Re: [PATCH resend v5 02/11] ceph: add caps perf metric for each session

[Xiubo Li <xiubli@redhat.com>]

On 2020/1/31 9:34, Xiubo Li wrote:
> On 2020/1/31 3:00, Jeffrey Layton wrote:
>> On Thu, 2020-01-30 at 10:22 +0800, Xiubo Li wrote:
>>> On 2020/1/29 22:21, Jeff Layton wrote:
>>>> On Wed, 2020-01-29 at 03:27 -0500, xiubli@redhat.com wrote:
>>>>> From: Xiubo Li <xiubli@redhat.com>
>>>>>
>>>>> This will fulfill the caps hit/miss metric for each session. When
>>>>> checking the "need" mask and if one cap has the subset of the
>>>>> "need"
>>>>> mask it means hit, or missed.
>>>>>
>>>>> item          total           miss            hit
>>>>> -------------------------------------------------
>>>>> d_lease       295             0               993
>>>>>
>>>>> session       caps            miss            hit
>>>>> -------------------------------------------------
>>>>> 0             295             107             4119
>>>>> 1             1               107             9
>>>>>
>>>>> URL: https://tracker.ceph.com/issues/43215
>>>>> Signed-off-by: Xiubo Li <xiubli@redhat.com>
>>>>> ---
>>>>>    fs/ceph/acl.c        |  2 ++
>>>>>    fs/ceph/addr.c       |  2 ++
>>>>>    fs/ceph/caps.c       | 74
>>>>> ++++++++++++++++++++++++++++++++++++++++++++
>>>>>    fs/ceph/debugfs.c    | 20 ++++++++++++
>>>>>    fs/ceph/dir.c        |  9 ++++--
>>>>>    fs/ceph/file.c       |  3 ++
>>>>>    fs/ceph/mds_client.c | 16 +++++++++-
>>>>>    fs/ceph/mds_client.h |  3 ++
>>>>>    fs/ceph/quota.c      |  9 ++++--
>>>>>    fs/ceph/super.h      | 11 +++++++
>>>>>    fs/ceph/xattr.c      | 17 ++++++++--
>>>>>    11 files changed, 158 insertions(+), 8 deletions(-)
>>>>>
>>>>> diff --git a/fs/ceph/acl.c b/fs/ceph/acl.c
>>>>> index 26be6520d3fb..58e119e3519f 100644
>>>>> --- a/fs/ceph/acl.c
>>>>> +++ b/fs/ceph/acl.c
>>>>> @@ -22,6 +22,8 @@ static inline void ceph_set_cached_acl(struct
>>>>> inode *inode,
>>>>>        struct ceph_inode_info *ci = ceph_inode(inode);
>>>>>           spin_lock(&ci->i_ceph_lock);
>>>>> +    __ceph_caps_metric(ci, CEPH_CAP_XATTR_SHARED);
>>>>> +
>>>>>        if (__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED,
>>>>> 0))
>>>>>            set_cached_acl(inode, type, acl);
>>>>>        else
>>>>> diff --git a/fs/ceph/addr.c b/fs/ceph/addr.c
>>>>> index 7ab616601141..29d4513eff8c 100644
>>>>> --- a/fs/ceph/addr.c
>>>>> +++ b/fs/ceph/addr.c
>>>>> @@ -1706,6 +1706,8 @@ int ceph_uninline_data(struct file *filp,
>>>>> struct page *locked_page)
>>>>>                err = -ENOMEM;
>>>>>                goto out;
>>>>>            }
>>>>> +
>>>>> +        ceph_caps_metric(ci, CEPH_STAT_CAP_INLINE_DATA);
>>>> Should a check for inline data really count here?
>>> Currently all the INLINE_DATA is in 'force' mode, so we can ignore
>>> it.
