[PATCH] [0/7] Drop BKL in ext[234] ioctls

[PATCH] [0/7] Drop BKL in ext[234] ioctls

[Andi Kleen]

Remove the BKL from the ext* ioctls.

This is a slightly updated version of the ext[2-4] patches that hit
linux-fsdevel earlier.

-Andi

[PATCH] [1/7] Convert ext2 over to use unlocked_ioctl

[Andi Kleen]

I checked ext2_ioctl and could not find anything in there that would
need the BKL. So convert it over to use unlocked_ioctl

Signed-off-by: Andi Kleen <ak@suse.de>

---
 fs/ext2/dir.c   |    2 +-
 fs/ext2/ext2.h  |    3 +--
 fs/ext2/file.c  |    4 ++--
 fs/ext2/ioctl.c |   12 +++---------
 4 files changed, 7 insertions(+), 14 deletions(-)

Index: linux/fs/ext2/dir.c
===================================================================
--- linux.orig/fs/ext2/dir.c
+++ linux/fs/ext2/dir.c
@@ -703,7 +703,7 @@ const struct file_operations ext2_dir_op
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= ext2_readdir,
-	.ioctl		= ext2_ioctl,
+	.unlocked_ioctl = ext2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,
 #endif
Index: linux/fs/ext2/ext2.h
===================================================================
--- linux.orig/fs/ext2/ext2.h
+++ linux/fs/ext2/ext2.h
@@ -139,8 +139,7 @@ int __ext2_write_begin(struct file *file
 		struct page **pagep, void **fsdata);
 
 /* ioctl.c */
-extern int ext2_ioctl (struct inode *, struct file *, unsigned int,
-		       unsigned long);
+extern long ext2_ioctl(struct file *, unsigned int, unsigned long);
 extern long ext2_compat_ioctl(struct file *, unsigned int, unsigned long);
 
 /* namei.c */
Index: linux/fs/ext2/file.c
===================================================================
--- linux.orig/fs/ext2/file.c
+++ linux/fs/ext2/file.c
@@ -48,7 +48,7 @@ const struct file_operations ext2_file_o
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= generic_file_aio_write,
-	.ioctl		= ext2_ioctl,
+	.unlocked_ioctl = ext2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,
 #endif
@@ -65,7 +65,7 @@ const struct file_operations ext2_xip_fi
 	.llseek		= generic_file_llseek,
 	.read		= xip_file_read,
 	.write		= xip_file_write,
-	.ioctl		= ext2_ioctl,
+	.unlocked_ioctl = ext2_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext2_compat_ioctl,
 #endif
Index: linux/fs/ext2/ioctl.c
===================================================================
--- linux.orig/fs/ext2/ioctl.c
+++ linux/fs/ext2/ioctl.c
@@ -17,9 +17,9 @@
 #include <asm/uaccess.h>
 
 
-int ext2_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
-		unsigned long arg)
+long ext2_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
+	struct inode *inode = filp->f_dentry->d_inode;
 	struct ext2_inode_info *ei = EXT2_I(inode);
 	unsigned int flags;
 	unsigned short rsv_window_size;
@@ -141,9 +141,6 @@ int ext2_ioctl (struct inode * inode, st
 #ifdef CONFIG_COMPAT
 long ext2_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
-	int ret;
-
 	/* These are just misnamed, they actually get/put from/to user an int */
 	switch (cmd) {
 	case EXT2_IOC32_GETFLAGS:
@@ -161,9 +158,6 @@ long ext2_compat_ioctl(struct file *file
 	default:
 		return -ENOIOCTLCMD;
 	}
-	lock_kernel();
-	ret = ext2_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
-	unlock_kernel();
-	return ret;
+	return ext2_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 }
 #endif

[PATCH] [2/7] Remove incorrect BKL comment in ext2

[Andi Kleen]

No BKL used anywhere, so don't mention it.

Signed-off-by: Andi Kleen <ak@suse.de>

---
 fs/ext2/inode.c |    1 -
 1 file changed, 1 deletion(-)

Index: linux/fs/ext2/inode.c
===================================================================
--- linux.orig/fs/ext2/inode.c
+++ linux/fs/ext2/inode.c
@@ -569,7 +569,6 @@ static void ext2_splice_branch(struct in
  *
  * `handle' can be NULL if create == 0.
  *
- * The BKL may not be held on entry here.  Be sure to take it early.
  * return > 0, # of blocks mapped or allocated.
  * return = 0, if plain lookup failed.
  * return < 0, error case.

[PATCH] [3/7] Convert ext3 to use unlocked_ioctl v2

[Andi Kleen]

I checked ext3_ioctl and it looked largely safe to not be used
without BKL.  So convert it over to unlocked_ioctl.

