gfs2: Switch to generic xattr handlers

Switch to the generic xattr handlers and take the necessary glocks at
the layer below. The following are the new xattr "entry points"; they
are called with the glock held already in the following cases:

  gfs2_xattr_get: From SELinux, during lookups.
  gfs2_xattr_set: The glock is never held.
  gfs2_get_acl: From gfs2_create_inode -> posix_acl_create and
                gfs2_setattr -> posix_acl_chmod.
  gfs2_set_acl: From gfs2_setattr -> posix_acl_chmod.

Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c
index 7919326..363ba9e 100644 (file)
--- a/fs/gfs2/acl.c
+++ b/fs/gfs2/acl.c
@@ -24,6 +24,7 @@
 #include "glock.h"
 #include "inode.h"
 #include "meta_io.h"
+#include "rgrp.h"
 #include "trans.h"
 #include "util.h"
 
@@ -38,7 +39,7 @@ static const char *gfs2_acl_name(int type)
        return NULL;
 }
 
-struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
+static struct posix_acl *__gfs2_get_acl(struct inode *inode, int type)
 {
        struct gfs2_inode *ip = GFS2_I(inode);
        struct posix_acl *acl;
@@ -50,29 +51,41 @@ struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
                return NULL;
 
        name = gfs2_acl_name(type);
-       if (name == NULL)
-               return ERR_PTR(-EINVAL);
-
        len = gfs2_xattr_acl_get(ip, name, &data);
-       if (len < 0)
+       if (len <= 0)
                return ERR_PTR(len);
-       if (len == 0)
-               return NULL;
-
        acl = posix_acl_from_xattr(&init_user_ns, data, len);
        kfree(data);
        return acl;
 }
 
-int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+struct posix_acl *gfs2_get_acl(struct inode *inode, int type)
+{
+       struct gfs2_inode *ip = GFS2_I(inode);
+       struct gfs2_holder gh;
+       bool need_unlock = false;
+       struct posix_acl *acl;
+
+       if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
+               int ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED,
+                                            LM_FLAG_ANY, &gh);
+               if (ret)
+                       return ERR_PTR(ret);
+               need_unlock = true;
+       }
+       acl = __gfs2_get_acl(inode, type);
+       if (need_unlock)
+               gfs2_glock_dq_uninit(&gh);
+       return acl;
+}
+
+int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
 {
        int error;
        int len;
        char *data;
        const char *name = gfs2_acl_name(type);
 
-       BUG_ON(name == NULL);
-
        if (acl && acl->a_count > GFS2_ACL_MAX_ENTRIES(GFS2_SB(inode)))
                return -E2BIG;
 
@@ -115,3 +128,26 @@ out:
        kfree(data);
        return error;
 }
+
+int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type)
+{
+       struct gfs2_inode *ip = GFS2_I(inode);
+       struct gfs2_holder gh;
+       bool need_unlock = false;
+       int ret;
+
+       ret = gfs2_rsqa_alloc(ip);
+       if (ret)
+               return ret;
+
+       if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
+               ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
+               if (ret)
+                       return ret;
+               need_unlock = true;
+       }
+       ret = __gfs2_set_acl(inode, acl, type);
+       if (need_unlock)
+               gfs2_glock_dq_uninit(&gh);
+       return ret;
+}

diff --git a/fs/gfs2/acl.h b/fs/gfs2/acl.h
index 3af4f40..f674fdd 100644 (file)
--- a/fs/gfs2/acl.h
+++ b/fs/gfs2/acl.h
@@ -15,6 +15,7 @@
 #define GFS2_ACL_MAX_ENTRIES(sdp) ((300 << (sdp)->sd_sb.sb_bsize_shift) >> 12)
 
 extern struct posix_acl *gfs2_get_acl(struct inode *inode, int type);
+extern int __gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 extern int gfs2_set_acl(struct inode *inode, struct posix_acl *acl, int type);
 