>>>>>            err = __ceph_do_getattr(inode, page,
>>>>>                        CEPH_STAT_CAP_INLINE_DA
>>>>> TA, true);
>>>>>            if (err < 0) {
>>>>> diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
>>>>> index 7fc87b693ba4..af2e9e826f8c 100644
>>>>> --- a/fs/ceph/caps.c
>>>>> +++ b/fs/ceph/caps.c
>>>>> @@ -783,6 +783,75 @@ static int __cap_is_valid(struct ceph_cap
>>>>> *cap)
>>>>>        return 1;
>>>>>    }
>>>>>    +/*
>>>>> + * Counts the cap metric.
>>>>> + */
>>>> This needs some comments. Specifically, what should this be
>>>> counting and
>>>> how?
>>> Will add it.
>>>
>>> The __ceph_caps_metric() will traverse the inode's i_caps try to get
>>> the
>>> 'issued' excepting the 'invoking' caps until it get enough caps in
>>> 'mask'. The i_caps traverse logic is following
>>> __ceph_caps_issued_mask().
>>>
>>>
>>>>> +void __ceph_caps_metric(struct ceph_inode_info *ci, int mask)
>>>>> +{
>>>>> +    int have = ci->i_snap_caps;
>>>>> +    struct ceph_mds_session *s;
>>>>> +    struct ceph_cap *cap;
>>>>> +    struct rb_node *p;
>>>>> +    bool skip_auth = false;
>>>>> +
>>>>> +    lockdep_assert_held(&ci->i_ceph_lock);
>>>>> +
>>>>> +    if (mask <= 0)
>>>>> +        return;
>>>>> +
>>>>> +    /* Counts the snap caps metric in the auth cap */
>>>>> +    if (ci->i_auth_cap) {
>>>>> +        cap = ci->i_auth_cap;
>>>>> +        if (have) {
>>>>> +            have |= cap->issued;
>>>>> +
>>>>> +            dout("%s %p cap %p issued %s, mask %s\n",
>>>>> __func__,
>>>>> +                 &ci->vfs_inode, cap, ceph_cap_string(cap-
>>>>>> issued),
>>>>> +                 ceph_cap_string(mask));
>>>>> +
>>>>> +            s = ceph_get_mds_session(cap->session);
>>>>> +            if (s) {
>>>>> +                if (mask & have)
>>>>> +                    percpu_counter_inc(&s-
>>>>>> i_caps_hit);
>>>>> +                else
>>>>> +                    percpu_counter_inc(&s-
>>>>>> i_caps_mis);
>>>>> +                ceph_put_mds_session(s);
>>>>> +            }
>>>>> +            skip_auth = true;
>>>>> +        }
>>>>> +    }
>>>>> +
>>>>> +    if ((mask & have) == mask)
>>>>> +        return;
>>>>> +
>>>>> +    /* Checks others */
>>>>> +    for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
>>>>> +        cap = rb_entry(p, struct ceph_cap, ci_node);
>>>>> +        if (!__cap_is_valid(cap))
>>>>> +            continue;
>>>>> +
>>>>> +        if (skip_auth && cap == ci->i_auth_cap)
>>>>> +            continue;
>>>>> +
>>>>> +        dout("%s %p cap %p issued %s, mask %s\n", __func__,
>>>>> +             &ci->vfs_inode, cap, ceph_cap_string(cap->issued),
>>>>> +             ceph_cap_string(mask));
>>>>> +
>>>>> +        s = ceph_get_mds_session(cap->session);
>>>>> +        if (s) {
>>>>> +            if (mask & cap->issued)
>>>>> + percpu_counter_inc(&s->i_caps_hit);
>>>>> +            else
>>>>> + percpu_counter_inc(&s->i_caps_mis);
>>>>> +            ceph_put_mds_session(s);
>>>>> +        }
>>>>> +
>>>>> +        have |= cap->issued;
>>>>> +        if ((mask & have) == mask)
>>>>> +            return;
>>>>> +    }
>>>>> +}
>>>>> +
>>>> I'm trying to understand what happens with the above when more than
>>>> one
>>>> ceph_cap has the same bit set in "issued". For instance:
>>>>
>>>> Suppose we're doing the check for a statx call, and we're trying to
>>>> get
>>>> caps for pAsFsLs. We have two MDS's and they've each granted us
>>>> caps for
>>>> the inode, say:
>>>>
>>>> MDS 0: pAs
>>>> MDS 1: pAsLsFs
>>>>
>>>> We check the cap0 first, and consider it a hit, and then we check
>>>> cap1
>>>> and consider it a hit as well. So that seems like it's being
>>>> double-
>>>> counted.
