[RFC PATCH 2/3] erofs-utils: fuse: export erofs_xattr_foreach
Gao Xiang
xiang at kernel.org
Thu Aug 4 05:46:24 AEST 2022
Hi Yong,
On Wed, Aug 03, 2022 at 10:22:22PM +0800, Sheng Yong wrote:
> This patch exports erofs_xattr_foreach() to iterate all xattrs.
> Each xattr entry is handled by operations defined in `struct
> xattr_iter_ops'.
>
Thanks for your hard effort!
Could we import in-kernel xattr implementation with verify enabled
(or unify these implementations) instead?
( Jianan ported a kernel implementation before, could we enhance
it with verification?
https://lore.kernel.org/r/20220728120910.61636-1-jnhuang@linux.alibaba.com)
Thanks,
Gao Xiang
> Signed-off-by: Sheng Yong <shengyong at oppo.com>
> ---
> fsck/main.c | 83 ++++------------------------
> include/erofs/xattr.h | 7 ++-
> lib/xattr.c | 123 ++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 139 insertions(+), 74 deletions(-)
>
> diff --git a/fsck/main.c b/fsck/main.c
> index 5a2f659..237ccc1 100644
> --- a/fsck/main.c
> +++ b/fsck/main.c
> @@ -14,6 +14,7 @@
> #include "erofs/compress.h"
> #include "erofs/decompress.h"
> #include "erofs/dir.h"
> +#include "erofs/xattr.h"
>
> static int erofsfsck_check_inode(erofs_nid_t pnid, erofs_nid_t nid);
>
> @@ -283,82 +284,18 @@ static int erofs_check_sb_chksum(void)
> return 0;
> }
>
> -static int erofs_verify_xattr(struct erofs_inode *inode)
> +static int erofs_verify_xattr_entry(const struct erofs_xattr_entry *entry)
> {
> - unsigned int xattr_hdr_size = sizeof(struct erofs_xattr_ibody_header);
> - unsigned int xattr_entry_size = sizeof(struct erofs_xattr_entry);
> - erofs_off_t addr;
> - unsigned int ofs, xattr_shared_count;
> - struct erofs_xattr_ibody_header *ih;
> - struct erofs_xattr_entry *entry;
> - int i, remaining = inode->xattr_isize, ret = 0;
> - char buf[EROFS_BLKSIZ];
> -
> - if (inode->xattr_isize == xattr_hdr_size) {
> - erofs_err("xattr_isize %d of nid %llu is not supported yet",
> - inode->xattr_isize, inode->nid | 0ULL);
> - ret = -EFSCORRUPTED;
> - goto out;
> - } else if (inode->xattr_isize < xattr_hdr_size) {
> - if (inode->xattr_isize) {
> - erofs_err("bogus xattr ibody @ nid %llu",
> - inode->nid | 0ULL);
> - ret = -EFSCORRUPTED;
> - goto out;
> - }
> - }
> -
> - addr = iloc(inode->nid) + inode->inode_isize;
> - ret = dev_read(0, buf, addr, xattr_hdr_size);
> - if (ret < 0) {
> - erofs_err("failed to read xattr header @ nid %llu: %d",
> - inode->nid | 0ULL, ret);
> - goto out;
> - }
> - ih = (struct erofs_xattr_ibody_header *)buf;
> - xattr_shared_count = ih->h_shared_count;
> -
> - ofs = erofs_blkoff(addr) + xattr_hdr_size;
> - addr += xattr_hdr_size;
> - remaining -= xattr_hdr_size;
> - for (i = 0; i < xattr_shared_count; ++i) {
> - if (ofs >= EROFS_BLKSIZ) {
> - if (ofs != EROFS_BLKSIZ) {
> - erofs_err("unaligned xattr entry in xattr shared area @ nid %llu",
> - inode->nid | 0ULL);
> - ret = -EFSCORRUPTED;
> - goto out;
> - }
> - ofs = 0;
> - }
> - ofs += xattr_entry_size;
> - addr += xattr_entry_size;
> - remaining -= xattr_entry_size;
> - }
> -
> - while (remaining > 0) {
> - unsigned int entry_sz;
> + return 0;
> +}
>
> - ret = dev_read(0, buf, addr, xattr_entry_size);
> - if (ret) {
> - erofs_err("failed to read xattr entry @ nid %llu: %d",
> - inode->nid | 0ULL, ret);
> - goto out;
> - }
> +struct xattr_iter_ops erofs_verify_xattr_ops = {
> + .verify = erofs_verify_xattr_entry,
> +};
>
> - entry = (struct erofs_xattr_entry *)buf;
> - entry_sz = erofs_xattr_entry_size(entry);
> - if (remaining < entry_sz) {
> - erofs_err("xattr on-disk corruption: xattr entry beyond xattr_isize @ nid %llu",
> - inode->nid | 0ULL);
> - ret = -EFSCORRUPTED;
> - goto out;
> - }
> - addr += entry_sz;
> - remaining -= entry_sz;
> - }
> -out:
> - return ret;
> +static int erofs_verify_xattr(struct erofs_inode *inode)
> +{
> + return erofs_xattr_foreach(inode, &erofs_verify_xattr_ops, NULL);
> }
>
> static int erofs_verify_inode_data(struct erofs_inode *inode, int outfd)
> diff --git a/include/erofs/xattr.h b/include/erofs/xattr.h
> index 226e984..c592d47 100644
> --- a/include/erofs/xattr.h
> +++ b/include/erofs/xattr.h
> @@ -45,10 +45,15 @@ extern "C"
