There's a callback styled xattr parser, i.e. xattr_foreach(), which is shared among listxattr and getxattr. Convert it to two separate xattr parsers for listxattr and getxattr.
Signed-off-by: Jingbo Xu <[email protected]> --- fs/erofs/xattr.c | 389 +++++++++++++++++++++-------------------------- 1 file changed, 170 insertions(+), 219 deletions(-) diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index 435146628eed..111735fb6fbc 100644 --- a/fs/erofs/xattr.c +++ b/fs/erofs/xattr.c @@ -12,7 +12,7 @@ struct erofs_xattr_iter { struct erofs_buf buf; void *kaddr; erofs_blk_t blkaddr; - unsigned int ofs; + unsigned int ofs, t_ofs; char *buffer; int buffer_size, buffer_ofs; @@ -21,6 +21,7 @@ struct erofs_xattr_iter { struct qstr name; struct dentry *dentry; struct inode *inode; + unsigned int remaining; /* size of inline xattrs to be iterated */ bool getxattr; }; @@ -46,6 +47,28 @@ static inline int erofs_xattr_iter_fixup_aligned(struct erofs_xattr_iter *it) return erofs_xattr_iter_fixup(it); } +static int erofs_xattr_iter_prep(struct erofs_xattr_iter *it) +{ + unsigned int entry_sz; + int err; + + err = erofs_xattr_iter_fixup(it); + if (err) + return err; + + entry_sz = erofs_xattr_entry_size(it->kaddr + it->ofs); + it->t_ofs = it->ofs + entry_sz; + if (it->remaining) { + /* xattr on-disk corruption: xattr entry beyond xattr_isize */ + if (it->remaining < entry_sz) { + DBG_BUGON(1); + return -EFSCORRUPTED; + } + it->remaining -= entry_sz; + } + return 0; +} + static int erofs_init_inode_xattrs(struct inode *inode) { struct erofs_inode *const vi = EROFS_I(inode); @@ -144,183 +167,6 @@ static int erofs_init_inode_xattrs(struct inode *inode) return ret; } -/* - * the general idea for these return values is - * if 0 is returned, go on processing the current xattr; - * 1 (> 0) is returned, skip this round to process the next xattr; - * -err (< 0) is returned, an error (maybe ENOXATTR) occurred - * and need to be handled - */ -struct xattr_iter_handlers { - int (*entry)(struct erofs_xattr_iter *it, struct erofs_xattr_entry *entry); - int (*name)(struct erofs_xattr_iter *it, unsigned int processed, char *buf, - unsigned int len); - int (*alloc_buffer)(struct erofs_xattr_iter *it, unsigned int value_sz); - void (*value)(struct erofs_xattr_iter *it, unsigned int processed, char *buf, - unsigned int len); -}; - -/* - * Regardless of success or failure, `xattr_foreach' will end up with - * `ofs' pointing to the next xattr item rather than an arbitrary position. - */ -static int xattr_foreach(struct erofs_xattr_iter *it, - const struct xattr_iter_handlers *op, - unsigned int *tlimit) -{ - struct erofs_xattr_entry entry; - unsigned int value_sz, processed, slice; - int err; - - /* 0. fixup blkaddr, ofs, ipage */ - err = erofs_xattr_iter_fixup(it); - if (err) - return err; - - /* - * 1. read xattr entry to the memory, - * since we do EROFS_XATTR_ALIGN - * therefore entry should be in the page - */ - entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs); - if (tlimit) { - unsigned int entry_sz = erofs_xattr_entry_size(&entry); - - /* xattr on-disk corruption: xattr entry beyond xattr_isize */ - if (*tlimit < entry_sz) { - DBG_BUGON(1); - return -EFSCORRUPTED; - } - *tlimit -= entry_sz; - } - - it->ofs += sizeof(struct erofs_xattr_entry); - value_sz = le16_to_cpu(entry.e_value_size); - - /* handle entry */ - err = op->entry(it, &entry); - if (err) { - it->ofs += entry.e_name_len + value_sz; - goto out; - } - - /* 2. handle xattr name (ofs will finally be at the end of name) */ - processed = 0; - - while (processed < entry.e_name_len) { - err = erofs_xattr_iter_fixup_aligned(it); - if (err) - goto out; - - slice = min_t(unsigned int, it->sb->s_blocksize - it->ofs, - entry.e_name_len - processed); - - /* handle name */ - err = op->name(it, processed, it->kaddr + it->ofs, slice); - if (err) { - it->ofs += entry.e_name_len - processed + value_sz; - goto out; - } - - it->ofs += slice; - processed += slice; - } - - /* 3. handle xattr value */ - processed = 0; - - if (op->alloc_buffer) { - err = op->alloc_buffer(it, value_sz); - if (err) { - it->ofs += value_sz; - goto out; - } - } - - while (processed < value_sz) { - err = erofs_xattr_iter_fixup_aligned(it); - if (err) - goto out; - - slice = min_t(unsigned int, it->sb->s_blocksize - it->ofs, - value_sz - processed); - op->value(it, processed, it->kaddr + it->ofs, slice); - it->ofs += slice; - processed += slice; - } - -out: - /* xattrs should be 4-byte aligned (on-disk constraint) */ - it->ofs = EROFS_XATTR_ALIGN(it->ofs); - return err < 0 ? err : 0; -} - -static int erofs_xattr_long_entrymatch(struct erofs_xattr_iter *it, - struct erofs_xattr_entry *entry) -{ - 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 -ENOATTR; - - if (it->index != pf->prefix->base_index || - it->name.len != entry->e_name_len + pf->infix_len) - return -ENOATTR; - - if (memcmp(it->name.name, pf->prefix->infix, pf->infix_len)) - return -ENOATTR; - - it->infix_len = pf->infix_len; - return 0; -} - -static int xattr_entrymatch(struct erofs_xattr_iter *it, - struct erofs_xattr_entry *entry) -{ - /* 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); - - if (it->index != entry->e_name_index || - it->name.len != entry->e_name_len) - return -ENOATTR; - it->infix_len = 0; - return 0; -} - -static int xattr_namematch(struct erofs_xattr_iter *it, - unsigned int processed, char *buf, unsigned int len) -{ - if (memcmp(buf, it->name.name + it->infix_len + processed, len)) - return -ENOATTR; - return 0; -} - -static int xattr_checkbuffer(struct erofs_xattr_iter *it, - unsigned int value_sz) -{ - int err = it->buffer_size < value_sz ? -ERANGE : 0; - - it->buffer_ofs = value_sz; - return !it->buffer ? 1 : err; -} - -static void xattr_copyvalue(struct erofs_xattr_iter *it, - unsigned int processed, - char *buf, unsigned int len) -{ - memcpy(it->buffer + processed, buf, len); -} - -static const struct xattr_iter_handlers find_xattr_handlers = { - .entry = xattr_entrymatch, - .name = xattr_namematch, - .alloc_buffer = xattr_checkbuffer, - .value = xattr_copyvalue -}; - static bool erofs_xattr_user_list(struct dentry *dentry) { return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER); @@ -373,20 +219,74 @@ const struct xattr_handler *erofs_xattr_handlers[] = { NULL, }; -static int xattr_entrylist(struct erofs_xattr_iter *it, - struct erofs_xattr_entry *entry) +typedef int (*erofs_xattr_body_handler)(struct erofs_xattr_iter *it, + unsigned int processed, char *buf, unsigned int len); + +static int erofs_xattr_namematch(struct erofs_xattr_iter *it, + unsigned int processed, char *buf, unsigned int len) +{ + if (memcmp(buf, it->name.name + it->infix_len + processed, len)) + return -ENOATTR; + return 0; +} + +static int erofs_xattr_copy(struct erofs_xattr_iter *it, + unsigned int unused, char *buf, unsigned int len) +{ + memcpy(it->buffer + it->buffer_ofs, buf, len); + it->buffer_ofs += len; + return 0; +} + +static int erofs_xattr_body(struct erofs_xattr_iter *it, unsigned int len, + erofs_xattr_body_handler handler) +{ + unsigned int slice, processed = 0; + + while (processed < len) { + int err = erofs_xattr_iter_fixup_aligned(it); + if (err) + return err; + + slice = min_t(unsigned int, it->sb->s_blocksize - it->ofs, + len - processed); + err = handler(it, processed, it->kaddr + it->ofs, slice); + if (err) + return err; + + it->ofs += slice; + processed += slice; + } + return 0; +} + +/* + * Wen returning 0 or ENOATTR, erofs_[list|get]xattr_foreach() will end up + * with `ofs' pointing to the next xattr item rather than an arbitrary position. + */ +static int erofs_listxattr_foreach(struct erofs_xattr_iter *it) { - unsigned int base_index = entry->e_name_index; - unsigned int prefix_len, infix_len = 0; + struct erofs_xattr_entry entry; + unsigned int base_index, prefix_len, infix_len = 0; const char *prefix, *infix = NULL; + int err; + + err = erofs_xattr_iter_prep(it); + if (err) + return err; + + /* 1. handle xattr entry */ + entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs); + it->ofs += sizeof(struct erofs_xattr_entry); + base_index = entry.e_name_index; - if (entry->e_name_index & EROFS_XATTR_LONG_PREFIX) { + 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); + (entry.e_name_index & EROFS_XATTR_LONG_PREFIX_MASK); if (pf >= sbi->xattr_prefixes + sbi->xattr_prefix_count) - return 1; + goto out; infix = pf->prefix->infix; infix_len = pf->infix_len; base_index = pf->prefix->base_index; @@ -394,52 +294,102 @@ static int xattr_entrylist(struct erofs_xattr_iter *it, prefix = erofs_xattr_prefix(base_index, it->dentry); if (!prefix) - return 1; + goto out; prefix_len = strlen(prefix); if (!it->buffer) { - it->buffer_ofs += prefix_len + infix_len + - entry->e_name_len + 1; - return 1; + it->buffer_ofs += prefix_len + infix_len + entry.e_name_len + 1; + goto out; } if (it->buffer_ofs + prefix_len + infix_len + - + entry->e_name_len + 1 > it->buffer_size) + entry.e_name_len + 1 > it->buffer_size) return -ERANGE; memcpy(it->buffer + it->buffer_ofs, prefix, prefix_len); memcpy(it->buffer + it->buffer_ofs + prefix_len, infix, infix_len); it->buffer_ofs += prefix_len + infix_len; - return 0; -} -static int xattr_namelist(struct erofs_xattr_iter *it, - unsigned int processed, char *buf, unsigned int len) -{ - memcpy(it->buffer + it->buffer_ofs, buf, len); - it->buffer_ofs += len; + /* 2. handle xattr name (err can't be ENOATTR) */ + err = erofs_xattr_body(it, entry.e_name_len, erofs_xattr_copy); + if (err) + return err; + + it->buffer[it->buffer_ofs++] = '\0'; + it->ofs += le16_to_cpu(entry.e_value_size); + it->ofs = EROFS_XATTR_ALIGN(it->ofs); + return 0; +out: + it->ofs = it->t_ofs; return 0; } -static int xattr_skipvalue(struct erofs_xattr_iter *it, - unsigned int value_sz) +static int erofs_getxattr_foreach(struct erofs_xattr_iter *it) { - it->buffer[it->buffer_ofs++] = '\0'; - return 1; -} + struct erofs_xattr_entry entry; + unsigned int value_sz; + int err; -static const struct xattr_iter_handlers list_xattr_handlers = { - .entry = xattr_entrylist, - .name = xattr_namelist, - .alloc_buffer = xattr_skipvalue, - .value = NULL -}; + err = erofs_xattr_iter_prep(it); + if (err) + return err; + + /* 1. handle xattr entry */ + entry = *(struct erofs_xattr_entry *)(it->kaddr + it->ofs); + it->ofs += sizeof(struct erofs_xattr_entry); + value_sz = le16_to_cpu(entry.e_value_size); + + err = -ENOATTR; + /* should also match the infix for long name prefixes */ + 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) + goto out; + + if (it->index != pf->prefix->base_index || + it->name.len != entry.e_name_len + pf->infix_len) + goto out; + + if (memcmp(it->name.name, pf->prefix->infix, pf->infix_len)) + goto out; + + it->infix_len = pf->infix_len; + } else { + if (it->index != entry.e_name_index || + it->name.len != entry.e_name_len) + goto out; + it->infix_len = 0; + } + + /* 2. handle xattr name */ + err = erofs_xattr_body(it, entry.e_name_len, erofs_xattr_namematch); + if (err) + goto out; + + /* 3. handle xattr value */ + if (!it->buffer) { + it->buffer_ofs = value_sz; + goto out; /* err == 0 */ + } + if (it->buffer_size < value_sz) + return -ERANGE; + + /* no need normalizing ofs on error (err can't be ENOATTR) */ + err = erofs_xattr_body(it, value_sz, erofs_xattr_copy); + it->ofs = EROFS_XATTR_ALIGN(it->ofs); + return err; +out: + it->ofs = it->t_ofs; + return err; +} static int erofs_iter_inline_xattr(struct erofs_xattr_iter *it) { struct erofs_inode *const vi = EROFS_I(it->inode); - const struct xattr_iter_handlers *op; - unsigned int xattr_header_sz, remaining; + unsigned int xattr_header_sz; erofs_off_t pos; int ret; @@ -457,11 +407,12 @@ static int erofs_iter_inline_xattr(struct erofs_xattr_iter *it) if (IS_ERR(it->kaddr)) return PTR_ERR(it->kaddr); - remaining = vi->xattr_isize - xattr_header_sz; - op = it->getxattr ? &find_xattr_handlers : &list_xattr_handlers; - - while (remaining) { - ret = xattr_foreach(it, op, &remaining); + it->remaining = vi->xattr_isize - xattr_header_sz; + while (it->remaining) { + if (it->getxattr) + ret = erofs_getxattr_foreach(it); + else + ret = erofs_listxattr_foreach(it); if ((it->getxattr && ret != -ENOATTR) || (!it->getxattr && ret)) break; } @@ -472,12 +423,9 @@ static int erofs_iter_shared_xattr(struct erofs_xattr_iter *it) { struct erofs_inode *const vi = EROFS_I(it->inode); struct super_block *const sb = it->sb; - const struct xattr_iter_handlers *op; unsigned int i, xsid; int ret = -ENOATTR; - op = it->getxattr ? &find_xattr_handlers : &list_xattr_handlers; - for (i = 0; i < vi->xattr_shared_count; ++i) { xsid = vi->xattr_shared_xattrs[i]; it->blkaddr = EROFS_SB(sb)->xattr_blkaddr + @@ -487,7 +435,10 @@ static int erofs_iter_shared_xattr(struct erofs_xattr_iter *it) if (IS_ERR(it->kaddr)) return PTR_ERR(it->kaddr); - ret = xattr_foreach(it, op, NULL); + if (it->getxattr) + ret = erofs_getxattr_foreach(it); + else + ret = erofs_listxattr_foreach(it); if ((it->getxattr && ret != -ENOATTR) || (!it->getxattr && ret)) break; } -- 2.19.1.6.gb485710b
