559 строки
13 KiB
C
559 строки
13 KiB
C
// SPDX-License-Identifier: GPL-2.0
|
|
/*
|
|
* Functions to handle the cached directory entries
|
|
*
|
|
* Copyright (c) 2022, Ronnie Sahlberg <lsahlber@redhat.com>
|
|
*/
|
|
|
|
#include <linux/namei.h>
|
|
#include "cifsglob.h"
|
|
#include "cifsproto.h"
|
|
#include "cifs_debug.h"
|
|
#include "smb2proto.h"
|
|
#include "cached_dir.h"
|
|
|
|
static struct cached_fid *init_cached_dir(const char *path);
|
|
static void free_cached_dir(struct cached_fid *cfid);
|
|
|
|
static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
|
|
const char *path,
|
|
bool lookup_only)
|
|
{
|
|
struct cached_fid *cfid;
|
|
|
|
spin_lock(&cfids->cfid_list_lock);
|
|
list_for_each_entry(cfid, &cfids->entries, entry) {
|
|
if (!strcmp(cfid->path, path)) {
|
|
/*
|
|
* If it doesn't have a lease it is either not yet
|
|
* fully cached or it may be in the process of
|
|
* being deleted due to a lease break.
|
|
*/
|
|
if (!cfid->has_lease) {
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return NULL;
|
|
}
|
|
kref_get(&cfid->refcount);
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return cfid;
|
|
}
|
|
}
|
|
if (lookup_only) {
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return NULL;
|
|
}
|
|
if (cfids->num_entries >= MAX_CACHED_FIDS) {
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return NULL;
|
|
}
|
|
cfid = init_cached_dir(path);
|
|
if (cfid == NULL) {
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return NULL;
|
|
}
|
|
cfid->cfids = cfids;
|
|
cfids->num_entries++;
|
|
list_add(&cfid->entry, &cfids->entries);
|
|
cfid->on_list = true;
|
|
kref_get(&cfid->refcount);
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return cfid;
|
|
}
|
|
|
|
static struct dentry *
|
|
path_to_dentry(struct cifs_sb_info *cifs_sb, const char *path)
|
|
{
|
|
struct dentry *dentry;
|
|
const char *s, *p;
|
|
char sep;
|
|
|
|
sep = CIFS_DIR_SEP(cifs_sb);
|
|
dentry = dget(cifs_sb->root);
|
|
s = path;
|
|
|
|
do {
|
|
struct inode *dir = d_inode(dentry);
|
|
struct dentry *child;
|
|
|
|
if (!S_ISDIR(dir->i_mode)) {
|
|
dput(dentry);
|
|
dentry = ERR_PTR(-ENOTDIR);
|
|
break;
|
|
}
|
|
|
|
/* skip separators */
|
|
while (*s == sep)
|
|
s++;
|
|
if (!*s)
|
|
break;
|
|
p = s++;
|
|
/* next separator */
|
|
while (*s && *s != sep)
|
|
s++;
|
|
|
|
child = lookup_positive_unlocked(p, dentry, s - p);
|
|
dput(dentry);
|
|
dentry = child;
|
|
} while (!IS_ERR(dentry));
|
|
return dentry;
|
|
}
|
|
|
|
/*
|
|
* Open the and cache a directory handle.
|
|
* If error then *cfid is not initialized.
