erofs: enable long extended attribute name prefixes

Let's enable long xattr name prefix feature. Old kernels will just ignore / skip such extended attributes so that in case you don't want to mount such images. Add another incompatible feature as an option for this. Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com>
intel-lab-lkp · Apr 7, 2023 · 8cd5bbc · 8cd5bbc
1 parent fe228ab
commit 8cd5bbc
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Showing 3 changed files with 12 additions and 1 deletion.
diff --git a/fs/erofs/erofs_fs.h b/fs/erofs/erofs_fs.h
@@ -27,6 +27,7 @@
 #define EROFS_FEATURE_INCOMPAT_ZTAILPACKING	0x00000010
 #define EROFS_FEATURE_INCOMPAT_FRAGMENTS	0x00000020
 #define EROFS_FEATURE_INCOMPAT_DEDUPE		0x00000020
+#define EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES	0x00000040
 #define EROFS_ALL_FEATURE_INCOMPAT		\
 	(EROFS_FEATURE_INCOMPAT_ZERO_PADDING | \
 	 EROFS_FEATURE_INCOMPAT_COMPR_CFGS | \
@@ -36,7 +37,8 @@
 	 EROFS_FEATURE_INCOMPAT_COMPR_HEAD2 | \
 	 EROFS_FEATURE_INCOMPAT_ZTAILPACKING | \
 	 EROFS_FEATURE_INCOMPAT_FRAGMENTS | \
-	 EROFS_FEATURE_INCOMPAT_DEDUPE)
+	 EROFS_FEATURE_INCOMPAT_DEDUPE | \
+	 EROFS_FEATURE_INCOMPAT_XATTR_PREFIXES)
 
 #define EROFS_SB_EXTSLOT_SIZE	16
 

diff --git a/fs/erofs/internal.h b/fs/erofs/internal.h
@@ -285,6 +285,7 @@ EROFS_FEATURE_FUNCS(compr_head2, incompat, INCOMPAT_COMPR_HEAD2)
 EROFS_FEATURE_FUNCS(ztailpacking, incompat, INCOMPAT_ZTAILPACKING)
 EROFS_FEATURE_FUNCS(fragments, incompat, INCOMPAT_FRAGMENTS)
 EROFS_FEATURE_FUNCS(dedupe, incompat, INCOMPAT_DEDUPE)
+EROFS_FEATURE_FUNCS(xattr_prefixes, incompat, INCOMPAT_XATTR_PREFIXES)
 EROFS_FEATURE_FUNCS(sb_chksum, compat, COMPAT_SB_CHKSUM)
 
 /* atomic flag definitions */

diff --git a/fs/erofs/super.c b/fs/erofs/super.c
@@ -391,6 +391,9 @@ static int erofs_read_superblock(struct super_block *sb)
 	sbi->packed_nid = le64_to_cpu(dsb->packed_nid);
 	sbi->inos = le64_to_cpu(dsb->inos);
 
+	sbi->xattr_prefix_start = le32_to_cpu(dsb->xattr_prefix_start);
+	sbi->xattr_prefix_count = dsb->xattr_prefix_count;
+
 	sbi->build_time = le64_to_cpu(dsb->build_time);
 	sbi->build_time_nsec = le32_to_cpu(dsb->build_time_nsec);
 
@@ -822,6 +825,10 @@ static int erofs_fc_fill_super(struct super_block *sb, struct fs_context *fc)
 	if (err)
 		return err;
 
+	err = erofs_xattr_prefixes_init(sb);
+	if (err)
+		return err;
+
 	err = erofs_register_sysfs(sb);
 	if (err)
 		return err;
@@ -981,6 +988,7 @@ static void erofs_put_super(struct super_block *sb)
 
 	erofs_unregister_sysfs(sb);
 	erofs_shrinker_unregister(sb);
+	erofs_xattr_prefixes_cleanup(sb);
 #ifdef CONFIG_EROFS_FS_ZIP
 	iput(sbi->managed_cache);
 	sbi->managed_cache = NULL;