[XFS] use generic_permission

Now that all direct caller of xfs_iaccess are gone we can kill xfs_iaccess
and xfs_access and just use generic_permission with a check_acl callback.
This is required for the per-mount read-only patchset in -mm to work
properly with XFS.

SGI-PV: 971186
SGI-Modid: xfs-linux-melb:xfs-kern:30370a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Lachlan McIlroy <lachlan@sgi.com>

7 files changed, 25 insertions, 120 deletions

diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c
index 1ecd86a8c6e6..c3231a519361 100644
--- a/fs/xfs/linux-2.6/xfs_iops.c
+++ b/fs/xfs/linux-2.6/xfs_iops.c
@@ -559,12 +559,31 @@ xfs_vn_put_link(
 
 #ifdef CONFIG_XFS_POSIX_ACL
 STATIC int
+xfs_check_acl(
+        struct inode            *inode,
+        int                     mask)
+{
+        struct xfs_inode        *ip = XFS_I(inode);
+        int                     error;
+
+        xfs_itrace_entry(ip);
+
+        if (XFS_IFORK_Q(ip)) {
+                error = xfs_acl_iaccess(ip, mask, NULL);
+                if (error != -1)
+                        return -error;
+        }
+
+        return -EAGAIN;
+}
+
+STATIC int
 xfs_vn_permission(
-        struct inode    *inode,
-        int             mode,
-        struct nameidata *nd)
+        struct inode            *inode,
+        int                     mask,
+        struct nameidata        *nd)
 {
-        return -xfs_access(XFS_I(inode), mode << 6, NULL);
+        return generic_permission(inode, mask, xfs_check_acl);
 }
 #else
 #define xfs_vn_permission NULL
diff --git a/fs/xfs/xfs_acl.c b/fs/xfs/xfs_acl.c
index 5bfb66f33caf..7272fe39a92d 100644
--- a/fs/xfs/xfs_acl.c
+++ b/fs/xfs/xfs_acl.c
@@ -392,32 +392,6 @@ xfs_acl_allow_set(
 }
 
 /*
- * The access control process to determine the access permission:
- *      if uid == file owner id, use the file owner bits.
- *      if gid == file owner group id, use the file group bits.
- *      scan ACL for a matching user or group, and use matched entry
- *      permission. Use total permissions of all matching group entries,
- *      until all acl entries are exhausted. The final permission produced
- *      by matching acl entry or entries needs to be & with group permission.
- *      if not owner, owning group, or matching entry in ACL, use file
- *      other bits.  
- */
-STATIC int
-xfs_acl_capability_check(
-        mode_t          mode,
-        cred_t          *cr)
-{
-        if ((mode & ACL_READ) && !capable_cred(cr, CAP_DAC_READ_SEARCH))
-                return EACCES;
-        if ((mode & ACL_WRITE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
-                return EACCES;
-        if ((mode & ACL_EXECUTE) && !capable_cred(cr, CAP_DAC_OVERRIDE))
-                return EACCES;
-
-        return 0;
-}
-
-/*
  * Note: cr is only used here for the capability check if the ACL test fails.
  *       It is not used to find out the credentials uid or groups etc, as was
  *       done in IRIX. It is assumed that the uid and groups for the current
@@ -438,7 +412,6 @@ xfs_acl_access(
 
         matched.ae_tag = 0;     /* Invalid type */
         matched.ae_perm = 0;
-        md >>= 6;       /* Normalize the bits for comparison */
 
         for (i = 0; i < fap->acl_cnt; i++) {
                 /*
@@ -520,7 +493,8 @@ xfs_acl_access(
                 break;
         }
 
-        return xfs_acl_capability_check(md, cr);
+        /* EACCES tells generic_permission to check for capability overrides */
+        return EACCES;
 }
 
 /*
diff --git a/fs/xfs/xfs_acl.h b/fs/xfs/xfs_acl.h
index 34b7d3391299..332a772461c4 100644
--- a/fs/xfs/xfs_acl.h
+++ b/fs/xfs/xfs_acl.h
@@ -75,7 +75,6 @@ extern int xfs_acl_vremove(bhv_vnode_t *, int);
 #define _ACL_GET_DEFAULT(pv,pd) (xfs_acl_vtoacl(pv,NULL,pd) == 0)
 #define _ACL_ACCESS_EXISTS      xfs_acl_vhasacl_access
 #define _ACL_DEFAULT_EXISTS     xfs_acl_vhasacl_default
-#define _ACL_XFS_IACCESS(i,m,c) (XFS_IFORK_Q(i) ? xfs_acl_iaccess(i,m,c) : -1)
 
 #define _ACL_ALLOC(a)           ((a) = kmem_zone_alloc(xfs_acl_zone, KM_SLEEP))
 #define _ACL_FREE(a)            ((a)? kmem_zone_free(xfs_acl_zone, (a)):(void)0)
@@ -95,7 +94,6 @@ extern int xfs_acl_vremove(bhv_vnode_t *, int);
 #define _ACL_GET_DEFAULT(pv,pd) (0)
 #define _ACL_ACCESS_EXISTS      (NULL)
 #define _ACL_DEFAULT_EXISTS     (NULL)
-#define _ACL_XFS_IACCESS(i,m,c) (-1)
 #endif
 
