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-rw-r--r--drivers/staging/erofs/namei.c256
1 files changed, 0 insertions, 256 deletions
diff --git a/drivers/staging/erofs/namei.c b/drivers/staging/erofs/namei.c
deleted file mode 100644
index fd3ae78d0ba5..000000000000
--- a/drivers/staging/erofs/namei.c
+++ /dev/null
@@ -1,256 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/*
- * linux/drivers/staging/erofs/namei.c
- *
- * Copyright (C) 2017-2018 HUAWEI, Inc.
- * http://www.huawei.com/
- * Created by Gao Xiang <gaoxiang25@huawei.com>
- *
- * This file is subject to the terms and conditions of the GNU General Public
- * License. See the file COPYING in the main directory of the Linux
- * distribution for more details.
- */
-#include "internal.h"
-#include "xattr.h"
-
-#include <trace/events/erofs.h>
-
-struct erofs_qstr {
- const unsigned char *name;
- const unsigned char *end;
-};
-
-/* based on the end of qn is accurate and it must have the trailing '\0' */
-static inline int dirnamecmp(const struct erofs_qstr *qn,
- const struct erofs_qstr *qd,
- unsigned int *matched)
-{
- unsigned int i = *matched;
-
- /*
- * on-disk error, let's only BUG_ON in the debugging mode.
- * otherwise, it will return 1 to just skip the invalid name
- * and go on (in consideration of the lookup performance).
- */
- DBG_BUGON(qd->name > qd->end);
-
- /* qd could not have trailing '\0' */
- /* However it is absolutely safe if < qd->end */
- while (qd->name + i < qd->end && qd->name[i] != '\0') {
- if (qn->name[i] != qd->name[i]) {
- *matched = i;
- return qn->name[i] > qd->name[i] ? 1 : -1;
- }
- ++i;
- }
- *matched = i;
- /* See comments in __d_alloc on the terminating NUL character */
- return qn->name[i] == '\0' ? 0 : 1;
-}
-
-#define nameoff_from_disk(off, sz) (le16_to_cpu(off) & ((sz) - 1))
-
-static struct erofs_dirent *find_target_dirent(struct erofs_qstr *name,
- u8 *data,
- unsigned int dirblksize,
- const int ndirents)
-{
- int head, back;
- unsigned int startprfx, endprfx;
- struct erofs_dirent *const de = (struct erofs_dirent *)data;
-
- /* since the 1st dirent has been evaluated previously */
- head = 1;
- back = ndirents - 1;
- startprfx = endprfx = 0;
-
- while (head <= back) {
- const int mid = head + (back - head) / 2;
- const int nameoff = nameoff_from_disk(de[mid].nameoff,
- dirblksize);
- unsigned int matched = min(startprfx, endprfx);
- struct erofs_qstr dname = {
- .name = data + nameoff,
- .end = unlikely(mid >= ndirents - 1) ?