>>> Yeah, it will.
>>>
>>> In case2:
>>>
>>> MDS 0: pAsFs
>>>
>>> MDS 1: pAsLs
>>>
>>> For this case and yours both the i_cap0 and i_cap1 are 'hit'.
>>>
>>>
>>> In case3 :
>>>
>>> MDS0: pAsFsLs
>>>
>>> MDS1: pAs
>>>
>>> Only the i_cap0 is 'hit'.  i_cap1 will not be counted any 'hit' or
>>> 'mis'.
>>>
>>>
>>> In case4:
>>>
>>> MDS0: p
>>>
>>> MDS1: pAsLsFs
>>>
>>> i_cap0 will 'mis' and i_cap1 will 'hit'.
>>>
>>>
>>> All the logic are the same with __ceph_caps_issued_mask() does.
>>>
>>> The 'hit' means to get all the caps in 'mask we have checked the
>>> i_cap[0~N] and if they have a subset in 'mask', and the 'mis' means
>>> we
>>> have checked the i_cap[0~N] but they do not.
>>>
>>> For the i_cap[N+1 ~ M], if we won't touch them because we have
>>> already
>>> gotten enough caps needed in 'mask', they won't count any 'hit' or
>>> 'mis'
>>>
>>> All in all, the current logic is that the 'hit' means 'touched' and
>>> it
>>> have some of what we needed, and the 'mis' means 'touched' and
>>> missed
>>> any of what we needed.
>>>
>>>
>> That seems sort of arbitrary, given that you're going to get different
>> results depending on the index of the MDS with the caps. For instance:
>>
>>
>> MDS0: pAsLsFs
>> MDS1: pAs
>>
>> ...vs...
>>
>> MDS0: pAs
>> MDS1: pAsLsFs
>>
>> If we assume we're looking for pAsLsFs, then the first scenario will
>> just end up with 1 hit and the second will give you 2. AFAIU, the two
>> MDSs are peers, so it really seems like the index should not matter
>> here.
>>
>> I'm really struggling to understand how these numbers will be useful.
>> What, specifically, are we trying to count here and why?
>
> Maybe we need count the hit/mis only once, the fake code like:
>
> // Case1: check the auth caps first
>
> if (auth_cap & mask == mask) {
>
>     s->hit++;
>
>     return;
>
> }
>
> // Case2: check all the other one by one
>
> for (caps : i_caps) {
>
>     if (caps & mask == mask) {
>
>         s->hit++;
>
>         return;
>
>     }
>
>     c |= caps;
>
> }
>
> // Case3:
>
> if (c & mask == mask)
>
>     s->hit++;
>
> else
>
>     s->mis++;
>
> return;
>
> ....
>
> And for the session 's->' here, if one i_cap can hold all the 'mask' 
> requested, like the Case1 and Case2 it will be i_cap's corresponding 
> session. Or for Case3 we could choose any session.
>
> But the above is still not very graceful of counting the cap metrics too.
>
> IMO, for the cap hit/miss counter should be a global one just like the 
> dentry_lease does in [PATCH 01/11], will this make sense ?
>
Currently in fuse client, for each inode it is its auth_cap->session's 
responsibility to do all the cap hit/mis counting if it has a auth_cap, 
or choose any one exist.

Maybe this is one acceptable approach.