Signed-off-by: Andi Kleen <ak@suse.de>

v1->v2: drop lock kernel for online growth. resize.c seems to do enough
locking

---
 fs/ext3/dir.c           |    2 +-
 fs/ext3/file.c          |    2 +-
 fs/ext3/ioctl.c         |   21 +++++++++++----------
 include/linux/ext3_fs.h |    3 +--
 4 files changed, 14 insertions(+), 14 deletions(-)

Index: linux/fs/ext3/dir.c
===================================================================
--- linux.orig/fs/ext3/dir.c
+++ linux/fs/ext3/dir.c
@@ -42,7 +42,7 @@ const struct file_operations ext3_dir_op
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= ext3_readdir,		/* we take BKL. needed?*/
-	.ioctl		= ext3_ioctl,		/* BKL held */
+	.unlocked_ioctl = ext3_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext3_compat_ioctl,
 #endif
Index: linux/fs/ext3/file.c
===================================================================
--- linux.orig/fs/ext3/file.c
+++ linux/fs/ext3/file.c
@@ -112,7 +112,7 @@ const struct file_operations ext3_file_o
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= ext3_file_write,
-	.ioctl		= ext3_ioctl,
+	.unlocked_ioctl = ext3_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext3_compat_ioctl,
 #endif
Index: linux/fs/ext3/ioctl.c
===================================================================
--- linux.orig/fs/ext3/ioctl.c
+++ linux/fs/ext3/ioctl.c
@@ -17,9 +17,9 @@
 #include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 
-int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
-		unsigned long arg)
+long ext3_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
+	struct inode *inode = filp->f_dentry->d_inode;
 	struct ext3_inode_info *ei = EXT3_I(inode);
 	unsigned int flags;
 	unsigned short rsv_window_size;
@@ -263,9 +270,6 @@ flags_err:
 #ifdef CONFIG_COMPAT
 long ext3_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
-	int ret;
-
 	/* These are just misnamed, they actually get/put from/to user an int */
 	switch (cmd) {
 	case EXT3_IOC32_GETFLAGS:
@@ -305,9 +309,6 @@ long ext3_compat_ioctl(struct file *file
 	default:
 		return -ENOIOCTLCMD;
 	}
-	lock_kernel();
-	ret = ext3_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
-	unlock_kernel();
-	return ret;
+	return ext3_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 }
 #endif
Index: linux/include/linux/ext3_fs.h
===================================================================
--- linux.orig/include/linux/ext3_fs.h
+++ linux/include/linux/ext3_fs.h
@@ -838,8 +838,7 @@ extern void ext3_get_inode_flags(struct 
 extern void ext3_set_aops(struct inode *inode);
 
 /* ioctl.c */
-extern int ext3_ioctl (struct inode *, struct file *, unsigned int,
-		       unsigned long);
+extern long ext3_ioctl(struct file *, unsigned int, unsigned long);
 extern long ext3_compat_ioctl (struct file *, unsigned int, unsigned long);
 
 /* namei.c */

[PATCH] [4/7] ext3: Remove incorrect BKL comment

[Andi Kleen]

There is no BKL held on entry in ->fsync nor in the low level ext3_sync_file.

Signed-off-by: Andi Kleen <ak@suse.de>

---
 fs/ext3/dir.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Index: linux/fs/ext3/dir.c
===================================================================
--- linux.orig/fs/ext3/dir.c
+++ linux/fs/ext3/dir.c
@@ -46,7 +46,7 @@ const struct file_operations ext3_dir_op
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext3_compat_ioctl,
 #endif
-	.fsync		= ext3_sync_file,	/* BKL held */
+	.fsync		= ext3_sync_file,
 	.release	= ext3_release_dir,
 };
 

[PATCH] [5/7] Remove incorrect comment refering to lock_kernel() from jbd/jbd2

[Andi Kleen]

None of the callers of this function does actually take the BKL
as far as I can see. So remove the comment refering to the BKL.

Signed-off-by: Andi Kleen <ak@suse.de>

---
 fs/jbd/recovery.c  |    2 +-
 fs/jbd2/recovery.c |    2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

Index: linux/fs/jbd/recovery.c
===================================================================
--- linux.orig/fs/jbd/recovery.c
+++ linux/fs/jbd/recovery.c
@@ -354,7 +354,7 @@ static int do_one_pass(journal_t *journa
 		struct buffer_head *	obh;
 		struct buffer_head *	nbh;
 
-		cond_resched();		/* We're under lock_kernel() */
+		cond_resched();
 
 		/* If we already know where to stop the log traversal,
 		 * check right now that we haven't gone past the end of
Index: linux/fs/jbd2/recovery.c
===================================================================
--- linux.orig/fs/jbd2/recovery.c
+++ linux/fs/jbd2/recovery.c
@@ -364,7 +364,7 @@ static int do_one_pass(journal_t *journa
 		struct buffer_head *	obh;
 		struct buffer_head *	nbh;
 
-		cond_resched();		/* We're under lock_kernel() */
+		cond_resched();
 
 		/* If we already know where to stop the log traversal,
 		 * check right now that we haven't gone past the end of

[PATCH] [6/7] Convert ext4 to use unlocked_ioctl v2

[Andi Kleen]

I checked ext4_ioctl and it looked largely safe to not be used
without BKL.  So convert it over to unlocked_ioctl.

