bfs: kill BKL

Replace the BKL-based locking scheme used in the bfs driver by a private
filesystem-wide mutex.

Signed-off-by: Dmitri Vorobiev <dmitri.vorobiev@movial.fi>
Cc: Tigran Aivazian <tigran_aivazian@symantec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 44 insertions, 31 deletions

diff --git a/fs/bfs/bfs.h b/fs/bfs/bfs.h
index d1a6cd10afce..7109e451abf7 100644
--- a/fs/bfs/bfs.h
+++ b/fs/bfs/bfs.h
@@ -18,6 +18,7 @@ struct bfs_sb_info {
         unsigned long si_lasti;
         unsigned long *si_imap;
         struct buffer_head *si_sbh;             /* buffer header w/superblock */
+        struct mutex bfs_lock;
 };
 
 /*
diff --git a/fs/bfs/dir.c b/fs/bfs/dir.c
index 034950cb3cbe..87ee5ccee348 100644
--- a/fs/bfs/dir.c
+++ b/fs/bfs/dir.c
@@ -32,16 +32,17 @@ static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
         struct inode *dir = f->f_path.dentry->d_inode;
         struct buffer_head *bh;
         struct bfs_dirent *de;
+        struct bfs_sb_info *info = BFS_SB(dir->i_sb);
         unsigned int offset;
         int block;
 
-        lock_kernel();
+        mutex_lock(&info->bfs_lock);
 
         if (f->f_pos & (BFS_DIRENT_SIZE - 1)) {
                 printf("Bad f_pos=%08lx for %s:%08lx\n",
                                         (unsigned long)f->f_pos,
                                         dir->i_sb->s_id, dir->i_ino);
-                unlock_kernel();
+                mutex_unlock(&info->bfs_lock);
                 return -EBADF;
         }
 
@@ -61,7 +62,7 @@ static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
                                                 le16_to_cpu(de->ino),
                                                 DT_UNKNOWN) < 0) {
                                         brelse(bh);
-                                        unlock_kernel();
+                                        mutex_unlock(&info->bfs_lock);
                                         return 0;
                                 }
                         }
@@ -71,7 +72,7 @@ static int bfs_readdir(struct file *f, void *dirent, filldir_t filldir)
                 brelse(bh);
         }
 
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         return 0;       
 }
 
@@ -95,10 +96,10 @@ static int bfs_create(struct inode *dir, struct dentry *dentry, int mode,
         inode = new_inode(s);
         if (!inode)
                 return -ENOSPC;
-        lock_kernel();
+        mutex_lock(&info->bfs_lock);
         ino = find_first_zero_bit(info->si_imap, info->si_lasti);
         if (ino > info->si_lasti) {
-                unlock_kernel();
+                mutex_unlock(&info->bfs_lock);
                 iput(inode);
                 return -ENOSPC;
         }
@@ -125,10 +126,10 @@ static int bfs_create(struct inode *dir, struct dentry *dentry, int mode,
         if (err) {
                 inode_dec_link_count(inode);
                 iput(inode);
-                unlock_kernel();
+                mutex_unlock(&info->bfs_lock);
                 return err;
         }
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         d_instantiate(dentry, inode);
         return 0;
 }
@@ -139,22 +140,23 @@ static struct dentry *bfs_lookup(struct inode *dir, struct dentry *dentry,
         struct inode *inode = NULL;
         struct buffer_head *bh;
         struct bfs_dirent *de;
+        struct bfs_sb_info *info = BFS_SB(dir->i_sb);
 
         if (dentry->d_name.len > BFS_NAMELEN)
                 return ERR_PTR(-ENAMETOOLONG);
 
-        lock_kernel();
+        mutex_lock(&info->bfs_lock);
         bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
         if (bh) {
                 unsigned long ino = (unsigned long)le16_to_cpu(de->ino);
                 brelse(bh);
                 inode = bfs_iget(dir->i_sb, ino);
                 if (IS_ERR(inode)) {
-                        unlock_kernel();
+                        mutex_unlock(&info->bfs_lock);
                         return ERR_CAST(inode);
                 }
         }
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         d_add(dentry, inode);
         return NULL;
 }
@@ -163,13 +165,14 @@ static int bfs_link(struct dentry *old, struct inode *dir,
                                                 struct dentry *new)
 {
         struct inode *inode = old->d_inode;
+        struct bfs_sb_info *info = BFS_SB(inode->i_sb);
         int err;
 
-        lock_kernel();
+        mutex_lock(&info->bfs_lock);
         err = bfs_add_entry(dir, new->d_name.name, new->d_name.len,
                                                         inode->i_ino);
         if (err) {
-                unlock_kernel();
+                mutex_unlock(&info->bfs_lock);
                 return err;
         }
         inc_nlink(inode);
@@ -177,19 +180,19 @@ static int bfs_link(struct dentry *old, struct inode *dir,
         mark_inode_dirty(inode);
         atomic_inc(&inode->i_count);
         d_instantiate(new, inode);
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         return 0;
 }
 
 static int bfs_unlink(struct inode *dir, struct dentry *dentry)
 {
         int error = -ENOENT;
-        struct inode *inode;
+        struct inode *inode = dentry->d_inode;
         struct buffer_head *bh;
         struct bfs_dirent *de;
+        struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 
-        inode = dentry->d_inode;
-        lock_kernel();
+        mutex_lock(&info->bfs_lock);
         bh = bfs_find_entry(dir, dentry->d_name.name, dentry->d_name.len, &de);
         if (!bh || (le16_to_cpu(de->ino) != inode->i_ino))
                 goto out_brelse;
@@ -210,7 +213,7 @@ static int bfs_unlink(struct inode *dir, struct dentry *dentry)
 
 out_brelse:
         brelse(bh);
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         return error;
 }
 
