There were a set of issues brought up in 6.5 by the introduction of
the "laundromat" (which cleans up directory leases). After discussion
and testing with Paulo, Bernd Feige and others, we request that the
following set also be included to address these problems. They are
all in mainline (added in 6.6) and the patches (from mainline since
they apply cleanly) are also attached.
238b351d0935 ("smb3: allow controlling length of time
directory entries are cached with dir leases")
6a50d71d0fff ("smb3: allow controlling maximum number of
cached directories")
2da338ff752a ("smb3: do not start laundromat thread when dir
leases disabled")
3b8bb3171571 ("smb: client: do not start laundromat thread on
nohandlecache")
e95f3f744650 ("smb: client: make laundromat a delayed worker")
81ba10959970 ("smb: client: prevent new fids from being
removed by laundromat")
--
Thanks,
Steve,
From 81ba10959970d15c388bf29866b01b62f387e6a3 Mon Sep 17 00:00:00 2001
From: Paulo Alcantara <pc@xxxxxxxxxxxxx>
Date: Mon, 9 Oct 2023 17:37:40 -0300
Subject: [PATCH 46/50] smb: client: prevent new fids from being removed by
laundromat
Check if @cfid->time is set in laundromat so we guarantee that only
fully cached fids will be selected for removal. While we're at it,
add missing locks to protect access of @cfid fields in order to avoid
races with open_cached_dir() and cfids_laundromat_worker(),
respectively.
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
Reviewed-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/smb/client/cached_dir.c | 56 ++++++++++++++++++++++++--------------
1 file changed, 35 insertions(+), 21 deletions(-)
diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index a9e5d3b7e9a0..fe1bf5b6e0cb 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -170,15 +170,18 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
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.
+ * Return cached fid if it has a lease. Otherwise, it is either a new
+ * entry or laundromat worker removed it from @cfids->entries. Caller
+ * will put last reference if the latter.
*/
+ spin_lock(&cfids->cfid_list_lock);
if (cfid->has_lease) {
+ spin_unlock(&cfids->cfid_list_lock);
*ret_cfid = cfid;
kfree(utf16_path);
return 0;
}
+ spin_unlock(&cfids->cfid_list_lock);
/*
* Skip any prefix paths in @path as lookup_positive_unlocked() ends up
@@ -295,9 +298,11 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
goto oshr_free;
}
}
+ spin_lock(&cfids->cfid_list_lock);
cfid->dentry = dentry;
cfid->time = jiffies;
cfid->has_lease = true;
+ spin_unlock(&cfids->cfid_list_lock);
oshr_free:
kfree(utf16_path);
@@ -306,24 +311,28 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
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 (rc && !cfid->has_lease) {
- if (cfid->on_list) {
- list_del(&cfid->entry);
- cfid->on_list = false;
- cfids->num_entries--;
+ if (!cfid->has_lease) {
+ if (rc) {
+ if (cfid->on_list) {
+ list_del(&cfid->entry);
+ cfid->on_list = false;
+ cfids->num_entries--;
+ }
+ rc = -ENOENT;
+ } else {
+ /*
+ * We are guaranteed to have two references at this
+ * point. One for the caller and one for a potential
+ * lease. Release the Lease-ref so that the directory
+ * will be closed when the caller closes the cached
+ * handle.
+ */
+ spin_unlock(&cfids->cfid_list_lock);
+ kref_put(&cfid->refcount, smb2_close_cached_fid);
+ goto out;
}
- rc = -ENOENT;
}
spin_unlock(&cfids->cfid_list_lock);
- if (!rc && !cfid->has_lease) {
- /*
- * We are guaranteed to have two references at this point.
- * One for the caller and one for a potential lease.
- * Release the Lease-ref so that the directory will be closed
- * when the caller closes the cached handle.
