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WSL2-Linux-Kernel
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WSL2-Linux-Kernel/fs/cifs/readdir.c

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30 KiB
C
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/*
* fs/cifs/readdir.c
*
* Directory search handling
*
* Copyright (C) International Business Machines Corp., 2004, 2008
* Copyright (C) Red Hat, Inc., 2011
* Author(s): Steve French (sfrench@us.ibm.com)
*
* This library is free software; you can redistribute it and/or modify
* it under the terms of the GNU Lesser General Public License as published
* by the Free Software Foundation; either version 2.1 of the License, or
* (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
* the GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <linux/fs.h>
#include <linux/pagemap.h>
#include <linux/slab.h>
#include <linux/stat.h>
#include "cifspdu.h"
#include "cifsglob.h"
#include "cifsproto.h"
#include "cifs_unicode.h"
#include "cifs_debug.h"
#include "cifs_fs_sb.h"
#include "cifsfs.h"
#include "smb2proto.h"
/*
* To be safe - for UCS to UTF-8 with strings loaded with the rare long
* characters alloc more to account for such multibyte target UTF-8
* characters.
*/
#define UNICODE_NAME_MAX ((4 * NAME_MAX) + 2)
#ifdef CONFIG_CIFS_DEBUG2
static void dump_cifs_file_struct(struct file *file, char *label)
{
struct cifsFileInfo *cf;
if (file) {
cf = file->private_data;
if (cf == NULL) {
cifs_dbg(FYI, "empty cifs private file data\n");
return;
}
if (cf->invalidHandle)
cifs_dbg(FYI, "Invalid handle\n");
if (cf->srch_inf.endOfSearch)
cifs_dbg(FYI, "end of search\n");
if (cf->srch_inf.emptyDir)
cifs_dbg(FYI, "empty dir\n");
}
}
#else
static inline void dump_cifs_file_struct(struct file *file, char *label)
{
}
#endif /* DEBUG2 */
/*
* Attempt to preload the dcache with the results from the FIND_FIRST/NEXT
*
* Find the dentry that matches "name". If there isn't one, create one. If it's
* a negative dentry or the uniqueid or filetype(mode) changed,
* then drop it and recreate it.
*/
static void
cifs_prime_dcache(struct dentry *parent, struct qstr *name,
struct cifs_fattr *fattr)
{
struct dentry *dentry, *alias;
struct inode *inode;
struct super_block *sb = parent->d_sb;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
DECLARE_WAIT_QUEUE_HEAD_ONSTACK(wq);
cifs_dbg(FYI, "%s: for %s\n", __func__, name->name);
dentry = d_hash_and_lookup(parent, name);
if (!dentry) {
/*
* If we know that the inode will need to be revalidated
* immediately, then don't create a new dentry for it.
* We'll end up doing an on the wire call either way and
* this spares us an invalidation.
*/
if (fattr->cf_flags & CIFS_FATTR_NEED_REVAL)
return;
retry:
dentry = d_alloc_parallel(parent, name, &wq);
}
if (IS_ERR(dentry))
return;
if (!d_in_lookup(dentry)) {
inode = d_inode(dentry);
if (inode) {
if (d_mountpoint(dentry)) {
dput(dentry);
return;
}
/*
* If we're generating inode numbers, then we don't
* want to clobber the existing one with the one that
* the readdir code created.
*/
if (!(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM))
fattr->cf_uniqueid = CIFS_I(inode)->uniqueid;
/* update inode in place
* if both i_ino and i_mode didn't change */
if (CIFS_I(inode)->uniqueid == fattr->cf_uniqueid &&
(inode->i_mode & S_IFMT) ==
(fattr->cf_mode & S_IFMT)) {
cifs_fattr_to_inode(inode, fattr);
dput(dentry);
return;
}
}
d_invalidate(dentry);
dput(dentry);
goto retry;
} else {
inode = cifs_iget(sb, fattr);
if (!inode)
inode = ERR_PTR(-ENOMEM);
alias = d_splice_alias(inode, dentry);
d_lookup_done(dentry);
if (alias && !IS_ERR(alias))
dput(alias);
}
dput(dentry);
}
static bool reparse_file_needs_reval(const struct cifs_fattr *fattr)
{
if (!(fattr->cf_cifsattrs & ATTR_REPARSE))
return false;
/*
* The DFS tags should be only intepreted by server side as per
* MS-FSCC 2.1.2.1, but let's include them anyway.
