From 1bde083cbd1e06be66d00e4ca52075687cee0d60 Mon Sep 17 00:00:00 2001

From: Csaba Henk <csaba@redhat.com>

Date: Fri, 8 May 2020 23:01:04 +0200

Subject: [PATCH 441/449] fuse: occasional logging for fuse device 'weird'

 write errors

This change is a followup to

I510158843e4b1d482bdc496c2e97b1860dc1ba93.

In referred change we pushed log messages about 'weird'

write errors to fuse device out of sight, by reporting

them at Debug loglevel instead of Error (where

'weird' means errno is not POSIX compliant but having

meaningful semantics for FUSE protocol).

This solved the issue of spurious error reporting.

And so far so good: these messages don't indicate

an error condition by themselves. However, when they

come in high repetitions, that indicates a suboptimal

condition which should be reported.[1]

Therefore now we shall emit a Warning if a certain

errno occurs a certain number of times[2] as the

outcome of a write to the fuse device.

___

[1] typically ENOENTs and ENOTDIRs accumulate

when glusterfs' inode invalidation lags behind

the kernel's internal inode garbage collection

(in this case above errnos mean that the inode

which we requested to be invalidated is not found

in kernel). This can be mitigated with the

invalidate-limit command line / mount option,

cf. bz#1732717.

[2] 256, as of the current implementation.

Upstream on https://review.gluster.org/24415

> Change-Id: I8cc7fe104da43a88875f93b0db49d5677cc16045

> Updates: #1000

> Signed-off-by: Csaba Henk <csaba@redhat.com>

BUG: 1839137

Change-Id: I8448d6d328d47cb01d560cd99a2f43cd8dab312d

Signed-off-by: Csaba Henk <csaba@redhat.com>

Reviewed-on: https://code.engineering.redhat.com/gerrit/202646

Tested-by: RHGS Build Bot <nigelb@redhat.com>

Reviewed-by: Sunil Kumar Heggodu Gopala Acharya <sheggodu@redhat.com>

---

 xlators/mount/fuse/src/fuse-bridge.c | 36 +++++++++++++++++++++++++++++++++++-

 xlators/mount/fuse/src/fuse-bridge.h | 18 ++++++++++++++++++

 2 files changed, 53 insertions(+), 1 deletion(-)

diff --git a/xlators/mount/fuse/src/fuse-bridge.c b/xlators/mount/fuse/src/fuse-bridge.c

index 4264fad..2e7584c 100644

--- a/xlators/mount/fuse/src/fuse-bridge.c

+++ b/xlators/mount/fuse/src/fuse-bridge.c

@@ -218,14 +218,30 @@ check_and_dump_fuse_W(fuse_private_t *priv, struct iovec *iov_out, int count,

     if (res == -1) {

         const char *errdesc = NULL;

         gf_loglevel_t loglevel = GF_LOG_ERROR;

+        gf_boolean_t errno_degraded = _gf_false;

+        gf_boolean_t errno_promoted = _gf_false;

+

+#define ACCOUNT_ERRNO(eno)                                                     \

+    do {                                                                       \

+        if (errno_degraded) {                                                  \

+            pthread_mutex_lock(&priv->fusedev_errno_cnt_mutex);                \

+            {                                                                  \

+                if (!++priv->fusedev_errno_cnt[FUSEDEV_##eno])                 \

+                    errno_promoted = _gf_true;                                 \

+            }                                                                  \

+            pthread_mutex_unlock(&priv->fusedev_errno_cnt_mutex);              \

+        }                                                                      \

+    } while (0)

         /* If caller masked the errno, then it

          * does not indicate an error at the application

          * level, so we degrade the log severity to DEBUG.

