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Date: Fri, 22 Mar 2024 00:32:29 -0700
From: Ritvik Budhiraja <budhirajaritviksmb@...il.com>
To: sfrench@...ba.org, pc@...guebit.com, ronniesahlberg@...il.com,
sprasad@...rosoft.com, tom@...pey.com, linux-cifs@...r.kernel.org,
samba-technical@...ts.samba.org, linux-kernel@...r.kernel.org,
bharathsm.hsk@...il.com
Subject: Re: [PATCH] Retrying on failed server close
Attaching the updated patch
On Fri, 15 Mar 2024 at 01:12, Ritvik Budhiraja <budhirajaritviksmb@...il.com>
wrote:
> In the current implementation, CIFS close sends a close to the server
> and does not check for the success of the server close. This patch adds
> functionality to check for server close return status and retries
> in case of an EBUSY or EAGAIN error
>
> Signed-off-by: Ritvik Budhiraja <rbudhiraja@...rosoft.com>
> ---
> fs/smb/client/cifsfs.c | 11 +++++++
> fs/smb/client/cifsglob.h | 7 +++--
> fs/smb/client/file.c | 63 ++++++++++++++++++++++++++++++++++++----
> fs/smb/client/smb1ops.c | 4 +--
> fs/smb/client/smb2ops.c | 9 +++---
> 5 files changed, 80 insertions(+), 14 deletions(-)
>
> diff --git a/fs/smb/client/cifsfs.c b/fs/smb/client/cifsfs.c
> index fb368b191eef..e4b2ded86fce 100644
> --- a/fs/smb/client/cifsfs.c
> +++ b/fs/smb/client/cifsfs.c
> @@ -160,6 +160,7 @@ struct workqueue_struct *decrypt_wq;
> struct workqueue_struct *fileinfo_put_wq;
> struct workqueue_struct *cifsoplockd_wq;
> struct workqueue_struct *deferredclose_wq;
> +struct workqueue_struct *serverclose_wq;
> __u32 cifs_lock_secret;
>
> /*
> @@ -1890,6 +1891,13 @@ init_cifs(void)
> goto out_destroy_cifsoplockd_wq;
> }
>
> + serverclose_wq = alloc_workqueue("serverclose",
> + WQ_FREEZABLE|WQ_MEM_RECLAIM, 0);
> + if (!serverclose_wq) {
> + rc = -ENOMEM;
> + goto out_destroy_serverclose_wq;
> + }
> +
> rc = cifs_init_inodecache();
> if (rc)
> goto out_destroy_deferredclose_wq;
> @@ -1964,6 +1972,8 @@ init_cifs(void)
> destroy_workqueue(decrypt_wq);
> out_destroy_cifsiod_wq:
> destroy_workqueue(cifsiod_wq);
> +out_destroy_serverclose_wq:
> + destroy_workqueue(serverclose_wq);
> out_clean_proc:
> cifs_proc_clean();
> return rc;
> @@ -1993,6 +2003,7 @@ exit_cifs(void)
> destroy_workqueue(cifsoplockd_wq);
> destroy_workqueue(decrypt_wq);
> destroy_workqueue(fileinfo_put_wq);
> + destroy_workqueue(serverclose_wq);
> destroy_workqueue(cifsiod_wq);
> cifs_proc_clean();
> }
> diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
> index 53c75cfb33ab..c99bc3b3ff56 100644
> --- a/fs/smb/client/cifsglob.h
> +++ b/fs/smb/client/cifsglob.h
> @@ -429,10 +429,10 @@ struct smb_version_operations {
> /* set fid protocol-specific info */
> void (*set_fid)(struct cifsFileInfo *, struct cifs_fid *, __u32);
> /* close a file */
> - void (*close)(const unsigned int, struct cifs_tcon *,
> + int (*close)(const unsigned int, struct cifs_tcon *,
> struct cifs_fid *);
> /* close a file, returning file attributes and timestamps */
> - void (*close_getattr)(const unsigned int xid, struct cifs_tcon
> *tcon,
> + int (*close_getattr)(const unsigned int xid, struct cifs_tcon
> *tcon,
> struct cifsFileInfo *pfile_info);
> /* send a flush request to the server */
> int (*flush)(const unsigned int, struct cifs_tcon *, struct
> cifs_fid *);
> @@ -1420,6 +1420,7 @@ struct cifsFileInfo {
> bool invalidHandle:1; /* file closed via session abend */
> bool swapfile:1;
> bool oplock_break_cancelled:1;