- */
- kref_put(&cfid->refcount, smb2_close_cached_fid);
- }
if (rc) {
if (cfid->is_open)
SMB2_close(0, cfid->tcon, cfid->fid.persistent_fid,
@@ -331,7 +340,7 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
free_cached_dir(cfid);
cfid = NULL;
}
-
+out:
if (rc == 0) {
*ret_cfid = cfid;
atomic_inc(&tcon->num_remote_opens);
@@ -583,15 +592,18 @@ static void cfids_laundromat_worker(struct work_struct *work)
spin_lock(&cfids->cfid_list_lock);
list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
- if (time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
+ if (cfid->time &&
+ time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
+ cfid->on_list = false;
list_move(&cfid->entry, &entry);
cfids->num_entries--;
+ /* 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) {
- cfid->on_list = false;
list_del(&cfid->entry);
/*
* Cancel and wait for the work to finish in case we are racing
@@ -608,6 +620,8 @@ static void cfids_laundromat_worker(struct work_struct *work)
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);
}
queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
dir_cache_timeout * HZ);
--
2.39.2
From e95f3f74465072c2545d8e65a3c3a96e37129cf8 Mon Sep 17 00:00:00 2001
From: Paulo Alcantara <pc@xxxxxxxxxxxxx>
Date: Thu, 5 Oct 2023 16:04:25 -0300
Subject: [PATCH 45/50] smb: client: make laundromat a delayed worker
By having laundromat kthread processing cached directories on every
second turned out to be overkill, especially when having multiple SMB
mounts.
Relax it by using a delayed worker instead that gets scheduled on
every @dir_cache_timeout (default=30) seconds per tcon.
This also fixes the 1s delay when tearing down tcon.
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
Reviewed-by: Shyam Prasad N <sprasad@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/smb/client/cached_dir.c | 89 +++++++++++++++-----------------------
fs/smb/client/cached_dir.h | 2 +-
2 files changed, 36 insertions(+), 55 deletions(-)
diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index e2be8aedb26e..a9e5d3b7e9a0 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -15,6 +15,7 @@
static struct cached_fid *init_cached_dir(const char *path);
static void free_cached_dir(struct cached_fid *cfid);
static void smb2_close_cached_fid(struct kref *ref);
+static void cfids_laundromat_worker(struct work_struct *work);
static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
const char *path,
@@ -572,53 +573,46 @@ static void free_cached_dir(struct cached_fid *cfid)
kfree(cfid);
}
-static int
-cifs_cfids_laundromat_thread(void *p)
+static void cfids_laundromat_worker(struct work_struct *work)
{
- struct cached_fids *cfids = p;
+ struct cached_fids *cfids;
struct cached_fid *cfid, *q;
- struct list_head entry;
+ LIST_HEAD(entry);
- while (!kthread_should_stop()) {
- ssleep(1);
- INIT_LIST_HEAD(&entry);
- if (kthread_should_stop())
- return 0;
- spin_lock(&cfids->cfid_list_lock);
- list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
- if (time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
- list_del(&cfid->entry);
- list_add(&cfid->entry, &entry);
- cfids->num_entries--;
- }
+ cfids = container_of(work, struct cached_fids, laundromat_work.work);
+
+ spin_lock(&cfids->cfid_list_lock);
+ list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
+ if (time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
+ list_move(&cfid->entry, &entry);
+ cfids->num_entries--;
}
- spin_unlock(&cfids->cfid_list_lock);
+ }
+ spin_unlock(&cfids->cfid_list_lock);
- list_for_each_entry_safe(cfid, q, &entry, entry) {
- cfid->on_list = false;
- list_del(&cfid->entry);
+ list_for_each_entry_safe(cfid, q, &entry, entry) {
+ cfid->on_list = false;
+ list_del(&cfid->entry);
+ /*
+ * Cancel and wait for the work to finish in case we are racing
+ * with it.
+ */
+ cancel_work_sync(&cfid->lease_break);
+ if (cfid->has_lease) {
/*
- * Cancel, and wait for the work to finish in
- * case we are racing with it.
+ * Our lease has not yet been cancelled from the server
+ * so we need to drop the reference.
*/
- cancel_work_sync(&cfid->lease_break);
- if (cfid->has_lease) {
- /*
- * We lease has not yet been 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);
- }
+ spin_lock(&cfids->cfid_list_lock);
+ cfid->has_lease = false;
+ spin_unlock(&cfids->cfid_list_lock);
+ kref_put(&cfid->refcount, smb2_close_cached_fid);
}
}
-
- return 0;
+ queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
+ dir_cache_timeout * HZ);
}
-
struct cached_fids *init_cached_dirs(void)
{
struct cached_fids *cfids;
@@ -629,19 +623,10 @@ struct cached_fids *init_cached_dirs(void)
spin_lock_init(&cfids->cfid_list_lock);
INIT_LIST_HEAD(&cfids->entries);
- /*
- * since we're in a cifs function already, we know that
- * this will succeed. No need for try_module_get().