          */

         if (errnomask && errno < ERRNOMASK_MAX &&

-            GET_ERRNO_MASK(errnomask, errno))

+            GET_ERRNO_MASK(errnomask, errno)) {

             loglevel = GF_LOG_DEBUG;

+            errno_degraded = _gf_true;

+        }

         switch (errno) {

             /* The listed errnos are FUSE status indicators,

@@ -235,33 +251,43 @@ check_and_dump_fuse_W(fuse_private_t *priv, struct iovec *iov_out, int count,

              */

             case ENOENT:

                 errdesc = "ENOENT";

+                ACCOUNT_ERRNO(ENOENT);

                 break;

             case ENOTDIR:

                 errdesc = "ENOTDIR";

+                ACCOUNT_ERRNO(ENOTDIR);

                 break;

             case ENODEV:

                 errdesc = "ENODEV";

+                ACCOUNT_ERRNO(ENODEV);

                 break;

             case EPERM:

                 errdesc = "EPERM";

+                ACCOUNT_ERRNO(EPERM);

                 break;

             case ENOMEM:

                 errdesc = "ENOMEM";

+                ACCOUNT_ERRNO(ENOMEM);

                 break;

             case ENOTCONN:

                 errdesc = "ENOTCONN";

+                ACCOUNT_ERRNO(ENOTCONN);

                 break;

             case ECONNREFUSED:

                 errdesc = "ECONNREFUSED";

+                ACCOUNT_ERRNO(ECONNREFUSED);

                 break;

             case EOVERFLOW:

                 errdesc = "EOVERFLOW";

+                ACCOUNT_ERRNO(EOVERFLOW);

                 break;

             case EBUSY:

                 errdesc = "EBUSY";

+                ACCOUNT_ERRNO(EBUSY);

                 break;

             case ENOTEMPTY:

                 errdesc = "ENOTEMPTY";

+                ACCOUNT_ERRNO(ENOTEMPTY);

                 break;

             default:

                 errdesc = strerror(errno);

@@ -269,7 +295,13 @@ check_and_dump_fuse_W(fuse_private_t *priv, struct iovec *iov_out, int count,

         gf_log_callingfn("glusterfs-fuse", loglevel,

                          "writing to fuse device failed: %s", errdesc);

+        if (errno_promoted)

+            gf_log("glusterfs-fuse", GF_LOG_WARNING,

+                   "writing to fuse device yielded %s %d times", errdesc,

+                   UINT8_MAX + 1);

         return errno;

+

+#undef ACCOUNT_ERRNO

     }

     fouh = iov_out[0].iov_base;

@@ -6584,6 +6616,8 @@ init(xlator_t *this_xl)

     INIT_LIST_HEAD(&priv->interrupt_list);

     pthread_mutex_init(&priv->interrupt_mutex, NULL);

+    pthread_mutex_init(&priv->fusedev_errno_cnt_mutex, NULL);

+

     /* get options from option dictionary */

     ret = dict_get_str(options, ZR_MOUNTPOINT_OPT, &value_string);

     if (ret == -1 || value_string == NULL) {

diff --git a/xlators/mount/fuse/src/fuse-bridge.h b/xlators/mount/fuse/src/fuse-bridge.h

index d2d462c..2fb15a6 100644

--- a/xlators/mount/fuse/src/fuse-bridge.h

+++ b/xlators/mount/fuse/src/fuse-bridge.h

@@ -78,6 +78,20 @@ typedef struct fuse_in_header fuse_in_header_t;

 typedef void(fuse_handler_t)(xlator_t *this, fuse_in_header_t *finh, void *msg,

                              struct iobuf *iobuf);

+enum fusedev_errno {

+    FUSEDEV_ENOENT,

+    FUSEDEV_ENOTDIR,

+    FUSEDEV_ENODEV,

+    FUSEDEV_EPERM,

+    FUSEDEV_ENOMEM,

+    FUSEDEV_ENOTCONN,

+    FUSEDEV_ECONNREFUSED,

+    FUSEDEV_EOVERFLOW,

+    FUSEDEV_EBUSY,

+    FUSEDEV_ENOTEMPTY,

+    FUSEDEV_EMAXPLUS

+};

+

 struct fuse_private {

     int fd;

     uint32_t proto_minor;

@@ -192,6 +206,10 @@ struct fuse_private {

     /* LRU Limit, if not set, default is 64k for now */

     uint32_t lru_limit;

     uint32_t invalidate_limit;

+

+    /* counters for fusdev errnos */

+    uint8_t fusedev_errno_cnt[FUSEDEV_EMAXPLUS];

+    pthread_mutex_t fusedev_errno_cnt_mutex;

 };

 typedef struct fuse_private fuse_private_t;

-- 

1.8.3.1