From cabc97fe740d2c7664988e76f218318aecd5ec18 Mon Sep 17 00:00:00 2001
From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
Date: Mon, 7 Jun 2010 14:45:15 +0900
Subject: [PATCH 1/5] aufs: tiny, test task flags instead of mm

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/loop.c  | 13 +++++++++----
 fs/aufs/super.h |  3 ++-
 fs/aufs/wkq.h   |  2 +-
 3 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/fs/aufs/loop.c b/fs/aufs/loop.c
index 5fceec75814b..646cd39714c4 100644
--- a/fs/aufs/loop.c
+++ b/fs/aufs/loop.c
@@ -47,9 +47,14 @@ int au_test_loopback_overlap(struct super_block *sb, struct dentry *h_d1,
 /* true if a kernel thread named 'loop[0-9].*' accesses a file */
 int au_test_loopback_kthread(void)
 {
-	const char c = current->comm[4];
+	int ret;
 
-	return current->mm == NULL
-	       && '0' <= c && c <= '9'
-	       && strncmp(current->comm, "loop", 4) == 0;
+	ret = 0;
+	if (current->flags & PF_KTHREAD) {
+		const char c = current->comm[4];
+		ret = ('0' <= c && c <= '9'
+		       && !strncmp(current->comm, "loop", 4));
+	}
+
+	return ret;
 }
diff --git a/fs/aufs/super.h b/fs/aufs/super.h
index cd6fdc4bc15c..4d96c8b121f3 100644
--- a/fs/aufs/super.h
+++ b/fs/aufs/super.h
@@ -231,7 +231,8 @@ void au_export_init(struct super_block *sb);
 
 static inline int au_test_nfsd(struct task_struct *tsk)
 {
-	return !tsk->mm && !strcmp(tsk->comm, "nfsd");
+	return (current->flags & PF_KTHREAD)
+		&& !strcmp(tsk->comm, "nfsd");
 }
 
 int au_xigen_inc(struct inode *inode);
diff --git a/fs/aufs/wkq.h b/fs/aufs/wkq.h
index 3fe36b31d148..143d4c3ad393 100644
--- a/fs/aufs/wkq.h
+++ b/fs/aufs/wkq.h
@@ -63,7 +63,7 @@ void au_wkq_fin(void);
 
 static inline int au_test_wkq(struct task_struct *tsk)
 {
-	return !tsk->mm
+	return (current->flags & PF_KTHREAD)
 		&& !strncmp(tsk->comm, AUFS_WKQ_NAME "/",
 			    sizeof(AUFS_WKQ_NAME));
 }

From ea824b7a71cd905fdadcb0998ab2005fcb3786e9 Mon Sep 17 00:00:00 2001
From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
Date: Tue, 8 Jun 2010 00:06:55 +0900
Subject: [PATCH 2/5] aufs: minor optimization, pass the 'verbose' flag

Stop testing the 'verbose' flag in all test_dentry_busy(),
test_inode_busy() and au_br_del() functions. Instead pass the tested
result from au_br_del() to test_dentry_busy() and test_inode_busy().

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/branch.c | 17 +++++++----------
 1 file changed, 7 insertions(+), 10 deletions(-)

diff --git a/fs/aufs/branch.c b/fs/aufs/branch.c
index f3fd47debb3f..00fd8a0f448c 100644
--- a/fs/aufs/branch.c
+++ b/fs/aufs/branch.c
@@ -526,11 +526,10 @@ int au_br_add(struct super_block *sb, struct au_opt_add *add, int remount)
  * test if the branch is deletable or not.
  */
 static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
-			    unsigned int sigen)
+			    unsigned int sigen, const unsigned int verbose)
 {
 	int err, i, j, ndentry;
 	aufs_bindex_t bstart, bend;
-	unsigned char verbose;
 	struct au_dcsub_pages dpages;
 	struct au_dpage *dpage;
 	struct dentry *d;
@@ -543,7 +542,6 @@ static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
 	if (unlikely(err))
 		goto out_dpages;
 