> + bool offload:1; /* offload final part of _put to a wq */
> unsigned int oplock_epoch; /* epoch from the lease break */
> __u32 oplock_level; /* oplock/lease level from the lease break */
> int count;
> @@ -1428,6 +1429,7 @@ struct cifsFileInfo {
> struct cifs_search_info srch_inf;
> struct work_struct oplock_break; /* work for oplock breaks */
> struct work_struct put; /* work for the final part of _put */
> + struct work_struct serverclose; /* work for serverclose */
> struct delayed_work deferred;
> bool deferred_close_scheduled; /* Flag to indicate close is
> scheduled */
> char *symlink_target;
> @@ -2085,6 +2087,7 @@ extern struct workqueue_struct *decrypt_wq;
> extern struct workqueue_struct *fileinfo_put_wq;
> extern struct workqueue_struct *cifsoplockd_wq;
> extern struct workqueue_struct *deferredclose_wq;
> +extern struct workqueue_struct *serverclose_wq;
> extern __u32 cifs_lock_secret;
>
> extern mempool_t *cifs_mid_poolp;
> diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
> index c3b8e7091a4d..c1379ec27dcd 100644
> --- a/fs/smb/client/file.c
> +++ b/fs/smb/client/file.c
> @@ -445,6 +445,7 @@ cifs_down_write(struct rw_semaphore *sem)
> }
>
> static void cifsFileInfo_put_work(struct work_struct *work);
> +void serverclose_work(struct work_struct *work);
>
> struct cifsFileInfo *cifs_new_fileinfo(struct cifs_fid *fid, struct file
> *file,
> struct tcon_link *tlink, __u32
> oplock,
> @@ -491,6 +492,7 @@ struct cifsFileInfo *cifs_new_fileinfo(struct cifs_fid
> *fid, struct file *file,
> cfile->tlink = cifs_get_tlink(tlink);
> INIT_WORK(&cfile->oplock_break, cifs_oplock_break);
> INIT_WORK(&cfile->put, cifsFileInfo_put_work);
> + INIT_WORK(&cfile->serverclose, serverclose_work);
> INIT_DELAYED_WORK(&cfile->deferred, smb2_deferred_work_close);
> mutex_init(&cfile->fh_mutex);
> spin_lock_init(&cfile->file_info_lock);
> @@ -582,6 +584,40 @@ static void cifsFileInfo_put_work(struct work_struct
> *work)
> cifsFileInfo_put_final(cifs_file);
> }
>
> +void serverclose_work(struct work_struct *work)
> +{
> + struct cifsFileInfo *cifs_file = container_of(work,
> + struct cifsFileInfo, serverclose);
> +
> + struct cifs_tcon *tcon = tlink_tcon(cifs_file->tlink);
> +
> + struct TCP_Server_Info *server = tcon->ses->server;
> + int rc;
> + int retries = 0;
> + int MAX_RETRIES = 4;
> +
> + do {
> + if (server->ops->close_getattr)
> + rc = server->ops->close_getattr(0, tcon,
> cifs_file);
> + else if (server->ops->close)
> + rc = server->ops->close(0, tcon, &cifs_file->fid);
> +
> + if (rc == -EBUSY || rc == -EAGAIN) {
> + retries++;
> + msleep(250);
> + }
> + } while ((rc == -EBUSY || rc == -EAGAIN) && (retries < MAX_RETRIES)
> + );
> +
> + if (retries == MAX_RETRIES)
> + printk(KERN_WARNING "[CIFS_CLOSE] Serverclose failed %d
> times, giving up\n", MAX_RETRIES);
> +
> + if (cifs_file->offload)
> + queue_work(fileinfo_put_wq, &cifs_file->put);
> + else
> + cifsFileInfo_put_final(cifs_file);
> +}
> +
> /**
> * cifsFileInfo_put - release a reference of file priv data
> *
> @@ -622,10 +658,13 @@ void _cifsFileInfo_put(struct cifsFileInfo
> *cifs_file,
> struct cifs_fid fid = {};
> struct cifs_pending_open open;
> bool oplock_break_cancelled;
> + bool serverclose_offloaded = false;
>
> spin_lock(&tcon->open_file_lock);
> spin_lock(&cifsi->open_file_lock);
> spin_lock(&cifs_file->file_info_lock);
> +
> + cifs_file->offload = offload;
> if (--cifs_file->count > 0) {
