@@ -87,18 +87,70 @@
}
/*
+ * Calculate and dget next entry in the subdirs list under root.
+ */
+static struct dentry *get_next_positive_subdir(struct dentry *prev,
+ struct dentry *root)
+{
+ struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
+ struct list_head *next;
+ struct dentry *p, *q;
+
+ spin_lock(&sbi->lookup_lock);
+
+ if (prev == NULL) {
+ spin_lock(&root->d_lock);
+ prev = dget_dlock(root);
+ next = prev->d_subdirs.next;
+ p = prev;
+ goto start;
+ }
+
+ p = prev;
+ spin_lock(&p->d_lock);
+again:
+ next = p->d_u.d_child.next;
+start:
+ if (next == &root->d_subdirs) {
+ spin_unlock(&p->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+ dput(prev);
+ return NULL;
+ }
+
+ q = list_entry(next, struct dentry, d_u.d_child);
+
+ spin_lock_nested(&q->d_lock, DENTRY_D_LOCK_NESTED);
+ /* Negative dentry - try next */
+ if (!simple_positive(q)) {
+ spin_unlock(&p->d_lock);
+ p = q;
+ goto again;
+ }
+ dget_dlock(q);
+ spin_unlock(&q->d_lock);
+ spin_unlock(&p->d_lock);
+ spin_unlock(&sbi->lookup_lock);
+
+ dput(prev);
+
+ return q;
+}
+
+/*
* Calculate and dget next entry in top down tree traversal.
*/
static struct dentry *get_next_positive_dentry(struct dentry *prev,
struct dentry *root)
{
+ struct autofs_sb_info *sbi = autofs4_sbi(root->d_sb);
struct list_head *next;
struct dentry *p, *ret;
if (prev == NULL)
return dget(root);
- spin_lock(&autofs4_lock);
+ spin_lock(&sbi->lookup_lock);
relock:
p = prev;
spin_lock(&p->d_lock);
@@ -110,7 +162,7 @@
if (p == root) {
spin_unlock(&p->d_lock);
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->lookup_lock);
dput(prev);
return NULL;
}
@@ -140,7 +192,7 @@
dget_dlock(ret);
spin_unlock(&ret->d_lock);
spin_unlock(&p->d_lock);
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->lookup_lock);
dput(prev);
@@ -290,11 +342,8 @@
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(root);
/* No point expiring a pending mount */
- if (ino->flags & AUTOFS_INF_PENDING) {
- spin_unlock(&sbi->fs_lock);
- return NULL;
- }
- managed_dentry_set_transit(root);
+ if (ino->flags & AUTOFS_INF_PENDING)
+ goto out;
if (!autofs4_direct_busy(mnt, root, timeout, do_now)) {
struct autofs_info *ino = autofs4_dentry_ino(root);
ino->flags |= AUTOFS_INF_EXPIRING;
@@ -302,7 +351,7 @@
spin_unlock(&sbi->fs_lock);
return root;
}
- managed_dentry_clear_transit(root);
+out:
spin_unlock(&sbi->fs_lock);
dput(root);
@@ -336,13 +385,12 @@
timeout = sbi->exp_timeout;
dentry = NULL;
- while ((dentry = get_next_positive_dentry(dentry, root))) {
+ while ((dentry = get_next_positive_subdir(dentry, root))) {
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
/* No point expiring a pending mount */
if (ino->flags & AUTOFS_INF_PENDING)
- goto cont;
- managed_dentry_set_transit(dentry);
+ goto next;
/*
* Case 1: (i) indirect mount or top level pseudo direct mount
@@ -402,8 +450,6 @@
}
}
next:
- managed_dentry_clear_transit(dentry);
-cont:
spin_unlock(&sbi->fs_lock);
}
return NULL;
@@ -415,13 +461,13 @@
ino->flags |= AUTOFS_INF_EXPIRING;
init_completion(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
- spin_lock(&autofs4_lock);
+ spin_lock(&sbi->lookup_lock);
spin_lock(&expired->d_parent->d_lock);
spin_lock_nested(&expired->d_lock, DENTRY_D_LOCK_NESTED);
list_move(&expired->d_parent->d_subdirs, &expired->d_u.d_child);
spin_unlock(&expired->d_lock);
spin_unlock(&expired->d_parent->d_lock);
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->lookup_lock);
return expired;
}
@@ -484,8 +530,6 @@
spin_lock(&sbi->fs_lock);
ino = autofs4_dentry_ino(dentry);
ino->flags &= ~AUTOFS_INF_EXPIRING;
- if (!d_unhashed(dentry))
- managed_dentry_clear_transit(dentry);
complete_all(&ino->expire_complete);
spin_unlock(&sbi->fs_lock);
@@ -513,9 +557,7 @@
spin_lock(&sbi->fs_lock);
ino->flags &= ~AUTOFS_INF_EXPIRING;
spin_lock(&dentry->d_lock);
- if (ret)
- __managed_dentry_clear_transit(dentry);
- else {
+ if (!ret) {
if ((IS_ROOT(dentry) ||
(autofs_type_indirect(sbi->type) &&
IS_ROOT(dentry->d_parent))) &&
diff --git a/fs/autofs4/root.c b/fs/autofs4/root.c
index e6f84d2..96804a1 100644
--- a/fs/autofs4/root.c
+++ b/fs/autofs4/root.c
@@ -23,8 +23,6 @@
#include "autofs_i.h"
-DEFINE_SPINLOCK(autofs4_lock);
-
static int autofs4_dir_symlink(struct inode *,struct dentry *,const char *);
static int autofs4_dir_unlink(struct inode *,struct dentry *);
static int autofs4_dir_rmdir(struct inode *,struct dentry *);
@@ -125,15 +123,15 @@
* autofs file system so just let the libfs routines handle
* it.
*/
- spin_lock(&autofs4_lock);
+ spin_lock(&sbi->lookup_lock);
spin_lock(&dentry->d_lock);
if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->lookup_lock);
return -ENOENT;
}
spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->lookup_lock);
out:
return dcache_dir_open(inode, file);
@@ -171,7 +169,6 @@
const unsigned char *str = name->name;
struct list_head *p, *head;
- spin_lock(&autofs4_lock);
spin_lock(&sbi->lookup_lock);
head = &sbi->active_list;
list_for_each(p, head) {
@@ -204,14 +201,12 @@
dget_dlock(active);
spin_unlock(&active->d_lock);
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&autofs4_lock);
return active;
}
next:
spin_unlock(&active->d_lock);
}
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&autofs4_lock);
return NULL;
}
@@ -226,7 +221,6 @@
const unsigned char *str = name->name;
struct list_head *p, *head;
- spin_lock(&autofs4_lock);
spin_lock(&sbi->lookup_lock);
head = &sbi->expiring_list;
list_for_each(p, head) {
@@ -259,14 +253,12 @@
dget_dlock(expiring);
spin_unlock(&expiring->d_lock);
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&autofs4_lock);
return expiring;
}
next:
spin_unlock(&expiring->d_lock);
}
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&autofs4_lock);
return NULL;
}
@@ -275,17 +267,16 @@
{
struct autofs_sb_info *sbi = autofs4_sbi(dentry->d_sb);
struct autofs_info *ino = autofs4_dentry_ino(dentry);
- int status;
+ int status = 0;
if (ino->flags & AUTOFS_INF_PENDING) {
DPRINTK("waiting for mount name=%.*s",
dentry->d_name.len, dentry->d_name.name);
status = autofs4_wait(sbi, dentry, NFY_MOUNT);
DPRINTK("mount wait done status=%d", status);
- ino->last_used = jiffies;
- return status;
}
- return 0;
+ ino->last_used = jiffies;
+ return status;
}
static int do_expire_wait(struct dentry *dentry)
@@ -319,9 +310,12 @@
*/
if (autofs_type_indirect(sbi->type) && d_unhashed(dentry)) {
struct dentry *parent = dentry->d_parent;
+ struct autofs_info *ino;
struct dentry *new = d_lookup(parent, &dentry->d_name);
if (!new)
return NULL;
+ ino = autofs4_dentry_ino(new);
+ ino->last_used = jiffies;
dput(path->dentry);
path->dentry = new;
}
@@ -338,18 +332,6 @@
DPRINTK("dentry=%p %.*s",
dentry, dentry->d_name.len, dentry->d_name.name);
- /*
- * Someone may have manually umounted this or it was a submount
- * that has gone away.