-	verbose = !!au_opt_test(au_mntflags(root->d_sb), VERBOSE);
 	for (i = 0; !err && i < dpages.ndpage; i++) {
 		dpage = dpages.dpages + i;
 		ndentry = dpage->ndentry;
@@ -584,15 +582,13 @@ static int test_dentry_busy(struct dentry *root, aufs_bindex_t bindex,
 }
 
 static int test_inode_busy(struct super_block *sb, aufs_bindex_t bindex,
-			   unsigned int sigen)
+			   unsigned int sigen, const unsigned int verbose)
 {
 	int err;
 	struct inode *i;
 	aufs_bindex_t bstart, bend;
-	unsigned char verbose;
 
 	err = 0;
-	verbose = !!au_opt_test(au_mntflags(sb), VERBOSE);
 	list_for_each_entry(i, &sb->s_inodes, i_sb_list) {
 		AuDebugOn(!atomic_read(&i->i_count));
 		if (!list_empty(&i->i_dentry))
@@ -628,7 +624,8 @@ static int test_inode_busy(struct super_block *sb, aufs_bindex_t bindex,
 	return err;
 }
 
-static int test_children_busy(struct dentry *root, aufs_bindex_t bindex)
+static int test_children_busy(struct dentry *root, aufs_bindex_t bindex,
+			      const unsigned int verbose)
 {
 	int err;
 	unsigned int sigen;
@@ -637,9 +634,9 @@ static int test_children_busy(struct dentry *root, aufs_bindex_t bindex)
 	DiMustNoWaiters(root);
 	IiMustNoWaiters(root->d_inode);
 	di_write_unlock(root);
-	err = test_dentry_busy(root, bindex, sigen);
+	err = test_dentry_busy(root, bindex, sigen, verbose);
 	if (!err)
-		err = test_inode_busy(root->d_sb, bindex, sigen);
+		err = test_inode_busy(root->d_sb, bindex, sigen, verbose);
 	di_write_lock_child(root); /* aufs_write_lock() calls ..._child() */
 
 	return err;
@@ -776,7 +773,7 @@ int au_br_del(struct super_block *sb, struct au_opt_del *del, int remount)
 		}
 	}
 
-	err = test_children_busy(sb->s_root, bindex);
+	err = test_children_busy(sb->s_root, bindex, verbose);
 	if (unlikely(err)) {
 		if (do_wh)
 			goto out_wh;

From 7e7b86c68cf5d3638ceb19a0a1d7a254d8501bde Mon Sep 17 00:00:00 2001
From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
Date: Tue, 8 Jun 2010 00:08:00 +0900
Subject: [PATCH 3/5] aufs: tiny, remove an unnecessary variable

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/plink.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/fs/aufs/plink.c b/fs/aufs/plink.c
index a9121df442ef..b5225637c83e 100644
--- a/fs/aufs/plink.c
+++ b/fs/aufs/plink.c
@@ -421,7 +421,6 @@ long au_plink_ioctl(struct file *file, unsigned int cmd)
 {
 	long err;
 	struct super_block *sb;
-	struct au_sbinfo *sbinfo;
 
 	err = -EACCES;
 	if (!capable(CAP_SYS_ADMIN))
@@ -429,7 +428,6 @@ long au_plink_ioctl(struct file *file, unsigned int cmd)
 
 	err = 0;
 	sb = file->f_dentry->d_sb;
-	sbinfo = au_sbi(sb);
 	switch (cmd) {
 	case AUFS_CTL_PLINK_MAINT:
 		/*
@@ -440,7 +438,7 @@ long au_plink_ioctl(struct file *file, unsigned int cmd)
 		break;
 	case AUFS_CTL_PLINK_CLEAN:
 		aufs_write_lock(sb->s_root);
-		if (au_opt_test(sbinfo->si_mntflags, PLINK))
+		if (au_opt_test(au_mntflags(sb), PLINK))
 			au_plink_put(sb);
 		aufs_write_unlock(sb->s_root);
 		break;

From bdc941c464fd4181f7ab76fbb992b6ab150ac188 Mon Sep 17 00:00:00 2001
From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
Date: Tue, 8 Jun 2010 23:28:03 +0900
Subject: [PATCH 4/5] aufs: minor optimization au_iinfo_fin()

- extract a part of au_iinfo_fin(), create a new function
  au_xino_delete_inode(), and remove au_iinfo_write0().
- simplify au_xino_write0() and rename to au_xib_clear_bit().
- convert the type of au_xigen_inc() into void.
- stop testing 'xino' option in au_xigen_inc().

