GFS2: Fix up system xattrs

This code has been shamelessly stolen from XFS at the suggestion of Christoph Hellwig. I've not added support for cached ACLs so far... watch for that in a later patch, although this is designed in such a way that they should be easy to add. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Christoph Hellwig <hch@infradead.org>

GFS2: Fix up system xattrs
This code has been shamelessly stolen from XFS at the suggestion of Christoph Hellwig. I've not added support for cached ACLs so far... watch for that in a later patch, although this is designed in such a way that they should be easy to add. Signed-off-by: Steven Whitehouse <swhiteho@redhat.com> Cc: Christoph Hellwig <hch@infradead.org>
Steven Whitehouse
1 parent f55073ff1e
Showing 3 changed files with 120 additions and 92 deletions Side-by-side Diff
fs/gfs2/acl.c
fs/gfs2/acl.h
fs/gfs2/xattr.c
@@ -12,6 +12,7 @@
 #include <linux/spinlock.h>
 #include <linux/completion.h>
 #include <linux/buffer_head.h>
+#include <linux/xattr.h>
 #include <linux/posix_acl.h>
 #include <linux/posix_acl_xattr.h>
 #include <linux/gfs2_ondisk.h>
@@ -26,61 +27,6 @@
 #include "trans.h"
 #include "util.h"
  
-#define ACL_ACCESS 1
-#define ACL_DEFAULT 0
-
-int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
-			  struct gfs2_ea_request *er, int *remove, mode_t *mode)
-{
-	struct posix_acl *acl;
-	int error;
-
-	error = gfs2_acl_validate_remove(ip, access);
-	if (error)
-		return error;
-
-	if (!er->er_data)
-		return -EINVAL;
-
-	acl = posix_acl_from_xattr(er->er_data, er->er_data_len);
-	if (IS_ERR(acl))
-		return PTR_ERR(acl);
-	if (!acl) {
-		*remove = 1;
-		return 0;
-	}
-
-	error = posix_acl_valid(acl);
-	if (error)
-		goto out;
-
-	if (access) {
-		error = posix_acl_equiv_mode(acl, mode);
-		if (!error)
-			*remove = 1;
-		else if (error > 0)
-			error = 0;
-	}
-
-out:
-	posix_acl_release(acl);
-	return error;
-}
-
-int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
-{
-	if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
-		return -EOPNOTSUPP;
-	if (!is_owner_or_cap(&ip->i_inode))
-		return -EPERM;
-	if (S_ISLNK(ip->i_inode.i_mode))
-		return -EOPNOTSUPP;
-	if (!access && !S_ISDIR(ip->i_inode.i_mode))
-		return -EACCES;
-
-	return 0;
-}
-
 static int acl_get(struct gfs2_inode *ip, const char *name,
 		   struct posix_acl **acl, struct gfs2_ea_location *el,
 		   char **datap, unsigned int *lenp)
@@ -276,4 +222,118 @@
 	brelse(el.el_bh);
 	return error;
 }
+
+static int gfs2_acl_type(const char *name)
+{
+	if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
+		return ACL_TYPE_ACCESS;
+	if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
+		return ACL_TYPE_DEFAULT;
+	return -EINVAL;
+}
+
+static int gfs2_xattr_system_get(struct inode *inode, const char *name,
+				 void *buffer, size_t size)
+{
+	int type;
+
+	type = gfs2_acl_type(name);
+	if (type < 0)
+		return type;
+
+	return gfs2_xattr_get(inode, GFS2_EATYPE_SYS, name, buffer, size);
+}
+
+static int gfs2_set_mode(struct inode *inode, mode_t mode)
+{
+	int error = 0;
+
+	if (mode != inode->i_mode) {
+		struct iattr iattr;
+
+		iattr.ia_valid = ATTR_MODE;
+		iattr.ia_mode = mode;
+
+		error = gfs2_setattr_simple(GFS2_I(inode), &iattr);
+	}
+
+	return error;
+}
+
+static int gfs2_xattr_system_set(struct inode *inode, const char *name,
+				 const void *value, size_t size, int flags)
+{
+	struct gfs2_sbd *sdp = GFS2_SB(inode);
+	struct posix_acl *acl = NULL;
+	int error = 0, type;
+
+	if (!sdp->sd_args.ar_posix_acl)
+		return -EOPNOTSUPP;
+
+	type = gfs2_acl_type(name);
+	if (type < 0)
+		return type;
+	if (flags & XATTR_CREATE)
+		return -EINVAL;
+	if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
+		return value ? -EACCES : 0;
+	if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
+		return -EPERM;
+	if (S_ISLNK(inode->i_mode))
+		return -EOPNOTSUPP;
+
+	if (!value)
+		goto set_acl;
+
+	acl = posix_acl_from_xattr(value, size);
+	if (!acl) {
+		/*
+		 * acl_set_file(3) may request that we set default ACLs with
+		 * zero length -- defend (gracefully) against that here.
