Hello Joe & list,

This is v2 patch.

v1 patch overwrites some correct code in lib/label/label.c 
label_scan_pvscan_all().
```
     while ((dev = dev_iter_get(iter))) {
-       if (!(devl = dm_zalloc(sizeof(*devl)))) {
-           log_error("Failed to allocated device list.");
-           dev_iter_destroy(iter);
+       if (!(devl = dm_zalloc(sizeof(*devl))))
             return 0;
-       }
```

------ v2 patch ------
 From a4b53d6fd670c3046784b9cce3925ec5d187b138 Mon Sep 17 00:00:00 2001
From: Zhao Heming <[email protected]>
Date: Mon, 28 Oct 2019 16:31:01 +0800
Subject: [PATCH] bcache: fix mistakenly write data to another disk when writes
  error

When bcache write data error, the errored fd and its data is saved in
cache->errored, then this fd is closed. Later lvm will reuse this
closed fd to new opened devs, but the fd related data still in
cache->errored and flags with BF_DIRTY. It make the data may mistakenly
write to another disk.

Signed-off-by: Zhao Heming <[email protected]>
---
  .gitignore                    |  2 +-
  lib/cache/lvmcache.c          |  2 +-
  lib/device/bcache.c           | 46 ++++++++++++++++++++++++++++++-------------
  lib/format_text/format-text.c | 11 ++++-------
  lib/label/label.c             | 22 ++++++++++++---------
  lib/metadata/mirror.c         |  1 -
  6 files changed, 51 insertions(+), 33 deletions(-)

diff --git a/.gitignore b/.gitignore
index f51bb67fca..57bb007005 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,7 +28,7 @@ make.tmpl
  /config.log
  /config.status
  /configure.scan
-/cscope.out
+/cscope.*
  /tags
  /tmp/
  
diff --git a/lib/cache/lvmcache.c b/lib/cache/lvmcache.c
index 9890325d2e..9c6e8032d6 100644
--- a/lib/cache/lvmcache.c
+++ b/lib/cache/lvmcache.c
@@ -1429,7 +1429,7 @@ int lvmcache_label_rescan_vg(struct cmd_context *cmd, 
const char *vgname, const
   * incorrectly placed PVs should have been moved from the orphan vginfo
   * onto their correct vginfo's, and the orphan vginfo should (in theory)
   * represent only real orphan PVs.  (Note: if lvmcache_label_scan is run
- * after vg_read udpates to lvmcache state, then the lvmcache will be
+ * after vg_read updates to lvmcache state, then the lvmcache will be
   * incorrect again, so do not run lvmcache_label_scan during the
   * processing phase.)
   *
diff --git a/lib/device/bcache.c b/lib/device/bcache.c
index d487ca2a77..1959b333ba 100644
--- a/lib/device/bcache.c
+++ b/lib/device/bcache.c
@@ -293,6 +293,10 @@ static bool _async_issue(struct io_engine *ioe, enum dir 
d, int fd,
  
        if (r < 0) {
                _cb_free(e->cbs, cb);
+               ((struct block *)context)->error = r;
+               log_warn("io_submit <%c> off %llu bytes %llu return %d:%s",
+                       (d == DIR_READ) ? 'R' : 'W', (long long unsigned)offset,
+                       (long long unsigned)nbytes, r, strerror(-r));
                return false;
        }
  
@@ -869,7 +873,7 @@ static void _complete_io(void *context, int err)
  
        if (b->error) {
                dm_list_add(&cache->errored, &b->list);
-
+               log_warn("_complete_io fd: %d error: %d", b->fd, err);
        } else {
                _clear_flags(b, BF_DIRTY);
                _link_block(b);
@@ -896,8 +900,7 @@ static void _issue_low_level(struct block *b, enum dir d)
        dm_list_move(&cache->io_pending, &b->list);
  
        if (!cache->engine->issue(cache->engine, d, b->fd, sb, se, b->data, b)) 
{
-               /* FIXME: if io_submit() set an errno, return that instead of 
EIO? */
-               _complete_io(b, -EIO);
+               _complete_io(b, b->error);
                return;
        }
  }
@@ -921,16 +924,20 @@ static bool _wait_io(struct bcache *cache)
   * High level IO handling
   *--------------------------------------------------------------*/
  