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/branch.h |  3 +-
 fs/aufs/export.c | 23 +++----------
 fs/aufs/iinfo.c  | 55 +++++++-----------------------
 fs/aufs/super.c  |  1 +
 fs/aufs/super.h  |  4 +--
 fs/aufs/xino.c   | 88 +++++++++++++++++++++++++++++++++++++-----------
 6 files changed, 91 insertions(+), 83 deletions(-)

diff --git a/fs/aufs/branch.h b/fs/aufs/branch.h
index b4a8c2eaba3c..9e7747600217 100644
--- a/fs/aufs/branch.h
+++ b/fs/aufs/branch.h
@@ -157,8 +157,7 @@ ssize_t xino_fwrite(au_writef_t func, struct file *file, void *buf, size_t size,
 struct file *au_xino_create2(struct file *base_file, struct file *copy_src);
 struct file *au_xino_create(struct super_block *sb, char *fname, int silent);
 ino_t au_xino_new_ino(struct super_block *sb);
-int au_xino_write0(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
-		   ino_t ino);
+void au_xino_delete_inode(struct inode *inode, const int unlinked);
 int au_xino_write(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
 		  ino_t ino);
 int au_xino_read(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
diff --git a/fs/aufs/export.c b/fs/aufs/export.c
index 6b01678cc8f7..647666042310 100644
--- a/fs/aufs/export.c
+++ b/fs/aufs/export.c
@@ -89,41 +89,28 @@ static int au_test_anon(struct dentry *dentry)
 /* ---------------------------------------------------------------------- */
 /* inode generation external table */
 
-int au_xigen_inc(struct inode *inode)
+void au_xigen_inc(struct inode *inode)
 {
-	int err;
 	loff_t pos;
 	ssize_t sz;
 	__u32 igen;
 	struct super_block *sb;
 	struct au_sbinfo *sbinfo;
 
-	err = 0;
 	sb = inode->i_sb;
-	sbinfo = au_sbi(sb);
-	/*
-	 * temporary workaround for escaping from SiMustAnyLock() in
-	 * au_mntflags(), since this function is called from au_iinfo_fin().
-	 */
-	if (unlikely(!au_opt_test(sbinfo->si_mntflags, XINO)))
-		goto out;
+	AuDebugOn(!au_opt_test(au_mntflags(sb), XINO));
 
+	sbinfo = au_sbi(sb);
 	pos = inode->i_ino;
 	pos *= sizeof(igen);
 	igen = inode->i_generation + 1;
 	sz = xino_fwrite(sbinfo->si_xwrite, sbinfo->si_xigen, &igen,
 			 sizeof(igen), &pos);
 	if (sz == sizeof(igen))
-		goto out; /* success */
+		return; /* success */
 
-	err = sz;
-	if (unlikely(sz >= 0)) {
-		err = -EIO;
+	if (unlikely(sz >= 0))
 		AuIOErr("xigen error (%zd)\n", sz);
-	}
-
- out:
-	return err;
 }
 
 int au_xigen_new(struct inode *inode)
diff --git a/fs/aufs/iinfo.c b/fs/aufs/iinfo.c
index eaab5571fd7c..1c8f6630e44b 100644
--- a/fs/aufs/iinfo.c
+++ b/fs/aufs/iinfo.c
@@ -211,67 +211,38 @@ int au_ii_realloc(struct au_iinfo *iinfo, int nbr)
 	return err;
 }
 
-static int au_iinfo_write0(struct super_block *sb, struct au_hinode *hinode,
-			   ino_t ino)
-{
-	int err;
-	aufs_bindex_t bindex;
-	unsigned char locked;
-
-	err = 0;
-	locked = !!si_noflush_read_trylock(sb);
-	bindex = au_br_index(sb, hinode->hi_id);
-	if (bindex >= 0)
-		err = au_xino_write0(sb, bindex, hinode->hi_inode->i_ino, ino);
-	/* error action? */
-	if (locked)
-		si_read_unlock(sb);
-	return err;
-}
-
 void au_iinfo_fin(struct inode *inode)
 {
-	ino_t ino;
-	aufs_bindex_t bend;
-	unsigned char unlinked = !inode->i_nlink;
 	struct au_iinfo *iinfo;
 	struct au_hinode *hi;
 	struct super_block *sb;
-
-	if (unlinked) {
-		int err = au_xigen_inc(inode);
-		if (unlikely(err))
-			AuWarn1("failed resetting i_generation, %d\n", err);
-	}
+	aufs_bindex_t bindex, bend;
+	unsigned char locked;
 
 	iinfo = au_ii(inode);
 	/* bad_inode case */
 	if (!iinfo)
 		return;
 
