hpfs: remove the BKL
This removes the BKL in hpfs in a rather awful
way, by making the code only work on uniprocessor
systems without kernel preemption, as suggested
by Andi Kleen.
The HPFS code probably has close to zero remaining
users on current kernels, all archeological uses of
the file system can probably be done with the significant
restrictions.
The hpfs_lock/hpfs_unlock functions are left in the
code, sincen Mikulas has indicated that he is still
interested in fixing it in a better way.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Andi Kleen <ak@linux.intel.com>
Cc: Mikulas Patocka <mikulas@artax.karlin.mff.cuni.cz>
Cc: linux-fsdevel@vger.kernel.org
diff --git a/fs/hpfs/Kconfig b/fs/hpfs/Kconfig
index 63b6f56..0c39dc3 100644
--- a/fs/hpfs/Kconfig
+++ b/fs/hpfs/Kconfig
@@ -1,7 +1,7 @@
config HPFS_FS
tristate "OS/2 HPFS file system support"
depends on BLOCK
- depends on BKL # nontrivial to fix
+ depends on BROKEN || !PREEMPT
help
OS/2 is IBM's operating system for PC's, the same as Warp, and HPFS
is the file system used for organizing files on OS/2 hard disk
diff --git a/fs/hpfs/dir.c b/fs/hpfs/dir.c
index d32f63a..b3d7c0d 100644
--- a/fs/hpfs/dir.c
+++ b/fs/hpfs/dir.c
@@ -6,16 +6,15 @@
* directory VFS functions
*/
-#include <linux/smp_lock.h>
#include <linux/slab.h>
#include "hpfs_fn.h"
static int hpfs_dir_release(struct inode *inode, struct file *filp)
{
- lock_kernel();
+ hpfs_lock(inode->i_sb);
hpfs_del_pos(inode, &filp->f_pos);
/*hpfs_write_if_changed(inode);*/
- unlock_kernel();
+ hpfs_unlock(inode->i_sb);
return 0;
}
@@ -30,7 +29,7 @@
struct hpfs_inode_info *hpfs_inode = hpfs_i(i);
struct super_block *s = i->i_sb;
- lock_kernel();
+ hpfs_lock(s);
/*printk("dir lseek\n");*/
if (new_off == 0 || new_off == 1 || new_off == 11 || new_off == 12 || new_off == 13) goto ok;
@@ -43,12 +42,12 @@
}
mutex_unlock(&i->i_mutex);
ok:
- unlock_kernel();
+ hpfs_unlock(s);
return filp->f_pos = new_off;
fail:
mutex_unlock(&i->i_mutex);
/*printk("illegal lseek: %016llx\n", new_off);*/
- unlock_kernel();
+ hpfs_unlock(s);
return -ESPIPE;
}
@@ -64,7 +63,7 @@
int c1, c2 = 0;
int ret = 0;
- lock_kernel();
+ hpfs_lock(inode->i_sb);
if (hpfs_sb(inode->i_sb)->sb_chk) {
if (hpfs_chk_sectors(inode->i_sb, inode->i_ino, 1, "dir_fnode")) {
@@ -167,7 +166,7 @@
hpfs_brelse4(&qbh);
}
out:
- unlock_kernel();
+ hpfs_unlock(inode->i_sb);
return ret;
}
@@ -197,10 +196,10 @@
struct inode *result = NULL;
struct hpfs_inode_info *hpfs_result;
- lock_kernel();
+ hpfs_lock(dir->i_sb);
if ((err = hpfs_chk_name(name, &len))) {
if (err == -ENAMETOOLONG) {
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return ERR_PTR(-ENAMETOOLONG);
}
goto end_add;
@@ -298,7 +297,7 @@
end:
end_add:
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
d_add(dentry, result);
return NULL;
@@ -311,7 +310,7 @@
/*bail:*/
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return ERR_PTR(-ENOENT);
}
diff --git a/fs/hpfs/file.c b/fs/hpfs/file.c
index c034088..2dbae20 100644
--- a/fs/hpfs/file.c