*
* Besides, if cf_cifstag is unset (0), then we still need it to be
* revalidated to know exactly what reparse point it is.
*/
switch (fattr->cf_cifstag) {
case IO_REPARSE_TAG_DFS:
case IO_REPARSE_TAG_DFSR:
case IO_REPARSE_TAG_SYMLINK:
case IO_REPARSE_TAG_NFS:
case 0:
return true;
}
return false;
}
static void
cifs_fill_common_info(struct cifs_fattr *fattr, struct cifs_sb_info *cifs_sb)
{
fattr->cf_uid = cifs_sb->mnt_uid;
fattr->cf_gid = cifs_sb->mnt_gid;
/*
* The IO_REPARSE_TAG_LX_ tags originally were used by WSL but they
* are preferred by the Linux client in some cases since, unlike
* the NFS reparse tag (or EAs), they don't require an extra query
* to determine which type of special file they represent.
* TODO: go through all documented reparse tags to see if we can
* reasonably map some of them to directories vs. files vs. symlinks
*/
if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
fattr->cf_dtype = DT_DIR;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_SYMLINK) {
fattr->cf_mode |= S_IFLNK | cifs_sb->mnt_file_mode;
fattr->cf_dtype = DT_LNK;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_FIFO) {
fattr->cf_mode |= S_IFIFO | cifs_sb->mnt_file_mode;
fattr->cf_dtype = DT_FIFO;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_AF_UNIX) {
fattr->cf_mode |= S_IFSOCK | cifs_sb->mnt_file_mode;
fattr->cf_dtype = DT_SOCK;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_CHR) {
fattr->cf_mode |= S_IFCHR | cifs_sb->mnt_file_mode;
fattr->cf_dtype = DT_CHR;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_BLK) {
fattr->cf_mode |= S_IFBLK | cifs_sb->mnt_file_mode;
fattr->cf_dtype = DT_BLK;
} else { /* TODO: should we mark some other reparse points (like DFSR) as directories? */
fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
fattr->cf_dtype = DT_REG;
}
/*
* We need to revalidate it further to make a decision about whether it
* is a symbolic link, DFS referral or a reparse point with a direct
* access like junctions, deduplicated files, NFS symlinks.
*/
if (reparse_file_needs_reval(fattr))
fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
/* non-unix readdir doesn't provide nlink */
fattr->cf_flags |= CIFS_FATTR_UNKNOWN_NLINK;
if (fattr->cf_cifsattrs & ATTR_READONLY)
fattr->cf_mode &= ~S_IWUGO;
/*
* We of course don't get ACL info in FIND_FIRST/NEXT results, so
* mark it for revalidation so that "ls -l" will look right. It might
* be super-slow, but if we don't do this then the ownership of files
* may look wrong since the inodes may not have timed out by the time
* "ls" does a stat() call on them.
*/
if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_CIFS_ACL) ||
(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MODE_FROM_SID))
fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_UNX_EMUL &&
fattr->cf_cifsattrs & ATTR_SYSTEM) {
if (fattr->cf_eof == 0) {
fattr->cf_mode &= ~S_IFMT;
fattr->cf_mode |= S_IFIFO;
fattr->cf_dtype = DT_FIFO;
} else {
/*
* trying to get the type and mode via SFU can be slow,
* so just call those regular files for now, and mark
* for reval
*/
fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
}
}
}
/* Fill a cifs_fattr struct with info from SMB_FIND_FILE_POSIX_INFO. */
static void
cifs_posix_to_fattr(struct cifs_fattr *fattr, struct smb2_posix_info *info,
struct cifs_sb_info *cifs_sb)
{
struct smb2_posix_info_parsed parsed;
posix_info_parse(info, NULL, &parsed);
memset(fattr, 0, sizeof(*fattr));
fattr->cf_uniqueid = le64_to_cpu(info->Inode);
fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
fattr->cf_eof = le64_to_cpu(info->EndOfFile);
fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
fattr->cf_ctime = cifs_NTtimeToUnix(info->CreationTime);
fattr->cf_nlink = le32_to_cpu(info->HardLinks);
fattr->cf_cifsattrs = le32_to_cpu(info->DosAttributes);
/*
* Since we set the inode type below we need to mask off
* to avoid strange results if bits set above.
* XXX: why not make server&client use the type bits?