|
|
*/
|
|
int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
|
|
const char *path,
|
|
struct cifs_sb_info *cifs_sb,
|
|
bool lookup_only, struct cached_fid **ret_cfid)
|
|
{
|
|
struct cifs_ses *ses;
|
|
struct TCP_Server_Info *server;
|
|
struct cifs_open_parms oparms;
|
|
struct smb2_create_rsp *o_rsp = NULL;
|
|
struct smb2_query_info_rsp *qi_rsp = NULL;
|
|
int resp_buftype[2];
|
|
struct smb_rqst rqst[2];
|
|
struct kvec rsp_iov[2];
|
|
struct kvec open_iov[SMB2_CREATE_IOV_SIZE];
|
|
struct kvec qi_iov[1];
|
|
int rc, flags = 0;
|
|
__le16 *utf16_path = NULL;
|
|
u8 oplock = SMB2_OPLOCK_LEVEL_II;
|
|
struct cifs_fid *pfid;
|
|
struct dentry *dentry = NULL;
|
|
struct cached_fid *cfid;
|
|
struct cached_fids *cfids;
|
|
|
|
if (tcon == NULL || tcon->cfids == NULL || tcon->nohandlecache ||
|
|
is_smb1_server(tcon->ses->server))
|
|
return -EOPNOTSUPP;
|
|
|
|
ses = tcon->ses;
|
|
server = ses->server;
|
|
cfids = tcon->cfids;
|
|
|
|
if (!server->ops->new_lease_key)
|
|
return -EIO;
|
|
|
|
if (cifs_sb->root == NULL)
|
|
return -ENOENT;
|
|
|
|
utf16_path = cifs_convert_path_to_utf16(path, cifs_sb);
|
|
if (!utf16_path)
|
|
return -ENOMEM;
|
|
|
|
cfid = find_or_create_cached_dir(cfids, path, lookup_only);
|
|
if (cfid == NULL) {
|
|
kfree(utf16_path);
|
|
return -ENOENT;
|
|
}
|
|
/*
|
|
* At this point we either have a lease already and we can just
|
|
* return it. If not we are guaranteed to be the only thread accessing
|
|
* this cfid.
|
|
*/
|
|
if (cfid->has_lease) {
|
|
*ret_cfid = cfid;
|
|
kfree(utf16_path);
|
|
return 0;
|
|
}
|
|
|
|
/*
|
|
* We do not hold the lock for the open because in case
|
|
* SMB2_open needs to reconnect.
|
|
* This is safe because no other thread will be able to get a ref
|
|
* to the cfid until we have finished opening the file and (possibly)
|
|
* acquired a lease.
|
|
*/
|
|
if (smb3_encryption_required(tcon))
|
|
flags |= CIFS_TRANSFORM_REQ;
|
|
|
|
pfid = &cfid->fid;
|
|
server->ops->new_lease_key(pfid);
|
|
|
|
memset(rqst, 0, sizeof(rqst));
|
|
resp_buftype[0] = resp_buftype[1] = CIFS_NO_BUFFER;
|
|
memset(rsp_iov, 0, sizeof(rsp_iov));
|
|
|
|
/* Open */
|
|
memset(&open_iov, 0, sizeof(open_iov));
|
|
rqst[0].rq_iov = open_iov;
|
|
rqst[0].rq_nvec = SMB2_CREATE_IOV_SIZE;
|
|
|
|
oparms.tcon = tcon;
|
|
oparms.create_options = cifs_create_options(cifs_sb, CREATE_NOT_FILE);
|
|
oparms.desired_access = FILE_READ_ATTRIBUTES;
|
|
oparms.disposition = FILE_OPEN;
|
|
oparms.fid = pfid;
|
|
oparms.reconnect = false;
|
|
|
|
rc = SMB2_open_init(tcon, server,
|
|
&rqst[0], &oplock, &oparms, utf16_path);
|
|
if (rc)
|
|
goto oshr_free;
|
|
smb2_set_next_command(tcon, &rqst[0]);
|
|
|
|
memset(&qi_iov, 0, sizeof(qi_iov));
|
|
rqst[1].rq_iov = qi_iov;
|
|
rqst[1].rq_nvec = 1;
|
|
|
|
rc = SMB2_query_info_init(tcon, server,
|
|
&rqst[1], COMPOUND_FID,
|
|
COMPOUND_FID, FILE_ALL_INFORMATION,
|
|
SMB2_O_INFO_FILE, 0,
|
|