+++ b/fs/hpfs/file.c
@@ -6,16 +6,15 @@
* file VFS functions
*/
-#include <linux/smp_lock.h>
#include "hpfs_fn.h"
#define BLOCKS(size) (((size) + 511) >> 9)
static int hpfs_file_release(struct inode *inode, struct file *file)
{
- lock_kernel();
+ hpfs_lock(inode->i_sb);
hpfs_write_if_changed(inode);
- unlock_kernel();
+ hpfs_unlock(inode->i_sb);
return 0;
}
@@ -49,14 +48,14 @@
static void hpfs_truncate(struct inode *i)
{
if (IS_IMMUTABLE(i)) return /*-EPERM*/;
- lock_kernel();
+ hpfs_lock(i->i_sb);
hpfs_i(i)->i_n_secs = 0;
i->i_blocks = 1 + ((i->i_size + 511) >> 9);
hpfs_i(i)->mmu_private = i->i_size;
hpfs_truncate_btree(i->i_sb, i->i_ino, 1, ((i->i_size + 511) >> 9));
hpfs_write_inode(i);
hpfs_i(i)->i_n_secs = 0;
- unlock_kernel();
+ hpfs_unlock(i->i_sb);
}
static int hpfs_get_block(struct inode *inode, sector_t iblock, struct buffer_head *bh_result, int create)
diff --git a/fs/hpfs/hpfs_fn.h b/fs/hpfs/hpfs_fn.h
index 1c43dbe..c15adbc 100644
--- a/fs/hpfs/hpfs_fn.h
+++ b/fs/hpfs/hpfs_fn.h
@@ -342,3 +342,25 @@
extern struct timezone sys_tz;
return t - sys_tz.tz_minuteswest * 60 - hpfs_sb(s)->sb_timeshift;
}
+
+/*
+ * Locking:
+ *
+ * hpfs_lock() is a leftover from the big kernel lock.
+ * Right now, these functions are empty and only left
+ * for documentation purposes. The file system no longer
+ * works on SMP systems, so the lock is not needed
+ * any more.
+ *
+ * If someone is interested in making it work again, this
+ * would be the place to start by adding a per-superblock
+ * mutex and fixing all the bugs and performance issues
+ * caused by that.
+ */
+static inline void hpfs_lock(struct super_block *s)
+{
+}
+
+static inline void hpfs_unlock(struct super_block *s)
+{
+}
diff --git a/fs/hpfs/inode.c b/fs/hpfs/inode.c
index 1ae35ba..87f1f78 100644
--- a/fs/hpfs/inode.c
+++ b/fs/hpfs/inode.c
@@ -6,7 +6,6 @@
* inode VFS functions
*/
-#include <linux/smp_lock.h>
#include <linux/slab.h>
#include "hpfs_fn.h"
@@ -267,7 +266,7 @@
struct inode *inode = dentry->d_inode;
int error = -EINVAL;
- lock_kernel();
+ hpfs_lock(inode->i_sb);
if (inode->i_ino == hpfs_sb(inode->i_sb)->sb_root)
goto out_unlock;
if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size > inode->i_size)
@@ -290,7 +289,7 @@
hpfs_write_inode(inode);
out_unlock:
- unlock_kernel();
+ hpfs_unlock(inode->i_sb);
return error;
}
@@ -307,8 +306,8 @@
truncate_inode_pages(&inode->i_data, 0);
end_writeback(inode);
if (!inode->i_nlink) {
- lock_kernel();
+ hpfs_lock(inode->i_sb);
hpfs_remove_fnode(inode->i_sb, inode->i_ino);
- unlock_kernel();
+ hpfs_unlock(inode->i_sb);
}
}
diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c
index f4ad9e3..d5f8c8a 100644
--- a/fs/hpfs/namei.c
+++ b/fs/hpfs/namei.c
@@ -6,7 +6,6 @@
* adding & removing files & directories
*/
#include <linux/sched.h>
-#include <linux/smp_lock.h>
#include "hpfs_fn.h"
static int hpfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
@@ -25,7 +24,7 @@
struct hpfs_dirent dee;
int err;
if ((err = hpfs_chk_name(name, &len))) return err==-ENOENT ? -EINVAL : err;