@@ -220,6 +223,7 @@ static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
         struct inode *old_inode, *new_inode;
         struct buffer_head *old_bh, *new_bh;
         struct bfs_dirent *old_de, *new_de;
+        struct bfs_sb_info *info;
         int error = -ENOENT;
 
         old_bh = new_bh = NULL;
@@ -227,7 +231,9 @@ static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
         if (S_ISDIR(old_inode->i_mode))
                 return -EINVAL;
 
-        lock_kernel();
+        info = BFS_SB(old_inode->i_sb);
+
+        mutex_lock(&info->bfs_lock);
         old_bh = bfs_find_entry(old_dir, 
                                 old_dentry->d_name.name, 
                                 old_dentry->d_name.len, &old_de);
@@ -264,7 +270,7 @@ static int bfs_rename(struct inode *old_dir, struct dentry *old_dentry,
         error = 0;
 
 end_rename:
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         brelse(old_bh);
         brelse(new_bh);
         return error;
diff --git a/fs/bfs/file.c b/fs/bfs/file.c
index b11e63e8fbcd..6a021265f018 100644
--- a/fs/bfs/file.c
+++ b/fs/bfs/file.c
@@ -99,7 +99,7 @@ static int bfs_get_block(struct inode *inode, sector_t block,
                 return -ENOSPC;
 
         /* The rest has to be protected against itself. */
-        lock_kernel();
+        mutex_lock(&info->bfs_lock);
 
         /*
          * If the last data block for this file is the last allocated
@@ -151,7 +151,7 @@ static int bfs_get_block(struct inode *inode, sector_t block,
         mark_buffer_dirty(sbh);
         map_bh(bh_result, sb, phys);
 out:
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         return err;
 }
 
diff --git a/fs/bfs/inode.c b/fs/bfs/inode.c
index c8b3982e11ca..053e690ec9ed 100644
--- a/fs/bfs/inode.c
+++ b/fs/bfs/inode.c
@@ -104,6 +104,7 @@ static int bfs_write_inode(struct inode *inode, int unused)
         struct bfs_inode *di;
         struct buffer_head *bh;
         int block, off;
+        struct bfs_sb_info *info = BFS_SB(inode->i_sb);
 
         dprintf("ino=%08x\n", ino);
 
@@ -112,13 +113,13 @@ static int bfs_write_inode(struct inode *inode, int unused)
                 return -EIO;
         }
 
-        lock_kernel();
+        mutex_lock(&info->bfs_lock);
         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
         bh = sb_bread(inode->i_sb, block);
         if (!bh) {
                 printf("Unable to read inode %s:%08x\n",
                                 inode->i_sb->s_id, ino);
-                unlock_kernel();
+                mutex_unlock(&info->bfs_lock);
                 return -EIO;
         }
 
@@ -145,7 +146,7 @@ static int bfs_write_inode(struct inode *inode, int unused)
 
         mark_buffer_dirty(bh);
         brelse(bh);
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         return 0;
 }
 
@@ -170,7 +171,7 @@ static void bfs_delete_inode(struct inode *inode)
         
         inode->i_size = 0;
         inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
-        lock_kernel();
+        mutex_lock(&info->bfs_lock);
         mark_inode_dirty(inode);
 
         block = (ino - BFS_ROOT_INO) / BFS_INODES_PER_BLOCK + 1;
@@ -178,7 +179,7 @@ static void bfs_delete_inode(struct inode *inode)
         if (!bh) {
                 printf("Unable to read inode %s:%08lx\n",
                                         inode->i_sb->s_id, ino);
-                unlock_kernel();
+                mutex_unlock(&info->bfs_lock);
                 return;
         }
         off = (ino - BFS_ROOT_INO) % BFS_INODES_PER_BLOCK;
@@ -204,14 +205,16 @@ static void bfs_delete_inode(struct inode *inode)
                 info->si_lf_eblk = bi->i_sblock - 1;
                 mark_buffer_dirty(info->si_sbh);
         }
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
         clear_inode(inode);
 }
 
 static void bfs_put_super(struct super_block *s)
 {
         struct bfs_sb_info *info = BFS_SB(s);
+
         brelse(info->si_sbh);
+        mutex_destroy(&info->bfs_lock);
         kfree(info->si_imap);
         kfree(info);
         s->s_fs_info = NULL;
@@ -236,11 +239,13 @@ static int bfs_statfs(struct dentry *dentry, struct kstatfs *buf)
 
 static void bfs_write_super(struct super_block *s)
 {
-        lock_kernel();
+        struct bfs_sb_info *info = BFS_SB(s);
+
+        mutex_lock(&info->bfs_lock);
         if (!(s->s_flags & MS_RDONLY))
-                mark_buffer_dirty(BFS_SB(s)->si_sbh);
+                mark_buffer_dirty(info->si_sbh);
         s->s_dirt = 0;
-        unlock_kernel();
+        mutex_unlock(&info->bfs_lock);
 }
 
 static struct kmem_cache *bfs_inode_cachep;
@@ -409,6 +414,7 @@ static int bfs_fill_super(struct super_block *s, void *data, int silent)
                 s->s_dirt = 1;
         } 
         dump_imap("read_super", s);
+        mutex_init(&info->bfs_lock);
         return 0;
 
 out: