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ceph: consider inode's last read/write when calculating wanted caps
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Add i_last_rd and i_last_wr to ceph_inode_info. These fields are
used to track the last time the client acquired read/write caps for
the inode.

If there is no read/write on an inode for 'caps_wanted_delay_max'
seconds, __ceph_caps_file_wanted() does not request caps for read/write
even there are open files.

Call __ceph_touch_fmode() for dir operations. __ceph_caps_file_wanted()
calculates dir's wanted caps according to last dir read/modification. If
there is recent dir read, dir inode wants CEPH_CAP_ANY_SHARED caps. If
there is recent dir modification, also wants CEPH_CAP_FILE_EXCL.

Readdir is a special case. Dir inode wants CEPH_CAP_FILE_EXCL after
readdir, as with that, modifications do not need to release
CEPH_CAP_FILE_SHARED or invalidate all dentry leases issued by readdir.

Signed-off-by: "Yan, Zheng" <[email protected]>
Reviewed-by: Jeff Layton <[email protected]>
Signed-off-by: Ilya Dryomov <[email protected]>
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@ukernel @idryomov
ukernel authored and idryomov committed Mar 30, 2020
1 parent c0e385b commit 719a251
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Showing 8 changed files with 188 additions and 74 deletions.
183 changes: 129 additions & 54 deletions fs/ceph/caps.c
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Original file line number Diff line number Diff line change
Expand Up @@ -978,19 +978,67 @@ int __ceph_caps_used(struct ceph_inode_info *ci)
return used;
}

#define FMODE_WAIT_BIAS 1000

/*
* wanted, by virtue of open file modes
*/
int __ceph_caps_file_wanted(struct ceph_inode_info *ci)
{
int i, bits = 0;
for (i = 0; i < CEPH_FILE_MODE_BITS; i++) {
if (ci->i_nr_by_mode[i])
bits |= 1 << i;
const int PIN_SHIFT = ffs(CEPH_FILE_MODE_PIN);
const int RD_SHIFT = ffs(CEPH_FILE_MODE_RD);
const int WR_SHIFT = ffs(CEPH_FILE_MODE_WR);
const int LAZY_SHIFT = ffs(CEPH_FILE_MODE_LAZY);
struct ceph_mount_options *opt =
ceph_inode_to_client(&ci->vfs_inode)->mount_options;
unsigned long used_cutoff = jiffies - opt->caps_wanted_delay_max * HZ;
unsigned long idle_cutoff = jiffies - opt->caps_wanted_delay_min * HZ;

if (S_ISDIR(ci->vfs_inode.i_mode)) {
int want = 0;

/* use used_cutoff here, to keep dir's wanted caps longer */
if (ci->i_nr_by_mode[RD_SHIFT] > 0 ||
time_after(ci->i_last_rd, used_cutoff))
want |= CEPH_CAP_ANY_SHARED;

if (ci->i_nr_by_mode[WR_SHIFT] > 0 ||
time_after(ci->i_last_wr, used_cutoff)) {
want |= CEPH_CAP_ANY_SHARED | CEPH_CAP_FILE_EXCL;
if (opt->flags & CEPH_MOUNT_OPT_ASYNC_DIROPS)
want |= CEPH_CAP_ANY_DIR_OPS;
}

if (want || ci->i_nr_by_mode[PIN_SHIFT] > 0)
want |= CEPH_CAP_PIN;

return want;
} else {
int bits = 0;

if (ci->i_nr_by_mode[RD_SHIFT] > 0) {
if (ci->i_nr_by_mode[RD_SHIFT] >= FMODE_WAIT_BIAS ||
time_after(ci->i_last_rd, used_cutoff))
bits |= 1 << RD_SHIFT;
} else if (time_after(ci->i_last_rd, idle_cutoff)) {
bits |= 1 << RD_SHIFT;
}

if (ci->i_nr_by_mode[WR_SHIFT] > 0) {
if (ci->i_nr_by_mode[WR_SHIFT] >= FMODE_WAIT_BIAS ||
time_after(ci->i_last_wr, used_cutoff))
bits |= 1 << WR_SHIFT;
} else if (time_after(ci->i_last_wr, idle_cutoff)) {
bits |= 1 << WR_SHIFT;
}

/* check lazyio only when read/write is wanted */
if ((bits & (CEPH_FILE_MODE_RDWR << 1)) &&
ci->i_nr_by_mode[LAZY_SHIFT] > 0)
bits |= 1 << LAZY_SHIFT;

return bits ? ceph_caps_for_mode(bits >> 1) : 0;
}
if (bits == 0)
return 0;
return ceph_caps_for_mode(bits >> 1);
}

/*
Expand Down Expand Up @@ -1032,14 +1080,6 @@ int __ceph_caps_mds_wanted(struct ceph_inode_info *ci, bool check)
return mds_wanted;
}