- lock_kernel();
+ hpfs_lock(dir->i_sb);
err = -ENOSPC;
fnode = hpfs_alloc_fnode(dir->i_sb, hpfs_i(dir)->i_dno, &fno, &bh);
if (!fnode)
@@ -103,7 +102,7 @@
}
d_instantiate(dentry, result);
mutex_unlock(&hpfs_i(dir)->i_mutex);
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return 0;
bail3:
mutex_unlock(&hpfs_i(dir)->i_mutex);
@@ -115,7 +114,7 @@
brelse(bh);
hpfs_free_sectors(dir->i_sb, fno, 1);
bail:
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return err;
}
@@ -132,7 +131,7 @@
int err;
if ((err = hpfs_chk_name(name, &len)))
return err==-ENOENT ? -EINVAL : err;
- lock_kernel();
+ hpfs_lock(dir->i_sb);
err = -ENOSPC;
fnode = hpfs_alloc_fnode(dir->i_sb, hpfs_i(dir)->i_dno, &fno, &bh);
if (!fnode)
@@ -195,7 +194,7 @@
}
d_instantiate(dentry, result);
mutex_unlock(&hpfs_i(dir)->i_mutex);
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return 0;
bail2:
@@ -205,7 +204,7 @@
brelse(bh);
hpfs_free_sectors(dir->i_sb, fno, 1);
bail:
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return err;
}
@@ -224,7 +223,7 @@
if (hpfs_sb(dir->i_sb)->sb_eas < 2) return -EPERM;
if (!new_valid_dev(rdev))
return -EINVAL;
- lock_kernel();
+ hpfs_lock(dir->i_sb);
err = -ENOSPC;
fnode = hpfs_alloc_fnode(dir->i_sb, hpfs_i(dir)->i_dno, &fno, &bh);
if (!fnode)
@@ -274,7 +273,7 @@
d_instantiate(dentry, result);
mutex_unlock(&hpfs_i(dir)->i_mutex);
brelse(bh);
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return 0;
bail2:
mutex_unlock(&hpfs_i(dir)->i_mutex);
@@ -283,7 +282,7 @@
brelse(bh);
hpfs_free_sectors(dir->i_sb, fno, 1);
bail:
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return err;
}
@@ -299,9 +298,9 @@
struct inode *result;
int err;
if ((err = hpfs_chk_name(name, &len))) return err==-ENOENT ? -EINVAL : err;
- lock_kernel();
+ hpfs_lock(dir->i_sb);
if (hpfs_sb(dir->i_sb)->sb_eas < 2) {
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return -EPERM;
}
err = -ENOSPC;
@@ -354,7 +353,7 @@
hpfs_write_inode_nolock(result);
d_instantiate(dentry, result);
mutex_unlock(&hpfs_i(dir)->i_mutex);
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return 0;
bail2:
mutex_unlock(&hpfs_i(dir)->i_mutex);
@@ -363,7 +362,7 @@
brelse(bh);
hpfs_free_sectors(dir->i_sb, fno, 1);
bail:
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return err;
}
@@ -380,7 +379,7 @@
int rep = 0;
int err;
- lock_kernel();
+ hpfs_lock(dir->i_sb);
hpfs_adjust_length(name, &len);
again:
mutex_lock(&hpfs_i(inode)->i_parent_mutex);
@@ -416,7 +415,7 @@
dentry_unhash(dentry);
if (!d_unhashed(dentry)) {
dput(dentry);
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return -ENOSPC;
}
if (generic_permission(inode, MAY_WRITE, 0, NULL) ||
@@ -435,7 +434,7 @@
if (!err)
goto again;
}
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return -ENOSPC;
default:
drop_nlink(inode);
@@ -448,7 +447,7 @@
out:
mutex_unlock(&hpfs_i(dir)->i_mutex);
mutex_unlock(&hpfs_i(inode)->i_parent_mutex);
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return err;
}
@@ -466,7 +465,7 @@
int r;
