From: Xiubo Li <xiubli@redhat.com>
To: Jeff Layton <jlayton@kernel.org>
Cc: idryomov@gmail.com, pdonnell@redhat.com, ceph-devel@vger.kernel.org
Subject: Re: [PATCH v4] ceph: defer flushing the capsnap if the Fb is used
Date: Wed, 3 Feb 2021 09:05:46 +0800 [thread overview]
Message-ID: <cc823610-bc7b-0ea8-303d-22edd84a15d7@redhat.com> (raw)
In-Reply-To: <d260d1e6c379dd16168df73003daa88f875bd4d8.camel@kernel.org>
On 2021/2/2 23:59, Jeff Layton wrote:
> On Tue, 2021-02-02 at 14:54 +0800, xiubli@redhat.com wrote:
>> From: Xiubo Li <xiubli@redhat.com>
>>
>> If the Fb cap is used it means the current inode is flushing the
>> dirty data to OSD, just defer flushing the capsnap.
>>
>> URL: https://tracker.ceph.com/issues/48679
>> URL: https://tracker.ceph.com/issues/48640
>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>> ---
>>
>> V4:
>> - Fix stuck issue when running the snaptest-git-ceph.sh pointed by Jeff.
>>
>> V3:
>> - Add more comments about putting the inode ref
>> - A small change about the code style
>>
>> V2:
>> - Fix inode reference leak bug
>>
>>
>> fs/ceph/caps.c | 33 ++++++++++++++++++++-------------
>> fs/ceph/snap.c | 10 ++++++++++
>> 2 files changed, 30 insertions(+), 13 deletions(-)
>>
>> diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
>> index abbf48fc6230..570731c4d019 100644
>> --- a/fs/ceph/caps.c
>> +++ b/fs/ceph/caps.c
>> @@ -3047,6 +3047,7 @@ static void __ceph_put_cap_refs(struct ceph_inode_info *ci, int had,
>> {
>> struct inode *inode = &ci->vfs_inode;
>> int last = 0, put = 0, flushsnaps = 0, wake = 0;
>> + bool check_flushsnaps = false;
>>
>>
>> spin_lock(&ci->i_ceph_lock);
>> if (had & CEPH_CAP_PIN)
>> @@ -3063,26 +3064,17 @@ static void __ceph_put_cap_refs(struct ceph_inode_info *ci, int had,
>> if (had & CEPH_CAP_FILE_BUFFER) {
>> if (--ci->i_wb_ref == 0) {
>> last++;
>> + /* put the ref held by ceph_take_cap_refs() */
>> put++;
>> + check_flushsnaps = true;
>> }
>> dout("put_cap_refs %p wb %d -> %d (?)\n",
>> inode, ci->i_wb_ref+1, ci->i_wb_ref);
>> }
>> - if (had & CEPH_CAP_FILE_WR)
>> + if (had & CEPH_CAP_FILE_WR) {
>> if (--ci->i_wr_ref == 0) {
>> last++;
>> - if (__ceph_have_pending_cap_snap(ci)) {
>> - struct ceph_cap_snap *capsnap =
>> - list_last_entry(&ci->i_cap_snaps,
>> - struct ceph_cap_snap,
>> - ci_item);
>> - capsnap->writing = 0;
>> - if (ceph_try_drop_cap_snap(ci, capsnap))
>> - put++;
>> - else if (__ceph_finish_cap_snap(ci, capsnap))
>> - flushsnaps = 1;
>> - wake = 1;
>> - }
>> + check_flushsnaps = true;
>> if (ci->i_wrbuffer_ref_head == 0 &&
>> ci->i_dirty_caps == 0 &&
>> ci->i_flushing_caps == 0) {
>> @@ -3094,6 +3086,21 @@ static void __ceph_put_cap_refs(struct ceph_inode_info *ci, int had,
>> if (!__ceph_is_any_real_caps(ci) && ci->i_snap_realm)
>> drop_inode_snap_realm(ci);
>> }
>> + }
>> + if (check_flushsnaps && __ceph_have_pending_cap_snap(ci)) {
>> + struct ceph_cap_snap *capsnap =
>> + list_last_entry(&ci->i_cap_snaps,
>> + struct ceph_cap_snap,
>> + ci_item);
>> +
>> + capsnap->writing = 0;
>> + if (ceph_try_drop_cap_snap(ci, capsnap))
>> + /* put the ref held by ceph_queue_cap_snap() */
>> + put++;
>> + else if (__ceph_finish_cap_snap(ci, capsnap))
>> + flushsnaps = 1;
>> + wake = 1;
>> + }
>> spin_unlock(&ci->i_ceph_lock);
>>
>>
>> dout("put_cap_refs %p had %s%s%s\n", inode, ceph_cap_string(had),
>> diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c
>> index b611f829cb61..0728b01d4d43 100644
>> --- a/fs/ceph/snap.c
>> +++ b/fs/ceph/snap.c
>> @@ -623,6 +623,16 @@ int __ceph_finish_cap_snap(struct ceph_inode_info *ci,
>> return 0;
>> }
>>
>>
>> + /* Fb cap still in use, delay it */
>> + if (ci->i_wb_ref) {
>> + dout("finish_cap_snap %p cap_snap %p snapc %p %llu %s s=%llu "
>> + "used WRBUFFER, delaying\n", inode, capsnap,
>> + capsnap->context, capsnap->context->seq,
>> + ceph_cap_string(capsnap->dirty), capsnap->size);
>> + capsnap->writing = 1;
>> + return 0;
>> + }
>> +
>> ci->i_ceph_flags |= CEPH_I_FLUSH_SNAPS;
>> dout("finish_cap_snap %p cap_snap %p snapc %p %llu %s s=%llu\n",
>> inode, capsnap, capsnap->context,
> Much better. This one seems to behave better. I've gone ahead and taken
> this into testing branch.
Sure, thanks.
BRs
> Thanks!
prev parent reply other threads:[~2021-02-03 1:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-02 6:54 [PATCH v4] ceph: defer flushing the capsnap if the Fb is used xiubli
2021-02-02 15:59 ` Jeff Layton
2021-02-03 1:05 ` Xiubo Li [this message]
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