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

2 files changed, 0 insertions, 16 deletions

diff --git a/fs/ext2/inode.c b/fs/ext2/inode.c
index 5d15442abbd0..b90c3bf6e9ba 100644
--- a/fs/ext2/inode.c
+++ b/fs/ext2/inode.c
@@ -22,7 +22,6 @@
  *  Assorted race fixes, rewrite of ext2_get_block() by Al Viro, 2000
  */
 
-#include <linux/smp_lock.h>
 #include <linux/time.h>
 #include <linux/highuid.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
                                 * created, add a flag to the superblock.
                                 */
-                                lock_kernel();
                                 spin_lock(&EXT2_SB(sb)->s_lock);
                                 ext2_update_dynamic_rev(sb);
                                 EXT2_SET_RO_COMPAT_FEATURE(sb,
                                         EXT2_FEATURE_RO_COMPAT_LARGE_FILE);
                                 spin_unlock(&EXT2_SB(sb)->s_lock);
-                                unlock_kernel();
                                 ext2_write_super(sb);
                         }
                 }
diff --git a/fs/ext2/super.c b/fs/ext2/super.c
index 28f65609589d..71e9eb1fa696 100644
--- a/fs/ext2/super.c
+++ b/fs/ext2/super.c
@@ -26,7 +26,6 @@
 #include <linux/random.h>
 #include <linux/buffer_head.h>
 #include <linux/exportfs.h>
-#include <linux/smp_lock.h>
 #include <linux/vfs.h>
 #include <linux/seq_file.h>
 #include <linux/mount.h>
@@ -120,8 +119,6 @@ static void ext2_put_super (struct super_block * sb)
         int i;
         struct ext2_sb_info *sbi = EXT2_SB(sb);
 
-        lock_kernel();
-
         if (sb->s_dirt)
                 ext2_write_super(sb);
 
@@ -147,8 +144,6 @@ static void ext2_put_super (struct super_block * sb)
         sb->s_fs_info = NULL;
         kfree(sbi->s_blockgroup_lock);
         kfree(sbi);
-
-        unlock_kernel();
 }
 
 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_super_block *es = EXT2_SB(sb)->s_es;
 
-        lock_kernel();
         spin_lock(&sbi->s_lock);
         if (es->s_state & cpu_to_le16(EXT2_VALID_FS)) {
                 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);
         ext2_sync_super(sb, es, wait);
-        unlock_kernel();
-
         return 0;
 }
 
@@ -1201,7 +1193,6 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
         unsigned long old_sb_flags;
         int err;
 
-        lock_kernel();
         spin_lock(&sbi->s_lock);
 
         /* 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)) {
                 spin_unlock(&sbi->s_lock);
-                unlock_kernel();
                 return 0;
         }
         if (*flags & MS_RDONLY) {
                 if (le16_to_cpu(es->s_state) & EXT2_VALID_FS ||
                     !(sbi->s_mount_state & EXT2_VALID_FS)) {
                         spin_unlock(&sbi->s_lock);
-                        unlock_kernel();
                         return 0;
                 }
                 /*
@@ -1282,7 +1271,6 @@ static int ext2_remount (struct super_block * sb, int * flags, char * data)
                 spin_unlock(&sbi->s_lock);
                 ext2_write_super(sb);
         }
-        unlock_kernel();
         return 0;
 restore_opts:
         sbi->s_mount_opt = old_opts.s_mount_opt;
@@ -1290,7 +1278,6 @@ restore_opts:
         sbi->s_resgid = old_opts.s_resgid;
         sb->s_flags = old_sb_flags;
         spin_unlock(&sbi->s_lock);
-        unlock_kernel();
         return err;
 }