Messages in this thread Patch in this message | | | From | Jingbo Xu <> | Subject | [PATCH v2 6/7] erofs: handle long xattr name prefixes properly | Date | Mon, 10 Apr 2023 14:39:18 +0800 |
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Make .{list,get}xattr routines adapted to long xattr name prefixes. When the bit 7 of erofs_xattr_entry.e_name_index is set, it indicates that it refers to a long xattr name prefix.
Signed-off-by: Jingbo Xu <jefflexu@linux.alibaba.com> --- v2: remove "idx" temporary variable (Gao Xiang) --- fs/erofs/xattr.c | 57 +++++++++++++++++++++++++++++++++++++++++------- 1 file changed, 49 insertions(+), 8 deletions(-)
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index 684571e83a2c..4ad290b6acb7 100644 --- a/fs/erofs/xattr.c +++ b/fs/erofs/xattr.c @@ -301,11 +301,38 @@ struct getxattr_iter { struct qstr name; }; +static int erofs_xattr_long_entrymatch(struct getxattr_iter *it, + struct erofs_xattr_entry *entry) +{ + struct erofs_sb_info *sbi = EROFS_SB(it->it.sb); + struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes + + (entry->e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); + + if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) + return -ENOATTR; + + if (it->index != pf->prefix->base_index) + return -ENOATTR; + + if (strncmp(it->name.name, pf->prefix->infix, pf->infix_len)) + return -ENOATTR; + + it->name.name += pf->infix_len; + it->name.len -= pf->infix_len; + if (it->name.len != entry->e_name_len) + return -ENOATTR; + return 0; +} + static int xattr_entrymatch(struct xattr_iter *_it, struct erofs_xattr_entry *entry) { struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it); + /* should also match the infix for long name prefixes */ + if (entry->e_name_index & EROFS_XATTR_LONG_PREFIX) + return erofs_xattr_long_entrymatch(it, entry); + return (it->index != entry->e_name_index || it->name.len != entry->e_name_len) ? -ENOATTR : 0; } @@ -487,12 +514,24 @@ static int xattr_entrylist(struct xattr_iter *_it, { struct listxattr_iter *it = container_of(_it, struct listxattr_iter, it); - unsigned int prefix_len; - const char *prefix; - - const struct xattr_handler *h = - erofs_xattr_handler(entry->e_name_index); + unsigned int base_index = entry->e_name_index; + unsigned int prefix_len, infix_len = 0; + const char *prefix, *infix = NULL; + const struct xattr_handler *h; + + if (entry->e_name_index & EROFS_XATTR_LONG_PREFIX) { + struct erofs_sb_info *sbi = EROFS_SB(_it->sb); + struct erofs_xattr_prefix_item *pf = sbi->xattr_prefixes + + (entry->e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); + + if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) + return 1; + infix = pf->prefix->infix; + infix_len = pf->infix_len; + base_index = pf->prefix->base_index; + } + h = erofs_xattr_handler(base_index); if (!h || (h->list && !h->list(it->dentry))) return 1; @@ -500,16 +539,18 @@ static int xattr_entrylist(struct xattr_iter *_it, prefix_len = strlen(prefix); if (!it->buffer) { - it->buffer_ofs += prefix_len + entry->e_name_len + 1; + it->buffer_ofs += prefix_len + infix_len + + entry->e_name_len + 1; return 1; } - if (it->buffer_ofs + prefix_len + if (it->buffer_ofs + prefix_len + infix_len + + entry->e_name_len + 1 > it->buffer_size) return -ERANGE; memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len); - it->buffer_ofs += prefix_len; + memcpy(it->buffer + it->buffer_ofs + prefix_len, infix, infix_len); + it->buffer_ofs += prefix_len + infix_len; return 0; } -- 2.19.1.6.gb485710b
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