squashfs: add xattr id support

This patch adds support for mapping xattr ids (stored in inodes) into the on-disk location of the xattrs themselves. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>

squashfs: add xattr id support
This patch adds support for mapping xattr ids (stored in inodes) into the on-disk location of the xattrs themselves. Signed-off-by: Phillip Lougher <phillip@lougher.demon.co.uk>
Phillip Lougher
1 parent b57f95a382
Showing 6 changed files with 161 additions and 4 deletions Side-by-side Diff
fs/squashfs/Makefile
fs/squashfs/squashfs.h
fs/squashfs/squashfs_fs.h
fs/squashfs/squashfs_fs_sb.h
fs/squashfs/super.c
fs/squashfs/xattr_id.c
@@ -5,4 +5,5 @@
 obj-$(CONFIG_SQUASHFS) += squashfs.o
 squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
 squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
+squashfs-y += xattr_id.o
@@ -73,6 +73,12 @@
 				unsigned int);
 extern int squashfs_read_inode(struct inode *, long long);
  
+/* xattr_id.c */
+extern int squashfs_xattr_lookup(struct super_block *, unsigned int, int *,
+				int *, long long *);
+extern __le64 *squashfs_read_xattr_id_table(struct super_block *, u64,
+				u64 *, int *);
+
 /*
  * Inodes, files and decompressor operations
  */
@@ -174,7 +174,25 @@
  
 #define SQUASHFS_ID_BLOCK_BYTES(A)	(SQUASHFS_ID_BLOCKS(A) *\
 					sizeof(u64))
+/* xattr id lookup table defines */
+#define SQUASHFS_XATTR_BYTES(A)		((A) * sizeof(struct squashfs_xattr_id))
  
+#define SQUASHFS_XATTR_BLOCK(A)		(SQUASHFS_XATTR_BYTES(A) / \
+					SQUASHFS_METADATA_SIZE)
+
+#define SQUASHFS_XATTR_BLOCK_OFFSET(A)	(SQUASHFS_XATTR_BYTES(A) % \
+					SQUASHFS_METADATA_SIZE)
+
+#define SQUASHFS_XATTR_BLOCKS(A)	((SQUASHFS_XATTR_BYTES(A) + \
+					SQUASHFS_METADATA_SIZE - 1) / \
+					SQUASHFS_METADATA_SIZE)
+
+#define SQUASHFS_XATTR_BLOCK_BYTES(A)	(SQUASHFS_XATTR_BLOCKS(A) *\
+					sizeof(u64))
+#define SQUASHFS_XATTR_BLK(A)		((unsigned int) ((A) >> 16))
+
+#define SQUASHFS_XATTR_OFFSET(A)	((unsigned int) ((A) & 0xffff))
+
 /* cached data constants for filesystem */
 #define SQUASHFS_CACHED_BLKS		8
  
@@ -228,7 +246,7 @@
 	__le64			root_inode;
 	__le64			bytes_used;
 	__le64			id_table_start;
-	__le64			xattr_table_start;
+	__le64			xattr_id_table_start;
 	__le64			inode_table_start;
 	__le64			directory_table_start;
 	__le64			fragment_table_start;
@@ -375,6 +393,18 @@
 	__le64			start_block;
 	__le32			size;
 	unsigned int		unused;
+};
+
+struct squashfs_xattr_id {
+	__le64			xattr;
+	__le32			count;
+	__le32			size;
+};
+
+struct squashfs_xattr_id_table {
+	__le64			xattr_table_start;
+	__le32			xattr_ids;
+	__le32			unused;
 };
  
 #endif
@@ -61,6 +61,7 @@
 	int					next_meta_index;
 	__le64					*id_table;
 	__le64					*fragment_index;
+	__le64					*xattr_id_table;
 	struct mutex				read_data_mutex;
 	struct mutex				meta_index_mutex;
 	struct meta_index			*meta_index;
  
@@ -68,10 +69,12 @@
 	__le64					*inode_lookup_table;
 	u64					inode_table;
 	u64					directory_table;
+	u64					xattr_table;
 	unsigned int				block_size;
 	unsigned short				block_log;
 	long long				bytes_used;
 	unsigned int				inodes;
+	int					xattr_ids;
 };
 #endif
@@ -36,6 +36,7 @@
 #include <linux/init.h>
 #include <linux/module.h>
 #include <linux/magic.h>
+#include <linux/xattr.h>
  
