From 4b077b501266c6c6784656cd8721db37c090c5df Mon Sep 17 00:00:00 2001 From: Jingbo Xu Date: Tue, 13 Jun 2023 15:41:13 +0800 Subject: [PATCH] erofs: unify inline/shared xattr iterators for listxattr/getxattr Make inline_{list,get}xattr() as well as inline_xattr_iter_begin() unified as erofs_xattr_iter_inline(), and shared_{list,get}xattr() unified as erofs_xattr_iter_shared(). After these changes, both erofs_xattr_iter_{inline,shared}() return 0 on success, and negative error on failure. One thing worth noting is that, the logic of returning it->buffer_ofs when there's no shared xattrs in shared_listxattr() is moved to erofs_listxattr() to make the unification possible. The only difference is that, semantically the old behavior will return ENOATTR rather than it->buffer_ofs if ENOATTR encountered when listxattr is parsing upon a specific shared xattr, while now the new behavior will return it->buffer_ofs in this case. This is not an issue, as listxattr upon a specific xattr won't return ENOATTR. Signed-off-by: Jingbo Xu Reviewed-by: Gao Xiang Link: https://lore.kernel.org/r/20230613074114.120115-5-jefflexu@linux.alibaba.com Signed-off-by: Gao Xiang --- fs/erofs/xattr.c | 190 ++++++++++++++++++----------------------------- 1 file changed, 73 insertions(+), 117 deletions(-) diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c index 8a114c7b6c66..abbf8e0bcdac 100644 --- a/fs/erofs/xattr.c +++ b/fs/erofs/xattr.c @@ -139,27 +139,6 @@ struct xattr_iter_handlers { unsigned int len); }; -static int inline_xattr_iter_begin(struct erofs_xattr_iter *it, - struct inode *inode) -{ - struct erofs_inode *const vi = EROFS_I(inode); - unsigned int xattr_header_sz; - - xattr_header_sz = sizeof(struct erofs_xattr_ibody_header) + - sizeof(u32) * vi->xattr_shared_count; - if (xattr_header_sz >= vi->xattr_isize) { - DBG_BUGON(xattr_header_sz > vi->xattr_isize); - return -ENOATTR; - } - - it->pos = erofs_iloc(inode) + vi->inode_isize + xattr_header_sz; - it->kaddr = erofs_bread(&it->buf, erofs_blknr(it->sb, it->pos), - EROFS_KMAP); - if (IS_ERR(it->kaddr)) - return PTR_ERR(it->kaddr); - return vi->xattr_isize - xattr_header_sz; -} - /* * Regardless of success or failure, `xattr_foreach' will end up with * `pos' pointing to the next xattr item rather than an arbitrary position. @@ -333,47 +312,6 @@ static const struct xattr_iter_handlers find_xattr_handlers = { .value = xattr_copyvalue }; -static int inline_getxattr(struct inode *inode, struct erofs_xattr_iter *it) -{ - int ret; - unsigned int remaining; - - ret = inline_xattr_iter_begin(it, inode); - if (ret < 0) - return ret; - - remaining = ret; - while (remaining) { - ret = xattr_foreach(it, &find_xattr_handlers, &remaining); - if (ret != -ENOATTR) - break; - } - return ret ? ret : it->buffer_ofs; -} - -static int shared_getxattr(struct inode *inode, struct erofs_xattr_iter *it) -{ - struct erofs_inode *const vi = EROFS_I(inode); - struct super_block *const sb = it->sb; - struct erofs_sb_info *sbi = EROFS_SB(sb); - unsigned int i; - int ret = -ENOATTR; - - for (i = 0; i < vi->xattr_shared_count; ++i) { - it->pos = erofs_pos(sb, sbi->xattr_blkaddr) + - vi->xattr_shared_xattrs[i] * sizeof(__le32); - it->kaddr = erofs_bread(&it->buf, erofs_blknr(sb, it->pos), - EROFS_KMAP); - if (IS_ERR(it->kaddr)) - return PTR_ERR(it->kaddr); - - ret = xattr_foreach(it, &find_xattr_handlers, NULL); - if (ret != -ENOATTR) - break; - } - return ret ? ret : it->buffer_ofs; -} - static bool erofs_xattr_user_list(struct dentry *dentry) { return test_opt(&EROFS_SB(dentry->d_sb)->opt, XATTR_USER); @@ -384,39 +322,6 @@ static bool erofs_xattr_trusted_list(struct dentry *dentry) return capable(CAP_SYS_ADMIN); } -int erofs_getxattr(struct inode *inode, int index, - const char *name, - void *buffer, size_t buffer_size) -{ - int ret; - struct erofs_xattr_iter it; - - if (!name) - return -EINVAL; - - ret = erofs_init_inode_xattrs(inode); - if (ret) - return ret; - - it.index = index; - it.name = (struct qstr)QSTR_INIT(name, strlen(name)); - if (it.name.len > EROFS_NAME_LEN) - return -ERANGE; - - it.sb = inode->i_sb; - it.buf = __EROFS_BUF_INITIALIZER; - erofs_init_metabuf(&it.buf, it.sb); - it.buffer = buffer; - it.buffer_size = buffer_size; - it.buffer_ofs = 0; - - ret = inline_getxattr(inode, &it); - if (ret == -ENOATTR) - ret = shared_getxattr(inode, &it); - erofs_put_metabuf(&it.buf); - return ret; -} - static int erofs_xattr_generic_get(const struct xattr_handler *handler, struct dentry *unused, struct inode *inode, const char *name, void *buffer, size_t size) @@ -521,32 +426,49 @@ static const struct xattr_iter_handlers list_xattr_handlers = { .value = NULL }; -static int inline_listxattr(struct erofs_xattr_iter *it) +static int erofs_xattr_iter_inline(struct erofs_xattr_iter *it, + struct inode *inode, bool getxattr) { + struct erofs_inode *const vi = EROFS_I(inode); + const struct xattr_iter_handlers *op; + unsigned int xattr_header_sz, remaining; int ret; - unsigned int remaining; - ret = inline_xattr_iter_begin(it, d_inode(it->dentry)); - if (ret < 0) - return ret; + xattr_header_sz = sizeof(struct erofs_xattr_ibody_header) + + sizeof(u32) * vi->xattr_shared_count; + if (xattr_header_sz >= vi->xattr_isize) { + DBG_BUGON(xattr_header_sz > vi->xattr_isize); + return -ENOATTR; + } + + it->pos = erofs_iloc(inode) + vi->inode_isize + xattr_header_sz; + it->kaddr = erofs_bread(&it->buf, erofs_blknr(it->sb, it->pos), + EROFS_KMAP); + if (IS_ERR(it->kaddr)) + return PTR_ERR(it->kaddr); + + remaining = vi->xattr_isize - xattr_header_sz; + op = getxattr ? &find_xattr_handlers : &list_xattr_handlers; - remaining = ret; while (remaining) { - ret = xattr_foreach(it, &list_xattr_handlers, &remaining); - if (ret) + ret = xattr_foreach(it, op, &remaining); + if ((getxattr && ret != -ENOATTR) || (!getxattr && ret)) break; } - return ret ? ret : it->buffer_ofs; + return ret; } -static int shared_listxattr(struct erofs_xattr_iter *it) +static int erofs_xattr_iter_shared(struct erofs_xattr_iter *it, + struct inode *inode, bool getxattr) { - struct inode *const inode = d_inode(it->dentry); struct erofs_inode *const vi = EROFS_I(inode); struct super_block *const sb = it->sb; struct erofs_sb_info *sbi = EROFS_SB(sb); unsigned int i; - int ret = 0; + const struct xattr_iter_handlers *op; + int ret = -ENOATTR; + + op = getxattr ? &find_xattr_handlers : &list_xattr_handlers; for (i = 0; i < vi->xattr_shared_count; ++i) { it->pos = erofs_pos(sb, sbi->xattr_blkaddr) + @@ -556,20 +478,52 @@ static int shared_listxattr(struct erofs_xattr_iter *it) if (IS_ERR(it->kaddr)) return PTR_ERR(it->kaddr); - ret = xattr_foreach(it, &list_xattr_handlers, NULL); - if (ret) + ret = xattr_foreach(it, op, NULL); + if ((getxattr && ret != -ENOATTR) || (!getxattr && ret)) break; } - return ret ? ret : it->buffer_ofs; + return ret; } -ssize_t erofs_listxattr(struct dentry *dentry, - char *buffer, size_t buffer_size) +int erofs_getxattr(struct inode *inode, int index, const char *name, + void *buffer, size_t buffer_size) { int ret; struct erofs_xattr_iter it; - ret = erofs_init_inode_xattrs(d_inode(dentry)); + if (!name) + return -EINVAL; + + ret = erofs_init_inode_xattrs(inode); + if (ret) + return ret; + + it.index = index; + it.name = (struct qstr)QSTR_INIT(name, strlen(name)); + if (it.name.len > EROFS_NAME_LEN) + return -ERANGE; + + it.sb = inode->i_sb; + it.buf = __EROFS_BUF_INITIALIZER; + erofs_init_metabuf(&it.buf, it.sb); + it.buffer = buffer; + it.buffer_size = buffer_size; + it.buffer_ofs = 0; + + ret = erofs_xattr_iter_inline(&it, inode, true); + if (ret == -ENOATTR) + ret = erofs_xattr_iter_shared(&it, inode, true); + erofs_put_metabuf(&it.buf); + return ret ? ret : it.buffer_ofs; +} + +ssize_t erofs_listxattr(struct dentry *dentry, char *buffer, size_t buffer_size) +{ + int ret; + struct erofs_xattr_iter it; + struct inode *inode = d_inode(dentry); + + ret = erofs_init_inode_xattrs(inode); if (ret == -ENOATTR) return 0; if (ret) @@ -583,11 +537,13 @@ ssize_t erofs_listxattr(struct dentry *dentry, it.buffer_size = buffer_size; it.buffer_ofs = 0; - ret = inline_listxattr(&it); - if (ret >= 0 || ret == -ENOATTR) - ret = shared_listxattr(&it); + ret = erofs_xattr_iter_inline(&it, inode, false); + if (!ret || ret == -ENOATTR) + ret = erofs_xattr_iter_shared(&it, inode, false); + if (ret == -ENOATTR) + ret = 0; erofs_put_metabuf(&it.buf); - return ret; + return ret ? ret : it.buffer_ofs; } void erofs_xattr_prefixes_cleanup(struct super_block *sb)