*/
fattr->cf_mode = le32_to_cpu(info->Mode) & ~S_IFMT;
cifs_dbg(FYI, "posix fattr: dev %d, reparse %d, mode %o\n",
le32_to_cpu(info->DeviceId),
le32_to_cpu(info->ReparseTag),
le32_to_cpu(info->Mode));
if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
fattr->cf_mode |= S_IFDIR;
fattr->cf_dtype = DT_DIR;
} else {
/*
* mark anything that is not a dir as regular
* file. special files should have the REPARSE
* attribute and will be marked as needing revaluation
*/
fattr->cf_mode |= S_IFREG;
fattr->cf_dtype = DT_REG;
}
if (reparse_file_needs_reval(fattr))
fattr->cf_flags |= CIFS_FATTR_NEED_REVAL;
sid_to_id(cifs_sb, &parsed.owner, fattr, SIDOWNER);
sid_to_id(cifs_sb, &parsed.group, fattr, SIDGROUP);
}
static void __dir_info_to_fattr(struct cifs_fattr *fattr, const void *info)
{
const FILE_DIRECTORY_INFO *fi = info;
memset(fattr, 0, sizeof(*fattr));
fattr->cf_cifsattrs = le32_to_cpu(fi->ExtFileAttributes);
fattr->cf_eof = le64_to_cpu(fi->EndOfFile);
fattr->cf_bytes = le64_to_cpu(fi->AllocationSize);
fattr->cf_createtime = le64_to_cpu(fi->CreationTime);
fattr->cf_atime = cifs_NTtimeToUnix(fi->LastAccessTime);
fattr->cf_ctime = cifs_NTtimeToUnix(fi->ChangeTime);
fattr->cf_mtime = cifs_NTtimeToUnix(fi->LastWriteTime);
}
void
cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
struct cifs_sb_info *cifs_sb)
{
__dir_info_to_fattr(fattr, info);
cifs_fill_common_info(fattr, cifs_sb);
}
static void cifs_fulldir_info_to_fattr(struct cifs_fattr *fattr,
SEARCH_ID_FULL_DIR_INFO *info,
struct cifs_sb_info *cifs_sb)
{
__dir_info_to_fattr(fattr, info);
/* See MS-FSCC 2.4.18 FileIdFullDirectoryInformation */
if (fattr->cf_cifsattrs & ATTR_REPARSE)
fattr->cf_cifstag = le32_to_cpu(info->EaSize);
cifs_fill_common_info(fattr, cifs_sb);
}
static void
cifs_std_info_to_fattr(struct cifs_fattr *fattr, FIND_FILE_STANDARD_INFO *info,
struct cifs_sb_info *cifs_sb)
{
int offset = cifs_sb_master_tcon(cifs_sb)->ses->server->timeAdj;
memset(fattr, 0, sizeof(*fattr));
fattr->cf_atime = cnvrtDosUnixTm(info->LastAccessDate,
info->LastAccessTime, offset);
fattr->cf_ctime = cnvrtDosUnixTm(info->LastWriteDate,
info->LastWriteTime, offset);
fattr->cf_mtime = cnvrtDosUnixTm(info->LastWriteDate,
info->LastWriteTime, offset);
fattr->cf_cifsattrs = le16_to_cpu(info->Attributes);
fattr->cf_bytes = le32_to_cpu(info->AllocationSize);
fattr->cf_eof = le32_to_cpu(info->DataSize);
cifs_fill_common_info(fattr, cifs_sb);
}
/* BB eventually need to add the following helper function to
resolve NT_STATUS_STOPPED_ON_SYMLINK return code when
we try to do FindFirst on (NTFS) directory symlinks */
/*
int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb,
unsigned int xid)
{
__u16 fid;
int len;
int oplock = 0;
int rc;
struct cifs_tcon *ptcon = cifs_sb_tcon(cifs_sb);
char *tmpbuffer;
rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ,
OPEN_REPARSE_POINT, &fid, &oplock, NULL,
cifs_sb->local_nls,
cifs_remap(cifs_sb);
if (!rc) {
tmpbuffer = kmalloc(maxpath);
rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
tmpbuffer,
maxpath -1,
fid,
cifs_sb->local_nls);
if (CIFSSMBClose(xid, ptcon, fid)) {
cifs_dbg(FYI, "Error closing temporary reparsepoint open\n");
}
}
}
*/
static int
initiate_cifs_search(const unsigned int xid, struct file *file,
char *full_path)
{
__u16 search_flags;
int rc = 0;
struct cifsFileInfo *cifsFile;
struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
struct tcon_link *tlink = NULL;
struct cifs_tcon *tcon;