-static void _wait_all(struct bcache *cache)
+static bool _wait_all(struct bcache *cache)
  {
+       bool ret = true;
        while (!dm_list_empty(&cache->io_pending))
-               _wait_io(cache);
+               ret = _wait_io(cache);
+       return ret;
  }
  
-static void _wait_specific(struct block *b)
+static bool _wait_specific(struct block *b)
  {
+       bool ret = true;
        while (_test_flags(b, BF_IO_PENDING))
-               _wait_io(b->cache);
+               ret = _wait_io(b->cache);
+       return ret;
  }
  
  static unsigned _writeback(struct bcache *cache, unsigned count)
@@ -1125,7 +1132,7 @@ struct bcache *bcache_create(sector_t block_sectors, 
unsigned nr_cache_blocks,
        unsigned max_io = engine->max_io(engine);
        long pgsize = sysconf(_SC_PAGESIZE);
  
-       if ((pgsize = sysconf(_SC_PAGESIZE)) < 0) {
+       if (pgsize < 0) {
                log_warn("bcache cannot read pagesize.");
                return NULL;
        }
@@ -1290,10 +1297,7 @@ void bcache_put(struct block *b)
  
  bool bcache_flush(struct bcache *cache)
  {
-       // Only dirty data is on the errored list, since bad read blocks get
-       // recycled straight away.  So we put these back on the dirty list, and
-       // try and rewrite everything.
-       dm_list_splice(&cache->dirty, &cache->errored);
+       bool write_ret = true, wait_ret = true;
  
        while (!dm_list_empty(&cache->dirty)) {
                struct block *b = dm_list_item(_list_pop(&cache->dirty), struct 
block);
@@ -1303,11 +1307,16 @@ bool bcache_flush(struct bcache *cache)
                }
  
                _issue_write(b);
+               if (b->error) write_ret = false;
        }
  
-       _wait_all(cache);
+       wait_ret = _wait_all(cache);
  
-       return dm_list_empty(&cache->errored);
+       if (write_ret == false || wait_ret == false ||
+                       !dm_list_empty(&cache->errored))
+               return false;
+       else
+               return true;
  }
  
  /*
@@ -1352,6 +1361,15 @@ bool bcache_invalidate_fd(struct bcache *cache, int fd)
        struct block *b, *tmp;
        bool r = true;
  
+       // clean cache->errored list
+       dm_list_iterate_items_safe (b, tmp, &cache->errored) {
+               b->flags = 0;
+               b->index = 0;
+               b->ref_count = 0;
+               b->error = 0;
+               _recycle_block(cache, b);
+       }
+
        // Start writing back any dirty blocks on this fd.
        dm_list_iterate_items_safe (b, tmp, &cache->dirty)
                if (b->fd == fd)
diff --git a/lib/format_text/format-text.c b/lib/format_text/format-text.c
index 6eea07fe46..86e2caaad6 100644
--- a/lib/format_text/format-text.c
+++ b/lib/format_text/format-text.c
@@ -402,8 +402,7 @@ static int _raw_write_mda_header(const struct format_type 
*fmt,
        dev_set_last_byte(dev, start_byte + MDA_HEADER_SIZE);
  
        if (!dev_write_bytes(dev, start_byte, MDA_HEADER_SIZE, mdah)) {
-               dev_unset_last_byte(dev);
-               log_error("Failed to write mda header to %s fd %d", 
dev_name(dev), dev->bcache_fd);
+               log_error("Failed to write mda header to %s", dev_name(dev));
                return 0;
        }
        dev_unset_last_byte(dev);
@@ -690,8 +689,7 @@ static int _vg_write_raw(struct format_instance *fid, 
struct volume_group *vg,
        if (!dev_write_bytes(mdac->area.dev, mdac->area.start + 
mdac->rlocn.offset,
                                (size_t) (mdac->rlocn.size - new_wrap),
                                fidtc->raw_metadata_buf)) {
-               log_error("Failed to write metadata to %s fd %d", 
dev_name(mdac->area.dev), mdac->area.dev->bcache_fd);
-               dev_unset_last_byte(mdac->area.dev);
+               log_error("Failed to write metadata to %s", 
dev_name(mdac->area.dev));
                goto out;
        }
  