sizeof(struct smb2_file_all_info) +
|
|
PATH_MAX * 2, 0, NULL);
|
|
if (rc)
|
|
goto oshr_free;
|
|
|
|
smb2_set_related(&rqst[1]);
|
|
|
|
rc = compound_send_recv(xid, ses, server,
|
|
flags, 2, rqst,
|
|
resp_buftype, rsp_iov);
|
|
if (rc) {
|
|
if (rc == -EREMCHG) {
|
|
tcon->need_reconnect = true;
|
|
pr_warn_once("server share %s deleted\n",
|
|
tcon->tree_name);
|
|
}
|
|
goto oshr_free;
|
|
}
|
|
|
|
atomic_inc(&tcon->num_remote_opens);
|
|
|
|
o_rsp = (struct smb2_create_rsp *)rsp_iov[0].iov_base;
|
|
oparms.fid->persistent_fid = o_rsp->PersistentFileId;
|
|
oparms.fid->volatile_fid = o_rsp->VolatileFileId;
|
|
#ifdef CONFIG_CIFS_DEBUG2
|
|
oparms.fid->mid = le64_to_cpu(o_rsp->hdr.MessageId);
|
|
#endif /* CIFS_DEBUG2 */
|
|
|
|
if (o_rsp->OplockLevel != SMB2_OPLOCK_LEVEL_LEASE)
|
|
goto oshr_free;
|
|
|
|
|
|
smb2_parse_contexts(server, o_rsp,
|
|
&oparms.fid->epoch,
|
|
oparms.fid->lease_key, &oplock,
|
|
NULL, NULL);
|
|
|
|
qi_rsp = (struct smb2_query_info_rsp *)rsp_iov[1].iov_base;
|
|
if (le32_to_cpu(qi_rsp->OutputBufferLength) < sizeof(struct smb2_file_all_info))
|
|
goto oshr_free;
|
|
if (!smb2_validate_and_copy_iov(
|
|
le16_to_cpu(qi_rsp->OutputBufferOffset),
|
|
sizeof(struct smb2_file_all_info),
|
|
&rsp_iov[1], sizeof(struct smb2_file_all_info),
|
|
(char *)&cfid->file_all_info))
|
|
cfid->file_all_info_is_valid = true;
|
|
|
|
if (!path[0])
|
|
dentry = dget(cifs_sb->root);
|
|
else {
|
|
dentry = path_to_dentry(cifs_sb, path);
|
|
if (IS_ERR(dentry)) {
|
|
rc = -ENOENT;
|
|
goto oshr_free;
|
|
}
|
|
}
|
|
cfid->dentry = dentry;
|
|
cfid->tcon = tcon;
|
|
cfid->time = jiffies;
|
|
cfid->is_open = true;
|
|
cfid->has_lease = true;
|
|
|
|
oshr_free:
|
|
kfree(utf16_path);
|
|
SMB2_open_free(&rqst[0]);
|
|
SMB2_query_info_free(&rqst[1]);
|
|
free_rsp_buf(resp_buftype[0], rsp_iov[0].iov_base);
|
|
free_rsp_buf(resp_buftype[1], rsp_iov[1].iov_base);
|
|
spin_lock(&cfids->cfid_list_lock);
|
|
if (!cfid->has_lease) {
|
|
if (cfid->on_list) {
|
|
list_del(&cfid->entry);
|
|
cfid->on_list = false;
|
|
cfids->num_entries--;
|
|
}
|
|
rc = -ENOENT;
|
|
}
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
if (rc) {
|
|
free_cached_dir(cfid);
|
|
cfid = NULL;
|
|
}
|
|
|
|
if (rc == 0)
|
|
*ret_cfid = cfid;
|
|
|
|
return rc;
|
|
}
|
|
|
|
int open_cached_dir_by_dentry(struct cifs_tcon *tcon,
|
|
struct dentry *dentry,
|
|
struct cached_fid **ret_cfid)
|
|
{
|
|
struct cached_fid *cfid;
|
|
struct cached_fids *cfids = tcon->cfids;
|
|
|
|
if (cfids == NULL)
|
|
return -ENOENT;
|
|
|
|
spin_lock(&cfids->cfid_list_lock);
|
|
list_for_each_entry(cfid, &cfids->entries, entry) {
|
|
if (dentry && cfid->dentry == dentry) {
|
|
cifs_dbg(FYI, "found a cached root file handle by dentry\n");
|
|
kref_get(&cfid->refcount);
|
|
*ret_cfid = cfid;
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return 0;
|
|
}
|
|
}
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return -ENOENT;