- */
- spin_lock(&dentry->d_lock);
- if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
- if (!(dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
- (dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
- __managed_dentry_set_transit(path->dentry);
- }
- spin_unlock(&dentry->d_lock);
-
/* The daemon never triggers a mount. */
if (autofs4_oz_mode(sbi))
return NULL;
@@ -418,18 +400,17 @@
done:
if (!(ino->flags & AUTOFS_INF_EXPIRING)) {
/*
- * Any needed mounting has been completed and the path updated
- * so turn this into a normal dentry so we don't continually
- * call ->d_automount() and ->d_manage().
- */
- spin_lock(&dentry->d_lock);
- __managed_dentry_clear_transit(dentry);
- /*
+ * Any needed mounting has been completed and the path
+ * updated so clear DCACHE_NEED_AUTOMOUNT so we don't
+ * call ->d_automount() on rootless multi-mounts since
+ * it can lead to an incorrect ELOOP error return.
+ *
* Only clear DMANAGED_AUTOMOUNT for rootless multi-mounts and
* symlinks as in all other cases the dentry will be covered by
* an actual mount so ->d_automount() won't be called during
* the follow.
*/
+ spin_lock(&dentry->d_lock);
if ((!d_mountpoint(dentry) &&
!list_empty(&dentry->d_subdirs)) ||
(dentry->d_inode && S_ISLNK(dentry->d_inode->i_mode)))
@@ -455,6 +436,8 @@
/* The daemon never waits. */
if (autofs4_oz_mode(sbi)) {
+ if (rcu_walk)
+ return 0;
if (!d_mountpoint(dentry))
return -EISDIR;
return 0;
@@ -612,12 +595,12 @@
dir->i_mtime = CURRENT_TIME;
- spin_lock(&autofs4_lock);
- autofs4_add_expiring(dentry);
+ spin_lock(&sbi->lookup_lock);
+ __autofs4_add_expiring(dentry);
spin_lock(&dentry->d_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->lookup_lock);
return 0;
}
@@ -686,20 +669,17 @@
if (!autofs4_oz_mode(sbi))
return -EACCES;
- spin_lock(&autofs4_lock);
spin_lock(&sbi->lookup_lock);
spin_lock(&dentry->d_lock);
if (!list_empty(&dentry->d_subdirs)) {
spin_unlock(&dentry->d_lock);
spin_unlock(&sbi->lookup_lock);
- spin_unlock(&autofs4_lock);
return -ENOTEMPTY;
}
__autofs4_add_expiring(dentry);
- spin_unlock(&sbi->lookup_lock);
__d_drop(dentry);
spin_unlock(&dentry->d_lock);
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->lookup_lock);
if (sbi->version < 5)
autofs_clear_leaf_automount_flags(dentry);
diff --git a/fs/autofs4/waitq.c b/fs/autofs4/waitq.c
index 5601005..2543598 100644
--- a/fs/autofs4/waitq.c
+++ b/fs/autofs4/waitq.c
@@ -197,12 +197,12 @@
seq = read_seqbegin(&rename_lock);
rcu_read_lock();
- spin_lock(&autofs4_lock);
+ spin_lock(&sbi->fs_lock);
for (tmp = dentry ; tmp != root ; tmp = tmp->d_parent)
len += tmp->d_name.len + 1;
if (!len || --len > NAME_MAX) {
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->fs_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
@@ -218,7 +218,7 @@
p -= tmp->d_name.len;
strncpy(p, tmp->d_name.name, tmp->d_name.len);
}
- spin_unlock(&autofs4_lock);
+ spin_unlock(&sbi->fs_lock);
rcu_read_unlock();
if (read_seqretry(&rename_lock, seq))
goto rename_retry;
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 7d02afb..c1511c6 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -55,11 +55,13 @@
static void bdev_inode_switch_bdi(struct inode *inode,
struct backing_dev_info *dst)
{
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
+ spin_lock(&inode->i_lock);
inode->i_data.backing_dev_info = dst;
if (inode->i_state & I_DIRTY)
list_move(&inode->i_wb_list, &dst->wb.b_dirty);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_wb_list_lock);
}
static sector_t max_block(struct block_device *bdev)
diff --git a/fs/buffer.c b/fs/buffer.c
index 2e6b1a3..a08bb8e 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -1138,7 +1138,7 @@
* inode list.
*
* mark_buffer_dirty() is atomic. It takes bh->b_page->mapping->private_lock,
- * mapping->tree_lock and the global inode_lock.
+ * mapping->tree_lock and mapping->host->i_lock.
*/
void mark_buffer_dirty(struct buffer_head *bh)
{
diff --git a/fs/drop_caches.c b/fs/drop_caches.c
index 816f88e..98b77c8 100644
--- a/fs/drop_caches.c
+++ b/fs/drop_caches.c
@@ -8,6 +8,7 @@
#include <linux/writeback.h>
#include <linux/sysctl.h>
#include <linux/gfp.h>
+#include "internal.h"
/* A global variable is a bit ugly, but it keeps the code simple */
int sysctl_drop_caches;
@@ -16,20 +17,23 @@
{
struct inode *inode, *toput_inode = NULL;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
- if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+ spin_lock(&inode->i_lock);
+ if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
+ (inode->i_mapping->nrpages == 0)) {
+ spin_unlock(&inode->i_lock);
continue;
- if (inode->i_mapping->nrpages == 0)
- continue;
+ }
__iget(inode);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_sb_list_lock);
invalidate_mapping_pages(inode->i_mapping, 0, -1);
iput(toput_inode);
toput_inode = inode;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(toput_inode);
}
diff --git a/fs/fs-writeback.c b/fs/fs-writeback.c
index 59c6e49..b5ed541 100644
--- a/fs/fs-writeback.c
+++ b/fs/fs-writeback.c
@@ -176,6 +176,17 @@
}
/*
+ * Remove the inode from the writeback list it is on.
+ */
+void inode_wb_list_del(struct inode *inode)
+{
+ spin_lock(&inode_wb_list_lock);
+ list_del_init(&inode->i_wb_list);
+ spin_unlock(&inode_wb_list_lock);
+}
+
+
+/*
* Redirty an inode: set its when-it-was dirtied timestamp and move it to the
* furthest end of its superblock's dirty-inode list.
*
@@ -188,6 +199,7 @@
{
struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
+ assert_spin_locked(&inode_wb_list_lock);
if (!list_empty(&wb->b_dirty)) {
struct inode *tail;
@@ -205,14 +217,17 @@
{
struct bdi_writeback *wb = &inode_to_bdi(inode)->wb;
+ assert_spin_locked(&inode_wb_list_lock);
list_move(&inode->i_wb_list, &wb->b_more_io);
}
static void inode_sync_complete(struct inode *inode)
{
/*
- * Prevent speculative execution through spin_unlock(&inode_lock);
+ * Prevent speculative execution through
+ * spin_unlock(&inode_wb_list_lock);
*/
+
smp_mb();
wake_up_bit(&inode->i_state, __I_SYNC);
}
@@ -286,6 +301,7 @@
*/
static void queue_io(struct bdi_writeback *wb, unsigned long *older_than_this)
{
+ assert_spin_locked(&inode_wb_list_lock);
list_splice_init(&wb->b_more_io, &wb->b_io);
move_expired_inodes(&wb->b_dirty, &wb->b_io, older_than_this);
}
@@ -306,25 +322,25 @@
wait_queue_head_t *wqh;
wqh = bit_waitqueue(&inode->i_state, __I_SYNC);
- while (inode->i_state & I_SYNC) {
- spin_unlock(&inode_lock);
+ while (inode->i_state & I_SYNC) {
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_wb_list_lock);
__wait_on_bit(wqh, &wq, inode_wait, TASK_UNINTERRUPTIBLE);
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
+ spin_lock(&inode->i_lock);
}
}
/*
- * Write out an inode's dirty pages. Called under inode_lock. Either the
- * caller has ref on the inode (either via __iget or via syscall against an fd)
- * or the inode has I_WILL_FREE set (via generic_forget_inode)
+ * Write out an inode's dirty pages. Called under inode_wb_list_lock and
+ * inode->i_lock. Either the caller has an active reference on the inode or
+ * the inode has I_WILL_FREE set.
