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Commit e0a5cbac authored by Jan Blunck's avatar Jan Blunck Committed by Jan Kara
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BKL: Remove BKL from ext2 filesystem 



The BKL is still used in ext2_put_super(), ext2_fill_super(), ext2_sync_fs()
ext2_remount() and ext2_write_inode(). From these calls ext2_put_super(),
ext2_fill_super() and ext2_remount() are protected against each other by
the struct super_block s_umount rw semaphore. The call in ext2_write_inode()
could only protect the modification of the ext2_sb_info through
ext2_update_dynamic_rev() against concurrent ext2_sync_fs() or ext2_remount().
ext2_fill_super() and ext2_put_super() can be left out because you need a
valid filesystem reference in all three cases, which you do not have when
you are one of these functions.

If the BKL is only protecting the modification of the ext2_sb_info it can
safely be removed since this is protected by the struct ext2_sb_info s_lock.

Signed-off-by: default avatarJan Blunck <jblunck@suse.de>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: default avatarJan Kara <jack@suse.cz>
parent c15271f4

fs/ext2/inode.c

+0 −3
Original line number Original line Diff line number Diff line
@@ -22,7 +22,6 @@ 
 *  Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000

 *  Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000

 */

 */





#include <linux/smp_lock.h>

#include <linux/time.h>

#include <linux/time.h>

#include <linux/highuid.h>

#include <linux/highuid.h>

#include <linux/pagemap.h>

#include <linux/pagemap.h>
@@ -1406,13 +1405,11 @@ static int __ext2_write_inode(struct inode *inode, int do_sync) 
			       /* If this is the first large file

			       /* If this is the first large file

				* created, add a flag to the superblock.

				* created, add a flag to the superblock.

				*/

				*/

				lock_kernel();

				spin_lock(&EXT2_SB(sb)->s_lock);

				spin_lock(&EXT2_SB(sb)->s_lock);

				ext2_update_dynamic_rev(sb);

				ext2_update_dynamic_rev(sb);

				EXT2_SET_RO_COMPAT_FEATURE(sb,

				EXT2_SET_RO_COMPAT_FEATURE(sb,

					EXT2_FEATURE_RO_COMPAT_LARGE_FILE);

					EXT2_FEATURE_RO_COMPAT_LARGE_FILE);

				spin_unlock(&EXT2_SB(sb)->s_lock);

				spin_unlock(&EXT2_SB(sb)->s_lock);

				unlock_kernel();

				ext2_write_super(sb);

				ext2_write_super(sb);

			}

			}

		}

		}

fs/ext2/super.c

+0 −13
Original line number Original line Diff line number Diff line
@@ -26,7 +26,6 @@ 
#include <linux/random.h>

#include <linux/random.h>

#include <linux/buffer_head.h>

#include <linux/buffer_head.h>

#include <linux/exportfs.h>

#include <linux/exportfs.h>

#include <linux/smp_lock.h>

#include <linux/vfs.h>

#include <linux/vfs.h>

#include <linux/seq_file.h>

#include <linux/seq_file.h>

#include <linux/mount.h>

#include <linux/mount.h>
@@ -120,8 +119,6 @@ static void ext2_put_super (struct super_block * sb) 
	int i;

	int i;

	struct ext2_sb_info *sbi = EXT2_SB(sb);

	struct ext2_sb_info *sbi = EXT2_SB(sb);





	lock_kernel();



	if (sb->s_dirt)

	if (sb->s_dirt)

		ext2_write_super(sb);

		ext2_write_super(sb);
@@ -147,8 +144,6 @@ static void ext2_put_super (struct super_block * sb) 
	sb->s_fs_info = NULL;

	sb->s_fs_info = NULL;

	kfree(sbi->s_blockgroup_lock);

	kfree(sbi->s_blockgroup_lock);

	kfree(sbi);

	kfree(sbi);



	unlock_kernel();

}

}





static struct kmem_cache * ext2_inode_cachep;

static struct kmem_cache * ext2_inode_cachep;
@@ -1170,7 +1165,6 @@ static int ext2_sync_fs(struct super_block *sb, int wait) 
	struct ext2_sb_info *sbi = EXT2_SB(sb);

	struct ext2_sb_info *sbi = EXT2_SB(sb);

	struct ext2_super_block *es = EXT2_SB(sb)->s_es;

	struct ext2_super_block *es = EXT2_SB(sb)->s_es;





	lock_kernel();

	spin_lock(&sbi->s_lock);

	spin_lock(&sbi->s_lock);

	if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {

	if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {

		ext2_debug("setting valid to 0\n");

		ext2_debug("setting valid to 0\n");
@@ -1178,8 +1172,6 @@ static int ext2_sync_fs(struct super_block *sb, int wait) 
	}

	}

	spin_unlock(&sbi->s_lock);

	spin_unlock(&sbi->s_lock);

	ext2_sync_super(sb, es, wait);

	ext2_sync_super(sb, es, wait);

	unlock_kernel();



	return 0;

	return 0;

}

}
@@ -1201,7 +1193,6 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) 
	unsigned long old_sb_flags;

	unsigned long old_sb_flags;

	int err;

	int err;





	lock_kernel();

	spin_lock(&sbi->s_lock);

	spin_lock(&sbi->s_lock);





	/* Store the old options */

	/* Store the old options */
@@ -1242,14 +1233,12 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) 
	}

	}

	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {

	if ((*flags & MS_RDONLY) == (sb->s_flags & MS_RDONLY)) {

		spin_unlock(&sbi->s_lock);

		spin_unlock(&sbi->s_lock);

		unlock_kernel();

		return 0;

		return 0;

	}

	}

	if (*flags & MS_RDONLY) {

	if (*flags & MS_RDONLY) {

		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||

		if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||

		    !(sbi->s_mount_state & EXT2_VALID_FS)) {

		    !(sbi->s_mount_state & EXT2_VALID_FS)) {

			spin_unlock(&sbi->s_lock);

			spin_unlock(&sbi->s_lock);

			unlock_kernel();

			return 0;

			return 0;

		}

		}

		/*

		/*
@@ -1282,7 +1271,6 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data) 
		spin_unlock(&sbi->s_lock);

		spin_unlock(&sbi->s_lock);

		ext2_write_super(sb);

		ext2_write_super(sb);

	}

	}

	unlock_kernel();

	return 0;

	return 0;

restore_opts:

restore_opts:

	sbi->s_mount_opt = old_opts.s_mount_opt;

	sbi->s_mount_opt = old_opts.s_mount_opt;
@@ -1290,7 +1278,6 @@ restore_opts: 
	sbi->s_resgid = old_opts.s_resgid;

	sbi->s_resgid = old_opts.s_resgid;

	sb->s_flags = old_sb_flags;

	sb->s_flags = old_sb_flags;

	spin_unlock(&sbi->s_lock);

	spin_unlock(&sbi->s_lock);

	unlock_kernel();

	return err;

	return err;

}

}