+		 */
+		goto out;
+	}
+	if (IS_ERR(acl)) {
+		error = PTR_ERR(acl);
+		goto out;
+	}
+
+	error = posix_acl_valid(acl);
+	if (error)
+		goto out_release;
+
+	error = -EINVAL;
+	if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
+		goto out_release;
+
+	if (type == ACL_TYPE_ACCESS) {
+		mode_t mode = inode->i_mode;
+		error = posix_acl_equiv_mode(acl, &mode);
+
+		if (error <= 0) {
+			posix_acl_release(acl);
+			acl = NULL;
+
+			if (error < 0)
+				return error;
+		}
+
+		error = gfs2_set_mode(inode, mode);
+		if (error)
+			goto out_release;
+	}
+
+set_acl:
+	error = gfs2_xattr_set(inode, GFS2_EATYPE_SYS, name, value, size, 0);
+out_release:
+	posix_acl_release(acl);
+out:
+	return error;
+}
+
+struct xattr_handler gfs2_xattr_system_handler = {
+	.prefix = XATTR_SYSTEM_PREFIX,
+	.get    = gfs2_xattr_system_get,
+	.set    = gfs2_xattr_system_set,
+};
@@ -13,27 +13,13 @@
 #include "incore.h"
  
 #define GFS2_POSIX_ACL_ACCESS		"posix_acl_access"
-#define GFS2_POSIX_ACL_ACCESS_LEN	16
 #define GFS2_POSIX_ACL_DEFAULT		"posix_acl_default"
-#define GFS2_POSIX_ACL_DEFAULT_LEN	17
+#define GFS2_ACL_MAX_ENTRIES		25
  
-#define GFS2_ACL_IS_ACCESS(name, len) \
-         ((len) == GFS2_POSIX_ACL_ACCESS_LEN && \
-         !memcmp(GFS2_POSIX_ACL_ACCESS, (name), (len)))
-
-#define GFS2_ACL_IS_DEFAULT(name, len) \
-         ((len) == GFS2_POSIX_ACL_DEFAULT_LEN && \
-         !memcmp(GFS2_POSIX_ACL_DEFAULT, (name), (len)))
-
-struct gfs2_ea_request;
-
-int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
-			  struct gfs2_ea_request *er,
-			  int *remove, mode_t *mode);
-int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access);
-int gfs2_check_acl(struct inode *inode, int mask);
-int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip);
-int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr);
+extern int gfs2_check_acl(struct inode *inode, int mask);
+extern int gfs2_acl_create(struct gfs2_inode *dip, struct gfs2_inode *ip);
+extern int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr);
+extern struct xattr_handler gfs2_xattr_system_handler;
  
 #endif /* __ACL_DOT_H__ */
@@ -1507,18 +1507,6 @@
 	return gfs2_xattr_set(inode, GFS2_EATYPE_USR, name, value, size, flags);
 }
  
-static int gfs2_xattr_system_get(struct inode *inode, const char *name,
-				 void *buffer, size_t size)
-{
-	return gfs2_xattr_get(inode, GFS2_EATYPE_SYS, name, buffer, size);
-}
-
-static int gfs2_xattr_system_set(struct inode *inode, const char *name,
-				 const void *value, size_t size, int flags)
-{
-	return gfs2_xattr_set(inode, GFS2_EATYPE_SYS, name, value, size, flags);