*
* If `wait' is set, wait on the writeout.
*
* The whole writeout design is quite complex and fragile. We want to avoid
* starvation of particular inodes when others are being redirtied, prevent
* livelocks, etc.
- *
- * Called under inode_lock.
*/
static int
writeback_single_inode(struct inode *inode, struct writeback_control *wbc)
@@ -333,6 +349,9 @@
unsigned dirty;
int ret;
+ assert_spin_locked(&inode_wb_list_lock);
+ assert_spin_locked(&inode->i_lock);
+
if (!atomic_read(&inode->i_count))
WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING)));
else
@@ -363,7 +382,8 @@
/* Set I_SYNC, reset I_DIRTY_PAGES */
inode->i_state |= I_SYNC;
inode->i_state &= ~I_DIRTY_PAGES;
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_wb_list_lock);
ret = do_writepages(mapping, wbc);
@@ -383,10 +403,10 @@
* due to delalloc, clear dirty metadata flags right before
* write_inode()
*/
- spin_lock(&inode_lock);
+ spin_lock(&inode->i_lock);
dirty = inode->i_state & I_DIRTY;
inode->i_state &= ~(I_DIRTY_SYNC | I_DIRTY_DATASYNC);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
/* Don't write the inode if only I_DIRTY_PAGES was set */
if (dirty & (I_DIRTY_SYNC | I_DIRTY_DATASYNC)) {
int err = write_inode(inode, wbc);
@@ -394,7 +414,8 @@
ret = err;
}
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
+ spin_lock(&inode->i_lock);
inode->i_state &= ~I_SYNC;
if (!(inode->i_state & I_FREEING)) {
if (mapping_tagged(mapping, PAGECACHE_TAG_DIRTY)) {
@@ -506,7 +527,9 @@
* kind does not need peridic writeout yet, and for the latter
* kind writeout is handled by the freer.
*/
+ spin_lock(&inode->i_lock);
if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
+ spin_unlock(&inode->i_lock);
requeue_io(inode);
continue;
}
@@ -515,10 +538,13 @@
* Was this inode dirtied after sync_sb_inodes was called?
* This keeps sync from extra jobs and livelock.
*/
- if (inode_dirtied_after(inode, wbc->wb_start))
+ if (inode_dirtied_after(inode, wbc->wb_start)) {
+ spin_unlock(&inode->i_lock);
return 1;
+ }
__iget(inode);
+
pages_skipped = wbc->pages_skipped;
writeback_single_inode(inode, wbc);
if (wbc->pages_skipped != pages_skipped) {
@@ -528,10 +554,11 @@
*/
redirty_tail(inode);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_wb_list_lock);
iput(inode);
cond_resched();
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
if (wbc->nr_to_write <= 0) {
wbc->more_io = 1;
return 1;
@@ -550,7 +577,7 @@
if (!wbc->wb_start)
wbc->wb_start = jiffies; /* livelock avoidance */
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
if (!wbc->for_kupdate || list_empty(&wb->b_io))
queue_io(wb, wbc->older_than_this);
@@ -568,7 +595,7 @@
if (ret)
break;
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
/* Leave any unwritten inodes on b_io */
}
@@ -577,11 +604,11 @@
{
WARN_ON(!rwsem_is_locked(&sb->s_umount));
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
if (!wbc->for_kupdate || list_empty(&wb->b_io))
queue_io(wb, wbc->older_than_this);
writeback_sb_inodes(sb, wb, wbc, true);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
}
/*
@@ -720,13 +747,15 @@
* become available for writeback. Otherwise
* we'll just busyloop.
*/
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
if (!list_empty(&wb->b_more_io)) {
inode = wb_inode(wb->b_more_io.prev);
trace_wbc_writeback_wait(&wbc, wb->bdi);
+ spin_lock(&inode->i_lock);
inode_wait_for_writeback(inode);
+ spin_unlock(&inode->i_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
}
return wrote;
@@ -992,7 +1021,6 @@
{
struct super_block *sb = inode->i_sb;
struct backing_dev_info *bdi = NULL;
- bool wakeup_bdi = false;
/*
* Don't do this for I_DIRTY_PAGES - that doesn't actually
@@ -1016,7 +1044,7 @@
if (unlikely(block_dump))
block_dump___mark_inode_dirty(inode);
- spin_lock(&inode_lock);
+ spin_lock(&inode->i_lock);
if ((inode->i_state & flags) != flags) {
const int was_dirty = inode->i_state & I_DIRTY;
@@ -1028,7 +1056,7 @@
* superblock list, based upon its state.
*/
if (inode->i_state & I_SYNC)
- goto out;
+ goto out_unlock_inode;
/*
* Only add valid (hashed) inodes to the superblock's
@@ -1036,16 +1064,17 @@
*/
if (!S_ISBLK(inode->i_mode)) {
if (inode_unhashed(inode))
- goto out;
+ goto out_unlock_inode;
}
if (inode->i_state & I_FREEING)
- goto out;
+ goto out_unlock_inode;
/*
* If the inode was already on b_dirty/b_io/b_more_io, don't
* reposition it (that would break b_dirty time-ordering).
*/
if (!was_dirty) {
+ bool wakeup_bdi = false;
bdi = inode_to_bdi(inode);
if (bdi_cap_writeback_dirty(bdi)) {
@@ -1062,15 +1091,20 @@
wakeup_bdi = true;
}
+ spin_unlock(&inode->i_lock);
+ spin_lock(&inode_wb_list_lock);
inode->dirtied_when = jiffies;
list_move(&inode->i_wb_list, &bdi->wb.b_dirty);
+ spin_unlock(&inode_wb_list_lock);
+
+ if (wakeup_bdi)
+ bdi_wakeup_thread_delayed(bdi);
+ return;
}
}
-out:
- spin_unlock(&inode_lock);
+out_unlock_inode:
+ spin_unlock(&inode->i_lock);
- if (wakeup_bdi)
- bdi_wakeup_thread_delayed(bdi);
}
EXPORT_SYMBOL(__mark_inode_dirty);
@@ -1101,7 +1135,7 @@
*/
WARN_ON(!rwsem_is_locked(&sb->s_umount));
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
/*
* Data integrity sync. Must wait for all pages under writeback,
@@ -1111,22 +1145,25 @@
* we still have to wait for that writeout.
*/
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
- struct address_space *mapping;
+ struct address_space *mapping = inode->i_mapping;
- if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+ spin_lock(&inode->i_lock);
+ if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
+ (mapping->nrpages == 0)) {
+ spin_unlock(&inode->i_lock);
continue;
- mapping = inode->i_mapping;
- if (mapping->nrpages == 0)
- continue;
+ }
__iget(inode);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_sb_list_lock);
+
/*
- * We hold a reference to 'inode' so it couldn't have
- * been removed from s_inodes list while we dropped the
- * inode_lock. We cannot iput the inode now as we can
- * be holding the last reference and we cannot iput it
- * under inode_lock. So we keep the reference and iput
- * it later.
+ * We hold a reference to 'inode' so it couldn't have been
+ * removed from s_inodes list while we dropped the
+ * inode_sb_list_lock. We cannot iput the inode now as we can
+ * be holding the last reference and we cannot iput it under
+ * inode_sb_list_lock. So we keep the reference and iput it
+ * later.