> Thanks,
>
>
>>>> ISTM, that what you really want to do here is logically or all of
>>>> the
>>>> cap->issued fields together, and then check that vs. the mask
>>>> value, and
>>>> count only one hit or miss per inode.
>>>>
>>>> That said, it's not 100% clear what you're counting as a hit or
>>>> miss
>>>> here, so please let me know if I have that wrong.
>>>>>    /*
>>>>>     * Return set of valid cap bits issued to us.  Note that caps
>>>>> time
>>>>>     * out, and may be invalidated in bulk if the client session
>>>>> times out
>>>>> @@ -2746,6 +2815,7 @@ static void check_max_size(struct inode
>>>>> *inode, loff_t endoff)
>>>>>    int ceph_try_get_caps(struct inode *inode, int need, int want,
>>>>>                  bool nonblock, int *got)
>>>>>    {
>>>>> +    struct ceph_inode_info *ci = ceph_inode(inode);
>>>>>        int ret;
>>>>>           BUG_ON(need & ~CEPH_CAP_FILE_RD);
>>>>> @@ -2758,6 +2828,7 @@ int ceph_try_get_caps(struct inode *inode,
>>>>> int need, int want,
>>>>>        BUG_ON(want & ~(CEPH_CAP_FILE_CACHE |
>>>>> CEPH_CAP_FILE_LAZYIO |
>>>>>                CEPH_CAP_FILE_SHARED |
>>>>> CEPH_CAP_FILE_EXCL |
>>>>>                CEPH_CAP_ANY_DIR_OPS));
>>>>> +    ceph_caps_metric(ci, need | want);
>>>>>        ret = try_get_cap_refs(inode, need, want, 0, nonblock,
>>>>> got);
>>>>>        return ret == -EAGAIN ? 0 : ret;
>>>>>    }
>>>>> @@ -2784,6 +2855,8 @@ int ceph_get_caps(struct file *filp, int
>>>>> need, int want,
>>>>>            fi->filp_gen != READ_ONCE(fsc->filp_gen))
>>>>>            return -EBADF;
>>>>>    +    ceph_caps_metric(ci, need | want);
>>>>> +
>>>>>        while (true) {
>>>>>            if (endoff > 0)
>>>>>                check_max_size(inode, endoff);
>>>>> @@ -2871,6 +2944,7 @@ int ceph_get_caps(struct file *filp, int
>>>>> need, int want,
>>>>>                 * getattr request will bring inline
>>>>> data into
>>>>>                 * page cache
>>>>>                 */
>>>>> +            ceph_caps_metric(ci,
>>>>> CEPH_STAT_CAP_INLINE_DATA);
>>>>>                ret = __ceph_do_getattr(inode, NULL,
>>>>>                            CEPH_STAT_CAP_I
>>>>> NLINE_DATA,
>>>>>                            true);
>>>>> diff --git a/fs/ceph/debugfs.c b/fs/ceph/debugfs.c
>>>>> index 40a22da0214a..c132fdb40d53 100644
>>>>> --- a/fs/ceph/debugfs.c
>>>>> +++ b/fs/ceph/debugfs.c
>>>>> @@ -128,6 +128,7 @@ static int metric_show(struct seq_file *s,
>>>>> void *p)
>>>>>    {
>>>>>        struct ceph_fs_client *fsc = s->private;
>>>>>        struct ceph_mds_client *mdsc = fsc->mdsc;
>>>>> +    int i;
>>>>>           seq_printf(s,
>>>>> "item          total           miss            hit\n");
>>>>>        seq_printf(s, "--------------------------------------
>>>>> -----------\n");
>>>>> @@ -137,6 +138,25 @@ static int metric_show(struct seq_file *s,
>>>>> void *p)
>>>>>               percpu_counter_sum(&mdsc-
>>>>>> metric.d_lease_mis),
>>>>>               percpu_counter_sum(&mdsc-
>>>>>> metric.d_lease_hit));
>>>>>    +    seq_printf(s, "\n");
>>>>> +    seq_printf(s,