struct TCP_Server_Info *server;
if (file->private_data == NULL) {
tlink = cifs_sb_tlink(cifs_sb);
if (IS_ERR(tlink))
return PTR_ERR(tlink);
cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
if (cifsFile == NULL) {
rc = -ENOMEM;
goto error_exit;
}
spin_lock_init(&cifsFile->file_info_lock);
file->private_data = cifsFile;
cifsFile->tlink = cifs_get_tlink(tlink);
tcon = tlink_tcon(tlink);
} else {
cifsFile = file->private_data;
tcon = tlink_tcon(cifsFile->tlink);
}
server = tcon->ses->server;
if (!server->ops->query_dir_first) {
rc = -ENOSYS;
goto error_exit;
}
cifsFile->invalidHandle = true;
cifsFile->srch_inf.endOfSearch = false;
cifs_dbg(FYI, "Full path: %s start at: %lld\n", full_path, file->f_pos);
ffirst_retry:
/* test for Unix extensions */
/* but now check for them on the share/mount not on the SMB session */
/* if (cap_unix(tcon->ses) { */
if (tcon->unix_ext)
cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
else if (tcon->posix_extensions)
cifsFile->srch_inf.info_level = SMB_FIND_FILE_POSIX_INFO;
else if ((tcon->ses->capabilities &
tcon->ses->server->vals->cap_nt_find) == 0) {
cifsFile->srch_inf.info_level = SMB_FIND_FILE_INFO_STANDARD;
} else if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM) {
cifsFile->srch_inf.info_level = SMB_FIND_FILE_ID_FULL_DIR_INFO;
} else /* not srvinos - BB fixme add check for backlevel? */ {
cifsFile->srch_inf.info_level = SMB_FIND_FILE_DIRECTORY_INFO;
}
search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
if (backup_cred(cifs_sb))
search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
rc = server->ops->query_dir_first(xid, tcon, full_path, cifs_sb,
&cifsFile->fid, search_flags,
&cifsFile->srch_inf);
if (rc == 0)
cifsFile->invalidHandle = false;
/* BB add following call to handle readdir on new NTFS symlink errors
else if STATUS_STOPPED_ON_SYMLINK
call get_symlink_reparse_path and retry with new path */
else if ((rc == -EOPNOTSUPP) &&
(cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
cifs_sb->mnt_cifs_flags &= ~CIFS_MOUNT_SERVER_INUM;
goto ffirst_retry;
}
error_exit:
cifs_put_tlink(tlink);
return rc;
}
/* return length of unicode string in bytes */
static int cifs_unicode_bytelen(const char *str)
{
int len;
const __le16 *ustr = (const __le16 *)str;
for (len = 0; len <= PATH_MAX; len++) {
if (ustr[len] == 0)
return len << 1;
}
cifs_dbg(FYI, "Unicode string longer than PATH_MAX found\n");
return len << 1;
}
static char *nxt_dir_entry(char *old_entry, char *end_of_smb, int level)
{
char *new_entry;
FILE_DIRECTORY_INFO *pDirInfo = (FILE_DIRECTORY_INFO *)old_entry;
if (level == SMB_FIND_FILE_INFO_STANDARD) {
FIND_FILE_STANDARD_INFO *pfData;
pfData = (FIND_FILE_STANDARD_INFO *)pDirInfo;
new_entry = old_entry + sizeof(FIND_FILE_STANDARD_INFO) +
pfData->FileNameLength;
} else {
u32 next_offset = le32_to_cpu(pDirInfo->NextEntryOffset);
if (old_entry + next_offset < old_entry) {
cifs_dbg(VFS, "Invalid offset %u\n", next_offset);
return NULL;
}
new_entry = old_entry + next_offset;
}
cifs_dbg(FYI, "new entry %p old entry %p\n", new_entry, old_entry);
/* validate that new_entry is not past end of SMB */
if (new_entry >= end_of_smb) {
cifs_dbg(VFS, "search entry %p began after end of SMB %p old entry %p\n",
new_entry, end_of_smb, old_entry);
return NULL;
} else if (((level == SMB_FIND_FILE_INFO_STANDARD) &&
(new_entry + sizeof(FIND_FILE_STANDARD_INFO) > end_of_smb))
|| ((level != SMB_FIND_FILE_INFO_STANDARD) &&
(new_entry + sizeof(FILE_DIRECTORY_INFO) > end_of_smb))) {