> spin_unlock(&cifs_file->file_info_lock);
> spin_unlock(&cifsi->open_file_lock);
> @@ -667,13 +706,20 @@ void _cifsFileInfo_put(struct cifsFileInfo
> *cifs_file,
> if (!tcon->need_reconnect && !cifs_file->invalidHandle) {
> struct TCP_Server_Info *server = tcon->ses->server;
> unsigned int xid;
> + int rc;
>
> xid = get_xid();
> if (server->ops->close_getattr)
> - server->ops->close_getattr(xid, tcon, cifs_file);
> + rc = server->ops->close_getattr(xid, tcon,
> cifs_file);
> else if (server->ops->close)
> - server->ops->close(xid, tcon, &cifs_file->fid);
> + rc = server->ops->close(xid, tcon,
> &cifs_file->fid);
> _free_xid(xid);
> +
> + if (rc == -EBUSY || rc == -EAGAIN) {
> + // Server close failed, hence offloading it as an
> async op
> + queue_work(serverclose_wq,
> &cifs_file->serverclose);
> + serverclose_offloaded = true;
> + }
> }
>
> if (oplock_break_cancelled)
> @@ -681,10 +727,15 @@ void _cifsFileInfo_put(struct cifsFileInfo
> *cifs_file,
>
> cifs_del_pending_open(&open);
>
> - if (offload)
> - queue_work(fileinfo_put_wq, &cifs_file->put);
> - else
> - cifsFileInfo_put_final(cifs_file);
> + // if serverclose has been offloaded to wq (on failure), it will
> + // handle offloading put as well. If serverclose not offloaded,
> + // we need to handle offloading put here.
> + if (!serverclose_offloaded) {
> + if (offload)
> + queue_work(fileinfo_put_wq, &cifs_file->put);
> + else
> + cifsFileInfo_put_final(cifs_file);
> + }
> }
>
> int cifs_open(struct inode *inode, struct file *file)
> diff --git a/fs/smb/client/smb1ops.c b/fs/smb/client/smb1ops.c
> index a9eaba8083b0..212ec6f66ec6 100644
> --- a/fs/smb/client/smb1ops.c
> +++ b/fs/smb/client/smb1ops.c
> @@ -753,11 +753,11 @@ cifs_set_fid(struct cifsFileInfo *cfile, struct
> cifs_fid *fid, __u32 oplock)
> cinode->can_cache_brlcks = CIFS_CACHE_WRITE(cinode);
> }
>
> -static void
> +static int
> cifs_close_file(const unsigned int xid, struct cifs_tcon *tcon,
> struct cifs_fid *fid)
> {
> - CIFSSMBClose(xid, tcon, fid->netfid);
> + return CIFSSMBClose(xid, tcon, fid->netfid);
> }
>
> static int
> diff --git a/fs/smb/client/smb2ops.c b/fs/smb/client/smb2ops.c
> index 4695433fcf39..1dcd4944958f 100644
> --- a/fs/smb/client/smb2ops.c
> +++ b/fs/smb/client/smb2ops.c
> @@ -1411,14 +1411,14 @@ smb2_set_fid(struct cifsFileInfo *cfile, struct
> cifs_fid *fid, __u32 oplock)
> memcpy(cfile->fid.create_guid, fid->create_guid, 16);
> }
>
> -static void
> +static int
> smb2_close_file(const unsigned int xid, struct cifs_tcon *tcon,
> struct cifs_fid *fid)
> {
> - SMB2_close(xid, tcon, fid->persistent_fid, fid->volatile_fid);
> + return SMB2_close(xid, tcon, fid->persistent_fid,
> fid->volatile_fid);
> }
>
> -static void
> +static int
> smb2_close_getattr(const unsigned int xid, struct cifs_tcon *tcon,
> struct cifsFileInfo *cfile)
> {
> @@ -1429,7 +1429,7 @@ smb2_close_getattr(const unsigned int xid, struct
> cifs_tcon *tcon,
> rc = __SMB2_close(xid, tcon, cfile->fid.persistent_fid,
> cfile->fid.volatile_fid, &file_inf);
> if (rc)
> - return;
> + return rc;
>
> inode = d_inode(cfile->dentry);
>
> @@ -1458,6 +1458,7 @@ smb2_close_getattr(const unsigned int xid, struct
> cifs_tcon *tcon,
>
> /* End of file and Attributes should not have to be updated on
> close */
> spin_unlock(&inode->i_lock);
> + return rc;
> }
>
> static int
> --
> 2.34.1
>
>
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