hpfs_adjust_length(name, &len);
- lock_kernel();
+ hpfs_lock(dir->i_sb);
mutex_lock(&hpfs_i(inode)->i_parent_mutex);
mutex_lock(&hpfs_i(dir)->i_mutex);
err = -ENOENT;
@@ -508,7 +507,7 @@
out:
mutex_unlock(&hpfs_i(dir)->i_mutex);
mutex_unlock(&hpfs_i(inode)->i_parent_mutex);
- unlock_kernel();
+ hpfs_unlock(dir->i_sb);
return err;
}
@@ -521,21 +520,21 @@
int err;
err = -EIO;
- lock_kernel();
+ hpfs_lock(i->i_sb);
if (!(fnode = hpfs_map_fnode(i->i_sb, i->i_ino, &bh)))
goto fail;
err = hpfs_read_ea(i->i_sb, fnode, "SYMLINK", link, PAGE_SIZE);
brelse(bh);
if (err)
goto fail;
- unlock_kernel();
+ hpfs_unlock(i->i_sb);
SetPageUptodate(page);
kunmap(page);
unlock_page(page);
return 0;
fail:
- unlock_kernel();
+ hpfs_unlock(i->i_sb);
SetPageError(page);
kunmap(page);
unlock_page(page);
@@ -567,7 +566,7 @@
err = 0;
hpfs_adjust_length(old_name, &old_len);
- lock_kernel();
+ hpfs_lock(i->i_sb);
/* order doesn't matter, due to VFS exclusion */
mutex_lock(&hpfs_i(i)->i_parent_mutex);
if (new_inode)
@@ -659,7 +658,7 @@
mutex_unlock(&hpfs_i(i)->i_parent_mutex);
if (new_inode)
mutex_unlock(&hpfs_i(new_inode)->i_parent_mutex);
- unlock_kernel();
+ hpfs_unlock(i->i_sb);
return err;
}
diff --git a/fs/hpfs/super.c b/fs/hpfs/super.c
index b30426b..c89b408 100644
--- a/fs/hpfs/super.c
+++ b/fs/hpfs/super.c
@@ -13,7 +13,6 @@
#include <linux/statfs.h>
#include <linux/magic.h>
#include <linux/sched.h>
-#include <linux/smp_lock.h>
#include <linux/bitmap.h>
#include <linux/slab.h>
@@ -103,15 +102,11 @@
{
struct hpfs_sb_info *sbi = hpfs_sb(s);
- lock_kernel();
-
kfree(sbi->sb_cp_table);
kfree(sbi->sb_bmp_dir);
unmark_dirty(s);
s->s_fs_info = NULL;
kfree(sbi);
-
- unlock_kernel();
}
unsigned hpfs_count_one_bitmap(struct super_block *s, secno secno)
@@ -143,7 +138,7 @@
struct super_block *s = dentry->d_sb;
struct hpfs_sb_info *sbi = hpfs_sb(s);
u64 id = huge_encode_dev(s->s_bdev->bd_dev);
- lock_kernel();
+ hpfs_lock(s);
/*if (sbi->sb_n_free == -1) {*/
sbi->sb_n_free = count_bitmaps(s);
@@ -160,7 +155,7 @@
buf->f_fsid.val[1] = (u32)(id >> 32);
buf->f_namelen = 254;
- unlock_kernel();
+ hpfs_unlock(s);
return 0;
}
@@ -406,7 +401,7 @@
*flags |= MS_NOATIME;
- lock_kernel();
+ hpfs_lock(s);
lock_super(s);
uid = sbi->sb_uid; gid = sbi->sb_gid;
umask = 0777 & ~sbi->sb_mode;
@@ -441,12 +436,12 @@
replace_mount_options(s, new_opts);
unlock_super(s);
- unlock_kernel();
+ hpfs_unlock(s);
return 0;
out_err:
unlock_super(s);
- unlock_kernel();
+ hpfs_unlock(s);
kfree(new_opts);
return -EINVAL;
}
@@ -484,13 +479,15 @@
int o;
- lock_kernel();
+ if (num_possible_cpus() > 1) {
+ printk(KERN_ERR "HPFS is not SMP safe\n");
+ return -EINVAL;
+ }
save_mount_options(s, options);
sbi = kzalloc(sizeof(*sbi), GFP_KERNEL);
if (!sbi) {
- unlock_kernel();
return -ENOMEM;
}
s->s_fs_info = sbi;
@@ -677,7 +674,6 @@
root->i_blocks = 5;
hpfs_brelse4(&qbh);
}
- unlock_kernel();
return 0;
bail4: brelse(bh2);
@@ -689,7 +685,6 @@
kfree(sbi->sb_cp_table);
s->s_fs_info = NULL;
kfree(sbi);
- unlock_kernel();
return -EINVAL;
}