cifs_dbg(VFS, "search entry %p extends after end of SMB %p\n",
new_entry, end_of_smb);
return NULL;
} else
return new_entry;
}
struct cifs_dirent {
const char *name;
size_t namelen;
u32 resume_key;
u64 ino;
};
static void cifs_fill_dirent_posix(struct cifs_dirent *de,
const struct smb2_posix_info *info)
{
struct smb2_posix_info_parsed parsed;
/* payload should have already been checked at this point */
if (posix_info_parse(info, NULL, &parsed) < 0) {
cifs_dbg(VFS, "Invalid POSIX info payload\n");
return;
}
de->name = parsed.name;
de->namelen = parsed.name_len;
de->resume_key = info->Ignored;
de->ino = le64_to_cpu(info->Inode);
}
static void cifs_fill_dirent_unix(struct cifs_dirent *de,
const FILE_UNIX_INFO *info, bool is_unicode)
{
de->name = &info->FileName[0];
if (is_unicode)
de->namelen = cifs_unicode_bytelen(de->name);
else
de->namelen = strnlen(de->name, PATH_MAX);
de->resume_key = info->ResumeKey;
de->ino = le64_to_cpu(info->basic.UniqueId);
}
static void cifs_fill_dirent_dir(struct cifs_dirent *de,
const FILE_DIRECTORY_INFO *info)
{
de->name = &info->FileName[0];
de->namelen = le32_to_cpu(info->FileNameLength);
de->resume_key = info->FileIndex;
}
static void cifs_fill_dirent_full(struct cifs_dirent *de,
const FILE_FULL_DIRECTORY_INFO *info)
{
de->name = &info->FileName[0];
de->namelen = le32_to_cpu(info->FileNameLength);
de->resume_key = info->FileIndex;
}
static void cifs_fill_dirent_search(struct cifs_dirent *de,
const SEARCH_ID_FULL_DIR_INFO *info)
{
de->name = &info->FileName[0];
de->namelen = le32_to_cpu(info->FileNameLength);
de->resume_key = info->FileIndex;
de->ino = le64_to_cpu(info->UniqueId);
}
static void cifs_fill_dirent_both(struct cifs_dirent *de,
const FILE_BOTH_DIRECTORY_INFO *info)
{
de->name = &info->FileName[0];
de->namelen = le32_to_cpu(info->FileNameLength);
de->resume_key = info->FileIndex;
}
static void cifs_fill_dirent_std(struct cifs_dirent *de,
const FIND_FILE_STANDARD_INFO *info)
{
de->name = &info->FileName[0];
/* one byte length, no endianess conversion */
de->namelen = info->FileNameLength;
de->resume_key = info->ResumeKey;
}
static int cifs_fill_dirent(struct cifs_dirent *de, const void *info,
u16 level, bool is_unicode)
{
memset(de, 0, sizeof(*de));
switch (level) {
case SMB_FIND_FILE_POSIX_INFO:
cifs_fill_dirent_posix(de, info);
break;
case SMB_FIND_FILE_UNIX:
cifs_fill_dirent_unix(de, info, is_unicode);
break;
case SMB_FIND_FILE_DIRECTORY_INFO:
cifs_fill_dirent_dir(de, info);
break;
case SMB_FIND_FILE_FULL_DIRECTORY_INFO:
cifs_fill_dirent_full(de, info);
break;
case SMB_FIND_FILE_ID_FULL_DIR_INFO:
cifs_fill_dirent_search(de, info);
break;
case SMB_FIND_FILE_BOTH_DIRECTORY_INFO:
cifs_fill_dirent_both(de, info);
break;
case SMB_FIND_FILE_INFO_STANDARD:
cifs_fill_dirent_std(de, info);
break;
default:
cifs_dbg(FYI, "Unknown findfirst level %d\n", level);
return -EINVAL;
}
return 0;
}
#define UNICODE_DOT cpu_to_le16(0x2e)
/* return 0 if no match and 1 for . (current directory) and 2 for .. (parent) */
static int cifs_entry_is_dot(struct cifs_dirent *de, bool is_unicode)
{
int rc = 0;
if (!de->name)
return 0;
if (is_unicode) {
__le16 *ufilename = (__le16 *)de->name;
if (de->namelen == 2) {
/* check for . */
if (ufilename[0] == UNICODE_DOT)
rc = 1;
} else if (de->namelen == 4) {
/* check for .. */
if (ufilename[0] == UNICODE_DOT &&
ufilename[1] == UNICODE_DOT)
rc = 2;
}
} else /* ASCII */ {
if (de->namelen == 1) {
if (de->name[0] == '.')