-}
-
 static int gfs2_xattr_security_get(struct inode *inode, const char *name,
 				   void *buffer, size_t size)
 {
@@ -1541,12 +1529,6 @@
 	.prefix = XATTR_SECURITY_PREFIX,
 	.get    = gfs2_xattr_security_get,
 	.set    = gfs2_xattr_security_set,
-};
-
-static struct xattr_handler gfs2_xattr_system_handler = {
-	.prefix = XATTR_SYSTEM_PREFIX,
-	.get    = gfs2_xattr_system_get,
-	.set    = gfs2_xattr_system_set,
 };
  
 struct xattr_handler *gfs2_xattr_handlers[] = {
...	...	@@ -12,6 +12,7 @@
12	12	#include <linux/spinlock.h>
13	13	#include <linux/completion.h>
14	14	#include <linux/buffer_head.h>
	15	+#include <linux/xattr.h>
15	16	#include <linux/posix_acl.h>
16	17	#include <linux/posix_acl_xattr.h>
17	18	#include <linux/gfs2_ondisk.h>
...	...	@@ -26,61 +27,6 @@
26	27	#include "trans.h"
27	28	#include "util.h"
28	29
29		-#define ACL_ACCESS 1
30		-#define ACL_DEFAULT 0
31		-
32		-int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
33		- struct gfs2_ea_request er, int remove, mode_t *mode)
34		-{
35		- struct posix_acl *acl;
36		- int error;
37		-
38		- error = gfs2_acl_validate_remove(ip, access);
39		- if (error)
40		- return error;
41		-
42		- if (!er->er_data)
43		- return -EINVAL;
44		-
45		- acl = posix_acl_from_xattr(er->er_data, er->er_data_len);
46		- if (IS_ERR(acl))
47		- return PTR_ERR(acl);
48		- if (!acl) {
49		- *remove = 1;
50		- return 0;
51		- }
52		-
53		- error = posix_acl_valid(acl);
54		- if (error)
55		- goto out;
56		-
57		- if (access) {
58		- error = posix_acl_equiv_mode(acl, mode);
59		- if (!error)
60		- *remove = 1;
61		- else if (error > 0)
62		- error = 0;
63		- }
64		-
65		-out:
66		- posix_acl_release(acl);
67		- return error;
68		-}
69		-
70		-int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access)
71		-{
72		- if (!GFS2_SB(&ip->i_inode)->sd_args.ar_posix_acl)
73		- return -EOPNOTSUPP;
74		- if (!is_owner_or_cap(&ip->i_inode))
75		- return -EPERM;
76		- if (S_ISLNK(ip->i_inode.i_mode))
77		- return -EOPNOTSUPP;
78		- if (!access && !S_ISDIR(ip->i_inode.i_mode))
79		- return -EACCES;
80		-
81		- return 0;
82		-}
83		-
84	30	static int acl_get(struct gfs2_inode ip, const char name,
85	31	struct posix_acl *acl, struct gfs2_ea_location el,
86	32	char *datap, unsigned int lenp)
...	...	@@ -276,4 +222,118 @@
276	222	brelse(el.el_bh);
277	223	return error;
278	224	}
	225	+
	226	+static int gfs2_acl_type(const char *name)
	227	+{
	228	+ if (strcmp(name, GFS2_POSIX_ACL_ACCESS) == 0)
	229	+ return ACL_TYPE_ACCESS;
	230	+ if (strcmp(name, GFS2_POSIX_ACL_DEFAULT) == 0)
	231	+ return ACL_TYPE_DEFAULT;
	232	+ return -EINVAL;
