The I_WILL_FREE is currently set for inodes that we write out during
umount after dropping their last reference. It is handled equally
to I_FREEING in most places. The two execptions are:
- writeback_single_inode skips all list manipulations for I_FREEING,
but not for I_WILL_FREE. We don't care about which list an
I_WILL_FREE inode is on, because we will remove it from the list
a little bit later.
- __mark_inode_dirty skips I_FREEING inodes but not I_WILL_FREE
inodes. This only matters for filesystem that re-dirty the inode
during writeback and then use the I_DIRTY flags inside ->evict_inode.
The formers is done by XFS, but it uses it's internal state to flush
the inode. I could not find any filesystem that looks at I_DIRTY
inside ->evict_inode either.
Besides cleaning up the code removing I_WILL_FREE will allow us to
avoid one i_lock roundtrip once inode_lock is split and keep iput_final
more logic. This includes removing the __remove_inode_hash call in
iput_final, given that we never drop the protection from lookups now
that I_FREEING is set earlier.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Index: linux-2.6/fs/btrfs/inode.c
===================================================================
--- linux-2.6.orig/fs/btrfs/inode.c 2010-10-24 16:30:05.000000000 +0200
+++ linux-2.6/fs/btrfs/inode.c 2010-10-24 16:32:43.647253791 +0200
@@ -3862,8 +3862,7 @@ again:
else if (inode->i_ino > entry->vfs_inode.i_ino)
p = &parent->rb_right;
else {
- WARN_ON(!(entry->vfs_inode.i_state &
- (I_WILL_FREE | I_FREEING)));
+ WARN_ON(!(entry->vfs_inode.i_state & I_FREEING));
rb_erase(parent, &root->inode_tree);
RB_CLEAR_NODE(parent);
spin_unlock(&root->inode_lock);
Index: linux-2.6/fs/drop_caches.c
===================================================================
--- linux-2.6.orig/fs/drop_caches.c 2010-10-24 16:30:05.000000000 +0200
+++ linux-2.6/fs/drop_caches.c 2010-10-24 16:32:43.647253791 +0200
@@ -18,7 +18,7 @@ static void drop_pagecache_sb(struct sup
spin_lock(&inode_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
- if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+ if (inode->i_state & (I_FREEING | I_NEW))
continue;
if (inode->i_mapping->nrpages == 0)
continue;
Index: linux-2.6/fs/gfs2/inode.c
===================================================================
--- linux-2.6.orig/fs/gfs2/inode.c 2010-10-24 16:30:05.000000000 +0200
+++ linux-2.6/fs/gfs2/inode.c 2010-10-24 16:32:43.650253651 +0200
@@ -84,7 +84,7 @@ static int iget_skip_test(struct inode *
struct gfs2_skip_data *data = opaque;
if (ip->i_no_addr == data->no_addr) {
- if (inode->i_state & (I_FREEING|I_WILL_FREE)){
+ if (inode->i_state & I_FREEING){
data->skipped = 1;
return 0;
}
Index: linux-2.6/fs/fs-writeback.c
===================================================================
--- linux-2.6.orig/fs/fs-writeback.c 2010-10-24 16:32:39.000000000 +0200
+++ linux-2.6/fs/fs-writeback.c 2010-10-24 16:32:43.654254629 +0200
@@ -301,8 +301,7 @@ static void inode_wait_for_writeback(str
/*
* 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)
+ * caller has ref on the inode or the inode is beeing freed.
*
* If `wait' is set, wait on the writeout.
*
@@ -320,9 +319,7 @@ writeback_single_inode(struct inode *ino
int ret;
if (!atomic_read(&inode->i_count))
- WARN_ON(!(inode->i_state & (I_WILL_FREE|I_FREEING)));
- else
- WARN_ON(inode->i_state & I_WILL_FREE);
+ WARN_ON(!(inode->i_state & I_FREEING));
if (inode->i_state & I_SYNC) {
/*
@@ -492,7 +489,7 @@ static int writeback_sb_inodes(struct su
* kind does not need peridic writeout yet, and for the latter
* kind writeout is handled by the freer.
*/
- if (inode->i_state & (I_NEW | I_FREEING | I_WILL_FREE)) {
+ if (inode->i_state & (I_NEW | I_FREEING)) {
requeue_io(inode);
continue;
}
@@ -1043,7 +1040,7 @@ static void wait_sb_inodes(struct super_
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
struct address_space *mapping;
- if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+ if (inode->i_state & (I_FREEING | I_NEW))
continue;
mapping = inode->i_mapping;
if (mapping->nrpages == 0)
@@ -1154,7 +1151,7 @@ EXPORT_SYMBOL(sync_inodes_sb);
* This function commits an inode to disk immediately if it is dirty. This is
* primarily needed by knfsd.