 #include "squashfs_fs.h"
 #include "squashfs_fs_sb.h"
@@ -82,7 +83,7 @@
 	long long root_inode;
 	unsigned short flags;
 	unsigned int fragments;
-	u64 lookup_table_start;
+	u64 lookup_table_start, xattr_id_table_start;
 	int err;
  
 	TRACE("Entered squashfs_fill_superblock\n");
@@ -143,7 +144,7 @@
 	 * Check if there's xattrs in the filesystem.  These are not
 	 * supported in this version, so warn that they will be ignored.
 	 */
-	if (le64_to_cpu(sblk->xattr_table_start) != SQUASHFS_INVALID_BLK)
+	if (le64_to_cpu(sblk->xattr_id_table_start) != SQUASHFS_INVALID_BLK)
 		ERROR("Xattrs in filesystem, these will be ignored\n");
  
 	/* Check the filesystem does not extend beyond the end of the
@@ -253,7 +254,7 @@
 allocate_lookup_table:
 	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
 	if (lookup_table_start == SQUASHFS_INVALID_BLK)
-		goto allocate_root;
+		goto allocate_xattr_table;
  
 	/* Allocate and read inode lookup table */
 	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
@@ -266,6 +267,19 @@
  
 	sb->s_export_op = &squashfs_export_ops;
  
