linux/fs/cifs/readdir.c
Jeff Layton 7023676f9e cifs: check for NULL last_entry before calling cifs_save_resume_key
Prior to commit eaf35b1, cifs_save_resume_key had some NULL pointer
checks at the top. It turns out that at least one of those NULL
pointer checks is needed after all.

When the LastNameOffset in a FIND reply appears to be beyond the end of
the buffer, CIFSFindFirst and CIFSFindNext will set srch_inf.last_entry
to NULL. Since eaf35b1, the code will now oops in this situation.

Fix this by having the callers check for a NULL last entry pointer
before calling cifs_save_resume_key. No change is needed for the
call site in cifs_readdir as it's not reachable with a NULL
current_entry pointer.

This should fix:

    https://bugzilla.redhat.com/show_bug.cgi?id=750247

Cc: stable@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Reported-by: Adam G. Metzler <adamgmetzler@gmail.com>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
2011-12-08 22:04:47 -06:00

831 lines
23 KiB
C

/*
* 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"
/*
* 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) {
cFYI(1, "empty cifs private file data");
return;
}
if (cf->invalidHandle)
cFYI(1, "invalid handle");
if (cf->srch_inf.endOfSearch)
cFYI(1, "end of search");
if (cf->srch_inf.emptyDir)
cFYI(1, "empty dir");
}
}
#else
static inline void dump_cifs_file_struct(struct file *file, char *label)
{
}
#endif /* DEBUG2 */
/*
* Find the dentry that matches "name". If there isn't one, create one. If it's
* a negative dentry or the uniqueid changed, then drop it and recreate it.
*/
static struct dentry *
cifs_readdir_lookup(struct dentry *parent, struct qstr *name,
struct cifs_fattr *fattr)
{
struct dentry *dentry, *alias;
struct inode *inode;
struct super_block *sb = parent->d_inode->i_sb;
cFYI(1, "For %s", name->name);
if (parent->d_op && parent->d_op->d_hash)
parent->d_op->d_hash(parent, parent->d_inode, name);
else
name->hash = full_name_hash(name->name, name->len);
dentry = d_lookup(parent, name);
if (dentry) {
/* FIXME: check for inode number changes? */
if (dentry->d_inode != NULL)
return dentry;
d_drop(dentry);
dput(dentry);
}
dentry = d_alloc(parent, name);
if (dentry == NULL)
return NULL;
inode = cifs_iget(sb, fattr);
if (!inode) {
dput(dentry);
return NULL;
}
alias = d_materialise_unique(dentry, inode);
if (alias != NULL) {
dput(dentry);
if (IS_ERR(alias))
return NULL;
dentry = alias;
}
return dentry;
}
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;
if (fattr->cf_cifsattrs & ATTR_DIRECTORY) {
fattr->cf_mode = S_IFDIR | cifs_sb->mnt_dir_mode;
fattr->cf_dtype = DT_DIR;
} else {
fattr->cf_mode = S_IFREG | cifs_sb->mnt_file_mode;
fattr->cf_dtype = DT_REG;
}
if (fattr->cf_cifsattrs & ATTR_READONLY)
fattr->cf_mode &= ~S_IWUGO;
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;
}
}
}
static void
cifs_dir_info_to_fattr(struct cifs_fattr *fattr, FILE_DIRECTORY_INFO *info,
struct cifs_sb_info *cifs_sb)
{
memset(fattr, 0, sizeof(*fattr));
fattr->cf_cifsattrs = le32_to_cpu(info->ExtFileAttributes);
fattr->cf_eof = le64_to_cpu(info->EndOfFile);
fattr->cf_bytes = le64_to_cpu(info->AllocationSize);
fattr->cf_createtime = le64_to_cpu(info->CreationTime);
fattr->cf_atime = cifs_NTtimeToUnix(info->LastAccessTime);
fattr->cf_ctime = cifs_NTtimeToUnix(info->ChangeTime);
fattr->cf_mtime = cifs_NTtimeToUnix(info->LastWriteTime);
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,
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_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR);
if (!rc) {
tmpbuffer = kmalloc(maxpath);
rc = CIFSSMBQueryReparseLinkInfo(xid, ptcon, full_path,
tmpbuffer,
maxpath -1,
fid,
cifs_sb->local_nls);
if (CIFSSMBClose(xid, ptcon, fid)) {
cFYI(1, "Error closing temporary reparsepoint open");
}
}
}
*/
static int initiate_cifs_search(const int xid, struct file *file)
{
int rc = 0;
char *full_path = NULL;
struct cifsFileInfo *cifsFile;
struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
struct tcon_link *tlink = NULL;
struct cifs_tcon *pTcon;
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;
}
file->private_data = cifsFile;
cifsFile->tlink = cifs_get_tlink(tlink);
pTcon = tlink_tcon(tlink);
} else {
cifsFile = file->private_data;
pTcon = tlink_tcon(cifsFile->tlink);
}
cifsFile->invalidHandle = true;