>>>>> "session       caps            miss            hit\n");
>>>>> +    seq_printf(s, "----------------------------------------------
>>>>> ---\n");
>>>>> +
>>>>> +    mutex_lock(&mdsc->mutex);
>>>>> +    for (i = 0; i < mdsc->max_sessions; i++) {
>>>>> +        struct ceph_mds_session *session;
>>>>> +
>>>>> +        session = __ceph_lookup_mds_session(mdsc, i);
>>>>> +        if (!session)
>>>>> +            continue;
>>>>> +        seq_printf(s, "%-14d%-16d%-16lld%lld\n", i,
>>>>> +               session->s_nr_caps,
>>>>> + percpu_counter_sum(&session->i_caps_mis),
>>>>> + percpu_counter_sum(&session->i_caps_hit));
>>>>> +        ceph_put_mds_session(session);
>>>>> +    }
>>>>> +    mutex_unlock(&mdsc->mutex);
>>>>> +
>>>>>        return 0;
>>>>>    }
>>>>>    diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
>>>>> index 658c55b323cc..33eb239e09e2 100644
>>>>> --- a/fs/ceph/dir.c
>>>>> +++ b/fs/ceph/dir.c
>>>>> @@ -313,7 +313,7 @@ static int ceph_readdir(struct file *file,
>>>>> struct dir_context *ctx)
>>>>>        struct ceph_fs_client *fsc =
>>>>> ceph_inode_to_client(inode);
>>>>>        struct ceph_mds_client *mdsc = fsc->mdsc;
>>>>>        int i;
>>>>> -    int err;
>>>>> +    int err, ret = -1;
>>>>>        unsigned frag = -1;
>>>>>        struct ceph_mds_reply_info_parsed *rinfo;
>>>>>    @@ -346,13 +346,16 @@ static int ceph_readdir(struct file *file,
>>>>> struct dir_context *ctx)
>>>>>            !ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
>>>>>            ceph_snap(inode) != CEPH_SNAPDIR &&
>>>>>            __ceph_dir_is_complete_ordered(ci) &&
>>>>> -        __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
>>>>> +        (ret = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED,
>>>>> 1))) {
>>>>>            int shared_gen = atomic_read(&ci-
>>>>>> i_shared_gen);
>>>>> +        __ceph_caps_metric(ci, CEPH_CAP_XATTR_SHARED);
>>>>>            spin_unlock(&ci->i_ceph_lock);
>>>>>            err = __dcache_readdir(file, ctx, shared_gen);
>>>>>            if (err != -EAGAIN)
>>>>>                return err;
>>>>>        } else {
>>>>> +        if (ret != -1)
>>>>> +            __ceph_caps_metric(ci, CEPH_CAP_XATTR_SHARED);
>>>>>            spin_unlock(&ci->i_ceph_lock);
>>>>>        }
>>>>>    @@ -757,6 +760,8 @@ static struct dentry *ceph_lookup(struct
>>>>> inode *dir, struct dentry *dentry,
>>>>>            struct ceph_dentry_info *di =
>>>>> ceph_dentry(dentry);
>>>>>               spin_lock(&ci->i_ceph_lock);
>>>>> +        __ceph_caps_metric(ci, CEPH_CAP_FILE_SHARED);
>>>>> +
>>>>>            dout(" dir %p flags are %d\n", dir, ci-
>>>>>> i_ceph_flags);
>>>>>            if (strncmp(dentry->d_name.name,
>>>>>                    fsc->mount_options->snapdir_name,
>>>>> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
>>>>> index 1e6cdf2dfe90..c78dfbbb7b91 100644
>>>>> --- a/fs/ceph/file.c
>>>>> +++ b/fs/ceph/file.c
>>>>> @@ -384,6 +384,8 @@ int ceph_open(struct inode *inode, struct
>>>>> file *file)
>>>>>         * asynchronously.