+allocate_xattr_table:
+	xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
+	if (xattr_id_table_start == SQUASHFS_INVALID_BLK)
+		goto allocate_root;
+
+	/* Allocate and read xattr id lookup table */
+	msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
+		xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
+	if (IS_ERR(msblk->xattr_id_table)) {
+		err = PTR_ERR(msblk->xattr_id_table);
+		msblk->xattr_id_table = NULL;
+		goto failed_mount;
+	}
 allocate_root:
 	root = new_inode(sb);
 	if (!root) {
@@ -301,6 +315,7 @@
 	kfree(msblk->inode_lookup_table);
 	kfree(msblk->fragment_index);
 	kfree(msblk->id_table);
+	kfree(msblk->xattr_id_table);
 	kfree(sb->s_fs_info);
 	sb->s_fs_info = NULL;
 	kfree(sblk);
@@ -355,6 +370,7 @@
 		kfree(sbi->fragment_index);
 		kfree(sbi->meta_index);
 		kfree(sbi->inode_lookup_table);
+		kfree(sbi->xattr_id_table);
 		kfree(sb->s_fs_info);
 		sb->s_fs_info = NULL;
 	}
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2010
+ * Phillip Lougher <phillip@lougher.demon.co.uk>
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2,
+ * or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
+ *
+ * xattr_id.c
+ */
+
+/*
+ * This file implements code to map the 32-bit xattr id stored in the inode
+ * into the on disk location of the xattr data.
+ */
+
+#include <linux/fs.h>
+#include <linux/vfs.h>
+#include <linux/slab.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs_fs_i.h"
+#include "squashfs.h"
+
+/*
+ * Map xattr id using the xattr id look up table
+ */
+int squashfs_xattr_lookup(struct super_block *sb, unsigned int index,
+		int *count, int *size, long long *xattr)
+{
+	struct squashfs_sb_info *msblk = sb->s_fs_info;
+	int block = SQUASHFS_XATTR_BLOCK(index);
+	int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index);
+	u64 start_block = le64_to_cpu(msblk->xattr_id_table[block]);
+	struct squashfs_xattr_id id;
+	int err;
+
+	err = squashfs_read_metadata(sb, &id, &start_block, &offset,
+							sizeof(id));
+	if (err < 0)
+		return err;
+
+	*xattr = le64_to_cpu(id.xattr);
+	*size = le32_to_cpu(id.size);
+	*count = le32_to_cpu(id.count);
+	return 0;
+}
+
+
+/*
+ * Read uncompressed xattr id lookup table indexes from disk into memory
+ */
+__le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 start,
+		u64 *xattr_table_start, int *xattr_ids)
+{
+	unsigned int len;
+	__le64 *xid_table;
+	struct squashfs_xattr_id_table id_table;
+	int err;
+
+	err = squashfs_read_table(sb, &id_table, start, sizeof(id_table));
+	if (err < 0) {
+		ERROR("unable to read xattr id table\n");
+		return ERR_PTR(err);
+	}
+	*xattr_table_start = le64_to_cpu(id_table.xattr_table_start);
+	*xattr_ids = le32_to_cpu(id_table.xattr_ids);
+	len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
+
+	TRACE("In read_xattr_index_table, length %d\n", len);
+
+	/* Allocate xattr id lookup table indexes */
+	xid_table = kmalloc(len, GFP_KERNEL);
+	if (xid_table == NULL) {
+		ERROR("Failed to allocate xattr id index table\n");
+		return ERR_PTR(-ENOMEM);
+	}
+
+	err = squashfs_read_table(sb, xid_table, start + sizeof(id_table), len);
+	if (err < 0) {
+		ERROR("unable to read xattr id index table\n");
+		kfree(xid_table);
+		return ERR_PTR(err);
+	}
+
+	return xid_table;
+}
...	...	@@ -5,4 +5,5 @@
5	5	obj-$(CONFIG_SQUASHFS) += squashfs.o
6	6	squashfs-y += block.o cache.o dir.o export.o file.o fragment.o id.o inode.o
7	7	squashfs-y += namei.o super.o symlink.o zlib_wrapper.o decompressor.o
	8	+squashfs-y += xattr_id.o
...	...	@@ -73,6 +73,12 @@
73	73	unsigned int);
74	74	extern int squashfs_read_inode(struct inode *, long long);
75	75
	76	+/* xattr_id.c */
	77	+extern int squashfs_xattr_lookup(struct super_block , unsigned int, int ,
	78	+ int , long long );
	79	+extern __le64 squashfs_read_xattr_id_table(struct super_block , u64,
	80	+ u64 , int );
	81	+
76	82	/*
77	83	* Inodes, files and decompressor operations
78	84	*/
...	...	@@ -174,7 +174,25 @@
174	174
