[PATCH 08/20] adfs: remove the big kernel lock

Arnd Bergmann
2011-01-25T22:20:43Z

According to Russell King, adfs was written to not require the big
kernel lock, and all inode updates are done under adfs_dir_lock.

All other metadata in adfs is read-only and does not require locking.
The use of the BKL is the result of various pushdowns from the VFS
operations.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Stuart Swales <stuart.swales.croftnuisk@gmail.com>
---
fs/adfs/Kconfig | 1 -
fs/adfs/dir.c | 6 ------
fs/adfs/inode.c | 6 ------
fs/adfs/super.c | 13 +------------
4 files changed, 1 insertions(+), 25 deletions(-)

diff --git a/fs/adfs/Kconfig b/fs/adfs/Kconfig
index 1dd5f34..e55182a 100644
--- a/fs/adfs/Kconfig
+++ b/fs/adfs/Kconfig
@@ -1,7 +1,6 @@
config ADFS_FS
tristate "ADFS file system support (EXPERIMENTAL)"
depends on BLOCK && EXPERIMENTAL
- depends on BKL # need to fix
help
The Acorn Disc Filing System is the standard file system of the
RiscOS operating system which runs on Acorn's ARM-based Risc PC
diff --git a/fs/adfs/dir.c b/fs/adfs/dir.c
index 3b4a764..3d83075 100644
--- a/fs/adfs/dir.c
+++ b/fs/adfs/dir.c
@@ -9,7 +9,6 @@
*
* Common directory handling for ADFS
*/
-#include <linux/smp_lock.h>
#include "adfs.h"

/*
@@ -27,8 +26,6 @@ adfs_readdir(struct file *filp, void *dirent, filldir_t filldir)
struct adfs_dir dir;
int ret = 0;

- lock_kernel();
-
if (filp->f_pos >> 32)
goto out;

@@ -70,7 +67,6 @@ free_out:
ops->free(&dir);

out:
- unlock_kernel();
return ret;
}

@@ -276,7 +272,6 @@ adfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
struct object_info obj;
int error;

- lock_kernel();
error = adfs_dir_lookup_byname(dir, &dentry->d_name, &obj);
if (error == 0) {
error = -EACCES;
@@ -288,7 +283,6 @@ adfs_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd)
if (inode)
error = 0;
}
- unlock_kernel();
d_add(dentry, inode);
return ERR_PTR(error);
}
diff --git a/fs/adfs/inode.c b/fs/adfs/inode.c
index 65794b8..09fe401 100644
--- a/fs/adfs/inode.c
+++ b/fs/adfs/inode.c
@@ -7,7 +7,6 @@
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*/
-#include <linux/smp_lock.h>
#include <linux/buffer_head.h>
#include <linux/writeback.h>
#include "adfs.h"
@@ -316,8 +315,6 @@ adfs_notify_change(struct dentry *dentry, struct iattr *attr)
unsigned int ia_valid = attr->ia_valid;
int error;

- lock_kernel();
-
error = inode_change_ok(inode, attr);

/*
@@ -359,7 +356,6 @@ adfs_notify_change(struct dentry *dentry, struct iattr *attr)
if (ia_valid & (ATTR_SIZE | ATTR_MTIME | ATTR_MODE))
mark_inode_dirty(inode);
out:
- unlock_kernel();
return error;
}

@@ -374,7 +370,6 @@ int adfs_write_inode(struct inode *inode, struct writeback_control *wbc)
struct object_info obj;
int ret;

- lock_kernel();
obj.file_id = inode->i_ino;
obj.name_len = 0;
obj.parent_id = ADFS_I(inode)->parent_id;
@@ -384,6 +379,5 @@ int adfs_write_inode(struct inode *inode, struct writeback_control *wbc)
obj.size = inode->i_size;

ret = adfs_dir_update(sb, &obj, wbc->sync_mode == WB_SYNC_ALL);
- unlock_kernel();
return ret;
}
diff --git a/fs/adfs/super.c b/fs/adfs/super.c
index 2d79540..06d7388 100644
--- a/fs/adfs/super.c
+++ b/fs/adfs/super.c
@@ -14,7 +14,6 @@
#include <linux/mount.h>
#include <linux/seq_file.h>
#include <linux/slab.h>
-#include <linux/smp_lock.h>
#include <linux/statfs.h>
#include "adfs.h"
#include "dir_f.h"
@@ -120,15 +119,11 @@ static void adfs_put_super(struct super_block *sb)
int i;
struct adfs_sb_info *asb = ADFS_SB(sb);

- lock_kernel();
-
for (i = 0; i < asb->s_map_size; i++)
brelse(asb->s_map[i].dm_bh);
kfree(asb->s_map);
kfree(asb);
sb->s_fs_info = NULL;
-
- unlock_kernel();
}

static int adfs_show_options(struct seq_file *seq, struct vfsmount *mnt)
@@ -359,15 +354,11 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
struct adfs_sb_info *asb;
struct inode *root;

- lock_kernel();
-
sb->s_flags |= MS_NODIRATIME;

asb = kzalloc(sizeof(*asb), GFP_KERNEL);
- if (!asb) {
- unlock_kernel();
+ if (!asb)
return -ENOMEM;
- }
sb->s_fs_info = asb;

/* set default options */
@@ -485,7 +476,6 @@ static int adfs_fill_super(struct super_block *sb, void *data, int silent)
adfs_error(sb, "get root inode failed\n");
goto error;
}
- unlock_kernel();
return 0;

error_free_bh:
@@ -493,7 +483,6 @@ error_free_bh:
error:
sb->s_fs_info = NULL;
kfree(asb);
- unlock_kernel();
return -EINVAL;
}

--
1.7.1