	233	+}
	234	+
	235	+static int gfs2_xattr_system_get(struct inode inode, const char name,
	236	+ void *buffer, size_t size)
	237	+{
	238	+ int type;
	239	+
	240	+ type = gfs2_acl_type(name);
	241	+ if (type < 0)
	242	+ return type;
	243	+
	244	+ return gfs2_xattr_get(inode, GFS2_EATYPE_SYS, name, buffer, size);
	245	+}
	246	+
	247	+static int gfs2_set_mode(struct inode *inode, mode_t mode)
	248	+{
	249	+ int error = 0;
	250	+
	251	+ if (mode != inode->i_mode) {
	252	+ struct iattr iattr;
	253	+
	254	+ iattr.ia_valid = ATTR_MODE;
	255	+ iattr.ia_mode = mode;
	256	+
	257	+ error = gfs2_setattr_simple(GFS2_I(inode), &iattr);
	258	+ }
	259	+
	260	+ return error;
	261	+}
	262	+
	263	+static int gfs2_xattr_system_set(struct inode inode, const char name,
	264	+ const void *value, size_t size, int flags)
	265	+{
	266	+ struct gfs2_sbd *sdp = GFS2_SB(inode);
	267	+ struct posix_acl *acl = NULL;
	268	+ int error = 0, type;
	269	+
	270	+ if (!sdp->sd_args.ar_posix_acl)
	271	+ return -EOPNOTSUPP;
	272	+
	273	+ type = gfs2_acl_type(name);
	274	+ if (type < 0)
	275	+ return type;
	276	+ if (flags & XATTR_CREATE)
	277	+ return -EINVAL;
	278	+ if (type == ACL_TYPE_DEFAULT && !S_ISDIR(inode->i_mode))
	279	+ return value ? -EACCES : 0;
	280	+ if ((current_fsuid() != inode->i_uid) && !capable(CAP_FOWNER))
	281	+ return -EPERM;
	282	+ if (S_ISLNK(inode->i_mode))
	283	+ return -EOPNOTSUPP;
	284	+
	285	+ if (!value)
	286	+ goto set_acl;
	287	+
	288	+ acl = posix_acl_from_xattr(value, size);
	289	+ if (!acl) {
	290	+ /*
	291	+ * acl_set_file(3) may request that we set default ACLs with
	292	+ * zero length -- defend (gracefully) against that here.
	293	+ */
	294	+ goto out;
	295	+ }
	296	+ if (IS_ERR(acl)) {
	297	+ error = PTR_ERR(acl);
	298	+ goto out;
	299	+ }
	300	+
	301	+ error = posix_acl_valid(acl);
	302	+ if (error)
	303	+ goto out_release;
	304	+
	305	+ error = -EINVAL;
	306	+ if (acl->a_count > GFS2_ACL_MAX_ENTRIES)
	307	+ goto out_release;
	308	+
	309	+ if (type == ACL_TYPE_ACCESS) {
	310	+ mode_t mode = inode->i_mode;
	311	+ error = posix_acl_equiv_mode(acl, &mode);
	312	+
	313	+ if (error <= 0) {
	314	+ posix_acl_release(acl);
	315	+ acl = NULL;
	316	+
	317	+ if (error < 0)
	318	+ return error;
	319	+ }
	320	+
	321	+ error = gfs2_set_mode(inode, mode);
	322	+ if (error)
	323	+ goto out_release;
	324	+ }
	325	+
	326	+set_acl:
	327	+ error = gfs2_xattr_set(inode, GFS2_EATYPE_SYS, name, value, size, 0);
	328	+out_release:
	329	+ posix_acl_release(acl);
	330	+out:
	331	+ return error;
	332	+}
	333	+
	334	+struct xattr_handler gfs2_xattr_system_handler = {