- */
- __module_get(THIS_MODULE);
- cfids->laundromat = kthread_run(cifs_cfids_laundromat_thread,
- cfids, "cifsd-cfid-laundromat");
- if (IS_ERR(cfids->laundromat)) {
- cifs_dbg(VFS, "Failed to start cfids laundromat thread.\n");
- kfree(cfids);
- module_put(THIS_MODULE);
- return NULL;
- }
+ INIT_DELAYED_WORK(&cfids->laundromat_work, cfids_laundromat_worker);
+ queue_delayed_work(cifsiod_wq, &cfids->laundromat_work,
+ dir_cache_timeout * HZ);
+
return cfids;
}
@@ -657,11 +642,7 @@ void free_cached_dirs(struct cached_fids *cfids)
if (cfids == NULL)
return;
- if (cfids->laundromat) {
- kthread_stop(cfids->laundromat);
- cfids->laundromat = NULL;
- module_put(THIS_MODULE);
- }
+ cancel_delayed_work_sync(&cfids->laundromat_work);
spin_lock(&cfids->cfid_list_lock);
list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
diff --git a/fs/smb/client/cached_dir.h b/fs/smb/client/cached_dir.h
index a82ff2cea789..81ba0fd5cc16 100644
--- a/fs/smb/client/cached_dir.h
+++ b/fs/smb/client/cached_dir.h
@@ -57,7 +57,7 @@ struct cached_fids {
spinlock_t cfid_list_lock;
int num_entries;
struct list_head entries;
- struct task_struct *laundromat;
+ struct delayed_work laundromat_work;
};
extern struct cached_fids *init_cached_dirs(void);
--
2.39.2
From 6a50d71d0ffff6791737eb502b27f74fb87d0cae Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Fri, 1 Sep 2023 02:15:14 -0500
Subject: [PATCH 31/50] smb3: allow controlling maximum number of cached
directories
Allow adjusting the maximum number of cached directories per share
(defaults to 16) via mount parm "max_cached_dirs"
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/smb/client/cached_dir.c | 7 ++++---
fs/smb/client/cached_dir.h | 2 +-
fs/smb/client/cifsfs.c | 2 ++
fs/smb/client/cifsglob.h | 1 +
fs/smb/client/connect.c | 1 +
fs/smb/client/fs_context.c | 11 ++++++++++-
fs/smb/client/fs_context.h | 4 +++-
7 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index 9d84c4a7bd0c..b17f067e4ada 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -18,7 +18,8 @@ static void smb2_close_cached_fid(struct kref *ref);
static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
const char *path,
- bool lookup_only)
+ bool lookup_only,
+ __u32 max_cached_dirs)
{
struct cached_fid *cfid;
@@ -43,7 +44,7 @@ static struct cached_fid *find_or_create_cached_dir(struct cached_fids *cfids,
spin_unlock(&cfids->cfid_list_lock);
return NULL;
}
- if (cfids->num_entries >= MAX_CACHED_FIDS) {
+ if (cfids->num_entries >= max_cached_dirs) {
spin_unlock(&cfids->cfid_list_lock);
return NULL;
}
@@ -162,7 +163,7 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
if (!utf16_path)
return -ENOMEM;
- cfid = find_or_create_cached_dir(cfids, path, lookup_only);
+ cfid = find_or_create_cached_dir(cfids, path, lookup_only, tcon->max_cached_dirs);
if (cfid == NULL) {
kfree(utf16_path);
return -ENOENT;
diff --git a/fs/smb/client/cached_dir.h b/fs/smb/client/cached_dir.h
index facc9b154d00..a82ff2cea789 100644
--- a/fs/smb/client/cached_dir.h
+++ b/fs/smb/client/cached_dir.h
@@ -49,7 +49,7 @@ struct cached_fid {
struct cached_dirents dirents;
};
-#define MAX_CACHED_FIDS 16
+/* default MAX_CACHED_FIDS is 16 */
struct cached_fids {
/* Must be held when:
* - accessing the cfids->entries list
diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index 52612bb52bd7..22869cda1356 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -699,6 +699,8 @@ cifs_show_options(struct seq_file *s, struct dentry *root)
seq_printf(s, ",snapshot=%llu", tcon->snapshot_time);
if (tcon->handle_timeout)
seq_printf(s, ",handletimeout=%u", tcon->handle_timeout);
+ if (tcon->max_cached_dirs != MAX_CACHED_FIDS)
+ seq_printf(s, ",max_cached_dirs=%u", tcon->max_cached_dirs);
/*
* Display file and directory attribute timeout in seconds.
