From 8e670f77c4a55013db6d23b962f9bf6673a5e7b6 Mon Sep 17 00:00:00 2001 From: Rohith Surabattula Date: Fri, 18 Sep 2020 05:37:28 +0000 Subject: [PATCH 1/1] Handle STATUS_IO_TIMEOUT gracefully 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 Reviewed-by: Aurelien Aptel Reviewed-by: Pavel Shilovsky Signed-off-by: Steve French --- fs/cifs/cifsglob.h | 2 ++ fs/cifs/connect.c | 15 ++++++++++++++- fs/cifs/smb2maperror.c | 2 +- fs/cifs/smb2ops.c | 15 +++++++++++++++ 4 files changed, 32 insertions(+), 2 deletions(-) diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index b565d83ba89e..5a491afafacc 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -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 { diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index a5731dd6e656..1a3b7793095e 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -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++) { diff --git a/fs/cifs/smb2maperror.c b/fs/cifs/smb2maperror.c index 7fde3775cb57..b004cf87692a 100644 --- a/fs/cifs/smb2maperror.c +++ b/fs/cifs/smb2maperror.c @@ -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"}, diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index 5f3b6e77b2a7..76d82a60a550 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -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 = { -- 2.25.1