- data + dirblksize :
- data + nameoff_from_disk(de[mid + 1].nameoff,
- dirblksize)
- };
-
- /* string comparison without already matched prefix */
- int ret = dirnamecmp(name, &dname, &matched);
-
- if (unlikely(!ret)) {
- return de + mid;
- } else if (ret > 0) {
- head = mid + 1;
- startprfx = matched;
- } else {
- back = mid - 1;
- endprfx = matched;
- }
- }
-
- return ERR_PTR(-ENOENT);
-}
-
-static struct page *find_target_block_classic(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);
-
- startprfx = endprfx = 0;
- head = 0;
- back = inode_datablocks(dir) - 1;
-
- while (head <= back) {
- const int mid = head + (back - head) / 2;
- struct page *page = read_mapping_page(mapping, mid, NULL);
-
- if (!IS_ERR(page)) {
- struct erofs_dirent *de = kmap_atomic(page);
- const int nameoff = nameoff_from_disk(de->nameoff,
- EROFS_BLKSIZ);
- const int ndirents = nameoff / sizeof(*de);
- int diff;
- unsigned int matched;
- struct erofs_qstr dname;
-
- if (unlikely(!ndirents)) {
- DBG_BUGON(1);
- kunmap_atomic(de);
- put_page(page);
- page = ERR_PTR(-EIO);
- goto out;
- }
-
- matched = min(startprfx, endprfx);
-
- dname.name = (u8 *)de + nameoff;
- if (ndirents == 1)
- dname.end = (u8 *)de + EROFS_BLKSIZ;
- else
- dname.end = (u8 *)de +
- nameoff_from_disk(de[1].nameoff,
- EROFS_BLKSIZ);
-
- /* string comparison without already matched prefix */
- diff = dirnamecmp(name, &dname, &matched);
- kunmap_atomic(de);
-
- if (unlikely(!diff)) {
- *_ndirents = 0;
- goto out;
- } else if (diff > 0) {
- head = mid + 1;
- startprfx = matched;
-
- if (!IS_ERR(candidate))
- put_page(candidate);
- candidate = page;
- *_ndirents = ndirents;
- } else {
- put_page(page);
-
- back = mid - 1;
- endprfx = matched;
- }
- continue;
- }
-out: /* free if the candidate is valid */
- if (!IS_ERR(candidate))
- put_page(candidate);
- return page;
- }
- return candidate;
-}
-
-int erofs_namei(struct inode *dir,
- struct qstr *name,
- erofs_nid_t *nid, unsigned int *d_type)
-{
- int ndirents;
- struct page *page;
- void *data;
- struct erofs_dirent *de;
- struct erofs_qstr qn;
-
- if (unlikely(!dir->i_size))
- return -ENOENT;
-
- qn.name = name->name;
- qn.end = name->name + name->len;
-
- ndirents = 0;
- page = find_target_block_classic(dir, &qn, &ndirents);
-
- if (IS_ERR(page))
- return PTR_ERR(page);
-
- 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;
-
- if (!IS_ERR(de)) {
- *nid = le64_to_cpu(de->nid);
- *d_type = de->file_type;
- }
-
- kunmap_atomic(data);
- put_page(page);
-
- return PTR_ERR_OR_ZERO(de);
-}
-
-/* NOTE: i_mutex is already held by vfs */
-static struct dentry *erofs_lookup(struct inode *dir,
- struct dentry *dentry,
- unsigned int flags)
-{
- int err;
- erofs_nid_t nid;
- unsigned int d_type;
- struct inode *inode;
-
- DBG_BUGON(!d_really_is_negative(dentry));
- /* dentry must be unhashed in lookup, no need to worry about */
- DBG_BUGON(!d_unhashed(dentry));
-
- trace_erofs_lookup(dir, dentry, flags);
-
- /* file name exceeds fs limit */
- if (unlikely(dentry->d_name.len > EROFS_NAME_LEN))
- return ERR_PTR(-ENAMETOOLONG);
-
- /* false uninitialized warnings on gcc 4.8.x */
- err = erofs_namei(dir, &dentry->d_name, &nid, &d_type);
-
- if (err == -ENOENT) {
- /* negative dentry */
- inode = NULL;
- } else if (unlikely(err)) {
- inode = ERR_PTR(err);
- } else {
- debugln("%s, %s (nid %llu) found, d_type %u", __func__,
- dentry->d_name.name, nid, d_type);
- inode = erofs_iget(dir->i_sb, nid, d_type == EROFS_FT_DIR);
- }
- return d_splice_alias(inode, dentry);
-}
-
-const struct inode_operations erofs_dir_iops = {
- .lookup = erofs_lookup,
- .getattr = erofs_getattr,
-#ifdef CONFIG_EROFS_FS_XATTR
- .listxattr = erofs_listxattr,
-#endif
- .get_acl = erofs_get_acl,
-};
-
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