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 501426ee39e7..032d8716f671 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -1210,6 +1210,7 @@ struct cifs_tcon {
__u32 max_chunks;
__u32 max_bytes_chunk;
__u32 max_bytes_copy;
+ __u32 max_cached_dirs;
#ifdef CONFIG_CIFS_FSCACHE
u64 resource_id; /* server resource id */
struct fscache_volume *fscache; /* cookie for share */
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 3bd71f982170..687754791bf0 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -2657,6 +2657,7 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
tcon->retry = ctx->retry;
tcon->nocase = ctx->nocase;
tcon->broken_sparse_sup = ctx->no_sparse;
+ tcon->max_cached_dirs = ctx->max_cached_dirs;
if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
tcon->nohandlecache = ctx->nohandlecache;
else
diff --git a/fs/smb/client/fs_context.c b/fs/smb/client/fs_context.c
index 67e16c2ac90e..e45ce31bbda7 100644
--- a/fs/smb/client/fs_context.c
+++ b/fs/smb/client/fs_context.c
@@ -150,6 +150,7 @@ const struct fs_parameter_spec smb3_fs_parameters[] = {
fsparam_u32("closetimeo", Opt_closetimeo),
fsparam_u32("echo_interval", Opt_echo_interval),
fsparam_u32("max_credits", Opt_max_credits),
+ fsparam_u32("max_cached_dirs", Opt_max_cached_dirs),
fsparam_u32("handletimeout", Opt_handletimeout),
fsparam_u64("snapshot", Opt_snapshot),
fsparam_u32("max_channels", Opt_max_channels),
@@ -1165,6 +1166,14 @@ static int smb3_fs_context_parse_param(struct fs_context *fc,
if (result.uint_32 > 1)
ctx->multichannel = true;
break;
+ case Opt_max_cached_dirs:
+ if (result.uint_32 < 1) {
+ cifs_errorf(fc, "%s: Invalid max_cached_dirs, needs to be 1 or more\n",
+ __func__);
+ goto cifs_parse_mount_err;
+ }
+ ctx->max_cached_dirs = result.uint_32;
+ break;
case Opt_handletimeout:
ctx->handle_timeout = result.uint_32;
if (ctx->handle_timeout > SMB3_MAX_HANDLE_TIMEOUT) {
@@ -1592,7 +1601,7 @@ int smb3_init_fs_context(struct fs_context *fc)
ctx->acregmax = CIFS_DEF_ACTIMEO;
ctx->acdirmax = CIFS_DEF_ACTIMEO;
ctx->closetimeo = SMB3_DEF_DCLOSETIMEO;
-
+ ctx->max_cached_dirs = MAX_CACHED_FIDS;
/* Most clients set timeout to 0, allows server to use its default */
ctx->handle_timeout = 0; /* See MS-SMB2 spec section 2.2.14.2.12 */
diff --git a/fs/smb/client/fs_context.h b/fs/smb/client/fs_context.h
index f4eaf8558902..9d8d34af0211 100644
--- a/fs/smb/client/fs_context.h
+++ b/fs/smb/client/fs_context.h
@@ -128,6 +128,7 @@ enum cifs_param {
Opt_closetimeo,
Opt_echo_interval,
Opt_max_credits,
+ Opt_max_cached_dirs,
Opt_snapshot,
Opt_max_channels,
Opt_handletimeout,
@@ -261,6 +262,7 @@ struct smb3_fs_context {
__u32 handle_timeout; /* persistent and durable handle timeout in ms */
unsigned int max_credits; /* smb3 max_credits 10 < credits < 60000 */
unsigned int max_channels;
+ unsigned int max_cached_dirs;
__u16 compression; /* compression algorithm 0xFFFF default 0=disabled */
bool rootfs:1; /* if it's a SMB root file system */
bool witness:1; /* use witness protocol */
@@ -287,7 +289,7 @@ extern void smb3_update_mnt_flags(struct cifs_sb_info *cifs_sb);
*/
#define SMB3_MAX_DCLOSETIMEO (1 << 30)
#define SMB3_DEF_DCLOSETIMEO (1 * HZ) /* even 1 sec enough to help eg open/write/close/open/read */
-
+#define MAX_CACHED_FIDS 16
extern char *cifs_sanitize_prepath(char *prepath, gfp_t gfp);
#endif
--
2.39.2
From 3b8bb3171571f92eda863e5f78b063604c61f72a Mon Sep 17 00:00:00 2001
From: Paulo Alcantara <pc@xxxxxxxxxxxxx>
Date: Wed, 4 Oct 2023 17:28:38 -0300
Subject: [PATCH 44/50] smb: client: do not start laundromat thread on
nohandlecache
Honor 'nohandlecache' mount option by not starting laundromat thread
even when SMB server supports directory leases. Do not waste system
resources by having laundromat thread running with no directory
caching at all.