 #endif /* __ACL_DOT_H__ */

diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c
index 45f516c..72e9c64 100644 (file)
--- a/fs/gfs2/inode.c
+++ b/fs/gfs2/inode.c
@@ -692,12 +692,12 @@ static int gfs2_create_inode(struct inode *dir, struct dentry *dentry,
                               considered free. Any failures need to undo
                               the gfs2 structures. */
        if (default_acl) {
-               error = gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
+               error = __gfs2_set_acl(inode, default_acl, ACL_TYPE_DEFAULT);
                posix_acl_release(default_acl);
        }
        if (acl) {
                if (!error)
-                       error = gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS);
+                       error = __gfs2_set_acl(inode, acl, ACL_TYPE_ACCESS);
                posix_acl_release(acl);
        }
 
@@ -1948,66 +1948,6 @@ static int gfs2_getattr(struct vfsmount *mnt, struct dentry *dentry,
        return 0;
 }
 
-static int gfs2_setxattr(struct dentry *dentry, const char *name,
-                        const void *data, size_t size, int flags)
-{
-       struct inode *inode = d_inode(dentry);
-       struct gfs2_inode *ip = GFS2_I(inode);
-       struct gfs2_holder gh;
-       int ret;
-
-       gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
-       ret = gfs2_glock_nq(&gh);
-       if (ret == 0) {
-               ret = gfs2_rsqa_alloc(ip);
-               if (ret == 0)
-                       ret = generic_setxattr(dentry, name, data, size, flags);
-               gfs2_glock_dq(&gh);
-       }
-       gfs2_holder_uninit(&gh);
-       return ret;
-}
-
-static ssize_t gfs2_getxattr(struct dentry *dentry, struct inode *inode,
-                            const char *name, void *data, size_t size)
-{
-       struct gfs2_inode *ip = GFS2_I(inode);
-       struct gfs2_holder gh;
-       int ret;
-
-       /* For selinux during lookup */
-       if (gfs2_glock_is_locked_by_me(ip->i_gl))
-               return generic_getxattr(dentry, inode, name, data, size);
-
-       gfs2_holder_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
-       ret = gfs2_glock_nq(&gh);
-       if (ret == 0) {
-               ret = generic_getxattr(dentry, inode, name, data, size);
-               gfs2_glock_dq(&gh);
-       }
-       gfs2_holder_uninit(&gh);
-       return ret;
-}
-
-static int gfs2_removexattr(struct dentry *dentry, const char *name)
-{
-       struct inode *inode = d_inode(dentry);
-       struct gfs2_inode *ip = GFS2_I(inode);
-       struct gfs2_holder gh;
-       int ret;
-
-       gfs2_holder_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
-       ret = gfs2_glock_nq(&gh);
-       if (ret == 0) {
-               ret = gfs2_rsqa_alloc(ip);
-               if (ret == 0)
-                       ret = generic_removexattr(dentry, name);
-               gfs2_glock_dq(&gh);
-       }
-       gfs2_holder_uninit(&gh);
-       return ret;
-}
-
 static int gfs2_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
                       u64 start, u64 len)
 {
@@ -2054,10 +1994,10 @@ const struct inode_operations gfs2_file_iops = {
        .permission = gfs2_permission,
        .setattr = gfs2_setattr,
        .getattr = gfs2_getattr,
-       .setxattr = gfs2_setxattr,
-       .getxattr = gfs2_getxattr,
+       .setxattr = generic_setxattr,
+       .getxattr = generic_getxattr,
        .listxattr = gfs2_listxattr,
-       .removexattr = gfs2_removexattr,
+       .removexattr = generic_removexattr,
        .fiemap = gfs2_fiemap,
        .get_acl = gfs2_get_acl,
        .set_acl = gfs2_set_acl,
@@ -2076,10 +2016,10 @@ const struct inode_operations gfs2_dir_iops = {
        .permission = gfs2_permission,
        .setattr = gfs2_setattr,
        .getattr = gfs2_getattr,
-       .setxattr = gfs2_setxattr,
-       .getxattr = gfs2_getxattr,
+       .setxattr = generic_setxattr,
+       .getxattr = generic_getxattr,
        .listxattr = gfs2_listxattr,
-       .removexattr = gfs2_removexattr,
+       .removexattr = generic_removexattr,
        .fiemap = gfs2_fiemap,
        .get_acl = gfs2_get_acl,
        .set_acl = gfs2_set_acl,
@@ -2092,10 +2032,10 @@ const struct inode_operations gfs2_symlink_iops = {
        .permission = gfs2_permission,
        .setattr = gfs2_setattr,
        .getattr = gfs2_getattr,
-       .setxattr = gfs2_setxattr,
-       .getxattr = gfs2_getxattr,
+       .setxattr = generic_setxattr,
+       .getxattr = generic_getxattr,
        .listxattr = gfs2_listxattr,
-       .removexattr = gfs2_removexattr,
+       .removexattr = generic_removexattr,
        .fiemap = gfs2_fiemap,
 };
 