rc = 1;
} else if (de->namelen == 2) {
if (de->name[0] == '.' && de->name[1] == '.')
rc = 2;
}
}
return rc;
}
/* Check if directory that we are searching has changed so we can decide
whether we can use the cached search results from the previous search */
static int is_dir_changed(struct file *file)
{
struct inode *inode = file_inode(file);
struct cifsInodeInfo *cifsInfo = CIFS_I(inode);
if (cifsInfo->time == 0)
return 1; /* directory was changed, perhaps due to unlink */
else
return 0;
}
static int cifs_save_resume_key(const char *current_entry,
struct cifsFileInfo *file_info)
{
struct cifs_dirent de;
int rc;
rc = cifs_fill_dirent(&de, current_entry, file_info->srch_inf.info_level,
file_info->srch_inf.unicode);
if (!rc) {
file_info->srch_inf.presume_name = de.name;
file_info->srch_inf.resume_name_len = de.namelen;
file_info->srch_inf.resume_key = de.resume_key;
}
return rc;
}
/*
* Find the corresponding entry in the search. Note that the SMB server returns
* search entries for . and .. which complicates logic here if we choose to
* parse for them and we do not assume that they are located in the findfirst
* return buffer. We start counting in the buffer with entry 2 and increment for
* every entry (do not increment for . or .. entry).
*/
static int
find_cifs_entry(const unsigned int xid, struct cifs_tcon *tcon, loff_t pos,
struct file *file, char *full_path,
char **current_entry, int *num_to_ret)
{
__u16 search_flags;
int rc = 0;
int pos_in_buf = 0;
loff_t first_entry_in_buffer;
loff_t index_to_find = pos;
struct cifsFileInfo *cfile = file->private_data;
struct cifs_sb_info *cifs_sb = CIFS_FILE_SB(file);
struct TCP_Server_Info *server = tcon->ses->server;
/* check if index in the buffer */
if (!server->ops->query_dir_first || !server->ops->query_dir_next)
return -ENOSYS;
if ((cfile == NULL) || (current_entry == NULL) || (num_to_ret == NULL))
return -ENOENT;
*current_entry = NULL;
first_entry_in_buffer = cfile->srch_inf.index_of_last_entry -
cfile->srch_inf.entries_in_buffer;
/*
* If first entry in buf is zero then is first buffer
* in search response data which means it is likely . and ..
* will be in this buffer, although some servers do not return
* . and .. for the root of a drive and for those we need
* to start two entries earlier.
*/
dump_cifs_file_struct(file, "In fce ");
if (((index_to_find < cfile->srch_inf.index_of_last_entry) &&
is_dir_changed(file)) || (index_to_find < first_entry_in_buffer)) {
/* close and restart search */
cifs_dbg(FYI, "search backing up - close and restart search\n");
spin_lock(&cfile->file_info_lock);
if (server->ops->dir_needs_close(cfile)) {
cfile->invalidHandle = true;
spin_unlock(&cfile->file_info_lock);
if (server->ops->close_dir)
server->ops->close_dir(xid, tcon, &cfile->fid);
} else
spin_unlock(&cfile->file_info_lock);
if (cfile->srch_inf.ntwrk_buf_start) {
cifs_dbg(FYI, "freeing SMB ff cache buf on search rewind\n");
if (cfile->srch_inf.smallBuf)
cifs_small_buf_release(cfile->srch_inf.
ntwrk_buf_start);
else
cifs_buf_release(cfile->srch_inf.