|
|
}
|
|
|
|
static void
|
|
smb2_close_cached_fid(struct kref *ref)
|
|
{
|
|
struct cached_fid *cfid = container_of(ref, struct cached_fid,
|
|
refcount);
|
|
|
|
spin_lock(&cfid->cfids->cfid_list_lock);
|
|
if (cfid->on_list) {
|
|
list_del(&cfid->entry);
|
|
cfid->on_list = false;
|
|
cfid->cfids->num_entries--;
|
|
}
|
|
spin_unlock(&cfid->cfids->cfid_list_lock);
|
|
|
|
dput(cfid->dentry);
|
|
cfid->dentry = NULL;
|
|
|
|
if (cfid->is_open) {
|
|
SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
|
|
cfid->fid.volatile_fid);
|
|
}
|
|
|
|
free_cached_dir(cfid);
|
|
}
|
|
|
|
void drop_cached_dir_by_name(const unsigned int xid, struct cifs_tcon *tcon,
|
|
const char *name, struct cifs_sb_info *cifs_sb)
|
|
{
|
|
struct cached_fid *cfid = NULL;
|
|
int rc;
|
|
|
|
rc = open_cached_dir(xid, tcon, name, cifs_sb, true, &cfid);
|
|
if (rc) {
|
|
cifs_dbg(FYI, "no cached dir found for rmdir(%s)\n", name);
|
|
return;
|
|
}
|
|
spin_lock(&cfid->cfids->cfid_list_lock);
|
|
if (cfid->has_lease) {
|
|
cfid->has_lease = false;
|
|
kref_put(&cfid->refcount, smb2_close_cached_fid);
|
|
}
|
|
spin_unlock(&cfid->cfids->cfid_list_lock);
|
|
close_cached_dir(cfid);
|
|
}
|
|
|
|
|
|
void close_cached_dir(struct cached_fid *cfid)
|
|
{
|
|
kref_put(&cfid->refcount, smb2_close_cached_fid);
|
|
}
|
|
|
|
/*
|
|
* Called from cifs_kill_sb when we unmount a share
|
|
*/
|
|
void close_all_cached_dirs(struct cifs_sb_info *cifs_sb)
|
|
{
|
|
struct rb_root *root = &cifs_sb->tlink_tree;
|
|
struct rb_node *node;
|
|
struct cached_fid *cfid;
|
|
struct cifs_tcon *tcon;
|
|
struct tcon_link *tlink;
|
|
struct cached_fids *cfids;
|
|
|
|
for (node = rb_first(root); node; node = rb_next(node)) {
|
|
tlink = rb_entry(node, struct tcon_link, tl_rbnode);
|
|
tcon = tlink_tcon(tlink);
|
|
if (IS_ERR(tcon))
|
|
continue;
|
|
cfids = tcon->cfids;
|
|
if (cfids == NULL)
|
|
continue;
|
|
list_for_each_entry(cfid, &cfids->entries, entry) {
|
|
dput(cfid->dentry);
|
|
cfid->dentry = NULL;
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Invalidate all cached dirs when a TCON has been reset
|
|
* due to a session loss.
|
|
*/
|
|
void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
|
|
{
|
|
struct cached_fids *cfids = tcon->cfids;
|
|
struct cached_fid *cfid, *q;
|
|
LIST_HEAD(entry);
|
|
|
|
spin_lock(&cfids->cfid_list_lock);
|
|
list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
|
|
list_move(&cfid->entry, &entry);
|
|
cfids->num_entries--;
|
|
cfid->is_open = false;
|
|
cfid->on_list = false;
|
|
/* To prevent race with smb2_cached_lease_break() */
|
|
kref_get(&cfid->refcount);
|
|
}
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
|
|
list_for_each_entry_safe(cfid, q, &entry, entry) {
|
|
list_del(&cfid->entry);
|
|
cancel_work_sync(&cfid->lease_break);
|
|
if (cfid->has_lease) {
|
|
/*
|
|
* We lease was never cancelled from the server so we
|
|
* need to drop the reference.
