Commit 9e382914 authored by Jingbo Xu's avatar Jingbo Xu Committed by Gao Xiang
Browse files

erofs: add helpers to load long xattr name prefixes 



Long xattr name prefixes will be scanned upon mounting and the in-memory
long xattr name prefix array will be initialized accordingly.

Signed-off-by: default avatarJingbo Xu <jefflexu@linux.alibaba.com>
Reviewed-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
Acked-by: default avatarChao Yu <chao@kernel.org>
Link: https://lore.kernel.org/r/20230407141710.113882-6-jefflexu@linux.alibaba.com


Signed-off-by: default avatarGao Xiang <hsiangkao@linux.alibaba.com>
parent b3bfcb9d

fs/erofs/internal.h

+10 −0
Original line number Diff line number Diff line
@@ -117,6 +117,11 @@ struct erofs_fscache { 
	char *name;

};



struct erofs_xattr_prefix_item {

	struct erofs_xattr_long_prefix *prefix;

	u8 infix_len;

};



struct erofs_sb_info {

	struct erofs_mount_opts opt;	/* options */

#ifdef CONFIG_EROFS_FS_ZIP
@@ -145,6 +150,9 @@ struct erofs_sb_info { 
	u32 meta_blkaddr;

#ifdef CONFIG_EROFS_FS_XATTR

	u32 xattr_blkaddr;

	u32 xattr_prefix_start;

	u8 xattr_prefix_count;

	struct erofs_xattr_prefix_item *xattr_prefixes;

#endif

	u16 device_id_mask;	/* valid bits of device id to be used */
@@ -440,6 +448,8 @@ extern const struct iomap_ops z_erofs_iomap_report_ops; 
#define EROFS_REG_COOKIE_SHARE		0x0001

#define EROFS_REG_COOKIE_NEED_NOEXIST	0x0002



void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,

			  erofs_off_t *offset, int *lengthp);

void erofs_unmap_metabuf(struct erofs_buf *buf);

void erofs_put_metabuf(struct erofs_buf *buf);

void *erofs_bread(struct erofs_buf *buf, erofs_blk_t blkaddr,

fs/erofs/super.c

+3 −3
Original line number Diff line number Diff line
@@ -126,9 +126,8 @@ static bool check_layout_compatibility(struct super_block *sb, 
	return true;

}



#ifdef CONFIG_EROFS_FS_ZIP

/* read variable-sized metadata, offset will be aligned by 4-byte */

static void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,

void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf,

			  erofs_off_t *offset, int *lengthp)

{

	u8 *buffer, *ptr;
@@ -162,6 +161,7 @@ static void *erofs_read_metadata(struct super_block *sb, struct erofs_buf *buf, 
	return buffer;

}



#ifdef CONFIG_EROFS_FS_ZIP

static int erofs_load_compr_cfgs(struct super_block *sb,

				 struct erofs_super_block *dsb)

{

fs/erofs/xattr.c

+56 −0
Original line number Diff line number Diff line
@@ -610,6 +610,62 @@ ssize_t erofs_listxattr(struct dentry *dentry, 
	return ret;

}



void erofs_xattr_prefixes_cleanup(struct super_block *sb)

{

	struct erofs_sb_info *sbi = EROFS_SB(sb);

	int i;



	if (sbi->xattr_prefixes) {

		for (i = 0; i < sbi->xattr_prefix_count; i++)

			kfree(sbi->xattr_prefixes[i].prefix);

		kfree(sbi->xattr_prefixes);

		sbi->xattr_prefixes = NULL;

	}

}



int erofs_xattr_prefixes_init(struct super_block *sb)

{

	struct erofs_sb_info *sbi = EROFS_SB(sb);

	struct erofs_buf buf = __EROFS_BUF_INITIALIZER;

	erofs_off_t pos = (erofs_off_t)sbi->xattr_prefix_start << 2;

	struct erofs_xattr_prefix_item *pfs;

	int ret = 0, i, len;



	if (!sbi->xattr_prefix_count)

		return 0;



	pfs = kzalloc(sbi->xattr_prefix_count * sizeof(*pfs), GFP_KERNEL);

	if (!pfs)

		return -ENOMEM;



	if (erofs_sb_has_fragments(sbi))

		buf.inode = sbi->packed_inode;

	else

		erofs_init_metabuf(&buf, sb);



	for (i = 0; i < sbi->xattr_prefix_count; i++) {

		void *ptr = erofs_read_metadata(sb, &buf, &pos, &len);



		if (IS_ERR(ptr)) {

			ret = PTR_ERR(ptr);

			break;

		} else if (len < sizeof(*pfs->prefix) ||

			   len > EROFS_NAME_LEN + sizeof(*pfs->prefix)) {

			kfree(ptr);

			ret = -EFSCORRUPTED;

			break;

		}

		pfs[i].prefix = ptr;

		pfs[i].infix_len = len - sizeof(struct erofs_xattr_long_prefix);

	}



	erofs_put_metabuf(&buf);

	sbi->xattr_prefixes = pfs;

	if (ret)

		erofs_xattr_prefixes_cleanup(sb);

	return ret;

}



#ifdef CONFIG_EROFS_FS_POSIX_ACL

struct posix_acl *erofs_get_acl(struct inode *inode, int type, bool rcu)

{

fs/erofs/xattr.h

+4 −0
Original line number Diff line number Diff line
@@ -40,9 +40,13 @@ static inline const struct xattr_handler *erofs_xattr_handler(unsigned int idx) 


extern const struct xattr_handler *erofs_xattr_handlers[];



int erofs_xattr_prefixes_init(struct super_block *sb);

void erofs_xattr_prefixes_cleanup(struct super_block *sb);

int erofs_getxattr(struct inode *, int, const char *, void *, size_t);

ssize_t erofs_listxattr(struct dentry *, char *, size_t);

#else

static inline int erofs_xattr_prefixes_init(struct super_block *sb) { return 0; }

static inline void erofs_xattr_prefixes_cleanup(struct super_block *sb) {}

static inline int erofs_getxattr(struct inode *inode, int index,

				 const char *name, void *buffer,

				 size_t buffer_size)