175	175	#define SQUASHFS_ID_BLOCK_BYTES(A) (SQUASHFS_ID_BLOCKS(A) *\
176	176	sizeof(u64))
	177	+/* xattr id lookup table defines */
	178	+#define SQUASHFS_XATTR_BYTES(A) ((A) * sizeof(struct squashfs_xattr_id))
177	179
	180	+#define SQUASHFS_XATTR_BLOCK(A) (SQUASHFS_XATTR_BYTES(A) / \
	181	+ SQUASHFS_METADATA_SIZE)
	182	+
	183	+#define SQUASHFS_XATTR_BLOCK_OFFSET(A) (SQUASHFS_XATTR_BYTES(A) % \
	184	+ SQUASHFS_METADATA_SIZE)
	185	+
	186	+#define SQUASHFS_XATTR_BLOCKS(A) ((SQUASHFS_XATTR_BYTES(A) + \
	187	+ SQUASHFS_METADATA_SIZE - 1) / \
	188	+ SQUASHFS_METADATA_SIZE)
	189	+
	190	+#define SQUASHFS_XATTR_BLOCK_BYTES(A) (SQUASHFS_XATTR_BLOCKS(A) *\
	191	+ sizeof(u64))
	192	+#define SQUASHFS_XATTR_BLK(A) ((unsigned int) ((A) >> 16))
	193	+
	194	+#define SQUASHFS_XATTR_OFFSET(A) ((unsigned int) ((A) & 0xffff))
	195	+
178	196	/* cached data constants for filesystem */
179	197	#define SQUASHFS_CACHED_BLKS 8
180	198
...	...	@@ -228,7 +246,7 @@
228	246	__le64 root_inode;
229	247	__le64 bytes_used;
230	248	__le64 id_table_start;
231		- __le64 xattr_table_start;
	249	+ __le64 xattr_id_table_start;
232	250	__le64 inode_table_start;
233	251	__le64 directory_table_start;
234	252	__le64 fragment_table_start;
...	...	@@ -375,6 +393,18 @@
375	393	__le64 start_block;
376	394	__le32 size;
377	395	unsigned int unused;
	396	+};
	397	+
	398	+struct squashfs_xattr_id {
	399	+ __le64 xattr;
	400	+ __le32 count;
	401	+ __le32 size;
	402	+};
	403	+
	404	+struct squashfs_xattr_id_table {
	405	+ __le64 xattr_table_start;
	406	+ __le32 xattr_ids;
	407	+ __le32 unused;
378	408	};
379	409
380	410	#endif
...	...	@@ -61,6 +61,7 @@
61	61	int next_meta_index;
62	62	__le64 *id_table;
63	63	__le64 *fragment_index;
	64	+ __le64 *xattr_id_table;
64	65	struct mutex read_data_mutex;
65	66	struct mutex meta_index_mutex;
66	67	struct meta_index *meta_index;
67	68
...	...	@@ -68,10 +69,12 @@
68	69	__le64 *inode_lookup_table;
69	70	u64 inode_table;
70	71	u64 directory_table;
	72	+ u64 xattr_table;
71	73	unsigned int block_size;
72	74	unsigned short block_log;
73	75	long long bytes_used;
74	76	unsigned int inodes;
	77	+ int xattr_ids;
75	78	};
76	79	#endif
...	...	@@ -36,6 +36,7 @@
36	36	#include <linux/init.h>
37	37	#include <linux/module.h>
38	38	#include <linux/magic.h>
	39	+#include <linux/xattr.h>
39	40
40	41	#include "squashfs_fs.h"
41	42	#include "squashfs_fs_sb.h"
...	...	@@ -82,7 +83,7 @@
82	83	long long root_inode;
83	84	unsigned short flags;
84	85	unsigned int fragments;
85		- u64 lookup_table_start;
	86	+ u64 lookup_table_start, xattr_id_table_start;
86	87	int err;
87	88
88	89	TRACE("Entered squashfs_fill_superblock\n");
...	...	@@ -143,7 +144,7 @@
143	144	* Check if there's xattrs in the filesystem. These are not
144	145	* supported in this version, so warn that they will be ignored.
145	146	*/
146		- if (le64_to_cpu(sblk->xattr_table_start) != SQUASHFS_INVALID_BLK)
	147	+ if (le64_to_cpu(sblk->xattr_id_table_start) != SQUASHFS_INVALID_BLK)
147	148	ERROR("Xattrs in filesystem, these will be ignored\n");
148	149
149	150	/* Check the filesystem does not extend beyond the end of the
...	...	@@ -253,7 +254,7 @@
253	254	allocate_lookup_table:
254	255	lookup_table_start = le64_to_cpu(sblk->lookup_table_start);
255	256	if (lookup_table_start == SQUASHFS_INVALID_BLK)
256		- goto allocate_root;
	257	+ goto allocate_xattr_table;
257	258
258	259	/* Allocate and read inode lookup table */
259	260	msblk->inode_lookup_table = squashfs_read_inode_lookup_table(sb,
...	...	@@ -266,6 +267,19 @@
266	267
267	268	sb->s_export_op = &squashfs_export_ops;
268	269
	270	+allocate_xattr_table:
	271	+ xattr_id_table_start = le64_to_cpu(sblk->xattr_id_table_start);
	272	+ if (xattr_id_table_start == SQUASHFS_INVALID_BLK)
	273	+ goto allocate_root;
	274	+
	275	+ /* Allocate and read xattr id lookup table */
	276	+ msblk->xattr_id_table = squashfs_read_xattr_id_table(sb,
	277	+ xattr_id_table_start, &msblk->xattr_table, &msblk->xattr_ids);
	278	+ if (IS_ERR(msblk->xattr_id_table)) {