*/
iput(old_inode);
old_inode = inode;
@@ -1135,9 +1172,9 @@
cond_resched();
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(old_inode);
}
@@ -1271,9 +1308,11 @@
wbc.nr_to_write = 0;
might_sleep();
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
+ spin_lock(&inode->i_lock);
ret = writeback_single_inode(inode, &wbc);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_wb_list_lock);
if (sync)
inode_sync_wait(inode);
return ret;
@@ -1295,9 +1334,11 @@
{
int ret;
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
+ spin_lock(&inode->i_lock);
ret = writeback_single_inode(inode, wbc);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_wb_list_lock);
return ret;
}
EXPORT_SYMBOL(sync_inode);
diff --git a/fs/inode.c b/fs/inode.c
index 0b3da4a..05a1f75 100644
--- a/fs/inode.c
+++ b/fs/inode.c
@@ -26,6 +26,38 @@
#include <linux/posix_acl.h>
#include <linux/ima.h>
#include <linux/cred.h>
+#include "internal.h"
+
+/*
+ * inode locking rules.
+ *
+ * inode->i_lock protects:
+ * inode->i_state, inode->i_hash, __iget()
+ * inode_lru_lock protects:
+ * inode_lru, inode->i_lru
+ * inode_sb_list_lock protects:
+ * sb->s_inodes, inode->i_sb_list
+ * inode_wb_list_lock protects:
+ * bdi->wb.b_{dirty,io,more_io}, inode->i_wb_list
+ * inode_hash_lock protects:
+ * inode_hashtable, inode->i_hash
+ *
+ * Lock ordering:
+ *
+ * inode_sb_list_lock
+ * inode->i_lock
+ * inode_lru_lock
+ *
+ * inode_wb_list_lock
+ * inode->i_lock
+ *
+ * inode_hash_lock
+ * inode_sb_list_lock
+ * inode->i_lock
+ *
+ * iunique_lock
+ * inode_hash_lock
+ */
/*
* This is needed for the following functions:
@@ -60,6 +92,8 @@
static unsigned int i_hash_mask __read_mostly;
static unsigned int i_hash_shift __read_mostly;
+static struct hlist_head *inode_hashtable __read_mostly;
+static __cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_hash_lock);
/*
* Each inode can be on two separate lists. One is
@@ -74,15 +108,10 @@
*/
static LIST_HEAD(inode_lru);
-static struct hlist_head *inode_hashtable __read_mostly;
+static DEFINE_SPINLOCK(inode_lru_lock);
-/*
- * A simple spinlock to protect the list manipulations.
- *
- * NOTE! You also have to own the lock if you change
- * the i_state of an inode while it is in use..
- */
-DEFINE_SPINLOCK(inode_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_sb_list_lock);
+__cacheline_aligned_in_smp DEFINE_SPINLOCK(inode_wb_list_lock);
/*
* iprune_sem provides exclusion between the icache shrinking and the
@@ -137,15 +166,6 @@
}
#endif
-static void wake_up_inode(struct inode *inode)
-{
- /*
- * Prevent speculative execution through spin_unlock(&inode_lock);
- */
- smp_mb();
- wake_up_bit(&inode->i_state, __I_NEW);
-}
-
/**
* inode_init_always - perform inode structure intialisation
* @sb: superblock inode belongs to
@@ -336,7 +356,7 @@
}
/*
- * inode_lock must be held
+ * inode->i_lock must be held
*/
void __iget(struct inode *inode)
{
@@ -354,23 +374,22 @@
static void inode_lru_list_add(struct inode *inode)
{
+ spin_lock(&inode_lru_lock);
if (list_empty(&inode->i_lru)) {
list_add(&inode->i_lru, &inode_lru);
inodes_stat.nr_unused++;
}
+ spin_unlock(&inode_lru_lock);
}
static void inode_lru_list_del(struct inode *inode)
{
+ spin_lock(&inode_lru_lock);
if (!list_empty(&inode->i_lru)) {
list_del_init(&inode->i_lru);
inodes_stat.nr_unused--;
}
-}
-
-static inline void __inode_sb_list_add(struct inode *inode)
-{
- list_add(&inode->i_sb_list, &inode->i_sb->s_inodes);
+ spin_unlock(&inode_lru_lock);
}
/**
@@ -379,15 +398,17 @@
*/
void inode_sb_list_add(struct inode *inode)
{
- spin_lock(&inode_lock);
- __inode_sb_list_add(inode);
- spin_unlock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
+ list_add(&inode->i_sb_list, &inode->i_sb->s_inodes);
+ spin_unlock(&inode_sb_list_lock);
}
EXPORT_SYMBOL_GPL(inode_sb_list_add);
-static inline void __inode_sb_list_del(struct inode *inode)
+static inline void inode_sb_list_del(struct inode *inode)
{
+ spin_lock(&inode_sb_list_lock);
list_del_init(&inode->i_sb_list);
+ spin_unlock(&inode_sb_list_lock);
}
static unsigned long hash(struct super_block *sb, unsigned long hashval)
@@ -412,24 +433,15 @@
{
struct hlist_head *b = inode_hashtable + hash(inode->i_sb, hashval);
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
+ spin_lock(&inode->i_lock);
hlist_add_head(&inode->i_hash, b);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_hash_lock);
}
EXPORT_SYMBOL(__insert_inode_hash);
/**
- * __remove_inode_hash - remove an inode from the hash
- * @inode: inode to unhash
- *
- * Remove an inode from the superblock.
- */
-static void __remove_inode_hash(struct inode *inode)
-{
- hlist_del_init(&inode->i_hash);
-}
-
-/**
* remove_inode_hash - remove an inode from the hash
* @inode: inode to unhash
*
@@ -437,9 +449,11 @@
*/
void remove_inode_hash(struct inode *inode)
{
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
+ spin_lock(&inode->i_lock);
hlist_del_init(&inode->i_hash);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_hash_lock);
}
EXPORT_SYMBOL(remove_inode_hash);
@@ -456,10 +470,29 @@
}
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));
+
+ inode_wb_list_del(inode);
+ inode_sb_list_del(inode);
+
if (op->evict_inode) {
op->evict_inode(inode);
} else {
@@ -471,6 +504,15 @@
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);
}
/*
@@ -489,14 +531,6 @@
list_del_init(&inode->i_lru);
evict(inode);
-
- spin_lock(&inode_lock);
- __remove_inode_hash(inode);
- __inode_sb_list_del(inode);
- spin_unlock(&inode_lock);
-
- wake_up_inode(inode);
- destroy_inode(inode);
}
}
@@ -514,25 +548,23 @@
struct inode *inode, *next;
LIST_HEAD(dispose);
- spin_lock(&inode_lock);
+ 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;
- if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE))
+
+ 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;
-
- /*
- * Move the inode off the IO lists and LRU once I_FREEING is
- * set so that it won't get moved back on there if it is dirty.
- */
- list_move(&inode->i_lru, &dispose);
- list_del_init(&inode->i_wb_list);
- if (!(inode->i_state & (I_DIRTY | I_SYNC)))
- inodes_stat.nr_unused--;
+ inode_lru_list_del(inode);
+ spin_unlock(&inode->i_lock);
+ list_add(&inode->i_lru, &dispose);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
dispose_list(&dispose);
@@ -561,31 +593,30 @@
struct inode *inode, *next;
LIST_HEAD(dispose);
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry_safe(inode, next, &sb->s_inodes, i_sb_list) {
- if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE))
+ 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;
-
- /*
- * Move the inode off the IO lists and LRU once I_FREEING is
- * set so that it won't get moved back on there if it is dirty.
- */
- list_move(&inode->i_lru, &dispose);
- list_del_init(&inode->i_wb_list);
- if (!(inode->i_state & (I_DIRTY | I_SYNC)))
- inodes_stat.nr_unused--;
+ inode_lru_list_del(inode);
+ spin_unlock(&inode->i_lock);
+ list_add(&inode->i_lru, &dispose);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
dispose_list(&dispose);
@@ -607,7 +638,7 @@
/*
* Scan `goal' inodes on the unused list for freeable ones. They are moved to a
- * temporary list and then are freed outside inode_lock by dispose_list().