>>>>>         */
>>>>>        spin_lock(&ci->i_ceph_lock);
>>>>> +    __ceph_caps_metric(ci, wanted);
>>>>> +
>>>>>        if (__ceph_is_any_real_caps(ci) &&
>>>>>            (((fmode & CEPH_FILE_MODE_WR) == 0) || ci-
>>>>>> i_auth_cap)) {
>>>>>            int mds_wanted = __ceph_caps_mds_wanted(ci,
>>>>> true);
>>>>> @@ -1340,6 +1342,7 @@ static ssize_t ceph_read_iter(struct kiocb
>>>>> *iocb, struct iov_iter *to)
>>>>>                    return -ENOMEM;
>>>>>            }
>>>>>    +        ceph_caps_metric(ci, CEPH_STAT_CAP_INLINE_DATA);
>>>>>            statret = __ceph_do_getattr(inode, page,
>>>>>                            CEPH_STAT_CAP_INLIN
>>>>> E_DATA, !!page);
>>>>>            if (statret < 0) {
>>>>> diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c
>>>>> index a24fd00676b8..141c1c03636c 100644
>>>>> --- a/fs/ceph/mds_client.c
>>>>> +++ b/fs/ceph/mds_client.c
>>>>> @@ -558,6 +558,8 @@ void ceph_put_mds_session(struct
>>>>> ceph_mds_session *s)
>>>>>        if (refcount_dec_and_test(&s->s_ref)) {
>>>>>            if (s->s_auth.authorizer)
>>>>>                ceph_auth_destroy_authorizer(s-
>>>>>> s_auth.authorizer);
>>>>> +        percpu_counter_destroy(&s->i_caps_hit);
>>>>> +        percpu_counter_destroy(&s->i_caps_mis);
>>>>>            kfree(s);
>>>>>        }
>>>>>    }
>>>>> @@ -598,6 +600,7 @@ static struct ceph_mds_session
>>>>> *register_session(struct ceph_mds_client *mdsc,
>>>>>                             int mds)
>>>>>    {
>>>>>        struct ceph_mds_session *s;
>>>>> +    int err;
>>>>>           if (mds >= mdsc->mdsmap->possible_max_rank)
>>>>>            return ERR_PTR(-EINVAL);
>>>>> @@ -612,8 +615,10 @@ static struct ceph_mds_session
>>>>> *register_session(struct ceph_mds_client *mdsc,
>>>>>               dout("%s: realloc to %d\n", __func__, newmax);
>>>>>            sa = kcalloc(newmax, sizeof(void *), GFP_NOFS);
>>>>> -        if (!sa)
>>>>> +        if (!sa) {
>>>>> +            err = -ENOMEM;
>>>>>                goto fail_realloc;
>>>>> +        }
>>>>>            if (mdsc->sessions) {
>>>>>                memcpy(sa, mdsc->sessions,
>>>>>                       mdsc->max_sessions * sizeof(void
>>>>> *));
>>>>> @@ -653,6 +658,13 @@ static struct ceph_mds_session
>>>>> *register_session(struct ceph_mds_client *mdsc,
>>>>>           INIT_LIST_HEAD(&s->s_cap_flushing);
>>>>>    +    err = percpu_counter_init(&s->i_caps_hit, 0, GFP_NOFS);
>>>>> +    if (err)
>>>>> +        goto fail_realloc;
>>>>> +    err = percpu_counter_init(&s->i_caps_mis, 0, GFP_NOFS);
>>>>> +    if (err)
>>>>> +        goto fail_init;
>>>>> +
>>>>>        mdsc->sessions[mds] = s;
>>>>>        atomic_inc(&mdsc->num_sessions);
>>>>>        refcount_inc(&s->s_ref);  /* one ref to sessions[], one
>>>>> to caller */
>>>>> @@ -662,6 +674,8 @@ static struct ceph_mds_session
