The patch below (against 2.5.21) removes the BKL from around the call
to i_op->permission() in fs/namei.c, and pushes the BKL into those
filesystems that have permission() methods that require it:
fs/nfs/dir.c:nfs_permission(): Take BKL if we need to do RPC
fs/coda/dir.c:coda_permission(): Take BKL if mask != 0
fs/coda/pioctl.c:coda_ioctl_permission(): BKL not needed
net/wanrouter/wanproc.c:router_proc_perms(): BKL not needed
fs/intermezzo/dir.c:presto_permission(): Always take BKL (and avoid
abuse of inode method table)
fs/proc/base.c:proc_permission(): BKL not needed
fs/smbfs/file.c:smb_file_permission(): BKL not needed
kernel/sysctl.c:proc_sys_permission(): BKL not needed
Out-of-tree filesystems that have their own permission() method will
need updating if they're relying on the BKL.
Al, please forward this patch to Linus if you're happy with it.
Paul
diff -aur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.21/Documentation/filesystems/Locking linux-2.5.21-permission/Documentation/filesystems/Locking
--- linux-2.5.21/Documentation/filesystems/Locking Sat Jun 8 22:28:48 2002
+++ linux-2.5.21-permission/Documentation/filesystems/Locking Sun Jun 9 20:54:51 2002
@@ -50,27 +50,27 @@
int (*removexattr) (struct dentry *, const char *);
locking rules:
- all may block
- BKL i_sem(inode)
-lookup: no yes
-create: no yes
-link: no yes (both)
-mknod: no yes
-symlink: no yes
-mkdir: no yes
-unlink: no yes (both)
-rmdir: no yes (both) (see below)
-rename: no yes (all) (see below)
-readlink: no no
-follow_link: no no
-truncate: no yes (see below)
-setattr: no yes
-permission: yes no
-getattr: no no
-setxattr: no yes
-getxattr: no yes
-listxattr: no yes
-removexattr: no yes
+ all may block, none have BKL
+ i_sem(inode)
+lookup: yes
+create: yes
+link: yes (both)
+mknod: yes
+symlink: yes
+mkdir: yes
+unlink: yes (both)
+rmdir: yes (both) (see below)
+rename: yes (all) (see below)
+readlink: no
+follow_link: no
+truncate: yes (see below)
+setattr: yes
+permission: no
+getattr: no
+setxattr: yes
+getxattr: yes
+listxattr: yes
+removexattr: yes
Additionally, ->rmdir(), ->unlink() and ->rename() have ->i_sem on
victim.
cross-directory ->rename() has (per-superblock) ->s_vfs_rename_sem.
diff -aur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.21/fs/coda/dir.c linux-2.5.21-permission/fs/coda/dir.c
--- linux-2.5.21/fs/coda/dir.c Sat Jun 8 22:27:26 2002
+++ linux-2.5.21-permission/fs/coda/dir.c Sun Jun 9 20:31:24 2002
@@ -147,21 +147,26 @@
int coda_permission(struct inode *inode, int mask)
{
- int error;
+ int error = 0;
if (!mask)
return 0;
+ lock_kernel();
+
coda_vfs_stat.permission++;
if (coda_cache_check(inode, mask))
- return 0;
+ goto out;
error = venus_access(inode->i_sb, coda_i2f(inode), mask);
if (!error)
coda_cache_enter(inode, mask);
+ out:
+ unlock_kernel();
+
return error;
}
diff -aur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.21/fs/intermezzo/dir.c linux-2.5.21-permission/fs/intermezzo/dir.c
--- linux-2.5.21/fs/intermezzo/dir.c Sat Jun 8 22:28:16 2002
+++ linux-2.5.21-permission/fs/intermezzo/dir.c Sun Jun 9 20:57:38 2002
@@ -785,13 +785,15 @@
{
unsigned short mode = inode->i_mode;
struct presto_cache *cache;
- int rc;
+ int rc = 0;
+ lock_kernel();
ENTRY;
+
if ( presto_can_ilookup() && !(mask & S_IWOTH)) {
CDEBUG(D_CACHE, "ilookup on %ld OK\n", inode->i_ino);
- EXIT;
- return 0;
+ EXIT;
+ goto out;
}
cache = presto_get_cache(inode);
@@ -803,25 +805,22 @@
if ( S_ISREG(mode) && fiops && fiops->permission ) {
EXIT;
- return fiops->permission(inode, mask);
+ rc = fiops->permission(inode, mask);
+ goto out;
}
if ( S_ISDIR(mode) && diops && diops->permission ) {
EXIT;
- return diops->permission(inode, mask);
+ rc = diops->permission(inode, mask);
+ goto out;
}
}
- /* The cache filesystem doesn't have its own permission function,
- * but we don't want to duplicate the VFS code here. In order
- * to avoid looping from permission calling this function again,
- * we temporarily override the permission operation while we call
- * the VFS permission function.
- */
- inode->i_op->permission = NULL;
- rc = permission(inode, mask);
- inode->i_op->permission = &presto_permission;
+ rc = vfs_permission(inode, mask);
EXIT;
+
+ out:
+ unlock_kernel();
return rc;
}
diff -aur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.21/fs/namei.c linux-2.5.21-permission/fs/namei.c
--- linux-2.5.21/fs/namei.c Sat Jun 8 22:28:50 2002
+++ linux-2.5.21-permission/fs/namei.c Sun Jun 9 20:25:31 2002
@@ -204,13 +204,8 @@
int permission(struct inode * inode,int mask)
{
- if (inode->i_op && inode->i_op->permission) {
- int retval;
- lock_kernel();
- retval = inode->i_op->permission(inode, mask);
- unlock_kernel();
- return retval;
- }
+ if (inode->i_op && inode->i_op->permission)
+ return inode->i_op->permission(inode, mask);
return vfs_permission(inode, mask);
}
diff -aur -X /mnt/elbrus/home/pmenage/dontdiff linux-2.5.21/fs/nfs/dir.c linux-2.5.21-permission/fs/nfs/dir.c
--- linux-2.5.21/fs/nfs/dir.c Sat Jun 8 22:29:55 2002
+++ linux-2.5.21-permission/fs/nfs/dir.c Sun Jun 9 20:30:36 2002
@@ -1123,6 +1123,8 @@
&& error != -EACCES)
goto out;
+ lock_kernel();
+
error = NFS_PROTO(inode)->access(inode, mask, 0);
if (error == -EACCES && NFS_CLIENT(inode)->cl_droppriv &&
@@ -1130,6 +1132,8 @@
(current->fsuid != current->uid || current->fsgid != current->gid))
error = NFS_PROTO(inode)->access(inode, mask, 1);
+ unlock_kernel();
+
out:
return error;
}