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erofs: use meta buffers for inode lookup 

This converts the remaining inode lookup part by using metabuf in a
straight-forward way. Except that it doesn't use kmap_atomic()
anymore since we now have to maintain two metabufs together.

After this patch, all uncompressed paths are handled with metabuf
instead of page structure.

Link: https://lore.kernel.org/r/20220316012246.95131-2-hsiangkao@linux.alibaba.com
Reviewed-by: Chao Yu <chao@kernel.org>
Signed-off-by: Gao Xiang <hsiangkao@linux.alibaba.com>
This commit is contained in:
Gao Xiang 2022-03-16 09:22:46 +08:00
parent fe5de5859d
commit 500edd0956
1 changed files with 24 additions and 30 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

50
fs/erofs/namei.c
View File

@ -2,6 +2,7 @@
/*
* Copyright (C) 2017-2018 HUAWEI, Inc.
* https://www.huawei.com/
* Copyright (C) 2022, Alibaba Cloud
*/
#include "xattr.h"
@ -86,14 +87,14 @@ static struct erofs_dirent *find_target_dirent(struct erofs_qstr *name,
return ERR_PTR(-ENOENT);
}
static struct page *find_target_block_classic(struct inode *dir,
static void *find_target_block_classic(struct erofs_buf *target,
struct inode *dir,
struct erofs_qstr *name,
int *_ndirents)
{
unsigned int startprfx, endprfx;
int head, back;
struct address_space *const mapping = dir->i_mapping;
struct page *candidate = ERR_PTR(-ENOENT);
void *candidate = ERR_PTR(-ENOENT);
startprfx = endprfx = 0;
head = 0;
@ -101,10 +102,11 @@ static struct page *find_target_block_classic(struct inode *dir,
while (head <= back) {
const int mid = head + (back - head) / 2;
struct page *page = read_mapping_page(mapping, mid, NULL);
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
struct erofs_dirent *de;
if (!IS_ERR(page)) {
struct erofs_dirent *de = kmap_atomic(page);
de = erofs_bread(&buf, dir, mid, EROFS_KMAP);
if (!IS_ERR(de)) {
const int nameoff = nameoff_from_disk(de->nameoff,
EROFS_BLKSIZ);
const int ndirents = nameoff / sizeof(*de);
@ -113,13 +115,12 @@ static struct page *find_target_block_classic(struct inode *dir,
struct erofs_qstr dname;
if (!ndirents) {
kunmap_atomic(de);
put_page(page);
erofs_put_metabuf(&buf);
erofs_err(dir->i_sb,
"corrupted dir block %d @ nid %llu",
mid, EROFS_I(dir)->nid);
DBG_BUGON(1);
page = ERR_PTR(-EFSCORRUPTED);
de = ERR_PTR(-EFSCORRUPTED);
goto out;
}
@ -135,7 +136,6 @@ static struct page *find_target_block_classic(struct inode *dir,
/* string comparison without already matched prefix */
diff = erofs_dirnamecmp(name, &dname, &matched);
kunmap_atomic(de);
if (!diff) {
*_ndirents = 0;
@ -145,11 +145,12 @@ static struct page *find_target_block_classic(struct inode *dir,
startprfx = matched;
if (!IS_ERR(candidate))
put_page(candidate);
candidate = page;
erofs_put_metabuf(target);
*target = buf;
candidate = de;
*_ndirents = ndirents;
} else {
put_page(page);
erofs_put_metabuf(&buf);
back = mid - 1;
endprfx = matched;
@ -158,8 +159,8 @@ static struct page *find_target_block_classic(struct inode *dir,
}
out: /* free if the candidate is valid */
if (!IS_ERR(candidate))
put_page(candidate);
return page;
erofs_put_metabuf(target);
return de;
}
return candidate;
}
@ -169,8 +170,7 @@ int erofs_namei(struct inode *dir,
erofs_nid_t *nid, unsigned int *d_type)
{
int ndirents;
struct page *page;
void *data;
struct erofs_buf buf = __EROFS_BUF_INITIALIZER;
struct erofs_dirent *de;
struct erofs_qstr qn;
@ -181,26 +181,20 @@ int erofs_namei(struct inode *dir,
qn.end = name->name + name->len;
ndirents = 0;
page = find_target_block_classic(dir, &qn, &ndirents);
if (IS_ERR(page))
return PTR_ERR(page);
de = find_target_block_classic(&buf, dir, &qn, &ndirents);
if (IS_ERR(de))
return PTR_ERR(de);
data = kmap_atomic(page);
/* the target page has been mapped */
if (ndirents)
de = find_target_dirent(&qn, data, EROFS_BLKSIZ, ndirents);
else
de = (struct erofs_dirent *)data;
de = find_target_dirent(&qn, (u8 *)de, EROFS_BLKSIZ, ndirents);
if (!IS_ERR(de)) {
*nid = le64_to_cpu(de->nid);
*d_type = de->file_type;
}
kunmap_atomic(data);
put_page(page);
erofs_put_metabuf(&buf);
return PTR_ERR_OR_ZERO(de);
}