ntwrk_buf_start);
cfile->srch_inf.ntwrk_buf_start = NULL;
}
rc = initiate_cifs_search(xid, file, full_path);
if (rc) {
cifs_dbg(FYI, "error %d reinitiating a search on rewind\n",
rc);
return rc;
}
/* FindFirst/Next set last_entry to NULL on malformed reply */
if (cfile->srch_inf.last_entry)
cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
}
search_flags = CIFS_SEARCH_CLOSE_AT_END | CIFS_SEARCH_RETURN_RESUME;
if (backup_cred(cifs_sb))
search_flags |= CIFS_SEARCH_BACKUP_SEARCH;
while ((index_to_find >= cfile->srch_inf.index_of_last_entry) &&
(rc == 0) && !cfile->srch_inf.endOfSearch) {
cifs_dbg(FYI, "calling findnext2\n");
rc = server->ops->query_dir_next(xid, tcon, &cfile->fid,
search_flags,
&cfile->srch_inf);
/* FindFirst/Next set last_entry to NULL on malformed reply */
if (cfile->srch_inf.last_entry)
cifs_save_resume_key(cfile->srch_inf.last_entry, cfile);
if (rc)
return -ENOENT;
}
if (index_to_find < cfile->srch_inf.index_of_last_entry) {
/* we found the buffer that contains the entry */
/* scan and find it */
int i;
char *cur_ent;
char *end_of_smb;
if (cfile->srch_inf.ntwrk_buf_start == NULL) {
cifs_dbg(VFS, "ntwrk_buf_start is NULL during readdir\n");
return -EIO;
}
end_of_smb = cfile->srch_inf.ntwrk_buf_start +
server->ops->calc_smb_size(
cfile->srch_inf.ntwrk_buf_start,
server);
cur_ent = cfile->srch_inf.srch_entries_start;
first_entry_in_buffer = cfile->srch_inf.index_of_last_entry
- cfile->srch_inf.entries_in_buffer;
pos_in_buf = index_to_find - first_entry_in_buffer;
cifs_dbg(FYI, "found entry - pos_in_buf %d\n", pos_in_buf);
for (i = 0; (i < (pos_in_buf)) && (cur_ent != NULL); i++) {
/* go entry by entry figuring out which is first */
cur_ent = nxt_dir_entry(cur_ent, end_of_smb,
cfile->srch_inf.info_level);
}
if ((cur_ent == NULL) && (i < pos_in_buf)) {
/* BB fixme - check if we should flag this error */
cifs_dbg(VFS, "reached end of buf searching for pos in buf %d index to find %lld rc %d\n",
pos_in_buf, index_to_find, rc);
}
rc = 0;
*current_entry = cur_ent;
} else {
cifs_dbg(FYI, "index not in buffer - could not findnext into it\n");
return 0;
}
if (pos_in_buf >= cfile->srch_inf.entries_in_buffer) {
cifs_dbg(FYI, "can not return entries pos_in_buf beyond last\n");
*num_to_ret = 0;
} else
*num_to_ret = cfile->srch_inf.entries_in_buffer - pos_in_buf;
return rc;
}
static int cifs_filldir(char *find_entry, struct file *file,
struct dir_context *ctx,
char *scratch_buf, unsigned int max_len)
{
struct cifsFileInfo *file_info = file->private_data;
struct super_block *sb = file_inode(file)->i_sb;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
struct cifs_dirent de = { NULL, };
struct cifs_fattr fattr;
struct qstr name;
int rc = 0;
ino_t ino;
rc = cifs_fill_dirent(&de, find_entry, file_info->srch_inf.info_level,
file_info->srch_inf.unicode);
if (rc)
return rc;
if (de.namelen > max_len) {
cifs_dbg(VFS, "bad search response length %zd past smb end\n",
de.namelen);
return -EINVAL;
}
/* skip . and .. since we added them first */
if (cifs_entry_is_dot(&de, file_info->srch_inf.unicode))
return 0;
if (file_info->srch_inf.unicode) {
struct nls_table *nlt = cifs_sb->local_nls;
int map_type;
map_type = cifs_remap(cifs_sb);
name.name = scratch_buf;
name.len =
cifs_from_utf16((char *)name.name, (__le16 *)de.name,
UNICODE_NAME_MAX,
min_t(size_t, de.namelen,
(size_t)max_len), nlt, map_type);
name.len -= nls_nullsize(nlt);
} else {
name.name = de.name;
name.len = de.namelen;
}
switch (file_info->srch_inf.info_level) {
case SMB_FIND_FILE_POSIX_INFO:
cifs_posix_to_fattr(&fattr,
(struct smb2_posix_info *)find_entry,
cifs_sb);
break;
case SMB_FIND_FILE_UNIX:
cifs_unix_basic_to_fattr(&fattr,
&((FILE_UNIX_INFO *)find_entry)->basic,
cifs_sb);
break;