cifsFile->srch_inf.endOfSearch = false;
full_path = build_path_from_dentry(file->f_path.dentry);
if (full_path == NULL) {
rc = -ENOMEM;
goto error_exit;
}
cFYI(1, "Full path: %s start at: %lld", 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 (pTcon->ses->capabilities & CAP_UNIX) { */
if (pTcon->unix_ext)
cifsFile->srch_inf.info_level = SMB_FIND_FILE_UNIX;
else if ((pTcon->ses->capabilities &
(CAP_NT_SMBS | 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;
}
rc = CIFSFindFirst(xid, pTcon, full_path, cifs_sb->local_nls,
&cifsFile->netfid, &cifsFile->srch_inf,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR, CIFS_DIR_SEP(cifs_sb));
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:
kfree(full_path);
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;
}
cFYI(1, "Unicode string longer than PATH_MAX found");
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
new_entry = old_entry + le32_to_cpu(pDirInfo->NextEntryOffset);
cFYI(1, "new entry %p old entry %p", new_entry, old_entry);
/* validate that new_entry is not past end of SMB */
if (new_entry >= end_of_smb) {
cERROR(1, "search entry %p began after end of SMB %p old entry %p",
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))) {
cERROR(1, "search entry %p extends after end of SMB %p",
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_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_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:
cFYI(1, "Unknown findfirst level %d", 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->f_path.dentry->d_inode;
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 int xid, struct cifs_tcon *pTcon,
struct file *file, char **ppCurrentEntry, int *num_to_ret)
{
int rc = 0;
int pos_in_buf = 0;
loff_t first_entry_in_buffer;
loff_t index_to_find = file->f_pos;
struct cifsFileInfo *cifsFile = file->private_data;
/* check if index in the buffer */
if ((cifsFile == NULL) || (ppCurrentEntry == NULL) ||
(num_to_ret == NULL))
return -ENOENT;
*ppCurrentEntry = NULL;
first_entry_in_buffer =
cifsFile->srch_inf.index_of_last_entry -
cifsFile->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 < cifsFile->srch_inf.index_of_last_entry) &&
is_dir_changed(file)) ||
(index_to_find < first_entry_in_buffer)) {
/* close and restart search */
cFYI(1, "search backing up - close and restart search");
spin_lock(&cifs_file_list_lock);
if (!cifsFile->srch_inf.endOfSearch &&
!cifsFile->invalidHandle) {
cifsFile->invalidHandle = true;
spin_unlock(&cifs_file_list_lock);
CIFSFindClose(xid, pTcon, cifsFile->netfid);
} else
spin_unlock(&cifs_file_list_lock);
if (cifsFile->srch_inf.ntwrk_buf_start) {
cFYI(1, "freeing SMB ff cache buf on search rewind");
if (cifsFile->srch_inf.smallBuf)
cifs_small_buf_release(cifsFile->srch_inf.
ntwrk_buf_start);
else
cifs_buf_release(cifsFile->srch_inf.
ntwrk_buf_start);
cifsFile->srch_inf.ntwrk_buf_start = NULL;
}
rc = initiate_cifs_search(xid, file);
if (rc) {
cFYI(1, "error %d reinitiating a search on rewind",
rc);
return rc;
}
/* FindFirst/Next set last_entry to NULL on malformed reply */
if (cifsFile->srch_inf.last_entry)
cifs_save_resume_key(cifsFile->srch_inf.last_entry,
cifsFile);
}
while ((index_to_find >= cifsFile->srch_inf.index_of_last_entry) &&
(rc == 0) && !cifsFile->srch_inf.endOfSearch) {
cFYI(1, "calling findnext2");
rc = CIFSFindNext(xid, pTcon, cifsFile->netfid,
&cifsFile->srch_inf);
/* FindFirst/Next set last_entry to NULL on malformed reply */
if (cifsFile->srch_inf.last_entry)
cifs_save_resume_key(cifsFile->srch_inf.last_entry,
cifsFile);
if (rc)
return -ENOENT;
}
if (index_to_find < cifsFile->srch_inf.index_of_last_entry) {
/* we found the buffer that contains the entry */
/* scan and find it */
int i;
char *current_entry;
char *end_of_smb = cifsFile->srch_inf.ntwrk_buf_start +
smbCalcSize((struct smb_hdr *)
cifsFile->srch_inf.ntwrk_buf_start);
current_entry = cifsFile->srch_inf.srch_entries_start;
first_entry_in_buffer = cifsFile->srch_inf.index_of_last_entry
- cifsFile->srch_inf.entries_in_buffer;
pos_in_buf = index_to_find - first_entry_in_buffer;
cFYI(1, "found entry - pos_in_buf %d", pos_in_buf);
for (i = 0; (i < (pos_in_buf)) && (current_entry != NULL); i++) {
/* go entry by entry figuring out which is first */
current_entry = nxt_dir_entry(current_entry, end_of_smb,