+ * temporary list and then are freed outside inode_lru_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
@@ -628,7 +659,7 @@
unsigned long reap = 0;
down_read(&iprune_sem);
- spin_lock(&inode_lock);
+ spin_lock(&inode_lru_lock);
for (nr_scanned = 0; nr_scanned < nr_to_scan; nr_scanned++) {
struct inode *inode;
@@ -638,53 +669,67 @@
inode = list_entry(inode_lru.prev, struct inode, i_lru);
/*
+ * we are inverting the 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(&inode->i_lru, &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);
inodes_stat.nr_unused--;
continue;
}
/* recently referenced inodes get one more pass */
if (inode->i_state & I_REFERENCED) {
- list_move(&inode->i_lru, &inode_lru);
inode->i_state &= ~I_REFERENCED;
+ list_move(&inode->i_lru, &inode_lru);
+ spin_unlock(&inode->i_lock);
continue;
}
if (inode_has_buffers(inode) || inode->i_data.nrpages) {
__iget(inode);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_lru_lock);
if (remove_inode_buffers(inode))
reap += invalidate_mapping_pages(&inode->i_data,
0, -1);
iput(inode);
- spin_lock(&inode_lock);
+ spin_lock(&inode_lru_lock);
if (inode != list_entry(inode_lru.next,
struct inode, i_lru))
continue; /* wrong inode or list_empty */
- if (!can_unuse(inode))
+ /* 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);
- /*
- * Move the inode off the IO lists and LRU once I_FREEING is
- * set so that it won't get moved back on there if it is dirty.
- */
list_move(&inode->i_lru, &freeable);
- list_del_init(&inode->i_wb_list);
inodes_stat.nr_unused--;
}
if (current_is_kswapd())
__count_vm_events(KSWAPD_INODESTEAL, reap);
else
__count_vm_events(PGINODESTEAL, reap);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_lru_lock);
dispose_list(&freeable);
up_read(&iprune_sem);
@@ -733,15 +778,21 @@
repeat:
hlist_for_each_entry(inode, node, head, i_hash) {
- if (inode->i_sb != sb)
+ spin_lock(&inode->i_lock);
+ if (inode->i_sb != sb) {
+ spin_unlock(&inode->i_lock);
continue;
- if (!test(inode, data))
+ }
+ 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;
@@ -759,15 +810,21 @@
repeat:
hlist_for_each_entry(inode, node, head, i_hash) {
- if (inode->i_ino != ino)
+ spin_lock(&inode->i_lock);
+ if (inode->i_ino != ino) {
+ spin_unlock(&inode->i_lock);
continue;
- if (inode->i_sb != sb)
+ }
+ 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;
@@ -827,19 +884,26 @@
{
struct inode *inode;
- spin_lock_prefetch(&inode_lock);
+ spin_lock_prefetch(&inode_sb_list_lock);
inode = alloc_inode(sb);
if (inode) {
- spin_lock(&inode_lock);
- __inode_sb_list_add(inode);
+ spin_lock(&inode->i_lock);
inode->i_state = 0;
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ inode_sb_list_add(inode);
}
return inode;
}
EXPORT_SYMBOL(new_inode);
+/**
+ * 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)
{
#ifdef CONFIG_DEBUG_LOCK_ALLOC
@@ -859,51 +923,67 @@
}
}
#endif
- /*
- * This is special! We do not need the spinlock when clearing I_NEW,
- * because we're guaranteed that nobody else tries to do anything about
- * the state of the inode when it is locked, as we just created it (so
- * there can be no old holders that haven't tested I_NEW).
- * However we must emit the memory barrier so that other CPUs reliably
- * see the clearing of I_NEW after the other inode initialisation has
- * completed.
- */
- smp_mb();
+ spin_lock(&inode->i_lock);
WARN_ON(!(inode->i_state & I_NEW));
inode->i_state &= ~I_NEW;
- wake_up_inode(inode);
+ wake_up_bit(&inode->i_state, __I_NEW);
+ spin_unlock(&inode->i_lock);
}
EXPORT_SYMBOL(unlock_new_inode);
-/*
- * This is called without the inode lock held.. Be careful.
+/**
+ * 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
*
- * We no longer cache the sb_flags in i_flags - see fs.h
- * -- rmk@arm.uk.linux.org
+ * 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.
*/
-static struct inode *get_new_inode(struct super_block *sb,
- struct hlist_head *head,
- int (*test)(struct inode *, void *),
- int (*set)(struct inode *, void *),
- void *data)
+struct inode *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_lock);
+ 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;
- hlist_add_head(&inode->i_hash, head);
- __inode_sb_list_add(inode);
+ spin_lock(&inode->i_lock);
inode->i_state = I_NEW;
- spin_unlock(&inode_lock);
+ 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
@@ -916,7 +996,7 @@
* us. Use the old inode instead of the one we just
* allocated.
*/
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
destroy_inode(inode);
inode = old;
wait_on_inode(inode);
@@ -924,33 +1004,53 @@
return inode;
set_failed:
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_hash_lock);
destroy_inode(inode);
return NULL;
}
+EXPORT_SYMBOL(iget5_locked);
-/*
- * get_new_inode_fast is the fast path version of get_new_inode, see the
- * comment at iget_locked for details.
+/**
+ * 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().
*/
-static struct inode *get_new_inode_fast(struct super_block *sb,
- struct hlist_head *head, unsigned long ino)
+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_lock);
+ spin_lock(&inode_hash_lock);
/* We released the lock, so.. */
old = find_inode_fast(sb, head, ino);
if (!old) {
inode->i_ino = ino;
- hlist_add_head(&inode->i_hash, head);
- __inode_sb_list_add(inode);
+ spin_lock(&inode->i_lock);
inode->i_state = I_NEW;
- spin_unlock(&inode_lock);
+ 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
@@ -963,13 +1063,14 @@
* us. Use the old inode instead of the one we just
* allocated.
*/
- spin_unlock(&inode_lock);
+ 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.
@@ -984,10 +1085,14 @@
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)
+ if (inode->i_ino == ino && inode->i_sb == sb) {
+ spin_unlock(&inode_hash_lock);
return 0;
+ }
}
+ spin_unlock(&inode_hash_lock);
return 1;
}
@@ -1017,7 +1122,6 @@
static unsigned int counter;
ino_t res;
- spin_lock(&inode_lock);
spin_lock(&iunique_lock);
do {
if (counter <= max_reserved)
@@ -1025,7 +1129,6 @@
res = counter++;
} while (!test_inode_iunique(sb, res));
spin_unlock(&iunique_lock);
- spin_unlock(&inode_lock);
return res;
}
@@ -1033,116 +1136,50 @@
struct inode *igrab(struct inode *inode)
{
- spin_lock(&inode_lock);
- if (!(inode->i_state & (I_FREEING|I_WILL_FREE)))
+ spin_lock(&inode->i_lock);
+ if (!(inode->i_state & (I_FREEING|I_WILL_FREE))) {
__iget(inode);
- else
+ 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;
- spin_unlock(&inode_lock);
+ }
return inode;
}
EXPORT_SYMBOL(igrab);
/**
- * ifind - internal function, you want ilookup5() or iget5().
- * @sb: super block of file system to search
- * @head: the head of the list to search
- * @test: callback used for comparisons between inodes
- * @data: opaque data pointer to pass to @test
- * @wait: if true wait for the inode to be unlocked, if false do not
- *
- * ifind() searches for the inode specified by @data in the inode
- * cache. This is a generalized version of ifind_fast() for file systems where
- * the inode number is not sufficient for unique identification of an inode.
- *
- * If the inode is in the cache, the inode is returned with an incremented
- * reference count.
- *
- * Otherwise NULL is returned.