/*
* called under i_ceph_lock
*/
static int __ceph_is_single_caps(struct ceph_inode_info *ci)
{
return rb_first(&ci->i_caps) == rb_last(&ci->i_caps);
}

int ceph_is_any_caps(struct inode *inode)
{
struct ceph_inode_info *ci = ceph_inode(inode);
Expand Down Expand Up @@ -1877,10 +1917,6 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
if (ci->i_ceph_flags & CEPH_I_FLUSH)
flags |= CHECK_CAPS_FLUSH;

if (!(flags & CHECK_CAPS_AUTHONLY) ||
(ci->i_auth_cap && __ceph_is_single_caps(ci)))
__cap_delay_cancel(mdsc, ci);

goto retry_locked;
retry:
spin_lock(&ci->i_ceph_lock);
Expand All @@ -1907,9 +1943,7 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
if (IS_RDONLY(inode)) {
want = CEPH_CAP_ANY_SHARED;
} else {
want = CEPH_CAP_ANY_SHARED |
CEPH_CAP_FILE_EXCL |
CEPH_CAP_ANY_DIR_OPS;
want |= CEPH_CAP_ANY_SHARED | CEPH_CAP_FILE_EXCL;
}
retain |= want;
} else {
Expand Down Expand Up @@ -2105,9 +2139,17 @@ void ceph_check_caps(struct ceph_inode_info *ci, int flags,
goto retry; /* retake i_ceph_lock and restart our cap scan. */
}

/* Reschedule delayed caps release if we delayed anything */
if (delayed)
__cap_delay_requeue(mdsc, ci, false);
if (list_empty(&ci->i_cap_delay_list)) {
if (delayed) {
/* Reschedule delayed caps release if we delayed anything */
__cap_delay_requeue(mdsc, ci, false);
} else if (__ceph_is_any_real_caps(ci) &&
(file_wanted & ~CEPH_CAP_PIN) &&
!(used & (CEPH_CAP_FILE_RD | CEPH_CAP_ANY_FILE_WR))) {
/* periodically re-calculate caps wanted by open files */
__cap_delay_requeue(mdsc, ci, true);
}
}

spin_unlock(&ci->i_ceph_lock);

Expand Down Expand Up @@ -2573,8 +2615,9 @@ void ceph_take_cap_refs(struct ceph_inode_info *ci, int got,
* FIXME: how does a 0 return differ from -EAGAIN?
*/
enum {
NON_BLOCKING = 1,
CHECK_FILELOCK = 2,
/* first 8 bits are reserved for CEPH_FILE_MODE_FOO */
NON_BLOCKING = (1 << 8),
CHECK_FILELOCK = (1 << 9),
};

static int try_get_cap_refs(struct inode *inode, int need, int want,
Expand All @@ -2584,7 +2627,6 @@ static int try_get_cap_refs(struct inode *inode, int need, int want,
struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
int ret = 0;
int have, implemented;
int file_wanted;
bool snap_rwsem_locked = false;

dout("get_cap_refs %p need %s want %s\n", inode,
Expand All @@ -2600,15 +2642,6 @@ static int try_get_cap_refs(struct inode *inode, int need, int want,
goto out_unlock;
}

/* make sure file is actually open */
file_wanted = __ceph_caps_file_wanted(ci);
if ((file_wanted & need) != need) {
dout("try_get_cap_refs need %s file_wanted %s, EBADF\n",
ceph_cap_string(need), ceph_cap_string(file_wanted));
ret = -EBADF;
goto out_unlock;
}

/* finish pending truncate */
while (ci->i_truncate_pending) {
spin_unlock(&ci->i_ceph_lock);
Expand Down Expand Up @@ -2719,6 +2752,9 @@ static int try_get_cap_refs(struct inode *inode, int need, int want,
ceph_cap_string(have), ceph_cap_string(need));
}
out_unlock:

__ceph_touch_fmode(ci, mdsc, flags);

spin_unlock(&ci->i_ceph_lock);
if (snap_rwsem_locked)
up_read(&mdsc->snap_rwsem);
Expand Down Expand Up @@ -2756,10 +2792,20 @@ static void check_max_size(struct inode *inode, loff_t endoff)
ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
}

static inline int get_used_fmode(int caps)
{
int fmode = 0;
if (caps & CEPH_CAP_FILE_RD)
fmode |= CEPH_FILE_MODE_RD;
if (caps & CEPH_CAP_FILE_WR)
fmode |= CEPH_FILE_MODE_WR;
return fmode;
}

int ceph_try_get_caps(struct inode *inode, int need, int want,
bool nonblock, int *got)
{
int ret;
int ret, flags;