case SMB_FIND_FILE_INFO_STANDARD:
cifs_std_info_to_fattr(&fattr,
(FIND_FILE_STANDARD_INFO *)find_entry,
cifs_sb);
break;
case SMB_FIND_FILE_ID_FULL_DIR_INFO:
cifs_fulldir_info_to_fattr(&fattr,
(SEARCH_ID_FULL_DIR_INFO *)find_entry,
cifs_sb);
break;
default:
cifs_dir_info_to_fattr(&fattr,
(FILE_DIRECTORY_INFO *)find_entry,
cifs_sb);
break;
}
if (de.ino && (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_SERVER_INUM)) {
fattr.cf_uniqueid = de.ino;
} else {
fattr.cf_uniqueid = iunique(sb, ROOT_I);
cifs_autodisable_serverino(cifs_sb);
}
if ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MF_SYMLINKS) &&
couldbe_mf_symlink(&fattr))
/*
* trying to get the type and mode can be slow,
* so just call those regular files for now, and mark
* for reval
*/
fattr.cf_flags |= CIFS_FATTR_NEED_REVAL;
cifs_prime_dcache(file_dentry(file), &name, &fattr);
ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
return !dir_emit(ctx, name.name, name.len, ino, fattr.cf_dtype);
}
int cifs_readdir(struct file *file, struct dir_context *ctx)
{
int rc = 0;
unsigned int xid;
int i;
struct cifs_tcon *tcon;
struct cifsFileInfo *cifsFile = NULL;
char *current_entry;
int num_to_fill = 0;
char *tmp_buf = NULL;
char *end_of_smb;
unsigned int max_len;
char *full_path = NULL;
xid = get_xid();
full_path = build_path_from_dentry(file_dentry(file));
if (full_path == NULL) {
rc = -ENOMEM;
goto rddir2_exit;
}
/*
* Ensure FindFirst doesn't fail before doing filldir() for '.' and
* '..'. Otherwise we won't be able to notify VFS in case of failure.
*/
if (file->private_data == NULL) {
rc = initiate_cifs_search(xid, file, full_path);
cifs_dbg(FYI, "initiate cifs search rc %d\n", rc);
if (rc)
goto rddir2_exit;
}
if (!dir_emit_dots(file, ctx))
goto rddir2_exit;
/* 1) If search is active,
is in current search buffer?
if it before then restart search
if after then keep searching till find it */
cifsFile = file->private_data;
if (cifsFile->srch_inf.endOfSearch) {
if (cifsFile->srch_inf.emptyDir) {
cifs_dbg(FYI, "End of search, empty dir\n");
rc = 0;
goto rddir2_exit;
}
} /* else {
cifsFile->invalidHandle = true;
tcon->ses->server->close(xid, tcon, &cifsFile->fid);
} */
tcon = tlink_tcon(cifsFile->tlink);
rc = find_cifs_entry(xid, tcon, ctx->pos, file, full_path,
&current_entry, &num_to_fill);
if (rc) {
cifs_dbg(FYI, "fce error %d\n", rc);
goto rddir2_exit;
} else if (current_entry != NULL) {
cifs_dbg(FYI, "entry %lld found\n", ctx->pos);
} else {
cifs_dbg(FYI, "Could not find entry\n");
goto rddir2_exit;
}
cifs_dbg(FYI, "loop through %d times filling dir for net buf %p\n",
num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
max_len = tcon->ses->server->ops->calc_smb_size(
cifsFile->srch_inf.ntwrk_buf_start,
tcon->ses->server);
end_of_smb = cifsFile->srch_inf.ntwrk_buf_start + max_len;
tmp_buf = kmalloc(UNICODE_NAME_MAX, GFP_KERNEL);
if (tmp_buf == NULL) {
rc = -ENOMEM;
goto rddir2_exit;
}
for (i = 0; i < num_to_fill; i++) {
if (current_entry == NULL) {
/* evaluate whether this case is an error */
cifs_dbg(VFS, "past SMB end, num to fill %d i %d\n",
num_to_fill, i);
break;
}
/*
* if buggy server returns . and .. late do we want to
* check for that here?
*/
*tmp_buf = 0;
rc = cifs_filldir(current_entry, file, ctx,
tmp_buf, max_len);
if (rc) {
if (rc > 0)
rc = 0;
break;
}
ctx->pos++;
if (ctx->pos ==
cifsFile->srch_inf.index_of_last_entry) {
cifs_dbg(FYI, "last entry in buf at pos %lld %s\n",
ctx->pos, tmp_buf);
cifs_save_resume_key(current_entry, cifsFile);
break;
} else
current_entry =
nxt_dir_entry(current_entry, end_of_smb,
cifsFile->srch_inf.info_level);
}
kfree(tmp_buf);
rddir2_exit:
kfree(full_path);
free_xid(xid);
return rc;
}
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