Signed-off-by: Andi Kleen <ak@suse.de>

v1->v2: drop BKL for online grow. resize.c seems to do enough locking

---
 fs/ext4/dir.c           |    2 +-
 fs/ext4/file.c          |    2 +-
 fs/ext4/ioctl.c         |   20 +++++++++++---------
 include/linux/ext4_fs.h |    3 +--
 4 files changed, 14 insertions(+), 13 deletions(-)

Index: linux/fs/ext4/dir.c
===================================================================
--- linux.orig/fs/ext4/dir.c
+++ linux/fs/ext4/dir.c
@@ -42,7 +42,7 @@ const struct file_operations ext4_dir_op
 	.llseek		= generic_file_llseek,
 	.read		= generic_read_dir,
 	.readdir	= ext4_readdir,		/* we take BKL. needed?*/
-	.ioctl		= ext4_ioctl,		/* BKL held */
+	.unlocked_ioctl = ext4_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext4_compat_ioctl,
 #endif
Index: linux/fs/ext4/file.c
===================================================================
--- linux.orig/fs/ext4/file.c
+++ linux/fs/ext4/file.c
@@ -112,7 +112,7 @@ const struct file_operations ext4_file_o
 	.write		= do_sync_write,
 	.aio_read	= generic_file_aio_read,
 	.aio_write	= ext4_file_write,
-	.ioctl		= ext4_ioctl,
+	.unlocked_ioctl = ext4_ioctl,
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext4_compat_ioctl,
 #endif
Index: linux/fs/ext4/ioctl.c
===================================================================
--- linux.orig/fs/ext4/ioctl.c
+++ linux/fs/ext4/ioctl.c
@@ -17,9 +17,9 @@
 #include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 
-int ext4_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
-		unsigned long arg)
+long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
 {
+	struct inode *inode = filp->f_dentry->d_inode;
 	struct ext4_inode_info *ei = EXT4_I(inode);
 	unsigned int flags;
 	unsigned short rsv_window_size;
@@ -262,9 +270,6 @@ flags_err:
 #ifdef CONFIG_COMPAT
 long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
-	struct inode *inode = file->f_path.dentry->d_inode;
-	int ret;
-
 	/* These are just misnamed, they actually get/put from/to user an int */
 	switch (cmd) {
 	case EXT4_IOC32_GETFLAGS:
@@ -304,9 +309,6 @@ long ext4_compat_ioctl(struct file *file
 	default:
 		return -ENOIOCTLCMD;
 	}
-	lock_kernel();
-	ret = ext4_ioctl(inode, file, cmd, (unsigned long) compat_ptr(arg));
-	unlock_kernel();
-	return ret;
+	return ext4_ioctl(file, cmd, (unsigned long) compat_ptr(arg));
 }
 #endif
Index: linux/include/linux/ext4_fs.h
===================================================================
--- linux.orig/include/linux/ext4_fs.h
+++ linux/include/linux/ext4_fs.h
@@ -939,8 +939,7 @@ extern int ext4_block_truncate_page(hand
 		struct address_space *mapping, loff_t from);
 
 /* ioctl.c */
-extern int ext4_ioctl (struct inode *, struct file *, unsigned int,
-		       unsigned long);
+extern long ext4_ioctl(struct file *, unsigned int, unsigned long);
 extern long ext4_compat_ioctl (struct file *, unsigned int, unsigned long);
 
 /* namei.c */

[PATCH] [7/7] Remove incorrect BKL comments in ext4

[Andi Kleen]

Signed-off-by: Andi Kleen <ak@suse.de>

---
 fs/ext4/dir.c   |    2 +-
 fs/ext4/inode.c |    1 -
 2 files changed, 1 insertion(+), 2 deletions(-)

Index: linux/fs/ext4/dir.c
===================================================================
--- linux.orig/fs/ext4/dir.c
+++ linux/fs/ext4/dir.c
@@ -46,7 +46,7 @@ const struct file_operations ext4_dir_op
 #ifdef CONFIG_COMPAT
 	.compat_ioctl	= ext4_compat_ioctl,
 #endif
-	.fsync		= ext4_sync_file,	/* BKL held */
+	.fsync		= ext4_sync_file,
 	.release	= ext4_release_dir,
 };
 
Index: linux/fs/ext4/inode.c
===================================================================
--- linux.orig/fs/ext4/inode.c
+++ linux/fs/ext4/inode.c
@@ -778,7 +778,6 @@ err_out:
  *
  * `handle' can be NULL if create == 0.
  *
- * The BKL may not be held on entry here.  Be sure to take it early.
  * return > 0, # of blocks mapped or allocated.
  * return = 0, if plain lookup failed.
  * return < 0, error case.

Re: [PATCH] [0/7] Drop BKL in ext[234] ioctls

[Theodore Tso]

On Mon, Jan 28, 2008 at 11:16:09AM +0100, Andi Kleen wrote:
> 
> Remove the BKL from the ext* ioctls.
> 
> This is a slightly updated version of the ext[2-4] patches that hit
> linux-fsdevel earlier.

Thanks, I've included these patches into the ext4 tree, and should
hopefully be pulled into the next -mm tree.

						- Ted