BUG_ON(need & ~CEPH_CAP_FILE_RD);
BUG_ON(want & ~(CEPH_CAP_FILE_CACHE | CEPH_CAP_FILE_LAZYIO |
Expand All @@ -2771,8 +2817,11 @@ int ceph_try_get_caps(struct inode *inode, int need, int want,
return ret;
}

ret = try_get_cap_refs(inode, need, want, 0,
(nonblock ? NON_BLOCKING : 0), got);
flags = get_used_fmode(need | want);
if (nonblock)
flags |= NON_BLOCKING;

ret = try_get_cap_refs(inode, need, want, 0, flags, got);
return ret == -EAGAIN ? 0 : ret;
}

Expand All @@ -2798,11 +2847,15 @@ int ceph_get_caps(struct file *filp, int need, int want,
fi->filp_gen != READ_ONCE(fsc->filp_gen))
return -EBADF;

flags = get_used_fmode(need | want);

while (true) {
if (endoff > 0)
check_max_size(inode, endoff);

flags = atomic_read(&fi->num_locks) ? CHECK_FILELOCK : 0;
flags &= CEPH_FILE_MODE_MASK;
if (atomic_read(&fi->num_locks))
flags |= CHECK_FILELOCK;
_got = 0;
ret = try_get_cap_refs(inode, need, want, endoff,
flags, &_got);
Expand All @@ -2822,6 +2875,8 @@ int ceph_get_caps(struct file *filp, int need, int want,
list_add(&cw.list, &mdsc->cap_wait_list);
spin_unlock(&mdsc->caps_list_lock);

/* make sure used fmode not timeout */
ceph_get_fmode(ci, flags, FMODE_WAIT_BIAS);
add_wait_queue(&ci->i_cap_wq, &wait);

flags |= NON_BLOCKING;
Expand All @@ -2835,6 +2890,7 @@ int ceph_get_caps(struct file *filp, int need, int want,
}

remove_wait_queue(&ci->i_cap_wq, &wait);
ceph_put_fmode(ci, flags, FMODE_WAIT_BIAS);

spin_lock(&mdsc->caps_list_lock);
list_del(&cw.list);
Expand All @@ -2854,7 +2910,7 @@ int ceph_get_caps(struct file *filp, int need, int want,
if (ret < 0) {
if (ret == -ESTALE) {
/* session was killed, try renew caps */
ret = ceph_renew_caps(inode);
ret = ceph_renew_caps(inode, flags);
if (ret == 0)
continue;
}
Expand Down Expand Up @@ -4153,6 +4209,33 @@ void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
dout("flush_dirty_caps done\n");
}

void __ceph_touch_fmode(struct ceph_inode_info *ci,
struct ceph_mds_client *mdsc, int fmode)
{
unsigned long now = jiffies;
if (fmode & CEPH_FILE_MODE_RD)
ci->i_last_rd = now;
if (fmode & CEPH_FILE_MODE_WR)
ci->i_last_wr = now;
/* queue periodic check */
if (fmode &&
__ceph_is_any_real_caps(ci) &&
list_empty(&ci->i_cap_delay_list))
__cap_delay_requeue(mdsc, ci, true);
}

void ceph_get_fmode(struct ceph_inode_info *ci, int fmode, int count)
{
int i;
int bits = (fmode << 1) | 1;
spin_lock(&ci->i_ceph_lock);
for (i = 0; i < CEPH_FILE_MODE_BITS; i++) {
if (bits & (1 << i))
ci->i_nr_by_mode[i] += count;
}
spin_unlock(&ci->i_ceph_lock);
}

void __ceph_get_fmode(struct ceph_inode_info *ci, int fmode)
{
int i;
Expand All @@ -4168,26 +4251,18 @@ void __ceph_get_fmode(struct ceph_inode_info *ci, int fmode)
* we may need to release capabilities to the MDS (or schedule
* their delayed release).
*/
void ceph_put_fmode(struct ceph_inode_info *ci, int fmode)
void ceph_put_fmode(struct ceph_inode_info *ci, int fmode, int count)
{
int i, last = 0;
int i;
int bits = (fmode << 1) | 1;
spin_lock(&ci->i_ceph_lock);
for (i = 0; i < CEPH_FILE_MODE_BITS; i++) {
if (bits & (1 << i)) {
BUG_ON(ci->i_nr_by_mode[i] == 0);
if (--ci->i_nr_by_mode[i] == 0)
last++;
BUG_ON(ci->i_nr_by_mode[i] < count);
ci->i_nr_by_mode[i] -= count;
}
}
dout("put_fmode %p fmode %d {%d,%d,%d,%d}\n",
&ci->vfs_inode, fmode,
ci->i_nr_by_mode[0], ci->i_nr_by_mode[1],
ci->i_nr_by_mode[2], ci->i_nr_by_mode[3]);
spin_unlock(&ci->i_ceph_lock);

if (last && ci->i_vino.snap == CEPH_NOSNAP)
ceph_check_caps(ci, 0, NULL);
}

/*
Expand Down
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