+	sb = inode->i_sb;
+	locked = !!si_noflush_read_trylock(sb);
+	au_xino_delete_inode(inode, !inode->i_nlink);
+	if (locked)
+		si_read_unlock(sb);
+
 	if (iinfo->ii_vdir)
 		au_vdir_free(iinfo->ii_vdir);
 
-	if (iinfo->ii_bstart >= 0) {
-		sb = inode->i_sb;
-		ino = 0;
-		if (unlinked)
-			ino = inode->i_ino;
-		hi = iinfo->ii_hinode + iinfo->ii_bstart;
+	bindex = iinfo->ii_bstart;
+	if (bindex >= 0) {
+		hi = iinfo->ii_hinode + bindex;
 		bend = iinfo->ii_bend;
-		while (iinfo->ii_bstart++ <= bend) {
-			if (hi->hi_inode) {
-				if (unlinked || !hi->hi_inode->i_nlink) {
-					au_iinfo_write0(sb, hi, ino);
-					/* ignore this error */
-					ino = 0;
-				}
+		while (bindex++ <= bend) {
+			if (hi->hi_inode)
 				au_hiput(hi);
-			}
 			hi++;
 		}
 	}
-
 	kfree(iinfo->ii_hinode);
 	AuRwDestroy(&iinfo->ii_rwsem);
 }
diff --git a/fs/aufs/super.c b/fs/aufs/super.c
index 7bb05ce63815..2579f27b981c 100644
--- a/fs/aufs/super.c
+++ b/fs/aufs/super.c
@@ -684,6 +684,7 @@ static int aufs_remount_fs(struct super_block *sb, int *flags, char *data)
 static const struct super_operations aufs_sop = {
 	.alloc_inode	= aufs_alloc_inode,
 	.destroy_inode	= aufs_destroy_inode,
+	/* always deleting, no clearing */
 	.drop_inode	= generic_delete_inode,
 	.show_options	= aufs_show_options,
 	.statfs		= aufs_statfs,
diff --git a/fs/aufs/super.h b/fs/aufs/super.h
index 4d96c8b121f3..9415a106e79c 100644
--- a/fs/aufs/super.h
+++ b/fs/aufs/super.h
@@ -235,7 +235,7 @@ static inline int au_test_nfsd(struct task_struct *tsk)
 		&& !strcmp(tsk->comm, "nfsd");
 }
 
-int au_xigen_inc(struct inode *inode);
+void au_xigen_inc(struct inode *inode);
 int au_xigen_new(struct inode *inode);
 int au_xigen_set(struct super_block *sb, struct file *base);
 void au_xigen_clr(struct super_block *sb);
@@ -249,7 +249,7 @@ static inline int au_busy_or_stale(void)
 #else
 AuStubVoid(au_export_init, struct super_block *sb)
 AuStubInt0(au_test_nfsd, struct task_struct *tsk)
-AuStubInt0(au_xigen_inc, struct inode *inode)
+AuStubVoid(au_xigen_inc, struct inode *inode)
 AuStubInt0(au_xigen_new, struct inode *inode)
 AuStubInt0(au_xigen_set, struct super_block *sb, struct file *base)
 AuStubVoid(au_xigen_clr, struct super_block *sb)
diff --git a/fs/aufs/xino.c b/fs/aufs/xino.c
index 6cee7060a780..add189eec981 100644
--- a/fs/aufs/xino.c
+++ b/fs/aufs/xino.c
@@ -487,33 +487,83 @@ static int xib_pindex(struct super_block *sb, unsigned long pindex)
 
 /* ---------------------------------------------------------------------- */
 
-int au_xino_write0(struct super_block *sb, aufs_bindex_t bindex, ino_t h_ino,
-		   ino_t ino)
+static void au_xib_clear_bit(struct inode *inode)
 {
 	int err, bit;
 	unsigned long pindex;
+	struct super_block *sb;
 	struct au_sbinfo *sbinfo;
 
-	if (!au_opt_test(au_mntflags(sb), XINO))
-		return 0;
+	AuDebugOn(inode->i_nlink);
 