*
- * The caller must either have a ref on the inode or must have set I_WILL_FREE.
+ * The caller must either have a ref on the inode or must have set I_FREEING.
*/
int write_inode_now(struct inode *inode, int sync)
{
Index: linux-2.6/fs/inode.c
===================================================================
--- linux-2.6.orig/fs/inode.c 2010-10-24 16:32:20.000000000 +0200
+++ linux-2.6/fs/inode.c 2010-10-24 16:33:46.912003547 +0200
@@ -667,7 +667,7 @@ repeat:
continue;
if (!test(inode, data))
continue;
- if (inode->i_state & (I_FREEING|I_WILL_FREE)) {
+ if (inode->i_state & I_FREEING) {
__wait_on_freeing_inode(inode);
goto repeat;
}
@@ -693,7 +693,7 @@ repeat:
continue;
if (inode->i_sb != sb)
continue;
- if (inode->i_state & (I_FREEING|I_WILL_FREE)) {
+ if (inode->i_state & I_FREEING) {
__wait_on_freeing_inode(inode);
goto repeat;
}
@@ -964,7 +964,7 @@ EXPORT_SYMBOL(iunique);
struct inode *igrab(struct inode *inode)
{
spin_lock(&inode_lock);
- if (!(inode->i_state & (I_FREEING|I_WILL_FREE)))
+ if (!(inode->i_state & I_FREEING))
__iget(inode);
else
/*
@@ -1211,7 +1211,7 @@ int insert_inode_locked(struct inode *in
continue;
if (old->i_sb != sb)
continue;
- if (old->i_state & (I_FREEING|I_WILL_FREE))
+ if (old->i_state & I_FREEING)
continue;
break;
}
@@ -1250,7 +1250,7 @@ int insert_inode_locked4(struct inode *i
continue;
if (!test(old, data))
continue;
- if (old->i_state & (I_FREEING|I_WILL_FREE))
+ if (old->i_state & I_FREEING)
continue;
break;
}
@@ -1305,6 +1305,8 @@ static void iput_final(struct inode *ino
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
@@ -1313,25 +1315,19 @@ static void iput_final(struct inode *ino
if (!drop) {
if (sb->s_flags & MS_ACTIVE) {
inode->i_state |= I_REFERENCED;
- if (!(inode->i_state & (I_DIRTY|I_SYNC))) {
+ 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;
+ inode->i_state |= I_FREEING;
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);
+ } else {
+ inode->i_state |= I_FREEING;
}
- WARN_ON(inode->i_state & I_NEW);
- 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.
Index: linux-2.6/fs/notify/inode_mark.c
===================================================================
--- linux-2.6.orig/fs/notify/inode_mark.c 2010-10-24 16:30:05.000000000 +0200
+++ linux-2.6/fs/notify/inode_mark.c 2010-10-24 16:32:43.661255957 +0200
@@ -244,11 +244,11 @@ void fsnotify_unmount_inodes(struct list
struct inode *need_iput_tmp;
/*
- * We cannot __iget() an inode in state I_FREEING,
- * I_WILL_FREE, or I_NEW which is fine because by that point
- * the inode cannot have any associated watches.
+ * We cannot __iget() an inode in state I_FREEING 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))
+ if (inode->i_state & (I_FREEING | I_NEW))
continue;
/*
@@ -272,7 +272,7 @@ void fsnotify_unmount_inodes(struct list
/* 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))) {
+ !(next_i->i_state & I_FREEING)) {
__iget(next_i);
need_iput = next_i;
}
Index: linux-2.6/fs/quota/dquot.c
===================================================================
--- linux-2.6.orig/fs/quota/dquot.c 2010-10-24 16:30:05.000000000 +0200
+++ linux-2.6/fs/quota/dquot.c 2010-10-24 16:32:43.665253722 +0200
@@ -898,7 +898,7 @@ static void add_dquot_ref(struct super_b
spin_lock(&inode_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
- if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW))
+ if (inode->i_state & (I_FREEING | I_NEW))
continue;
#ifdef CONFIG_QUOTA_DEBUG
if (unlikely(inode_get_rsv_space(inode) > 0))
Index: linux-2.6/fs/xfs/linux-2.6/xfs_iops.c
===================================================================
--- linux-2.6.orig/fs/xfs/linux-2.6/xfs_iops.c 2010-10-24 16:30:05.000000000 +0200
+++ linux-2.6/fs/xfs/linux-2.6/xfs_iops.c 2010-10-24 16:32:43.665253722 +0200
@@ -80,7 +80,7 @@ xfs_mark_inode_dirty_sync(
{
struct inode *inode = VFS_I(ip);
- if (!(inode->i_state & (I_WILL_FREE|I_FREEING)))
+ if (!(inode->i_state & I_FREEING))
mark_inode_dirty_sync(inode);
}
@@ -90,7 +90,7 @@ xfs_mark_inode_dirty(
{
struct inode *inode = VFS_I(ip);
- if (!(inode->i_state & (I_WILL_FREE|I_FREEING)))
+ if (!(inode->i_state & I_FREEING))
mark_inode_dirty(inode);
}
Index: linux-2.6/include/linux/fs.h
===================================================================
--- linux-2.6.orig/include/linux/fs.h 2010-10-24 16:30:05.000000000 +0200
+++ linux-2.6/include/linux/fs.h 2010-10-24 16:32:43.673253652 +0200
@@ -1601,8 +1601,8 @@ struct super_operations {
* I_DIRTY_DATASYNC and I_DIRTY_PAGES.