|
|
*/
|
|
spin_lock(&cfids->cfid_list_lock);
|
|
cfid->has_lease = false;
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
kref_put(&cfid->refcount, smb2_close_cached_fid);
|
|
}
|
|
/* Drop the extra reference opened above*/
|
|
kref_put(&cfid->refcount, smb2_close_cached_fid);
|
|
}
|
|
}
|
|
|
|
static void
|
|
smb2_cached_lease_break(struct work_struct *work)
|
|
{
|
|
struct cached_fid *cfid = container_of(work,
|
|
struct cached_fid, lease_break);
|
|
|
|
spin_lock(&cfid->cfids->cfid_list_lock);
|
|
cfid->has_lease = false;
|
|
spin_unlock(&cfid->cfids->cfid_list_lock);
|
|
kref_put(&cfid->refcount, smb2_close_cached_fid);
|
|
}
|
|
|
|
int cached_dir_lease_break(struct cifs_tcon *tcon, __u8 lease_key[16])
|
|
{
|
|
struct cached_fids *cfids = tcon->cfids;
|
|
struct cached_fid *cfid;
|
|
|
|
if (cfids == NULL)
|
|
return false;
|
|
|
|
spin_lock(&cfids->cfid_list_lock);
|
|
list_for_each_entry(cfid, &cfids->entries, entry) {
|
|
if (cfid->has_lease &&
|
|
!memcmp(lease_key,
|
|
cfid->fid.lease_key,
|
|
SMB2_LEASE_KEY_SIZE)) {
|
|
cfid->time = 0;
|
|
/*
|
|
* We found a lease remove it from the list
|
|
* so no threads can access it.
|
|
*/
|
|
list_del(&cfid->entry);
|
|
cfid->on_list = false;
|
|
cfids->num_entries--;
|
|
|
|
queue_work(cifsiod_wq,
|
|
&cfid->lease_break);
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return true;
|
|
}
|
|
}
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
return false;
|
|
}
|
|
|
|
static struct cached_fid *init_cached_dir(const char *path)
|
|
{
|
|
struct cached_fid *cfid;
|
|
|
|
cfid = kzalloc(sizeof(*cfid), GFP_ATOMIC);
|
|
if (!cfid)
|
|
return NULL;
|
|
cfid->path = kstrdup(path, GFP_ATOMIC);
|
|
if (!cfid->path) {
|
|
kfree(cfid);
|
|
return NULL;
|
|
}
|
|
|
|
INIT_WORK(&cfid->lease_break, smb2_cached_lease_break);
|
|
INIT_LIST_HEAD(&cfid->entry);
|
|
INIT_LIST_HEAD(&cfid->dirents.entries);
|
|
mutex_init(&cfid->dirents.de_mutex);
|
|
spin_lock_init(&cfid->fid_lock);
|
|
kref_init(&cfid->refcount);
|
|
return cfid;
|
|
}
|
|
|
|
static void free_cached_dir(struct cached_fid *cfid)
|
|
{
|
|
struct cached_dirent *dirent, *q;
|
|
|
|
dput(cfid->dentry);
|
|
cfid->dentry = NULL;
|
|
|
|
/*
|
|
* Delete all cached dirent names
|
|
*/
|
|
list_for_each_entry_safe(dirent, q, &cfid->dirents.entries, entry) {
|
|
list_del(&dirent->entry);
|
|
kfree(dirent->name);
|
|
kfree(dirent);
|
|
}
|
|
|
|
kfree(cfid->path);
|
|
cfid->path = NULL;
|
|
kfree(cfid);
|
|
}
|
|
|
|
struct cached_fids *init_cached_dirs(void)
|
|
{
|
|
struct cached_fids *cfids;
|
|
|
|
cfids = kzalloc(sizeof(*cfids), GFP_KERNEL);
|
|
if (!cfids)
|
|
return NULL;
|
|
spin_lock_init(&cfids->cfid_list_lock);
|
|
INIT_LIST_HEAD(&cfids->entries);
|
|
return cfids;
|
|
}
|
|
|
|
/*
|
|
* Called from tconInfoFree when we are tearing down the tcon.
|
|
* There are no active users or open files/directories at this point.
|
|
*/
|
|
void free_cached_dirs(struct cached_fids *cfids)
|
|
{
|
|
struct cached_fid *cfid, *q;
|
|
LIST_HEAD(entry);
|
|
|
|
spin_lock(&cfids->cfid_list_lock);
|
|
list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
|
|
cfid->on_list = false;
|
|
cfid->is_open = false;
|
|
list_move(&cfid->entry, &entry);
|
|
}
|
|
spin_unlock(&cfids->cfid_list_lock);
|
|
|
|
list_for_each_entry_safe(cfid, q, &entry, entry) {
|
|
list_del(&cfid->entry);
|
|
free_cached_dir(cfid);
|
|
}
|
|
|
|
kfree(cfids);
|
|
}
|