Re: [PATCH v3 2/5] erofs: unify xattr_iter structures

From: Gao Xiang
Date: Mon May 29 2023 - 23:55:49 EST




On 2023/5/18 10:45, Jingbo Xu wrote:
Unify xattr_iter/listxattr_iter/getxattr_iter structures into
erofs_xattr_iter structure.

This is in preparation for the following further cleanup.

Signed-off-by: Jingbo Xu <jefflexu@xxxxxxxxxxxxxxxxx>
---
fs/erofs/xattr.c | 172 ++++++++++++++++++++---------------------------
1 file changed, 72 insertions(+), 100 deletions(-)

diff --git a/fs/erofs/xattr.c b/fs/erofs/xattr.c
index b79be2a556ba..1e44aa108134 100644
--- a/fs/erofs/xattr.c
+++ b/fs/erofs/xattr.c
@@ -20,16 +20,22 @@ static inline unsigned int erofs_xattr_blkoff(struct super_block *sb,
return erofs_blkoff(sb, xattr_id * sizeof(__u32));
}
-struct xattr_iter {
+struct erofs_xattr_iter {
struct super_block *sb;
struct erofs_buf buf;
void *kaddr;
-
erofs_blk_t blkaddr;
unsigned int ofs;
+
+ char *buffer;
+ int buffer_size, buffer_ofs;
+
+ int index, infix_len;
+ struct qstr name;
+ struct dentry *dentry;
};
-static inline int erofs_xattr_iter_fixup(struct xattr_iter *it)
+static inline int erofs_xattr_iter_fixup(struct erofs_xattr_iter *it)
{
if (it->ofs < it->sb->s_blocksize)
return 0;
@@ -42,7 +48,7 @@ static inline int erofs_xattr_iter_fixup(struct xattr_iter *it)
return 0;
}
-static inline int erofs_xattr_iter_fixup_aligned(struct xattr_iter *it)
+static inline int erofs_xattr_iter_fixup_aligned(struct erofs_xattr_iter *it)
{
if (it->ofs > it->sb->s_blocksize) {
DBG_BUGON(1);
@@ -54,7 +60,7 @@ static inline int erofs_xattr_iter_fixup_aligned(struct xattr_iter *it)
static int erofs_init_inode_xattrs(struct inode *inode)
{
struct erofs_inode *const vi = EROFS_I(inode);
- struct xattr_iter it;
+ struct erofs_xattr_iter it;
unsigned int i;
struct erofs_xattr_ibody_header *ih;
struct super_block *sb = inode->i_sb;
@@ -157,15 +163,15 @@ static int erofs_init_inode_xattrs(struct inode *inode)
* and need to be handled
*/
struct xattr_iter_handlers {
- int (*entry)(struct xattr_iter *_it, struct erofs_xattr_entry *entry);
- int (*name)(struct xattr_iter *_it, unsigned int processed, char *buf,
+ 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 xattr_iter *_it, unsigned int value_sz);
- void (*value)(struct xattr_iter *_it, unsigned int processed, char *buf,
+ 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);
};
-static int inline_xattr_iter_begin(struct xattr_iter *it,
+static int inline_xattr_iter_begin(struct erofs_xattr_iter *it,
struct inode *inode)
{
struct erofs_inode *const vi = EROFS_I(inode);
@@ -193,7 +199,7 @@ static int inline_xattr_iter_begin(struct xattr_iter *it,
* 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 xattr_iter *it,
+static int xattr_foreach(struct erofs_xattr_iter *it,
const struct xattr_iter_handlers *op,
unsigned int *tlimit)
{
@@ -284,18 +290,10 @@ static int xattr_foreach(struct xattr_iter *it,
return err < 0 ? err : 0;
}
-struct getxattr_iter {
- struct xattr_iter it;
-
- char *buffer;
- int buffer_size, index, infix_len;
- struct qstr name;
-};
-
-static int erofs_xattr_long_entrymatch(struct getxattr_iter *it,