Fixes: 2da338ff752a ("smb3: do not start laundromat thread when dir leases disabled")
Signed-off-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/smb/client/connect.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index ce11165446cf..7b923e36501b 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -2474,8 +2474,9 @@ cifs_put_tcon(struct cifs_tcon *tcon)
static struct cifs_tcon *
cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
{
- int rc, xid;
struct cifs_tcon *tcon;
+ bool nohandlecache;
+ int rc, xid;
tcon = cifs_find_tcon(ses, ctx);
if (tcon) {
@@ -2493,14 +2494,17 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
goto out_fail;
}
- if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
- tcon = tcon_info_alloc(true);
+ if (ses->server->dialect >= SMB20_PROT_ID &&
+ (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING))
+ nohandlecache = ctx->nohandlecache;
else
- tcon = tcon_info_alloc(false);
+ nohandlecache = true;
+ tcon = tcon_info_alloc(!nohandlecache);
if (tcon == NULL) {
rc = -ENOMEM;
goto out_fail;
}
+ tcon->nohandlecache = nohandlecache;
if (ctx->snapshot_time) {
if (ses->server->vals->protocol_id == 0) {
@@ -2662,10 +2666,6 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
tcon->nocase = ctx->nocase;
tcon->broken_sparse_sup = ctx->no_sparse;
tcon->max_cached_dirs = ctx->max_cached_dirs;
- if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
- tcon->nohandlecache = ctx->nohandlecache;
- else
- tcon->nohandlecache = true;
tcon->nodelete = ctx->nodelete;
tcon->local_lease = ctx->local_lease;
INIT_LIST_HEAD(&tcon->pending_opens);
--
2.39.2
From 2da338ff752a2789470d733111a5241f30026675 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Tue, 19 Sep 2023 11:35:53 -0500
Subject: [PATCH 37/50] smb3: do not start laundromat thread when dir leases
disabled
When no directory lease support, or for IPC shares where directories
can not be opened, do not start an unneeded laundromat thread for
that mount (it wastes resources).
Fixes: d14de8067e3f ("cifs: Add a laundromat thread for cached directories")
Reviewed-by: Paulo Alcantara (SUSE) <pc@xxxxxxxxxxxxx>
Acked-by: Tom Talpey <tom@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/smb/client/cached_dir.c | 6 ++++++
fs/smb/client/cifsglob.h | 2 +-
fs/smb/client/cifsproto.h | 2 +-
fs/smb/client/connect.c | 8 ++++++--
fs/smb/client/misc.c | 14 +++++++++-----
fs/smb/client/smb2pdu.c | 2 +-
6 files changed, 24 insertions(+), 10 deletions(-)
diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index b17f067e4ada..e2be8aedb26e 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -452,6 +452,9 @@ void invalidate_all_cached_dirs(struct cifs_tcon *tcon)
struct cached_fid *cfid, *q;
LIST_HEAD(entry);
+ if (cfids == NULL)
+ return;
+
spin_lock(&cfids->cfid_list_lock);
list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
list_move(&cfid->entry, &entry);
@@ -651,6 +654,9 @@ void free_cached_dirs(struct cached_fids *cfids)
struct cached_fid *cfid, *q;
LIST_HEAD(entry);
+ if (cfids == NULL)
+ return;
+
if (cfids->laundromat) {
kthread_stop(cfids->laundromat);
cfids->laundromat = NULL;
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 032d8716f671..f594fcc0e889 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -1943,7 +1943,7 @@ require use of the stronger protocol */
