linux/fs/cifs/readdir.c
Steve French 099dd788e3 cifs: remove pathname for file from SPDX header
checkpatch complains about source files with filenames (e.g. in
these cases just below the SPDX header in comments at the top of
various files in fs/cifs). It also is helpful to change this now
so will be less confusing when the parent directory is renamed
e.g. from fs/cifs to fs/smb_client (or fs/smbfs)

Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-13 14:51:10 -05:00

1057 lines
30 KiB
C

// SPDX-License-Identifier: LGPL-2.1
/*
*
* 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)
*
*/
#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"
#include "fs_context.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 &&
cifs_fattr_to_inode(inode, fattr) == 0) {
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->ctx->linux_uid;
fattr->cf_gid = cifs_sb->ctx->linux_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->ctx->dir_mode;
fattr->cf_dtype = DT_DIR;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_SYMLINK) {
fattr->cf_mode |= S_IFLNK | cifs_sb->ctx->file_mode;
fattr->cf_dtype = DT_LNK;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_FIFO) {
fattr->cf_mode |= S_IFIFO | cifs_sb->ctx->file_mode;
fattr->cf_dtype = DT_FIFO;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_AF_UNIX) {
fattr->cf_mode |= S_IFSOCK | cifs_sb->ctx->file_mode;
fattr->cf_dtype = DT_SOCK;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_CHR) {
fattr->cf_mode |= S_IFCHR | cifs_sb->ctx->file_mode;
fattr->cf_dtype = DT_CHR;
} else if (fattr->cf_cifstag == IO_REPARSE_TAG_LX_BLK) {
fattr->cf_mode |= S_IFBLK | cifs_sb->ctx->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->ctx->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 2.4.19 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,
const 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;
}
static int
initiate_cifs_search(const unsigned int xid, struct file *file,
const char *full_path)
{
int rc, retry_count = 0;
do {
rc = _initiate_cifs_search(xid, file, full_path);
/*
* If we don't have enough credits to start reading the
* directory just try again after short wait.
*/
if (rc != -EDEADLK)
break;
usleep_range(512, 2048);
} while (retry_count++ < 5);
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, const 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;
const char *full_path;
void *page = alloc_dentry_path();
xid = get_xid();
full_path = build_path_from_dentry(file_dentry(file), page);
if (IS_ERR(full_path)) {
rc = PTR_ERR(full_path);
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:
free_dentry_path(page);
free_xid(xid);
return rc;
}