- *
- * Note, @test is called with the inode_lock held, so can't sleep.
- */
-static struct inode *ifind(struct super_block *sb,
- struct hlist_head *head, int (*test)(struct inode *, void *),
- void *data, const int wait)
-{
- struct inode *inode;
-
- spin_lock(&inode_lock);
- inode = find_inode(sb, head, test, data);
- if (inode) {
- spin_unlock(&inode_lock);
- if (likely(wait))
- wait_on_inode(inode);
- return inode;
- }
- spin_unlock(&inode_lock);
- return NULL;
-}
-
-/**
- * ifind_fast - internal function, you want ilookup() or iget().
- * @sb: super block of file system to search
- * @head: head of the list to search
- * @ino: inode number to search for
- *
- * ifind_fast() searches for the inode @ino in the inode cache. This is for
- * file systems where the inode number is sufficient for unique identification
- * of an inode.
- *
- * If the inode is in the cache, the inode is returned with an incremented
- * reference count.
- *
- * Otherwise NULL is returned.
- */
-static struct inode *ifind_fast(struct super_block *sb,
- struct hlist_head *head, unsigned long ino)
-{
- struct inode *inode;
-
- spin_lock(&inode_lock);
- inode = find_inode_fast(sb, head, ino);
- if (inode) {
- spin_unlock(&inode_lock);
- wait_on_inode(inode);
- return inode;
- }
- spin_unlock(&inode_lock);
- return NULL;
-}
-
-/**
* ilookup5_nowait - search for an inode in the inode cache
* @sb: super block of file system to search
* @hashval: hash value (usually inode number) to search for
* @test: callback used for comparisons between inodes
* @data: opaque data pointer to pass to @test
*
- * ilookup5() uses ifind() to search for the inode specified by @hashval and
- * @data in the inode cache. This is a generalized version of ilookup() for
- * file systems where the inode number is not sufficient for unique
- * identification of an inode.
- *
+ * 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, the inode lock is not waited upon so you have to be
- * very careful what you do with the returned inode. You probably should be
- * using ilookup5() instead.
+ * reference count.
*
- * Otherwise NULL is returned.
+ * 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.
*
- * Note, @test is called with the inode_lock held, so can't sleep.
+ * Note: @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;
- return ifind(sb, head, test, data, 0);
+ spin_lock(&inode_hash_lock);
+ inode = find_inode(sb, head, test, data);
+ spin_unlock(&inode_hash_lock);
+
+ return inode;
}
EXPORT_SYMBOL(ilookup5_nowait);
@@ -1153,24 +1190,24 @@
* @test: callback used for comparisons between inodes
* @data: opaque data pointer to pass to @test
*
- * ilookup5() uses ifind() to search for the inode specified by @hashval and
- * @data in the inode cache. This is a generalized version of ilookup() for
- * file systems where the inode number is not sufficient for unique
- * identification of an inode.
- *
- * If the inode is in the cache, the inode lock is waited upon and the inode is
+ * 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.
*
- * Otherwise NULL is returned.
+ * 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_lock held, so can't sleep.
+ * 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 hlist_head *head = inode_hashtable + hash(sb, hashval);
+ struct inode *inode = ilookup5_nowait(sb, hashval, test, data);
- return ifind(sb, head, test, data, 1);
+ if (inode)
+ wait_on_inode(inode);
+ return inode;
}
EXPORT_SYMBOL(ilookup5);
@@ -1179,119 +1216,57 @@
* @sb: super block of file system to search
* @ino: inode number to search for
*
- * ilookup() uses ifind_fast() to search for the inode @ino in the inode cache.
- * This is for file systems where the inode number is sufficient for unique
- * identification of an inode.
- *
- * If the inode is in the cache, the inode is returned with an incremented
- * reference count.
- *
- * Otherwise NULL is returned.
+ * 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;
- return ifind_fast(sb, head, ino);
+ 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);
-/**
- * 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
- *
- * iget5_locked() uses ifind() to search for the inode specified by @hashval
- * and @data in the inode cache and if present it is returned with an increased
- * reference count. This is a generalized version of iget_locked() for file
- * systems where the inode number is not sufficient for unique identification
- * of an inode.
- *
- * If the inode is not in cache, get_new_inode() is called to allocate a new
- * inode and this is returned locked, hashed, and with the I_NEW flag set. The
- * file system gets to fill it in before unlocking it via unlock_new_inode().
- *
- * Note both @test and @set are called with the inode_lock held, so can't sleep.
- */
-struct inode *iget5_locked(struct super_block *sb, unsigned long hashval,
- int (*test)(struct inode *, void *),
- int (*set)(struct inode *, void *), void *data)
-{
- struct hlist_head *head = inode_hashtable + hash(sb, hashval);
- struct inode *inode;
-
- inode = ifind(sb, head, test, data, 1);
- if (inode)
- return inode;
- /*
- * get_new_inode() will do the right thing, re-trying the search
- * in case it had to block at any point.
- */
- return get_new_inode(sb, head, test, set, data);
-}
-EXPORT_SYMBOL(iget5_locked);
-
-/**
- * iget_locked - obtain an inode from a mounted file system
- * @sb: super block of file system
- * @ino: inode number to get
- *
- * iget_locked() uses ifind_fast() to search for the inode specified by @ino in
- * the inode cache and if present it is returned with an increased reference
- * count. This is for file systems where the inode number is sufficient for
- * unique identification of an inode.
- *
- * If the inode is not in cache, get_new_inode_fast() is called to allocate a
- * new inode and this is returned locked, hashed, and with the I_NEW flag set.
- * The file system gets to fill it in before unlocking it via
- * unlock_new_inode().
- */
-struct inode *iget_locked(struct super_block *sb, unsigned long ino)
-{
- struct hlist_head *head = inode_hashtable + hash(sb, ino);
- struct inode *inode;
-
- inode = ifind_fast(sb, head, ino);
- if (inode)
- return inode;
- /*
- * get_new_inode_fast() will do the right thing, re-trying the search
- * in case it had to block at any point.
- */
- return get_new_inode_fast(sb, head, ino);
-}
-EXPORT_SYMBOL(iget_locked);
-
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);
- inode->i_state |= I_NEW;
while (1) {
struct hlist_node *node;
struct inode *old = NULL;
- spin_lock(&inode_lock);
+ 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;
- if (old->i_state & (I_FREEING|I_WILL_FREE))
+ 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_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_hash_lock);
return 0;
}
__iget(old);
- spin_unlock(&inode_lock);
+ spin_unlock(&old->i_lock);
+ spin_unlock(&inode_hash_lock);
wait_on_inode(old);
if (unlikely(!inode_unhashed(old))) {
iput(old);
@@ -1308,29 +1283,34 @@
struct super_block *sb = inode->i_sb;
struct hlist_head *head = inode_hashtable + hash(sb, hashval);
- inode->i_state |= I_NEW;
-
while (1) {
struct hlist_node *node;
struct inode *old = NULL;
- spin_lock(&inode_lock);
+ 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;
- if (old->i_state & (I_FREEING|I_WILL_FREE))
+ 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_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_hash_lock);
return 0;
}
__iget(old);
- spin_unlock(&inode_lock);
+ spin_unlock(&old->i_lock);
+ spin_unlock(&inode_hash_lock);
wait_on_inode(old);
if (unlikely(!inode_unhashed(old))) {
iput(old);
@@ -1375,47 +1355,35 @@
const struct super_operations *op = inode->i_sb->s_op;
int drop;
+ WARN_ON(inode->i_state & I_NEW);
+
if (op && op->drop_inode)
drop = op->drop_inode(inode);
else
drop = generic_drop_inode(inode);
- if (!drop) {
- if (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_lock);
- return;
- }
- WARN_ON(inode->i_state & I_NEW);
- inode->i_state |= I_WILL_FREE;
- spin_unlock(&inode_lock);
- write_inode_now(inode, 1);
- spin_lock(&inode_lock);
- WARN_ON(inode->i_state & I_NEW);
- inode->i_state &= ~I_WILL_FREE;
- __remove_inode_hash(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;
}
- WARN_ON(inode->i_state & I_NEW);
+ 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;
-
- /*
- * Move the inode off the IO lists and LRU once I_FREEING is
- * set so that it won't get moved back on there if it is dirty.
