[Btrfs-devel] [PATCH] Add btrfs acl checking
only flyer
onlyflyer at gmail.com
Sat Jan 19 05:47:17 PST 2008
Hi:
This patch add btrfs acl checking. It makes btrfs's acl checking
really work if you mount btrfs by using "acl" option, e.g. mount -t
btrfs -o acl /dev/hda1 /mnt/
Thanks
LiuHui
diff -r 6c243ad8dddf acl.c
--- a/acl.c Fri Jan 18 10:54:22 2008 -0500
+++ b/acl.c Sat Jan 19 21:38:02 2008 +0800
@@ -26,6 +26,35 @@
#define is_owner_or_cap(inode) \
((current->fsuid == (inode)->i_uid) || capable(CAP_FOWNER))
#endif
+
+struct posix_acl *btrfs_get_posix_acl(struct inode *inode, int type)
+{
+ int ret, len;
+ char *value = NULL;
+ struct posix_acl *acl;
+
+ len = btrfs_xattr_get(inode, type, "", NULL, 0);
+ if (len > 0) {
+ value = kmalloc(len, GFP_KERNEL);
+ if (!value) {
+ return ERR_PTR(-ENOMEM);
+ }
+
+ } else {
+ return NULL;
+ }
+ ret = btrfs_xattr_get(inode, type, "", value, len);
+ if (ret > 0) {
+ acl = posix_acl_from_xattr(value, len);
+ } else if (-ENODATA == ret) {
+ acl = NULL;
+ } else {
+ acl = ERR_PTR(ret);
+ }
+
+ kfree(value);
+ return acl;
+}
static int btrfs_xattr_set_acl(struct inode *inode, int type,
const void *value, size_t size)
diff -r 6c243ad8dddf ctree.h
--- a/ctree.h Fri Jan 18 10:54:22 2008 -0500
+++ b/ctree.h Sat Jan 19 21:38:02 2008 +0800
@@ -446,6 +446,7 @@ struct btrfs_root {
#define BTRFS_MOUNT_NODATACOW (1 << 1)
#define BTRFS_MOUNT_NOBARRIER (1 << 2)
#define BTRFS_MOUNT_SSD (1 << 3)
+#define BTRFS_MOUNT_POSIX_ACL (1 << 4)
#define btrfs_clear_opt(o, opt) ((o) &= ~BTRFS_MOUNT_##opt)
#define btrfs_set_opt(o, opt) ((o) |= BTRFS_MOUNT_##opt)
diff -r 6c243ad8dddf inode.c
--- a/inode.c Fri Jan 18 10:54:22 2008 -0500
+++ b/inode.c Sat Jan 19 21:38:02 2008 +0800
@@ -33,12 +33,16 @@
#include <linux/bit_spinlock.h>
#include <linux/version.h>
#include <linux/xattr.h>
+#include <linux/posix_acl.h>
#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"
#include "btrfs_inode.h"
#include "ioctl.h"
#include "print-tree.h"
+#include "xattr.h"
+
+extern struct posix_acl *btrfs_get_posix_acl(struct inode *inode, int type);
struct btrfs_iget_args {
u64 ino;
@@ -2886,12 +2890,29 @@ out_fail:
btrfs_throttle(root);
return err;
}
+
+static int btrfs_check_acl(struct inode *inode, int mask)
+{
+ struct posix_acl *acl;
+ acl = btrfs_get_posix_acl(inode, BTRFS_XATTR_INDEX_POSIX_ACL_ACCESS);
+
+ if (IS_ERR(acl))
+ return PTR_ERR(acl);
+ if (acl) {
+ int error = posix_acl_permission(inode, acl, mask);
+ posix_acl_release(acl);
+ return error;
+ }
+
+ return -EAGAIN;
+}
+
static int btrfs_permission(struct inode *inode, int mask,
struct nameidata *nd)
{
if (btrfs_test_flag(inode, READONLY) && (mask & MAY_WRITE))
return -EACCES;
- return generic_permission(inode, mask, NULL);
+ return generic_permission(inode, mask, btrfs_check_acl);
}
static struct inode_operations btrfs_dir_inode_operations = {
diff -r 6c243ad8dddf super.c
--- a/super.c Fri Jan 18 10:54:22 2008 -0500
+++ b/super.c Sat Jan 19 21:38:02 2008 +0800
@@ -64,7 +64,7 @@ static void btrfs_put_super (struct supe
enum {
Opt_subvol, Opt_nodatasum, Opt_nodatacow, Opt_max_extent,
- Opt_alloc_start, Opt_nobarrier, Opt_ssd, Opt_err,
+ Opt_alloc_start, Opt_nobarrier, Opt_ssd, Opt_posix_acl, Opt_err,
};
static match_table_t tokens = {
@@ -75,6 +75,7 @@ static match_table_t tokens = {
{Opt_max_extent, "max_extent=%s"},
{Opt_alloc_start, "alloc_start=%s"},
{Opt_ssd, "ssd"},
+ {Opt_posix_acl, "acl"},
{Opt_err, NULL}
};
@@ -162,6 +163,14 @@ static int parse_options (char * options
btrfs_set_opt(info->mount_opt, NOBARRIER);
}
break;
+
+ case Opt_posix_acl:
+ if (info) {
+ printk("btrfs: enabling posix acl\n");
+ btrfs_set_opt(info->mount_opt, POSIX_ACL);
+ }
+ break;
+
case Opt_max_extent:
if (info) {
char *num = match_strdup(&args[0]);
@@ -247,6 +256,12 @@ static int btrfs_fill_super(struct super
}
parse_options((char *)data, tree_root, NULL);
+
+ if (tree_root->fs_info->mount_opt & BTRFS_MOUNT_POSIX_ACL) {
+ sb->s_flags |= MS_POSIXACL;
+ } else {
+ sb->s_flags = sb->s_flags & ~MS_POSIXACL;
+ }
/* this does the super kobj at the same time */
err = btrfs_sysfs_add_super(tree_root->fs_info);
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