*
* Four bits define the lifetime of an inode. Initially, inodes are I_NEW,
- * until that flag is cleared. I_WILL_FREE, I_FREEING and I_CLEAR are set at
- * various stages of removing an inode.
+ * until that flag is cleared. I_FREEING and I_CLEAR are set at various
+ * stages of removing an inode.
*
* Two bits are used for locking and completion notification, I_NEW and I_SYNC.
*
@@ -1613,46 +1613,39 @@ struct super_operations {
* don't have to write inode on fdatasync() when only
* mtime has changed in it.
* I_DIRTY_PAGES Inode has dirty pages. Inode itself may be clean.
+ * I_FREEING Set when inode is about to be freed but still has dirty
+ * pages or buffers attached or the inode itself is still
+ * dirty.
+ * I_CLEAR Added by end_writeback(). In this state the inode is
+ * clean and can be destroyed. Inode keeps I_FREEING.
+ * I_REFERENCED Inode was recently referenced on the LRU and got another
+ * pass before eviction.
* I_NEW Serves as both a mutex and completion notification.
* New inodes set I_NEW. If two processes both create
* the same inode, one of them will release its inode and
* wait for I_NEW to be released before returning.
- * Inodes in I_WILL_FREE, I_FREEING or I_CLEAR state can
- * also cause waiting on I_NEW, without I_NEW actually
- * being set. find_inode() uses this to prevent returning
- * nearly-dead inodes.
- * I_WILL_FREE Must be set when calling write_inode_now() if i_count
- * is zero. I_FREEING must be set when I_WILL_FREE is
- * cleared.
- * I_FREEING Set when inode is about to be freed but still has dirty
- * pages or buffers attached or the inode itself is still
- * dirty.
- * I_CLEAR Added by end_writeback(). In this state the inode is clean
- * and can be destroyed. Inode keeps I_FREEING.
- *
- * Inodes that are I_WILL_FREE, I_FREEING or I_CLEAR are
- * prohibited for many purposes. iget() must wait for
- * the inode to be completely released, then create it
- * anew. Other functions will just ignore such inodes,
- * if appropriate. I_NEW is used for waiting.
- *
+ * Inodes in I_FREEING state can also cause waiting on
+ * I_NEW, without I_NEW actually being set. find_inode()
+ * uses this to prevent returning nearly-dead inodes.
* I_SYNC Synchonized write of dirty inode data. The bits is
* set during data writeback, and cleared with a wakeup
* on the bit address once it is done.
*
- * Q: What is the difference between I_WILL_FREE and I_FREEING?
+ * Inodes that have I_FREEING set are prohibited for many purposes.
+ * iget*_locked() must wait for the inode to be completely released, then
+ * create it anew. Other functions will just ignore such inodes, if
+ * appropriate. I_NEW is used for waiting.
*/
#define I_DIRTY_SYNC (1 << 0)
#define I_DIRTY_DATASYNC (1 << 1)
#define I_DIRTY_PAGES (1 << 2)
-#define __I_NEW 3
+#define I_FREEING (1 << 3)
+#define I_CLEAR (1 << 4)
+#define I_REFERENCED (1 << 5)
+#define __I_NEW 6
#define I_NEW (1 << __I_NEW)
-#define I_WILL_FREE (1 << 4)
-#define I_FREEING (1 << 5)
-#define I_CLEAR (1 << 6)
#define __I_SYNC 7
#define I_SYNC (1 << __I_SYNC)
-#define I_REFERENCED (1 << 8)
#define I_DIRTY (I_DIRTY_SYNC | I_DIRTY_DATASYNC | I_DIRTY_PAGES)
--
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