 #endif  /* __XFS_ACL_H__ */
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 75b636c14876..a550546a7083 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -3583,69 +3583,6 @@ xfs_iflush_all(
         XFS_MOUNT_IUNLOCK(mp);
 }
 
-/*
- * xfs_iaccess: check accessibility of inode for mode.
- */
-int
-xfs_iaccess(
-        xfs_inode_t     *ip,
-        mode_t          mode,
-        cred_t          *cr)
-{
-        int             error;
-        mode_t          orgmode = mode;
-        struct inode    *inode = vn_to_inode(XFS_ITOV(ip));
-
-        if (mode & S_IWUSR) {
-                umode_t         imode = inode->i_mode;
-
-                if (IS_RDONLY(inode) &&
-                    (S_ISREG(imode) || S_ISDIR(imode) || S_ISLNK(imode)))
-                        return XFS_ERROR(EROFS);
-
-                if (IS_IMMUTABLE(inode))
-                        return XFS_ERROR(EACCES);
-        }
-
-        /*
-         * If there's an Access Control List it's used instead of
-         * the mode bits.
-         */
-        if ((error = _ACL_XFS_IACCESS(ip, mode, cr)) != -1)
-                return error ? XFS_ERROR(error) : 0;
-
-        if (current_fsuid(cr) != ip->i_d.di_uid) {
-                mode >>= 3;
-                if (!in_group_p((gid_t)ip->i_d.di_gid))
-                        mode >>= 3;
-        }
-
-        /*
-         * If the DACs are ok we don't need any capability check.
-         */
-        if ((ip->i_d.di_mode & mode) == mode)
-                return 0;
-        /*
-         * Read/write DACs are always overridable.
-         * Executable DACs are overridable if at least one exec bit is set.
-         */
-        if (!(orgmode & S_IXUSR) ||
-            (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode))
-                if (capable_cred(cr, CAP_DAC_OVERRIDE))
-                        return 0;
-
-        if ((orgmode == S_IRUSR) ||
-            (S_ISDIR(inode->i_mode) && (!(orgmode & S_IWUSR)))) {
-                if (capable_cred(cr, CAP_DAC_READ_SEARCH))
-                        return 0;
-#ifdef  NOISE
-                cmn_err(CE_NOTE, "Ick: mode=%o, orgmode=%o", mode, orgmode);
-#endif  /* NOISE */
-                return XFS_ERROR(EACCES);
-        }
-        return XFS_ERROR(EACCES);
-}
-
 #ifdef XFS_ILOCK_TRACE
 ktrace_t        *xfs_ilock_trace_buf;
 
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index a8d6f5e251aa..bfcd72cbaeea 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -550,7 +550,6 @@ void		xfs_iunpin(xfs_inode_t *);
 int             xfs_iextents_copy(xfs_inode_t *, xfs_bmbt_rec_t *, int);
 int             xfs_iflush(xfs_inode_t *, uint);
 void            xfs_iflush_all(struct xfs_mount *);
-int             xfs_iaccess(xfs_inode_t *, mode_t, cred_t *);
 void            xfs_ichgtime(xfs_inode_t *, int);
 xfs_fsize_t     xfs_file_last_byte(xfs_inode_t *);
 void            xfs_lock_inodes(xfs_inode_t **, int, int, uint);
diff --git a/fs/xfs/xfs_vnodeops.c b/fs/xfs/xfs_vnodeops.c
index 076555e8763f..27e1bea8169f 100644
--- a/fs/xfs/xfs_vnodeops.c
+++ b/fs/xfs/xfs_vnodeops.c
@@ -898,27 +898,6 @@ xfs_setattr(
         return code;
 }
 
-
-/*
- * xfs_access
- * Null conversion from vnode mode bits to inode mode bits, as in efs.
- */
-int
-xfs_access(
-        xfs_inode_t     *ip,
-        int             mode,
-        cred_t          *credp)
-{
-        int             error;
-
-        xfs_itrace_entry(ip);
-        xfs_ilock(ip, XFS_ILOCK_SHARED);
-        error = xfs_iaccess(ip, mode, credp);
-        xfs_iunlock(ip, XFS_ILOCK_SHARED);
-        return error;
-}
-
-
 /*
  * The maximum pathlen is 1024 bytes. Since the minimum file system
  * blocksize is 512 bytes, we can get a max of 2 extents back from
diff --git a/fs/xfs/xfs_vnodeops.h b/fs/xfs/xfs_vnodeops.h
index a501aeffb808..4e3970f0e5e3 100644
--- a/fs/xfs/xfs_vnodeops.h
+++ b/fs/xfs/xfs_vnodeops.h
@@ -18,7 +18,6 @@ int xfs_open(struct xfs_inode *ip);
 int xfs_getattr(struct xfs_inode *ip, struct bhv_vattr *vap, int flags);
 int xfs_setattr(struct xfs_inode *ip, struct bhv_vattr *vap, int flags,
                 struct cred *credp);
-int xfs_access(struct xfs_inode *ip, int mode, struct cred *credp);
 int xfs_readlink(struct xfs_inode *ip, char *link);
 int xfs_fsync(struct xfs_inode *ip, int flag, xfs_off_t start,
                 xfs_off_t stop);