diff --git a/fs/gfs2/xattr.c b/fs/gfs2/xattr.c
index 619886b..f42ab53 100644 (file)
--- a/fs/gfs2/xattr.c
+++ b/fs/gfs2/xattr.c
@@ -583,13 +583,11 @@ out:
  *
  * Returns: actual size of data on success, -errno on error
  */
-static int gfs2_xattr_get(const struct xattr_handler *handler,
-                         struct dentry *unused, struct inode *inode,
-                         const char *name, void *buffer, size_t size)
+static int __gfs2_xattr_get(struct inode *inode, const char *name,
+                           void *buffer, size_t size, int type)
 {
        struct gfs2_inode *ip = GFS2_I(inode);
        struct gfs2_ea_location el;
-       int type = handler->flags;
        int error;
 
        if (!ip->i_eattr)
@@ -611,6 +609,29 @@ static int gfs2_xattr_get(const struct xattr_handler *handler,
        return error;
 }
 
+static int gfs2_xattr_get(const struct xattr_handler *handler,
+                         struct dentry *unused, struct inode *inode,
+                         const char *name, void *buffer, size_t size)
+{
+       struct gfs2_inode *ip = GFS2_I(inode);
+       struct gfs2_holder gh;
+       bool need_unlock = false;
+       int ret;
+
+       /* During lookup, SELinux calls this function with the glock locked. */
+
+       if (!gfs2_glock_is_locked_by_me(ip->i_gl)) {
+               ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &gh);
+               if (ret)
+                       return ret;
+               need_unlock = true;
+       }
+       ret = __gfs2_xattr_get(inode, name, buffer, size, handler->flags);
+       if (need_unlock)
+               gfs2_glock_dq_uninit(&gh);
+       return ret;
+}
+
 /**
  * ea_alloc_blk - allocates a new block for extended attributes.
  * @ip: A pointer to the inode that's getting extended attributes
@@ -1233,8 +1254,21 @@ static int gfs2_xattr_set(const struct xattr_handler *handler,
                          struct dentry *dentry, const char *name,
                          const void *value, size_t size, int flags)
 {
-       return __gfs2_xattr_set(d_inode(dentry), name, value,
-                               size, flags, handler->flags);
+       struct inode *inode = d_inode(dentry);
+       struct gfs2_inode *ip = GFS2_I(inode);
+       struct gfs2_holder gh;
+       int ret;
+
+       ret = gfs2_rsqa_alloc(ip);
+       if (ret)
+               return ret;
+
+       ret = gfs2_glock_nq_init(ip->i_gl, LM_ST_EXCLUSIVE, 0, &gh);
+       if (ret)
+               return ret;
+       ret = __gfs2_xattr_set(inode, name, value, size, flags, handler->flags);
+       gfs2_glock_dq_uninit(&gh);
+       return ret;
 }
 
 static int ea_dealloc_indirect(struct gfs2_inode *ip)