> #define XATTR_NAME_POSIX_ACL_DEFAULT "system.posix_acl_default"
> #endif
>
> +struct xattr_iter_ops {
> + int (*verify)(const struct erofs_xattr_entry *entry);
> +};
> +
> int erofs_prepare_xattr_ibody(struct erofs_inode *inode);
> char *erofs_export_xattr_ibody(struct list_head *ixattrs, unsigned int size);
> int erofs_build_shared_xattrs_from_path(const char *path);
> -
> +int erofs_xattr_foreach(struct erofs_inode *vi, struct xattr_iter_ops *ops,
> + void *data);
> #ifdef __cplusplus
> }
> #endif
> diff --git a/lib/xattr.c b/lib/xattr.c
> index c8ce278..92c155d 100644
> --- a/lib/xattr.c
> +++ b/lib/xattr.c
> @@ -714,3 +714,126 @@ char *erofs_export_xattr_ibody(struct list_head *ixattrs, unsigned int size)
> DBG_BUGON(p > size);
> return buf;
> }
> +
> +static struct erofs_xattr_entry *read_xattr_entry(erofs_blk_t addr,
> + char *buf, size_t size)
> +{
> + struct erofs_xattr_entry *entry;
> + size_t entry_sz = sizeof(struct erofs_xattr_entry);
> + int ret;
> +
> + if (size < entry_sz)
> + return ERR_PTR(-ERANGE);
> +
> + ret = dev_read(0, buf, addr, entry_sz);
> + if (ret) {
> + erofs_err("failed to read xattr entry at addr %x: %d",
> + addr, ret);
> + return ERR_PTR(ret);
> + }
> +
> + entry = (struct erofs_xattr_entry *)buf;
> + entry_sz = erofs_xattr_entry_size(entry);
> + if (size < entry_sz)
> + return ERR_PTR(-ERANGE);
> +
> + ret = dev_read(0, buf, addr, entry_sz);
> + if (ret) {
> + erofs_err("failed to read xattr entry at addr %x: %d",
> + addr, ret);
> + return ERR_PTR(ret);
> + }
> +
> + return entry;
> +}
> +
> +int erofs_xattr_foreach(struct erofs_inode *vi, struct xattr_iter_ops *ops,
> + void *data)
> +{
> + unsigned int xattr_hdr_size = sizeof(struct erofs_xattr_ibody_header);
> + unsigned int xattr_entry_size = sizeof(struct erofs_xattr_entry);
> + erofs_off_t addr;
> + unsigned int ofs, xattr_shared_count;
> + struct erofs_xattr_ibody_header *ih;
> + struct erofs_xattr_entry *entry;
> + int i, remaining = vi->xattr_isize, ret = 0;
> + char buf[EROFS_BLKSIZ];
> +
> + if (vi->xattr_isize == xattr_hdr_size) {
> + erofs_err("xattr_isize %d of nid %llu is not supported yet",
> + vi->xattr_isize, vi->nid | 0ULL);
> + return -EFSCORRUPTED;
> + } else if (vi->xattr_isize < xattr_hdr_size) {
> + if (vi->xattr_isize) {
> + erofs_err("bogus xattr ibody @ nid %llu",
> + vi->nid | 0ULL);
> + return -EFSCORRUPTED;
> + }
> + }
> +
> + addr = iloc(vi->nid) + vi->inode_isize;
> + ret = dev_read(0, buf, addr, xattr_hdr_size);
> + if (ret < 0) {
> + erofs_err("failed to read xattr header @ nid %llu: %d",
> + vi->nid | 0ULL, ret);
> + return ret;
> + }
> + ih = (struct erofs_xattr_ibody_header *)buf;
> + xattr_shared_count = ih->h_shared_count;
> +
> + ofs = erofs_blkoff(addr) + xattr_hdr_size;
> + addr += xattr_hdr_size;
> + ret = dev_read(0, buf, addr, xattr_entry_size * xattr_shared_count);
> + remaining -= xattr_hdr_size;
> + for (i = 0; i < xattr_shared_count; ++i) {
> + unsigned int xattr_id;
> + erofs_blk_t xattr_addr;
> + char tmp[EROFS_BLKSIZ];
> +
> + if (ofs >= EROFS_BLKSIZ) {
> + if (ofs != EROFS_BLKSIZ) {
> + erofs_err("unaligned xattr entry in xattr shared area @ nid %llu",
> + vi->nid | 0ULL);
> + return -EFSCORRUPTED;
> + }
> + ofs = 0;
> + }
> +
> + xattr_id = le32_to_cpu(*((__le32 *)buf + i));
> + xattr_addr = sbi.xattr_blkaddr * EROFS_BLKSIZ + 4 * xattr_id;
> +
> + entry = read_xattr_entry(xattr_addr, tmp, EROFS_BLKSIZ);
> + if (IS_ERR(entry))
> + return PTR_ERR(entry);
> +
> + if (ops->verify) {
> + ret = ops->verify(entry);
> + if (ret < 0)
> + return ret;
> + }
> +
> + ofs += xattr_entry_size;
> + addr += xattr_entry_size;
> + remaining -= xattr_entry_size;
> + }
> +
> + while (remaining > 0) {
> + unsigned int entry_sz;
> +
> + entry = read_xattr_entry(addr, buf, EROFS_BLKSIZ);
> + if (IS_ERR(entry))
> + return PTR_ERR(entry);
> + entry_sz = erofs_xattr_entry_size(entry);
> +
> + if (ops->verify) {
> + ret = ops->verify(entry);
> + if (ret < 0)
> + return ret;
> + }
> + addr += entry_sz;
> + remaining -= entry_sz;
> + }
> +
> + return ret;
> +
> +}
> --
> 2.25.1
>
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