+static int erofs_xattr_long_entrymatch(struct erofs_xattr_iter *it,
struct erofs_xattr_entry *entry)
{
- struct erofs_sb_info *sbi = EROFS_SB(it->it.sb);
+ 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);
@@ -313,11 +311,9 @@ static int erofs_xattr_long_entrymatch(struct getxattr_iter *it,
return 0;
}
-static int xattr_entrymatch(struct xattr_iter *_it,
+static int xattr_entrymatch(struct erofs_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);
@@ -329,32 +325,27 @@ static int xattr_entrymatch(struct xattr_iter *_it,
return 0;
}
-static int xattr_namematch(struct xattr_iter *_it,
+static int xattr_namematch(struct erofs_xattr_iter *it,
unsigned int processed, char *buf, unsigned int len)
{
- struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
-
if (memcmp(buf, it->name.name + it->infix_len + processed, len))
return -ENOATTR;
return 0;
}
-static int xattr_checkbuffer(struct xattr_iter *_it,
+static int xattr_checkbuffer(struct erofs_xattr_iter *it,
unsigned int value_sz)
{
- struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
int err = it->buffer_size < value_sz ? -ERANGE : 0;
it->buffer_size = value_sz;
return !it->buffer ? 1 : err;
}
-static void xattr_copyvalue(struct xattr_iter *_it,
+static void xattr_copyvalue(struct erofs_xattr_iter *it,
unsigned int processed,
char *buf, unsigned int len)
{
- struct getxattr_iter *it = container_of(_it, struct getxattr_iter, it);
-
memcpy(it->buffer + processed, buf, len);
}
@@ -365,41 +356,40 @@ static const struct xattr_iter_handlers find_xattr_handlers = {
.value = xattr_copyvalue
};
-static int inline_getxattr(struct inode *inode, struct getxattr_iter *it)
+static int inline_getxattr(struct inode *inode, struct erofs_xattr_iter *it)
{
int ret;
unsigned int remaining;
- ret = inline_xattr_iter_begin(&it->it, inode);
+ ret = inline_xattr_iter_begin(it, inode);
if (ret < 0)
return ret;
remaining = ret;
while (remaining) {
- ret = xattr_foreach(&it->it, &find_xattr_handlers, &remaining);
+ ret = xattr_foreach(it, &find_xattr_handlers, &remaining);
if (ret != -ENOATTR)
break;
}
return ret ? ret : it->buffer_size;
}
-static int shared_getxattr(struct inode *inode, struct getxattr_iter *it)
+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->it.sb;
+ 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->it.blkaddr = erofs_xattr_blkaddr(sb, xsid);
- it->it.ofs = erofs_xattr_blkoff(sb, xsid);
- it->it.kaddr = erofs_read_metabuf(&it->it.buf, sb,
- it->it.blkaddr, EROFS_KMAP);
- if (IS_ERR(it->it.kaddr))
- return PTR_ERR(it->it.kaddr);
-
- ret = xattr_foreach(&it->it, &find_xattr_handlers, NULL);
+ it->blkaddr = erofs_xattr_blkaddr(sb, xsid);
+ it->ofs = erofs_xattr_blkoff(sb, xsid);
+ it->kaddr = erofs_read_metabuf(&it->buf, sb, it->blkaddr, EROFS_KMAP);
+ if (IS_ERR(it->kaddr))
+ return PTR_ERR(it->kaddr);
+
+ ret = xattr_foreach(it, &find_xattr_handlers, NULL);
if (ret != -ENOATTR)
break;
}
@@ -421,31 +411,30 @@ int erofs_getxattr(struct inode *inode, int index,
void *buffer, size_t buffer_size)
{
int ret;
- struct getxattr_iter it;
+ struct erofs_xattr_iter it;
if (!name)
return -EINVAL;
+ if (strlen(name) > EROFS_NAME_LEN)
+ return -ERANGE;