@@ -704,8 +702,7 @@ static int _vg_write_raw(struct format_instance *fid, 
struct volume_group *vg,
                if (!dev_write_bytes(mdac->area.dev, mdac->area.start + 
MDA_HEADER_SIZE,
                                        (size_t) new_wrap,
                                        fidtc->raw_metadata_buf + 
mdac->rlocn.size - new_wrap)) {
-                       log_error("Failed to write metadata wrap to %s fd %d", 
dev_name(mdac->area.dev), mdac->area.dev->bcache_fd);
-                       dev_unset_last_byte(mdac->area.dev);
+                       log_error("Failed to write metadata wrap to %s", 
dev_name(mdac->area.dev));
                        goto out;
                }
        }
@@ -723,7 +720,7 @@ static int _vg_write_raw(struct format_instance *fid, 
struct volume_group *vg,
  
        r = 1;
  
-      out:
+out:
        if (!r) {
                dm_free(fidtc->raw_metadata_buf);
                fidtc->raw_metadata_buf = NULL;
diff --git a/lib/label/label.c b/lib/label/label.c
index e4a106854f..904dd23395 100644
--- a/lib/label/label.c
+++ b/lib/label/label.c
@@ -216,7 +216,7 @@ int label_write(struct device *dev, struct label *label)
  
        if (!dev_write_bytes(dev, offset, LABEL_SIZE, buf)) {
                log_debug_devs("Failed to write label to %s", dev_name(dev));
-               r = 0;
+               return 0;
        }
  
        dev_unset_last_byte(dev);
@@ -621,7 +621,6 @@ static int _scan_list(struct cmd_context *cmd, struct 
dev_filter *f,
        int submit_count;
        int scan_failed;
        int is_lvm_device;
-       int error;
        int ret;
  
        dm_list_init(&wait_devs);
@@ -668,12 +667,12 @@ static int _scan_list(struct cmd_context *cmd, struct 
dev_filter *f,
  
        dm_list_iterate_items_safe(devl, devl2, &wait_devs) {
                bb = NULL;
-               error = 0;
                scan_failed = 0;
                is_lvm_device = 0;
  
                if (!bcache_get(scan_bcache, devl->dev->bcache_fd, 0, 0, &bb)) {
-                       log_debug_devs("Scan failed to read %s error %d.", 
dev_name(devl->dev), error);
+                       log_debug_devs("Scan failed to read %s fd: %d bb %p 
error %d.",
+                                       dev_name(devl->dev), 
devl->dev->bcache_fd, bb, bb ? bb->error : 0);
                        scan_failed = 1;
                        scan_read_errors++;
                        scan_failed_count++;
@@ -1358,7 +1357,8 @@ bool dev_write_bytes(struct device *dev, uint64_t start, 
size_t len, void *data)
  
        if (!scan_bcache) {
                /* Should not happen */
-               log_error("dev_write bcache not set up %s", dev_name(dev));
+               log_error("dev_write bcache not set up %s fd: %d", 
dev_name(dev),
+                                       dev->bcache_fd);
                return false;
        }
  
@@ -1383,15 +1383,19 @@ bool dev_write_bytes(struct device *dev, uint64_t 
start, size_t len, void *data)
        }
  
        if (!bcache_write_bytes(scan_bcache, dev->bcache_fd, start, len, data)) 
{
-               log_error("Error writing device %s at %llu length %u.",
-                         dev_name(dev), (unsigned long long)start, 
(uint32_t)len);
+               log_error("Error writing device %s at %llu length %u fd %d.",
+                               dev_name(dev), (unsigned long long)start, 
(uint32_t)len,
+                               dev->bcache_fd);
+               dev_unset_last_byte(dev);
                label_scan_invalidate(dev);
                return false;
        }
  