	335	+ .prefix = XATTR_SYSTEM_PREFIX,
	336	+ .get = gfs2_xattr_system_get,
	337	+ .set = gfs2_xattr_system_set,
	338	+};
...	...	@@ -13,27 +13,13 @@
13	13	#include "incore.h"
14	14
15	15	#define GFS2_POSIX_ACL_ACCESS "posix_acl_access"
16		-#define GFS2_POSIX_ACL_ACCESS_LEN 16
17	16	#define GFS2_POSIX_ACL_DEFAULT "posix_acl_default"
18		-#define GFS2_POSIX_ACL_DEFAULT_LEN 17
	17	+#define GFS2_ACL_MAX_ENTRIES 25
19	18
20		-#define GFS2_ACL_IS_ACCESS(name, len) \
21		- ((len) == GFS2_POSIX_ACL_ACCESS_LEN && \
22		- !memcmp(GFS2_POSIX_ACL_ACCESS, (name), (len)))
23		-
24		-#define GFS2_ACL_IS_DEFAULT(name, len) \
25		- ((len) == GFS2_POSIX_ACL_DEFAULT_LEN && \
26		- !memcmp(GFS2_POSIX_ACL_DEFAULT, (name), (len)))
27		-
28		-struct gfs2_ea_request;
29		-
30		-int gfs2_acl_validate_set(struct gfs2_inode *ip, int access,
31		- struct gfs2_ea_request *er,
32		- int remove, mode_t mode);
33		-int gfs2_acl_validate_remove(struct gfs2_inode *ip, int access);
34		-int gfs2_check_acl(struct inode *inode, int mask);
35		-int gfs2_acl_create(struct gfs2_inode dip, struct gfs2_inode ip);
36		-int gfs2_acl_chmod(struct gfs2_inode ip, struct iattr attr);
	19	+extern int gfs2_check_acl(struct inode *inode, int mask);
	20	+extern int gfs2_acl_create(struct gfs2_inode dip, struct gfs2_inode ip);
	21	+extern int gfs2_acl_chmod(struct gfs2_inode ip, struct iattr attr);
	22	+extern struct xattr_handler gfs2_xattr_system_handler;
37	23
38	24	#endif /* __ACL_DOT_H__ */
...	...	@@ -1507,18 +1507,6 @@
1507	1507	return gfs2_xattr_set(inode, GFS2_EATYPE_USR, name, value, size, flags);
1508	1508	}
1509	1509
1510		-static int gfs2_xattr_system_get(struct inode inode, const char name,
1511		- void *buffer, size_t size)
1512		-{
1513		- return gfs2_xattr_get(inode, GFS2_EATYPE_SYS, name, buffer, size);
1514		-}
1515		-
1516		-static int gfs2_xattr_system_set(struct inode inode, const char name,
1517		- const void *value, size_t size, int flags)
1518		-{
1519		- return gfs2_xattr_set(inode, GFS2_EATYPE_SYS, name, value, size, flags);
1520		-}
1521		-
1522	1510	static int gfs2_xattr_security_get(struct inode inode, const char name,
1523	1511	void *buffer, size_t size)
1524	1512	{
...	...	@@ -1541,12 +1529,6 @@
1541	1529	.prefix = XATTR_SECURITY_PREFIX,
1542	1530	.get = gfs2_xattr_security_get,
1543	1531	.set = gfs2_xattr_security_set,
1544		-};
1545		-
1546		-static struct xattr_handler gfs2_xattr_system_handler = {
1547		- .prefix = XATTR_SYSTEM_PREFIX,
1548		- .get = gfs2_xattr_system_get,
1549		- .set = gfs2_xattr_system_set,
1550	1532	};
1551	1533
1552	1534	struct xattr_handler *gfs2_xattr_handlers[] = {