>>>>> *register_session(struct ceph_mds_client *mdsc,
>>>>>           return s;
>>>>>    +fail_init:
>>>>> +    percpu_counter_destroy(&s->i_caps_hit);
>>>>>    fail_realloc:
>>>>>        kfree(s);
>>>>>        return ERR_PTR(-ENOMEM);
>>>>> diff --git a/fs/ceph/mds_client.h b/fs/ceph/mds_client.h
>>>>> index dd1f417b90eb..ba74ff74c59c 100644
>>>>> --- a/fs/ceph/mds_client.h
>>>>> +++ b/fs/ceph/mds_client.h
>>>>> @@ -201,6 +201,9 @@ struct ceph_mds_session {
>>>>>           struct list_head  s_waiting;  /* waiting requests */
>>>>>        struct list_head  s_unsafe;   /* unsafe requests */
>>>>> +
>>>>> +    struct percpu_counter i_caps_hit;
>>>>> +    struct percpu_counter i_caps_mis;
>>>>>    };
>>>>>       /*
>>>>> diff --git a/fs/ceph/quota.c b/fs/ceph/quota.c
>>>>> index de56dee60540..4ce2f658e63d 100644
>>>>> --- a/fs/ceph/quota.c
>>>>> +++ b/fs/ceph/quota.c
>>>>> @@ -147,9 +147,14 @@ static struct inode
>>>>> *lookup_quotarealm_inode(struct ceph_mds_client *mdsc,
>>>>>            return NULL;
>>>>>        }
>>>>>        if (qri->inode) {
>>>>> +        struct ceph_inode_info *ci = ceph_inode(qri->inode);
>>>>> +        int ret;
>>>>> +
>>>>> +        ceph_caps_metric(ci, CEPH_STAT_CAP_INODE);
>>>>> +
>>>>>            /* get caps */
>>>>> -        int ret = __ceph_do_getattr(qri->inode, NULL,
>>>>> -                        CEPH_STAT_CAP_INODE, true);
>>>>> +        ret = __ceph_do_getattr(qri->inode, NULL,
>>>>> +                    CEPH_STAT_CAP_INODE, true);
>>>>>            if (ret >= 0)
>>>>>                in = qri->inode;
>>>>>            else
>>>>> diff --git a/fs/ceph/super.h b/fs/ceph/super.h
>>>>> index 7af91628636c..3f4829222528 100644
>>>>> --- a/fs/ceph/super.h
>>>>> +++ b/fs/ceph/super.h
>>>>> @@ -641,6 +641,14 @@ static inline bool
>>>>> __ceph_is_any_real_caps(struct ceph_inode_info *ci)
>>>>>        return !RB_EMPTY_ROOT(&ci->i_caps);
>>>>>    }
>>>>>    +extern void __ceph_caps_metric(struct ceph_inode_info *ci, int
>>>>> mask);
>>>>> +static inline void ceph_caps_metric(struct ceph_inode_info *ci,
>>>>> int mask)
>>>>> +{
>>>>> +    spin_lock(&ci->i_ceph_lock);
>>>>> +    __ceph_caps_metric(ci, mask);
>>>>> +    spin_unlock(&ci->i_ceph_lock);
>>>>> +}
>>>>> +
>>>>>    extern int __ceph_caps_issued(struct ceph_inode_info *ci, int
>>>>> *implemented);
>>>>>    extern int __ceph_caps_issued_mask(struct ceph_inode_info *ci,
>>>>> int mask, int t);
>>>>>    extern int __ceph_caps_issued_other(struct ceph_inode_info *ci,
>>>>> @@ -927,6 +935,9 @@ extern int __ceph_do_getattr(struct inode
>>>>> *inode, struct page *locked_page,
>>>>>                     int mask, bool force);
>>>>>    static inline int ceph_do_getattr(struct inode *inode, int
>>>>> mask, bool force)
>>>>>    {
>>>>> +    struct ceph_inode_info *ci = ceph_inode(inode);
>>>>> +
>>>>> +    ceph_caps_metric(ci, mask);