* cifsInodeInfo->lock_sem cifsInodeInfo->llist cifs_init_once
* ->can_cache_brlcks
* cifsInodeInfo->deferred_lock cifsInodeInfo->deferred_closes cifsInodeInfo_alloc
- * cached_fid->fid_mutex cifs_tcon->crfid tconInfoAlloc
+ * cached_fid->fid_mutex cifs_tcon->crfid tcon_info_alloc
* cifsFileInfo->fh_mutex cifsFileInfo cifs_new_fileinfo
* cifsFileInfo->file_info_lock cifsFileInfo->count cifs_new_fileinfo
* ->invalidHandle initiate_cifs_search
diff --git a/fs/smb/client/cifsproto.h b/fs/smb/client/cifsproto.h
index 7d8035846680..0c37eefa18a5 100644
--- a/fs/smb/client/cifsproto.h
+++ b/fs/smb/client/cifsproto.h
@@ -512,7 +512,7 @@ extern int CIFSSMBLogoff(const unsigned int xid, struct cifs_ses *ses);
extern struct cifs_ses *sesInfoAlloc(void);
extern void sesInfoFree(struct cifs_ses *);
-extern struct cifs_tcon *tconInfoAlloc(void);
+extern struct cifs_tcon *tcon_info_alloc(bool dir_leases_enabled);
extern void tconInfoFree(struct cifs_tcon *);
extern int cifs_sign_rqst(struct smb_rqst *rqst, struct TCP_Server_Info *server,
diff --git a/fs/smb/client/connect.c b/fs/smb/client/connect.c
index 687754791bf0..3902e90dca6b 100644
--- a/fs/smb/client/connect.c
+++ b/fs/smb/client/connect.c
@@ -1882,7 +1882,8 @@ cifs_setup_ipc(struct cifs_ses *ses, struct smb3_fs_context *ctx)
}
}
- tcon = tconInfoAlloc();
+ /* no need to setup directory caching on IPC share, so pass in false */
+ tcon = tcon_info_alloc(false);
if (tcon == NULL)
return -ENOMEM;
@@ -2492,7 +2493,10 @@ cifs_get_tcon(struct cifs_ses *ses, struct smb3_fs_context *ctx)
goto out_fail;
}
- tcon = tconInfoAlloc();
+ if (ses->server->capabilities & SMB2_GLOBAL_CAP_DIRECTORY_LEASING)
+ tcon = tcon_info_alloc(true);
+ else
+ tcon = tcon_info_alloc(false);
if (tcon == NULL) {
rc = -ENOMEM;
goto out_fail;
diff --git a/fs/smb/client/misc.c b/fs/smb/client/misc.c
index 366b755ca913..35b176457bbe 100644
--- a/fs/smb/client/misc.c
+++ b/fs/smb/client/misc.c
@@ -113,18 +113,22 @@ sesInfoFree(struct cifs_ses *buf_to_free)
}
struct cifs_tcon *
-tconInfoAlloc(void)
+tcon_info_alloc(bool dir_leases_enabled)
{
struct cifs_tcon *ret_buf;
ret_buf = kzalloc(sizeof(*ret_buf), GFP_KERNEL);
if (!ret_buf)
return NULL;
- ret_buf->cfids = init_cached_dirs();
- if (!ret_buf->cfids) {
- kfree(ret_buf);
- return NULL;
+
+ if (dir_leases_enabled == true) {
+ ret_buf->cfids = init_cached_dirs();
+ if (!ret_buf->cfids) {
+ kfree(ret_buf);
+ return NULL;
+ }
}
+ /* else ret_buf->cfids is already set to NULL above */
atomic_inc(&tconInfoAllocCount);
ret_buf->status = TID_NEW;
diff --git a/fs/smb/client/smb2pdu.c b/fs/smb/client/smb2pdu.c
index 44d4943e9c56..405ea324f28d 100644
--- a/fs/smb/client/smb2pdu.c
+++ b/fs/smb/client/smb2pdu.c
@@ -3878,7 +3878,7 @@ void smb2_reconnect_server(struct work_struct *work)
goto done;
/* allocate a dummy tcon struct used for reconnect */
- tcon = tconInfoAlloc();
+ tcon = tcon_info_alloc(false);
if (!tcon) {
resched = true;
list_for_each_entry_safe(ses, ses2, &tmp_ses_list, rlist) {
--
2.39.2
From 238b351d0935df568ecb3dc5aef25971778f0f7c Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@xxxxxxxxxxxxx>
Date: Wed, 30 Aug 2023 22:48:41 -0500
Subject: [PATCH 29/50] smb3: allow controlling length of time directory
entries are cached with dir leases
Currently with directory leases we cache directory contents for a fixed period