        if (!bcache_flush(scan_bcache)) {
-               log_error("Error writing device %s at %llu length %u.",
-                         dev_name(dev), (unsigned long long)start, 
(uint32_t)len);
+               log_error("Error writing device %s at %llu length %u fd %d.",
+                               dev_name(dev), (unsigned long long)start, 
(uint32_t)len,
+                               dev->bcache_fd);
+               dev_unset_last_byte(dev);
                label_scan_invalidate(dev);
                return false;
        }
diff --git a/lib/metadata/mirror.c b/lib/metadata/mirror.c
index cd8ce1e9e1..9792df7eac 100644
--- a/lib/metadata/mirror.c
+++ b/lib/metadata/mirror.c
@@ -305,7 +305,6 @@ static int _write_log_header(struct cmd_context *cmd, 
struct logical_volume *lv)
        dev_set_last_byte(dev, sizeof(log_header));
  
        if (!dev_write_bytes(dev, UINT64_C(0), sizeof(log_header), 
&log_header)) {
-               dev_unset_last_byte(dev);
                log_error("Failed to write log header to %s.", name);
                return 0;
        }
-- 
2.16.4

------------

Thanks.

On 10/24/19 11:13 AM, Heming Zhao wrote:
> Hello Joe,
> 
> Please see my comments in below. Thanks.
> (+joe, pls ignore previous mail. It is very wired: in last mail, Thunderbird 
> reply all not include joe.)
> 
> On 10/24/19 5:31 AM, Joe Thornber wrote:
>> On Tue, Oct 22, 2019 at 09:47:32AM +0000, Heming Zhao wrote:
>>> Hello List & David,
>>>
>>> This patch is responsible for legacy mail:
>>> [linux-lvm] pvresize will cause a meta-data corruption with error message 
>>> "Error writing device at 4096 length 512"
>>>
>>> I had send it to our customer, the code ran as expected. I think this code 
>>> is enough to fix this issue.
>>>
>>> Thanks
>>> zhm
>>>
>>> ------(patch for branch stable-2.02) ----------
>>>    From d0d77d0bdad6136c792c9664444d73dd47b809cb Mon Sep 17 00:00:00 2001
>>> From: Zhao Heming <[email protected]>
>>> Date: Tue, 22 Oct 2019 17:22:17 +0800
>>> Subject: [PATCH] bcache may mistakenly write data to another disk when 
>>> writes
>>>     error
>>>
>>> When bcache write data error, the errored fd and its data is saved in
>>> cache->errored, then this fd is closed. Later lvm will reuse this
>>> closed fd to new opened devs, but the fd related data still in
>>> cache->errored and flags with BF_DIRTY. It make the data may mistakenly
>>> write to another disk.
>>
>> I think real issue here is that the flush fails, and the error path for that
>> calls invalidate dev, which also fails, but that return value is not checked.
>> The fd is subsequently closed, and reopened with data still in the cache.
>>
> First fail is in bcache_flush, then bcache_invalidate_fd does nothing because 
> the data
> in cache->errored, which not belongs to dirty & clean list. Then the data 
> mistakenly
> move from cache->errored into cache->dirty by "bcache_get => 
> _lookup_or_read_block"
> (because the data holds BF_DIRTY flag).
> 
>> So I think the correct fix is to have a variant of invalidate, that doesn't
>> bother retrying the IO, and just throws away the dirty data.  bcache_abort()?
>> This should be called when the flush() fails.
>>
> Currently lvm2 calls bcache_invalidate_fd when flush fails. So I add abort 
> action
> in invalidate(). You can see the handle errored list codes in invalidate(). 
> It's
> not necessary to add a new func bcache_abort().
> 
> So IMO both bcache_flush &  bcache_invalidate_fd have bug.
> - bcache_flush should do more error/fail check.
> - invalidate should do abort job.
> 
> BTW, yesterday I found my patch a mistake, it overwrites some correct code. 
> And I
> only sent it to David with V2 patch.
> 
>> - Joe
>>
>> _______________________________________________
>> linux-lvm mailing list
>> [email protected]
>> https://www.redhat.com/mailman/listinfo/linux-lvm
>> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
>>
> 
> _______________________________________________
> linux-lvm mailing list
> [email protected]
> https://www.redhat.com/mailman/listinfo/linux-lvm
> read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
> 
> 

_______________________________________________
linux-lvm mailing list
[email protected]
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

Reply via email to