duplicated calculation.

ret = erofs_init_inode_xattrs(inode);
if (ret)
return ret;
- it.index = index;
- it.name.len = strlen(name);
- if (it.name.len > EROFS_NAME_LEN)
- return -ERANGE;
-
- it.it.buf = __EROFS_BUF_INITIALIZER;
- it.name.name = name;
-
- it.buffer = buffer;
- it.buffer_size = buffer_size;
+ it = (struct erofs_xattr_iter) {
+ .buf = __EROFS_BUF_INITIALIZER,
+ .sb = inode->i_sb,
+ .name = QSTR_INIT(name, strlen(name)),
+ .index = index,
+ .buffer = buffer,
+ .buffer_size = buffer_size,
+ };

No need to zero out the other fields like this?

- it.it.sb = inode->i_sb;
ret = inline_getxattr(inode, &it);
if (ret == -ENOATTR)
ret = shared_getxattr(inode, &it);
- erofs_put_metabuf(&it.it.buf);
+ erofs_put_metabuf(&it.buf);
return ret;
}
@@ -491,25 +480,15 @@ const struct xattr_handler *erofs_xattr_handlers[] = {
NULL,
};
-struct listxattr_iter {
- struct xattr_iter it;
-
- struct dentry *dentry;
- char *buffer;
- int buffer_size, buffer_ofs;
-};
-
-static int xattr_entrylist(struct xattr_iter *_it,
+static int xattr_entrylist(struct erofs_xattr_iter *it,
struct erofs_xattr_entry *entry)
{
- struct listxattr_iter *it =
- container_of(_it, struct listxattr_iter, it);
unsigned int base_index = entry->e_name_index;
unsigned int prefix_len, infix_len = 0;
const char *prefix, *infix = NULL;
if (entry->e_name_index & EROFS_XATTR_LONG_PREFIX) {
- struct erofs_sb_info *sbi = EROFS_SB(_it->sb);
+ 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);
@@ -541,23 +520,17 @@ static int xattr_entrylist(struct xattr_iter *_it,
return 0;
}
-static int xattr_namelist(struct xattr_iter *_it,
+static int xattr_namelist(struct erofs_xattr_iter *it,
unsigned int processed, char *buf, unsigned int len)
{
- struct listxattr_iter *it =
- container_of(_it, struct listxattr_iter, it);
-
memcpy(it->buffer + it->buffer_ofs, buf, len);
it->buffer_ofs += len;
return 0;
}
-static int xattr_skipvalue(struct xattr_iter *_it,
+static int xattr_skipvalue(struct erofs_xattr_iter *it,
unsigned int value_sz)
{
- struct listxattr_iter *it =
- container_of(_it, struct listxattr_iter, it);
-
it->buffer[it->buffer_ofs++] = '\0';
return 1;
}
@@ -569,42 +542,41 @@ static const struct xattr_iter_handlers list_xattr_handlers = {
.value = NULL
};
-static int inline_listxattr(struct listxattr_iter *it)
+static int inline_listxattr(struct erofs_xattr_iter *it)
{
int ret;
unsigned int remaining;
- ret = inline_xattr_iter_begin(&it->it, d_inode(it->dentry));
+ ret = inline_xattr_iter_begin(it, d_inode(it->dentry));
if (ret < 0)
return ret;
remaining = ret;
while (remaining) {
- ret = xattr_foreach(&it->it, &list_xattr_handlers, &remaining);
+ ret = xattr_foreach(it, &list_xattr_handlers, &remaining);
if (ret)
break;
}
return ret ? ret : it->buffer_ofs;
}
-static int shared_listxattr(struct listxattr_iter *it)
+static int shared_listxattr(struct erofs_xattr_iter *it)
{
struct inode *const inode = d_inode(it->dentry);
struct erofs_inode *const vi = EROFS_I(inode);
- struct super_block *const sb = it->it.sb;
+ struct super_block *const sb = it->sb;
unsigned int i, xsid;
int ret = 0;
for (i = 0; i < vi->xattr_shared_count; ++i) {
xsid = vi->xattr_shared_xattrs[i];
- it->it.blkaddr = erofs_xattr_blkaddr(sb, xsid);
- it->it.ofs = erofs_xattr_blkoff(sb, xsid);
- it->it.kaddr = erofs_read_metabuf(&it->it.buf, sb,
- it->it.blkaddr, EROFS_KMAP);
- if (IS_ERR(it->it.kaddr))
- return PTR_ERR(it->it.kaddr);
-
- ret = xattr_foreach(&it->it, &list_xattr_handlers, NULL);
+ it->blkaddr = erofs_xattr_blkaddr(sb, xsid);
+ it->ofs = erofs_xattr_blkoff(sb, xsid);
+ it->kaddr = erofs_read_metabuf(&it->buf, sb, it->blkaddr, EROFS_KMAP);
+ if (IS_ERR(it->kaddr))
+ return PTR_ERR(it->kaddr);
+
+ ret = xattr_foreach(it, &list_xattr_handlers, NULL);
if (ret)
break;
}
@@ -615,7 +587,7 @@ ssize_t erofs_listxattr(struct dentry *dentry,
char *buffer, size_t buffer_size)
{
int ret;
- struct listxattr_iter it;
+ struct erofs_xattr_iter it;
ret = erofs_init_inode_xattrs(d_inode(dentry));
if (ret == -ENOATTR)
@@ -623,18 +595,18 @@ ssize_t erofs_listxattr(struct dentry *dentry,
if (ret)
return ret;
- it.it.buf = __EROFS_BUF_INITIALIZER;
- it.dentry = dentry;
- it.buffer = buffer;
- it.buffer_size = buffer_size;
- it.buffer_ofs = 0;
-
- it.it.sb = dentry->d_sb;
+ it = (struct erofs_xattr_iter) {
+ .buf = __EROFS_BUF_INITIALIZER,
+ .sb = dentry->d_sb,
+ .dentry = dentry,
+ .buffer = buffer,
+ .buffer_size = buffer_size,
+ };

Same here.

Thanks,
Gao Xiang

ret = inline_listxattr(&it);
if (ret >= 0 || ret == -ENOATTR)
ret = shared_listxattr(&it);
- erofs_put_metabuf(&it.it.buf);
+ erofs_put_metabuf(&it.buf);
return ret;
}