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Handle STATUS_IO_TIMEOUT gracefully

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Currently STATUS_IO_TIMEOUT is not treated as retriable error.
It is currently mapped to ETIMEDOUT and returned to userspace
for most system calls. STATUS_IO_TIMEOUT is returned by server
in case of unavailability or throttling errors.

This patch will map the STATUS_IO_TIMEOUT to EAGAIN, so that it
can be retried. Also, added a check to drop the connection to
not overload the server in case of ongoing unavailability.

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Rohith Surabattula 2020-09-18 05:37:28 +00:00 committed by Steve French
parent d1542cf616
commit 8e670f77c4
4 changed files with 32 additions and 2 deletions
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2
fs/cifs/cifsglob.h
View File

@ -510,6 +510,8 @@ struct smb_version_operations {
struct fiemap_extent_info *, u64, u64);
/* version specific llseek implementation */
loff_t (*llseek)(struct file *, struct cifs_tcon *, loff_t, int);
/* Check for STATUS_IO_TIMEOUT */
bool (*is_status_io_timeout)(char *buf);
};
struct smb_version_values {

15
fs/cifs/connect.c
View File

@ -69,6 +69,9 @@ extern bool disable_legacy_dialects;
#define TLINK_ERROR_EXPIRE (1 * HZ)
#define TLINK_IDLE_EXPIRE (600 * HZ)
/* Drop the connection to not overload the server */
#define NUM_STATUS_IO_TIMEOUT 5
enum {
/* Mount options that take no arguments */
Opt_user_xattr, Opt_nouser_xattr,
@ -1117,7 +1120,7 @@ cifs_demultiplex_thread(void *p)
struct task_struct *task_to_wake = NULL;
struct mid_q_entry *mids[MAX_COMPOUND];
char *bufs[MAX_COMPOUND];
unsigned int noreclaim_flag;
unsigned int noreclaim_flag, num_io_timeout = 0;
noreclaim_flag = memalloc_noreclaim_save();
cifs_dbg(FYI, "Demultiplex PID: %d\n", task_pid_nr(current));
@ -1213,6 +1216,16 @@ next_pdu:
continue;
}
if (server->ops->is_status_io_timeout &&
server->ops->is_status_io_timeout(buf)) {
num_io_timeout++;
if (num_io_timeout > NUM_STATUS_IO_TIMEOUT) {
cifs_reconnect(server);
num_io_timeout = 0;
continue;
}
}
server->lstrp = jiffies;
for (i = 0; i < num_mids; i++) {

2
fs/cifs/smb2maperror.c
View File

@ -488,7 +488,7 @@ static const struct status_to_posix_error smb2_error_map_table[] = {
{STATUS_PIPE_CONNECTED, -EIO, "STATUS_PIPE_CONNECTED"},
{STATUS_PIPE_LISTENING, -EIO, "STATUS_PIPE_LISTENING"},
{STATUS_INVALID_READ_MODE, -EIO, "STATUS_INVALID_READ_MODE"},
{STATUS_IO_TIMEOUT, -ETIMEDOUT, "STATUS_IO_TIMEOUT"},
{STATUS_IO_TIMEOUT, -EAGAIN, "STATUS_IO_TIMEOUT"},
{STATUS_FILE_FORCED_CLOSED, -EIO, "STATUS_FILE_FORCED_CLOSED"},
{STATUS_PROFILING_NOT_STARTED, -EIO, "STATUS_PROFILING_NOT_STARTED"},
{STATUS_PROFILING_NOT_STOPPED, -EIO, "STATUS_PROFILING_NOT_STOPPED"},

15
fs/cifs/smb2ops.c
View File

@ -2354,6 +2354,17 @@ smb2_is_session_expired(char *buf)
return true;
}
static bool
smb2_is_status_io_timeout(char *buf)
{
struct smb2_sync_hdr *shdr = (struct smb2_sync_hdr *)buf;
if (shdr->Status == STATUS_IO_TIMEOUT)
return true;
else
return false;
}
static int
smb2_oplock_response(struct cifs_tcon *tcon, struct cifs_fid *fid,
struct cifsInodeInfo *cinode)
@ -4817,6 +4828,7 @@ struct smb_version_operations smb20_operations = {
.make_node = smb2_make_node,
.fiemap = smb3_fiemap,
.llseek = smb3_llseek,
.is_status_io_timeout = smb2_is_status_io_timeout,
};
struct smb_version_operations smb21_operations = {
@ -4917,6 +4929,7 @@ struct smb_version_operations smb21_operations = {
.make_node = smb2_make_node,
.fiemap = smb3_fiemap,
.llseek = smb3_llseek,
.is_status_io_timeout = smb2_is_status_io_timeout,
};
struct smb_version_operations smb30_operations = {
@ -5027,6 +5040,7 @@ struct smb_version_operations smb30_operations = {
.make_node = smb2_make_node,
.fiemap = smb3_fiemap,
.llseek = smb3_llseek,
.is_status_io_timeout = smb2_is_status_io_timeout,
};
struct smb_version_operations smb311_operations = {
@ -5138,6 +5152,7 @@ struct smb_version_operations smb311_operations = {
.make_node = smb2_make_node,
.fiemap = smb3_fiemap,
.llseek = smb3_llseek,
.is_status_io_timeout = smb2_is_status_io_timeout,
};
struct smb_version_values smb20_values = {