>>>>>        return __ceph_do_getattr(inode, NULL, mask, force);
>>>>>    }
>>>>>    extern int ceph_permission(struct inode *inode, int mask);
>>>>> diff --git a/fs/ceph/xattr.c b/fs/ceph/xattr.c
>>>>> index d58fa14c1f01..ebd522edb0a8 100644
>>>>> --- a/fs/ceph/xattr.c
>>>>> +++ b/fs/ceph/xattr.c
>>>>> @@ -829,6 +829,7 @@ ssize_t __ceph_getxattr(struct inode *inode,
>>>>> const char *name, void *value,
>>>>>        struct ceph_vxattr *vxattr = NULL;
>>>>>        int req_mask;
>>>>>        ssize_t err;
>>>>> +    int ret = -1;
>>>>>           /* let's see if a virtual xattr was requested */
>>>>>        vxattr = ceph_match_vxattr(inode, name);
>>>>> @@ -856,7 +857,9 @@ ssize_t __ceph_getxattr(struct inode *inode,
>>>>> const char *name, void *value,
>>>>>           if (ci->i_xattrs.version == 0 ||
>>>>>            !((req_mask & CEPH_CAP_XATTR_SHARED) ||
>>>>> -          __ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1))) {
>>>>> +          (ret = __ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED,
>>>>> 1)))) {
>>>>> +        if (ret != -1)
>>>>> +            __ceph_caps_metric(ci, CEPH_CAP_XATTR_SHARED);
>>>>>            spin_unlock(&ci->i_ceph_lock);
>>>>>               /* security module gets xattr while filling
>>>>> trace */
>>>>> @@ -871,6 +874,9 @@ ssize_t __ceph_getxattr(struct inode *inode,
>>>>> const char *name, void *value,
>>>>>            if (err)
>>>>>                return err;
>>>>>            spin_lock(&ci->i_ceph_lock);
>>>>> +    } else {
>>>>> +        if (ret != -1)
>>>>> +            __ceph_caps_metric(ci, CEPH_CAP_XATTR_SHARED);
>>>>>        }
>>>>>           err = __build_xattrs(inode);
>>>>> @@ -907,19 +913,24 @@ ssize_t ceph_listxattr(struct dentry
>>>>> *dentry, char *names, size_t size)
>>>>>        struct ceph_inode_info *ci = ceph_inode(inode);
>>>>>        bool len_only = (size == 0);
>>>>>        u32 namelen;
>>>>> -    int err;
>>>>> +    int err, ret = -1;
>>>>>           spin_lock(&ci->i_ceph_lock);
>>>>>        dout("listxattr %p ver=%lld index_ver=%lld\n", inode,
>>>>>             ci->i_xattrs.version, ci->i_xattrs.index_version);
>>>>>           if (ci->i_xattrs.version == 0 ||
>>>>> -        !__ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED, 1)) {
>>>>> +        !(ret = __ceph_caps_issued_mask(ci, CEPH_CAP_XATTR_SHARED,
>>>>> 1))) {
>>>>> +        if (ret != -1)
>>>>> +            __ceph_caps_metric(ci, CEPH_CAP_XATTR_SHARED);
>>>>>            spin_unlock(&ci->i_ceph_lock);
>>>>>            err = ceph_do_getattr(inode,
>>>>> CEPH_STAT_CAP_XATTR, true);
>>>>>            if (err)
>>>>>                return err;
>>>>>            spin_lock(&ci->i_ceph_lock);
>>>>> +    } else {
>>>>> +        if (ret != -1)
>>>>> +            __ceph_caps_metric(ci, CEPH_CAP_XATTR_SHARED);
>>>>>        }
>>>>>           err = __build_xattrs(inode);
>>>
>