	279	+ err = PTR_ERR(msblk->xattr_id_table);
	280	+ msblk->xattr_id_table = NULL;
	281	+ goto failed_mount;
	282	+ }
269	283	allocate_root:
270	284	root = new_inode(sb);
271	285	if (!root) {
...	...	@@ -301,6 +315,7 @@
301	315	kfree(msblk->inode_lookup_table);
302	316	kfree(msblk->fragment_index);
303	317	kfree(msblk->id_table);
	318	+ kfree(msblk->xattr_id_table);
304	319	kfree(sb->s_fs_info);
305	320	sb->s_fs_info = NULL;
306	321	kfree(sblk);
...	...	@@ -355,6 +370,7 @@
355	370	kfree(sbi->fragment_index);
356	371	kfree(sbi->meta_index);
357	372	kfree(sbi->inode_lookup_table);
	373	+ kfree(sbi->xattr_id_table);
358	374	kfree(sb->s_fs_info);
359	375	sb->s_fs_info = NULL;
360	376	}
	1	+/*
	2	+ * Squashfs - a compressed read only filesystem for Linux
	3	+ *
	4	+ * Copyright (c) 2010
	5	+ * Phillip Lougher <phillip@lougher.demon.co.uk>
	6	+ *
	7	+ * This program is free software; you can redistribute it and/or
	8	+ * modify it under the terms of the GNU General Public License
	9	+ * as published by the Free Software Foundation; either version 2,
	10	+ * or (at your option) any later version.
	11	+ *
	12	+ * This program is distributed in the hope that it will be useful,
	13	+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	+ * GNU General Public License for more details.
	16	+ *
	17	+ * You should have received a copy of the GNU General Public License
	18	+ * along with this program; if not, write to the Free Software
	19	+ * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
	20	+ *
	21	+ * xattr_id.c
	22	+ */
	23	+
	24	+/*
	25	+ * This file implements code to map the 32-bit xattr id stored in the inode
	26	+ * into the on disk location of the xattr data.
	27	+ */
	28	+
	29	+#include <linux/fs.h>
	30	+#include <linux/vfs.h>
	31	+#include <linux/slab.h>
	32	+
	33	+#include "squashfs_fs.h"
	34	+#include "squashfs_fs_sb.h"
	35	+#include "squashfs_fs_i.h"
	36	+#include "squashfs.h"
	37	+
	38	+/*
	39	+ * Map xattr id using the xattr id look up table
	40	+ */
	41	+int squashfs_xattr_lookup(struct super_block *sb, unsigned int index,
	42	+ int count, int size, long long *xattr)
	43	+{
	44	+ struct squashfs_sb_info *msblk = sb->s_fs_info;
	45	+ int block = SQUASHFS_XATTR_BLOCK(index);
	46	+ int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index);
	47	+ u64 start_block = le64_to_cpu(msblk->xattr_id_table[block]);
	48	+ struct squashfs_xattr_id id;
	49	+ int err;
	50	+
	51	+ err = squashfs_read_metadata(sb, &id, &start_block, &offset,
	52	+ sizeof(id));
	53	+ if (err < 0)
	54	+ return err;
	55	+
	56	+ *xattr = le64_to_cpu(id.xattr);
	57	+ *size = le32_to_cpu(id.size);
	58	+ *count = le32_to_cpu(id.count);
	59	+ return 0;
	60	+}
	61	+
	62	+
	63	+/*
	64	+ * Read uncompressed xattr id lookup table indexes from disk into memory
	65	+ */
	66	+__le64 squashfs_read_xattr_id_table(struct super_block sb, u64 start,
	67	+ u64 xattr_table_start, int xattr_ids)
	68	+{
	69	+ unsigned int len;
	70	+ __le64 *xid_table;
	71	+ struct squashfs_xattr_id_table id_table;
	72	+ int err;
	73	+
	74	+ err = squashfs_read_table(sb, &id_table, start, sizeof(id_table));
	75	+ if (err < 0) {
	76	+ ERROR("unable to read xattr id table\n");
	77	+ return ERR_PTR(err);
	78	+ }
	79	+ *xattr_table_start = le64_to_cpu(id_table.xattr_table_start);
	80	+ *xattr_ids = le32_to_cpu(id_table.xattr_ids);
	81	+ len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
	82	+
	83	+ TRACE("In read_xattr_index_table, length %d\n", len);
	84	+
	85	+ /* Allocate xattr id lookup table indexes */
	86	+ xid_table = kmalloc(len, GFP_KERNEL);
	87	+ if (xid_table == NULL) {
	88	+ ERROR("Failed to allocate xattr id index table\n");
	89	+ return ERR_PTR(-ENOMEM);
	90	+ }
	91	+
	92	+ err = squashfs_read_table(sb, xid_table, start + sizeof(id_table), len);
	93	+ if (err < 0) {
	94	+ ERROR("unable to read xattr id index table\n");
	95	+ kfree(xid_table);
	96	+ return ERR_PTR(err);
	97	+ }
	98	+
	99	+ return xid_table;
	100	+}