-	err = 0;
-	if (ino) {
-		sbinfo = au_sbi(sb);
-		xib_calc_bit(ino, &pindex, &bit);
-		AuDebugOn(page_bits <= bit);
-		mutex_lock(&sbinfo->si_xib_mtx);
-		err = xib_pindex(sb, pindex);
-		if (!err) {
-			clear_bit(bit, sbinfo->si_xib_buf);
-			sbinfo->si_xib_next_bit = bit;
-		}
-		mutex_unlock(&sbinfo->si_xib_mtx);
+	sb = inode->i_sb;
+	xib_calc_bit(inode->i_ino, &pindex, &bit);
+	AuDebugOn(page_bits <= bit);
+	sbinfo = au_sbi(sb);
+	mutex_lock(&sbinfo->si_xib_mtx);
+	err = xib_pindex(sb, pindex);
+	if (!err) {
+		clear_bit(bit, sbinfo->si_xib_buf);
+		sbinfo->si_xib_next_bit = bit;
 	}
+	mutex_unlock(&sbinfo->si_xib_mtx);
+}
 
-	if (!err)
-		err = au_xino_write(sb, bindex, h_ino, 0);
-	return err;
+/* for s_op->delete_inode() */
+void au_xino_delete_inode(struct inode *inode, const int unlinked)
+{
+	int err;
+	unsigned int mnt_flags;
+	aufs_bindex_t bindex, bend, bi;
+	unsigned char try_trunc;
+	struct au_iinfo *iinfo;
+	struct super_block *sb;
+	struct au_hinode *hi;
+	struct inode *h_inode;
+	struct au_branch *br;
+	au_writef_t xwrite;
+
+	sb = inode->i_sb;
+	mnt_flags = au_mntflags(sb);
+	if (!au_opt_test(mnt_flags, XINO)
+	    || inode->i_ino == AUFS_ROOT_INO)
+		return;
+
+	if (unlinked) {
+		au_xigen_inc(inode);
+		au_xib_clear_bit(inode);
+	}
+
+	iinfo = au_ii(inode);
+	if (!iinfo)
+		return;
+
+	bindex = iinfo->ii_bstart;
+	if (bindex < 0)
+		return;
+
+	xwrite = au_sbi(sb)->si_xwrite;
+	try_trunc = !!au_opt_test(mnt_flags, TRUNC_XINO);
+	hi = iinfo->ii_hinode + bindex;
+	bend = iinfo->ii_bend;
+	for (; bindex <= bend; bindex++, hi++) {
+		h_inode = hi->hi_inode;
+		if (!h_inode
+		    || (!unlinked && h_inode->i_nlink))
+			continue;
+
+		/* inode may not be revalidated */
+		bi = au_br_index(sb, hi->hi_id);
+		if (bi < 0)
+			continue;
+
+		br = au_sbr(sb, bi);
+		err = au_xino_do_write(xwrite, br->br_xino.xi_file,
+				       h_inode->i_ino, /*ino*/0);
+		if (!err && try_trunc
+		    && au_test_fs_trunc_xino(br->br_mnt->mnt_sb))
+			xino_try_trunc(sb, br);
+	}
 }
 
 /* get an unused inode number from bitmap */

From f2f51daf576fa90ad7209288ed8b19c8151ff92a Mon Sep 17 00:00:00 2001
From: "J. R. Okajima" <hooanon05@yahoo.co.jp>
Date: Wed, 9 Jun 2010 17:03:00 +0900
Subject: [PATCH 5/5] aufs: tiny, simplify the locks in au_do_flush()

The read-lock for dinfo is unnecessary.
Also the write-lock for iinfo should be a read-lock.

Signed-off-by: J. R. Okajima <hooanon05@yahoo.co.jp>
---
 fs/aufs/file.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/aufs/file.c b/fs/aufs/file.c
index 33d469e0bf6b..5cce91b339b1 100644
--- a/fs/aufs/file.c
+++ b/fs/aufs/file.c
@@ -338,12 +338,12 @@ int au_do_flush(struct file *file, fl_owner_t id,
 	inode = dentry->d_inode;
 	si_noflush_read_lock(sb);
 	fi_read_lock(file);
-	di_read_lock_child(dentry, AuLock_IW);
+	ii_read_lock_child(inode);
 
 	err = flush(file, id);
 	au_cpup_attr_timesizes(inode);
 
-	di_read_unlock(dentry, AuLock_IW);
+	ii_read_unlock(inode);
 	fi_read_unlock(file);
 	si_read_unlock(sb);
 	return err;