- */
inode_lru_list_del(inode);
- list_del_init(&inode->i_wb_list);
+ spin_unlock(&inode->i_lock);
- __inode_sb_list_del(inode);
- spin_unlock(&inode_lock);
evict(inode);
- remove_inode_hash(inode);
- wake_up_inode(inode);
- BUG_ON(inode->i_state != (I_FREEING | I_CLEAR));
- destroy_inode(inode);
}
/**
@@ -1432,7 +1400,7 @@
if (inode) {
BUG_ON(inode->i_state & I_CLEAR);
- if (atomic_dec_and_lock(&inode->i_count, &inode_lock))
+ if (atomic_dec_and_lock(&inode->i_count, &inode->i_lock))
iput_final(inode);
}
}
@@ -1611,9 +1579,8 @@
* to recheck inode state.
*
* It doesn't matter if I_NEW is not set initially, a call to
- * wake_up_inode() after removing from the hash list will DTRT.
- *
- * This is called with inode_lock held.
+ * 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)
{
@@ -1621,10 +1588,11 @@
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_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_hash_lock);
schedule();
finish_wait(wq, &wait.wait);
- spin_lock(&inode_lock);
+ spin_lock(&inode_hash_lock);
}
static __initdata unsigned long ihash_entries;
diff --git a/fs/internal.h b/fs/internal.h
index 8318059..b29c46e 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -125,6 +125,13 @@
/*
* inode.c
*/
+extern spinlock_t inode_sb_list_lock;
+
+/*
+ * fs-writeback.c
+ */
+extern void inode_wb_list_del(struct inode *inode);
+
extern int get_nr_dirty_inodes(void);
extern void evict_inodes(struct super_block *);
extern int invalidate_inodes(struct super_block *, bool);
diff --git a/fs/logfs/inode.c b/fs/logfs/inode.c
index 03b8c24..edfea7a 100644
--- a/fs/logfs/inode.c
+++ b/fs/logfs/inode.c
@@ -293,7 +293,7 @@
return ret;
}
-/* called with inode_lock held */
+/* called with inode->i_lock held */
static int logfs_drop_inode(struct inode *inode)
{
struct logfs_super *super = logfs_super(inode->i_sb);
diff --git a/fs/namei.c b/fs/namei.c
index d0066e1..3cb616d 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -992,6 +992,12 @@
return 0;
}
+static inline bool managed_dentry_might_block(struct dentry *dentry)
+{
+ return (dentry->d_flags & DCACHE_MANAGE_TRANSIT &&
+ dentry->d_op->d_manage(dentry, true) < 0);
+}
+
/*
* Skip to top of mountpoint pile in rcuwalk mode. We abort the rcu-walk if we
* meet a managed dentry and we're not walking to "..". True is returned to
@@ -1000,19 +1006,26 @@
static bool __follow_mount_rcu(struct nameidata *nd, struct path *path,
struct inode **inode, bool reverse_transit)
{
- while (d_mountpoint(path->dentry)) {
+ for (;;) {
struct vfsmount *mounted;
- if (unlikely(path->dentry->d_flags & DCACHE_MANAGE_TRANSIT) &&
- !reverse_transit &&
- path->dentry->d_op->d_manage(path->dentry, true) < 0)
+ /*
+ * Don't forget we might have a non-mountpoint managed dentry
+ * that wants to block transit.
+ */
+ *inode = path->dentry->d_inode;
+ if (!reverse_transit &&
+ unlikely(managed_dentry_might_block(path->dentry)))
return false;
+
+ if (!d_mountpoint(path->dentry))
+ break;
+
mounted = __lookup_mnt(path->mnt, path->dentry, 1);
if (!mounted)
break;
path->mnt = mounted;
path->dentry = mounted->mnt_root;
nd->seq = read_seqcount_begin(&path->dentry->d_seq);
- *inode = path->dentry->d_inode;
}
if (unlikely(path->dentry->d_flags & DCACHE_NEED_AUTOMOUNT))
diff --git a/fs/notify/inode_mark.c b/fs/notify/inode_mark.c
index 4c29fcf..07ea8d3 100644
--- a/fs/notify/inode_mark.c
+++ b/fs/notify/inode_mark.c
@@ -22,13 +22,14 @@
#include <linux/module.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
-#include <linux/writeback.h> /* for inode_lock */
#include <asm/atomic.h>
#include <linux/fsnotify_backend.h>
#include "fsnotify.h"
+#include "../internal.h"
+
/*
* Recalculate the mask of events relevant to a given inode locked.
*/
@@ -237,15 +238,14 @@
* fsnotify_unmount_inodes - an sb is unmounting. handle any watched inodes.
* @list: list of inodes being unmounted (sb->s_inodes)
*
- * Called with inode_lock held, protecting the unmounting super block's list
- * of inodes, and with iprune_mutex held, keeping shrink_icache_memory() at bay.
- * We temporarily drop inode_lock, however, and CAN block.
+ * Called during unmount with no locks held, so needs to be safe against
+ * concurrent modifiers. We temporarily drop inode_sb_list_lock and CAN block.
*/
void fsnotify_unmount_inodes(struct list_head *list)
{
struct inode *inode, *next_i, *need_iput = NULL;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry_safe(inode, next_i, list, i_sb_list) {
struct inode *need_iput_tmp;
@@ -254,8 +254,11 @@
* I_WILL_FREE, or I_NEW which is fine because by that point
* the inode cannot have any associated watches.
*/
- if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+ spin_lock(&inode->i_lock);
+ if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) {
+ spin_unlock(&inode->i_lock);
continue;
+ }
/*
* If i_count is zero, the inode cannot have any watches and
@@ -263,8 +266,10 @@
* evict all inodes with zero i_count from icache which is
* unnecessarily violent and may in fact be illegal to do.
*/
- if (!atomic_read(&inode->i_count))
+ if (!atomic_read(&inode->i_count)) {
+ spin_unlock(&inode->i_lock);
continue;
+ }
need_iput_tmp = need_iput;
need_iput = NULL;
@@ -274,22 +279,25 @@
__iget(inode);
else
need_iput_tmp = NULL;
+ spin_unlock(&inode->i_lock);
/* In case the dropping of a reference would nuke next_i. */
if ((&next_i->i_sb_list != list) &&
- atomic_read(&next_i->i_count) &&
- !(next_i->i_state & (I_FREEING | I_WILL_FREE))) {
- __iget(next_i);
- need_iput = next_i;
+ atomic_read(&next_i->i_count)) {
+ spin_lock(&next_i->i_lock);
+ if (!(next_i->i_state & (I_FREEING | I_WILL_FREE))) {
+ __iget(next_i);
+ need_iput = next_i;
+ }
+ spin_unlock(&next_i->i_lock);
}
/*
- * We can safely drop inode_lock here because we hold
+ * We can safely drop inode_sb_list_lock here because we hold
* references on both inode and next_i. Also no new inodes
- * will be added since the umount has begun. Finally,
- * iprune_mutex keeps shrink_icache_memory() away.
+ * will be added since the umount has begun.
*/
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
if (need_iput_tmp)
iput(need_iput_tmp);
@@ -301,7 +309,7 @@
iput(inode);
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
}
diff --git a/fs/notify/mark.c b/fs/notify/mark.c
index 325185e..50c0085 100644
--- a/fs/notify/mark.c
+++ b/fs/notify/mark.c
@@ -91,7 +91,6 @@
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/srcu.h>
-#include <linux/writeback.h> /* for inode_lock */
#include <asm/atomic.h>
diff --git a/fs/notify/vfsmount_mark.c b/fs/notify/vfsmount_mark.c
index 85eebff..e86577d 100644
--- a/fs/notify/vfsmount_mark.c
+++ b/fs/notify/vfsmount_mark.c
@@ -23,7 +23,6 @@
#include <linux/mount.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
-#include <linux/writeback.h> /* for inode_lock */
#include <asm/atomic.h>
diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index a627ed8..0b56c6b 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -54,7 +54,7 @@
*
* Return 1 if the attributes match and 0 if not.