cifsFile->srch_inf.info_level);
}
if ((current_entry == NULL) && (i < pos_in_buf)) {
/* BB fixme - check if we should flag this error */
cERROR(1, "reached end of buf searching for pos in buf"
" %d index to find %lld rc %d",
pos_in_buf, index_to_find, rc);
}
rc = 0;
*ppCurrentEntry = current_entry;
} else {
cFYI(1, "index not in buffer - could not findnext into it");
return 0;
}
if (pos_in_buf >= cifsFile->srch_inf.entries_in_buffer) {
cFYI(1, "can not return entries pos_in_buf beyond last");
*num_to_ret = 0;
} else
*num_to_ret = cifsFile->srch_inf.entries_in_buffer - pos_in_buf;
return rc;
}
static int cifs_filldir(char *find_entry, struct file *file, filldir_t filldir,
void *dirent, char *scratch_buf, unsigned int max_len)
{
struct cifsFileInfo *file_info = file->private_data;
struct super_block *sb = file->f_path.dentry->d_sb;
struct cifs_sb_info *cifs_sb = CIFS_SB(sb);
struct cifs_dirent de = { NULL, };
struct cifs_fattr fattr;
struct dentry *dentry;
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) {
cERROR(1, "bad search response length %zd past smb end",
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;
name.name = scratch_buf;
name.len =
cifs_from_ucs2((char *)name.name, (__le16 *)de.name,
UNICODE_NAME_MAX,
min(de.namelen, (size_t)max_len), nlt,
cifs_sb->mnt_cifs_flags &
CIFS_MOUNT_MAP_SPECIAL_CHR);
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_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;
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) &&
CIFSCouldBeMFSymlink(&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;
ino = cifs_uniqueid_to_ino_t(fattr.cf_uniqueid);
dentry = cifs_readdir_lookup(file->f_dentry, &name, &fattr);
rc = filldir(dirent, name.name, name.len, file->f_pos, ino,
fattr.cf_dtype);
dput(dentry);
return rc;
}
int cifs_readdir(struct file *file, void *direntry, filldir_t filldir)
{
int rc = 0;
int xid, i;
struct cifs_tcon *pTcon;
struct cifsFileInfo *cifsFile = NULL;
char *current_entry;
int num_to_fill = 0;
char *tmp_buf = NULL;
char *end_of_smb;
unsigned int max_len;
xid = GetXid();
/*
* 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);
cFYI(1, "initiate cifs search rc %d", rc);
if (rc)
goto rddir2_exit;
}
switch ((int) file->f_pos) {
case 0:
if (filldir(direntry, ".", 1, file->f_pos,
file->f_path.dentry->d_inode->i_ino, DT_DIR) < 0) {
cERROR(1, "Filldir for current dir failed");
rc = -ENOMEM;
break;
}
file->f_pos++;
case 1:
if (filldir(direntry, "..", 2, file->f_pos,
parent_ino(file->f_path.dentry), DT_DIR) < 0) {
cERROR(1, "Filldir for parent dir failed");
rc = -ENOMEM;
break;
}
file->f_pos++;
default:
/* 1) If search is active,
is in current search buffer?
if it before then restart search
if after then keep searching till find it */
if (file->private_data == NULL) {
rc = -EINVAL;
FreeXid(xid);
return rc;
}
cifsFile = file->private_data;
if (cifsFile->srch_inf.endOfSearch) {
if (cifsFile->srch_inf.emptyDir) {
cFYI(1, "End of search, empty dir");
rc = 0;
break;
}
} /* else {
cifsFile->invalidHandle = true;
CIFSFindClose(xid, pTcon, cifsFile->netfid);
} */
pTcon = tlink_tcon(cifsFile->tlink);
rc = find_cifs_entry(xid, pTcon, file,
&current_entry, &num_to_fill);
if (rc) {
cFYI(1, "fce error %d", rc);
goto rddir2_exit;
} else if (current_entry != NULL) {
cFYI(1, "entry %lld found", file->f_pos);
} else {
cFYI(1, "could not find entry");
goto rddir2_exit;
}
cFYI(1, "loop through %d times filling dir for net buf %p",
num_to_fill, cifsFile->srch_inf.ntwrk_buf_start);
max_len = smbCalcSize((struct smb_hdr *)
cifsFile->srch_inf.ntwrk_buf_start);
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;
break;
}
for (i = 0; (i < num_to_fill) && (rc == 0); i++) {
if (current_entry == NULL) {
/* evaluate whether this case is an error */
cERROR(1, "past SMB end, num to fill %d i %d",
num_to_fill, i);
break;
}
/* if buggy server returns . and .. late do
we want to check for that here? */
rc = cifs_filldir(current_entry, file,
filldir, direntry, tmp_buf, max_len);
if (rc == -EOVERFLOW) {
rc = 0;
break;
}
file->f_pos++;
if (file->f_pos ==
cifsFile->srch_inf.index_of_last_entry) {
cFYI(1, "last entry in buf at pos %lld %s",
file->f_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);
break;
} /* end switch */
rddir2_exit:
FreeXid(xid);
return rc;
}