of time (default 30 seconds) but for many workloads this is too short. Allow
configuring the maximum amount of time directory entries are cached when a
directory lease is held on that directory. Add module load parm "max_dir_cache"
For example to set the timeout to 10 minutes you would do:
echo 600 > /sys/module/cifs/parameters/dir_cache_timeout
or to disable caching directory contents:
echo 0 > /sys/module/cifs/parameters/dir_cache_timeout
Reviewed-by: Bharath SM <bharathsm@xxxxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
---
fs/smb/client/cached_dir.c | 4 ++--
fs/smb/client/cifsfs.c | 10 ++++++++++
fs/smb/client/cifsglob.h | 1 +
3 files changed, 13 insertions(+), 2 deletions(-)
diff --git a/fs/smb/client/cached_dir.c b/fs/smb/client/cached_dir.c
index 2d5e9a9d5b8b..9d84c4a7bd0c 100644
--- a/fs/smb/client/cached_dir.c
+++ b/fs/smb/client/cached_dir.c
@@ -145,7 +145,7 @@ int open_cached_dir(unsigned int xid, struct cifs_tcon *tcon,
const char *npath;
if (tcon == NULL || tcon->cfids == NULL || tcon->nohandlecache ||
- is_smb1_server(tcon->ses->server))
+ is_smb1_server(tcon->ses->server) || (dir_cache_timeout == 0))
return -EOPNOTSUPP;
ses = tcon->ses;
@@ -582,7 +582,7 @@ cifs_cfids_laundromat_thread(void *p)
return 0;
spin_lock(&cfids->cfid_list_lock);
list_for_each_entry_safe(cfid, q, &cfids->entries, entry) {
- if (time_after(jiffies, cfid->time + HZ * 30)) {
+ if (time_after(jiffies, cfid->time + HZ * dir_cache_timeout)) {
list_del(&cfid->entry);
list_add(&cfid->entry, &entry);
cfids->num_entries--;
diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
index 73c44e097a69..52612bb52bd7 100644
--- a/fs/smb/client/cifsfs.c
+++ b/fs/smb/client/cifsfs.c
@@ -117,6 +117,10 @@ module_param(cifs_max_pending, uint, 0444);
MODULE_PARM_DESC(cifs_max_pending, "Simultaneous requests to server for "
"CIFS/SMB1 dialect (N/A for SMB3) "
"Default: 32767 Range: 2 to 32767.");
+unsigned int dir_cache_timeout = 30;
+module_param(dir_cache_timeout, uint, 0644);
+MODULE_PARM_DESC(dir_cache_timeout, "Number of seconds to cache directory contents for which we have a lease. Default: 30 "
+ "Range: 1 to 65000 seconds, 0 to disable caching dir contents");
#ifdef CONFIG_CIFS_STATS2
unsigned int slow_rsp_threshold = 1;
module_param(slow_rsp_threshold, uint, 0644);
@@ -1679,6 +1683,12 @@ init_cifs(void)
CIFS_MAX_REQ);
}
+ /* Limit max to about 18 hours, and setting to zero disables directory entry caching */
+ if (dir_cache_timeout > 65000) {
+ dir_cache_timeout = 65000;
+ cifs_dbg(VFS, "dir_cache_timeout set to max of 65000 seconds\n");
+ }
+
cifsiod_wq = alloc_workqueue("cifsiod", WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
if (!cifsiod_wq) {
rc = -ENOMEM;
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 259e231f8b4f..501426ee39e7 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -2016,6 +2016,7 @@ extern unsigned int CIFSMaxBufSize; /* max size not including hdr */
extern unsigned int cifs_min_rcv; /* min size of big ntwrk buf pool */
extern unsigned int cifs_min_small; /* min size of small buf pool */
extern unsigned int cifs_max_pending; /* MAX requests at once to server*/
+extern unsigned int dir_cache_timeout; /* max time for directory lease caching of dir */
extern bool disable_legacy_dialects; /* forbid vers=1.0 and vers=2.0 mounts */
extern atomic_t mid_count;
--
2.39.2