*
- * NOTE: This function runs with the inode_lock spin lock held so it is not
+ * NOTE: This function runs with the inode->i_lock spin lock held so it is not
* allowed to sleep.
*/
int ntfs_test_inode(struct inode *vi, ntfs_attr *na)
@@ -98,7 +98,7 @@
*
* Return 0 on success and -errno on error.
*
- * NOTE: This function runs with the inode_lock spin lock held so it is not
+ * NOTE: This function runs with the inode->i_lock spin lock held so it is not
* allowed to sleep. (Hence the GFP_ATOMIC allocation.)
*/
static int ntfs_init_locked_inode(struct inode *vi, ntfs_attr *na)
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index a2a622e..fcc8ae7 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -76,7 +76,7 @@
#include <linux/buffer_head.h>
#include <linux/capability.h>
#include <linux/quotaops.h>
-#include <linux/writeback.h> /* for inode_lock, oddly enough.. */
+#include "../internal.h" /* ugh */
#include <asm/uaccess.h>
@@ -900,33 +900,38 @@
int reserved = 0;
#endif
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
- if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+ spin_lock(&inode->i_lock);
+ if ((inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW)) ||
+ !atomic_read(&inode->i_writecount) ||
+ !dqinit_needed(inode, type)) {
+ spin_unlock(&inode->i_lock);
continue;
+ }
#ifdef CONFIG_QUOTA_DEBUG
if (unlikely(inode_get_rsv_space(inode) > 0))
reserved = 1;
#endif
- if (!atomic_read(&inode->i_writecount))
- continue;
- if (!dqinit_needed(inode, type))
- continue;
-
__iget(inode);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode->i_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(old_inode);
__dquot_initialize(inode, type);
- /* We hold a reference to 'inode' so it couldn't have been
- * removed from s_inodes list while we dropped the inode_lock.
- * We cannot iput the inode now as we can be holding the last
- * reference and we cannot iput it under inode_lock. So we
- * keep the reference and iput it later. */
+
+ /*
+ * We hold a reference to 'inode' so it couldn't have been
+ * removed from s_inodes list while we dropped the
+ * inode_sb_list_lock We cannot iput the inode now as we can be
+ * holding the last reference and we cannot iput it under
+ * inode_sb_list_lock. So we keep the reference and iput it
+ * later.
+ */
old_inode = inode;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
iput(old_inode);
#ifdef CONFIG_QUOTA_DEBUG
@@ -1007,7 +1012,7 @@
struct inode *inode;
int reserved = 0;
- spin_lock(&inode_lock);
+ spin_lock(&inode_sb_list_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
/*
* We have to scan also I_NEW inodes because they can already
@@ -1021,7 +1026,7 @@
remove_inode_dquot_ref(inode, type, tofree_head);
}
}
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_sb_list_lock);
#ifdef CONFIG_QUOTA_DEBUG
if (reserved) {
printk(KERN_WARNING "VFS (%s): Writes happened after quota"
diff --git a/include/linux/fs.h b/include/linux/fs.h
index ce7e185..b677bd7 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -1636,7 +1636,7 @@
};
/*
- * Inode state bits. Protected by inode_lock.
+ * Inode state bits. Protected by inode->i_lock
*
* Three bits determine the dirty state of the inode, I_DIRTY_SYNC,
* I_DIRTY_DATASYNC and I_DIRTY_PAGES.
diff --git a/include/linux/quotaops.h b/include/linux/quotaops.h
index eb354f6..26f9e36 100644
--- a/include/linux/quotaops.h
+++ b/include/linux/quotaops.h
@@ -277,7 +277,7 @@
/*
* Mark inode fully dirty. Since we are allocating blocks, inode
* would become fully dirty soon anyway and it reportedly
- * reduces inode_lock contention.
+ * reduces lock contention.
*/
mark_inode_dirty(inode);
}
diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index 0ead399..17e7ccc 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -9,7 +9,7 @@
struct backing_dev_info;
-extern spinlock_t inode_lock;
+extern spinlock_t inode_wb_list_lock;
/*
* fs/fs-writeback.c
diff --git a/mm/backing-dev.c b/mm/backing-dev.c
index 8fe9d34..0d9a036 100644
--- a/mm/backing-dev.c
+++ b/mm/backing-dev.c
@@ -67,14 +67,14 @@
struct inode *inode;
nr_wb = nr_dirty = nr_io = nr_more_io = 0;
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
list_for_each_entry(inode, &wb->b_dirty, i_wb_list)
nr_dirty++;
list_for_each_entry(inode, &wb->b_io, i_wb_list)
nr_io++;
list_for_each_entry(inode, &wb->b_more_io, i_wb_list)
nr_more_io++;
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
global_dirty_limits(&background_thresh, &dirty_thresh);
bdi_thresh = bdi_dirty_limit(bdi, dirty_thresh);
@@ -676,11 +676,11 @@
if (bdi_has_dirty_io(bdi)) {
struct bdi_writeback *dst = &default_backing_dev_info.wb;
- spin_lock(&inode_lock);
+ spin_lock(&inode_wb_list_lock);
list_splice(&bdi->wb.b_dirty, &dst->b_dirty);
list_splice(&bdi->wb.b_io, &dst->b_io);
list_splice(&bdi->wb.b_more_io, &dst->b_more_io);
- spin_unlock(&inode_lock);
+ spin_unlock(&inode_wb_list_lock);
}
bdi_unregister(bdi);
diff --git a/mm/filemap.c b/mm/filemap.c
index 04d1992..c641edf 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -80,8 +80,8 @@
* ->i_mutex
* ->i_alloc_sem (various)
*
- * ->inode_lock
- * ->sb_lock (fs/fs-writeback.c)
+ * inode_wb_list_lock
+ * sb_lock (fs/fs-writeback.c)
* ->mapping->tree_lock (__sync_single_inode)
*
* ->i_mmap_lock
@@ -98,8 +98,10 @@
* ->zone.lru_lock (check_pte_range->isolate_lru_page)
* ->private_lock (page_remove_rmap->set_page_dirty)
* ->tree_lock (page_remove_rmap->set_page_dirty)
- * ->inode_lock (page_remove_rmap->set_page_dirty)
- * ->inode_lock (zap_pte_range->set_page_dirty)
+ * inode_wb_list_lock (page_remove_rmap->set_page_dirty)
+ * ->inode->i_lock (page_remove_rmap->set_page_dirty)
+ * inode_wb_list_lock (zap_pte_range->set_page_dirty)
+ * ->inode->i_lock (zap_pte_range->set_page_dirty)
* ->private_lock (zap_pte_range->__set_page_dirty_buffers)
*
* (code doesn't rely on that order, so you could switch it around)
diff --git a/mm/rmap.c b/mm/rmap.c
index 4a8e99a..8da044a 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -31,11 +31,12 @@
* swap_lock (in swap_duplicate, swap_info_get)
* mmlist_lock (in mmput, drain_mmlist and others)
* mapping->private_lock (in __set_page_dirty_buffers)
- * inode_lock (in set_page_dirty's __mark_inode_dirty)
+ * inode->i_lock (in set_page_dirty's __mark_inode_dirty)
+ * inode_wb_list_lock (in set_page_dirty's __mark_inode_dirty)
* sb_lock (within inode_lock in fs/fs-writeback.c)
* mapping->tree_lock (widely used, in set_page_dirty,
* in arch-dependent flush_dcache_mmap_lock,
- * within inode_lock in __sync_single_inode)
+ * within inode_wb_list_lock in __sync_single_inode)
*
* (code doesn't rely on that order so it could be switched around)
* ->tasklist_lock