Re: [PATCH v6 4/5] erofs: unify inline/share xattr iterators for listxattr/getxattr
From: Gao Xiang
Date: Sun Jun 11 2023 - 23:01:58 EST
On 2023/6/8 19:30, Jingbo Xu wrote:
Make inline_getxattr() and inline_listxattr() unified as
iter_inline_xattr(), shared_getxattr() and shared_listxattr() unified as
erofs_xattr_iter_inline() as well as shared_getxattr() and
shared_listxattr() unified as erofs_xattr_iter_shared() ?
iter_shared_xattr().
After the unification, both iter_inline_xattr() and iter_shared_xattr()
return 0 on success, and negative error on failure.
After these changes, both erofs_xattr_iter_{inline,shared} return 0 on
success, and negative values 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 <jefflexu@xxxxxxxxxxxxxxxxx>
Otherwise it looks good to me.
Thanks,
Gao Xiang
---
fs/erofs/xattr.c | 188 ++++++++++++++++++-----------------------------
1 file changed, 73 insertions(+), 115 deletions(-)
diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
index 4ae9b7cdd3ac..15a1a4042205 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;
- unsigned int i, xsid;
- int ret = -ENOATTR;
-
- for (i = 0; i < vi->xattr_shared_count; ++i) {
- xsid = vi->xattr_shared_xattrs[i];
- it->pos = erofs_pos(sb, EROFS_SB(sb)->xattr_blkaddr) +
- xsid * sizeof(__u32);
- 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)
@@ -521,31 +426,48 @@ static const struct xattr_iter_handlers list_xattr_handlers = {
.value = NULL
};
-static int inline_listxattr(struct erofs_xattr_iter *it)
+static int erofs_iter_inline_xattr(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_iter_shared_xattr(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;
+ const struct xattr_iter_handlers *op;
unsigned int i, xsid;
- int ret = 0;
+ int ret = -ENOATTR;
+
+ op = getxattr ? &find_xattr_handlers : &list_xattr_handlers;
for (i = 0; i < vi->xattr_shared_count; ++i) {
xsid = vi->xattr_shared_xattrs[i];
@@ -556,11 +478,44 @@ 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;
+}
+
+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 = erofs_iter_inline_xattr(&it, inode, true);
+ if (ret == -ENOATTR)
+ ret = erofs_iter_shared_xattr(&it, inode, true);
+ erofs_put_metabuf(&it.buf);
+ return ret ? ret : it.buffer_ofs;
}
ssize_t erofs_listxattr(struct dentry *dentry,
@@ -568,8 +523,9 @@ ssize_t erofs_listxattr(struct dentry *dentry,
{
int ret;
struct erofs_xattr_iter it;
+ struct inode *inode = d_inode(dentry);
- ret = erofs_init_inode_xattrs(d_inode(dentry));
+ ret = erofs_init_inode_xattrs(inode);
if (ret == -ENOATTR)
return 0;
if (ret)
@@ -583,11 +539,13 @@ 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_iter_inline_xattr(&it, inode, false);
+ if (!ret || ret == -ENOATTR)
+ ret = erofs_iter_shared_xattr(&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)