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linux/fs/ceph/caps.c
Sage Weil f818a73674 ceph: fix cap removal races 
The iterate_session_caps helper traverses the session caps list and tries
to grab an inode reference.  However, the __ceph_remove_cap was clearing
the inode backpointer _before_ removing itself from the session list,
causing a null pointer dereference.

Clear cap->ci under protection of s_cap_lock to avoid the race, and to
tightly couple the list and backpointer state.  Use a local flag to
indicate whether we are releasing the cap, as cap->session may be modified
by a racing thread in iterate_session_caps.

Signed-off-by: Sage Weil <sage@newdream.net>
2010-05-11 20:56:31 -07:00

2961 lines
80 KiB
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#include "ceph_debug.h"
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/vmalloc.h>
#include <linux/wait.h>
#include <linux/writeback.h>
#include "super.h"
#include "decode.h"
#include "messenger.h"
/*
* Capability management
*
* The Ceph metadata servers control client access to inode metadata
* and file data by issuing capabilities, granting clients permission
* to read and/or write both inode field and file data to OSDs
* (storage nodes). Each capability consists of a set of bits
* indicating which operations are allowed.
*
* If the client holds a *_SHARED cap, the client has a coherent value
* that can be safely read from the cached inode.
*
* In the case of a *_EXCL (exclusive) or FILE_WR capabilities, the
* client is allowed to change inode attributes (e.g., file size,
* mtime), note its dirty state in the ceph_cap, and asynchronously
* flush that metadata change to the MDS.
*
* In the event of a conflicting operation (perhaps by another
* client), the MDS will revoke the conflicting client capabilities.
*
* In order for a client to cache an inode, it must hold a capability
* with at least one MDS server. When inodes are released, release
* notifications are batched and periodically sent en masse to the MDS
* cluster to release server state.
*/
/*
* Generate readable cap strings for debugging output.
*/
#define MAX_CAP_STR 20
static char cap_str[MAX_CAP_STR][40];
static DEFINE_SPINLOCK(cap_str_lock);
static int last_cap_str;
static char *gcap_string(char *s, int c)
{
if (c & CEPH_CAP_GSHARED)
*s++ = 's';
if (c & CEPH_CAP_GEXCL)
*s++ = 'x';
if (c & CEPH_CAP_GCACHE)
*s++ = 'c';
if (c & CEPH_CAP_GRD)
*s++ = 'r';
if (c & CEPH_CAP_GWR)
*s++ = 'w';
if (c & CEPH_CAP_GBUFFER)
*s++ = 'b';
if (c & CEPH_CAP_GLAZYIO)
*s++ = 'l';
return s;
}
const char *ceph_cap_string(int caps)
{
int i;
char *s;
int c;
spin_lock(&cap_str_lock);
i = last_cap_str++;
if (last_cap_str == MAX_CAP_STR)
last_cap_str = 0;
spin_unlock(&cap_str_lock);
s = cap_str[i];
if (caps & CEPH_CAP_PIN)
*s++ = 'p';
c = (caps >> CEPH_CAP_SAUTH) & 3;
if (c) {
*s++ = 'A';
s = gcap_string(s, c);
}
c = (caps >> CEPH_CAP_SLINK) & 3;
if (c) {
*s++ = 'L';
s = gcap_string(s, c);
}
c = (caps >> CEPH_CAP_SXATTR) & 3;
if (c) {
*s++ = 'X';
s = gcap_string(s, c);
}
c = caps >> CEPH_CAP_SFILE;
if (c) {
*s++ = 'F';
s = gcap_string(s, c);
}
if (s == cap_str[i])
*s++ = '-';
*s = 0;
return cap_str[i];
}
/*
* Cap reservations
*
* Maintain a global pool of preallocated struct ceph_caps, referenced
* by struct ceph_caps_reservations. This ensures that we preallocate
* memory needed to successfully process an MDS response. (If an MDS
* sends us cap information and we fail to process it, we will have
* problems due to the client and MDS being out of sync.)
*
* Reservations are 'owned' by a ceph_cap_reservation context.
*/
static spinlock_t caps_list_lock;
static struct list_head caps_list; /* unused (reserved or unreserved) */
static int caps_total_count; /* total caps allocated */
static int caps_use_count; /* in use */
static int caps_reserve_count; /* unused, reserved */
static int caps_avail_count; /* unused, unreserved */
static int caps_min_count; /* keep at least this many (unreserved) */
void __init ceph_caps_init(void)
{
INIT_LIST_HEAD(&caps_list);
spin_lock_init(&caps_list_lock);
}
void ceph_caps_finalize(void)
{
struct ceph_cap *cap;
spin_lock(&caps_list_lock);
while (!list_empty(&caps_list)) {
cap = list_first_entry(&caps_list, struct ceph_cap, caps_item);
list_del(&cap->caps_item);
kmem_cache_free(ceph_cap_cachep, cap);
}
caps_total_count = 0;
caps_avail_count = 0;
caps_use_count = 0;
caps_reserve_count = 0;
caps_min_count = 0;
spin_unlock(&caps_list_lock);
}
void ceph_adjust_min_caps(int delta)
{
spin_lock(&caps_list_lock);
caps_min_count += delta;
BUG_ON(caps_min_count < 0);
spin_unlock(&caps_list_lock);
}
int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need)
{
int i;
struct ceph_cap *cap;
int have;
int alloc = 0;
LIST_HEAD(newcaps);
int ret = 0;
dout("reserve caps ctx=%p need=%d\n", ctx, need);
/* first reserve any caps that are already allocated */
spin_lock(&caps_list_lock);
if (caps_avail_count >= need)
have = need;
else
have = caps_avail_count;
caps_avail_count -= have;
caps_reserve_count += have;
BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
caps_avail_count);
spin_unlock(&caps_list_lock);
for (i = have; i < need; i++) {
cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
if (!cap) {
ret = -ENOMEM;
goto out_alloc_count;
}
list_add(&cap->caps_item, &newcaps);
alloc++;
}
BUG_ON(have + alloc != need);
spin_lock(&caps_list_lock);
caps_total_count += alloc;
caps_reserve_count += alloc;
list_splice(&newcaps, &caps_list);
BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
caps_avail_count);
spin_unlock(&caps_list_lock);
ctx->count = need;
dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
ctx, caps_total_count, caps_use_count, caps_reserve_count,
caps_avail_count);
return 0;
out_alloc_count:
/* we didn't manage to reserve as much as we needed */
pr_warning("reserve caps ctx=%p ENOMEM need=%d got=%d\n",
ctx, need, have);
return ret;
}
int ceph_unreserve_caps(struct ceph_cap_reservation *ctx)
{
dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
if (ctx->count) {
spin_lock(&caps_list_lock);
BUG_ON(caps_reserve_count < ctx->count);
caps_reserve_count -= ctx->count;
caps_avail_count += ctx->count;
ctx->count = 0;
dout("unreserve caps %d = %d used + %d resv + %d avail\n",
caps_total_count, caps_use_count, caps_reserve_count,
caps_avail_count);
BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
caps_avail_count);
spin_unlock(&caps_list_lock);
}
return 0;
}
static struct ceph_cap *get_cap(struct ceph_cap_reservation *ctx)
{
struct ceph_cap *cap = NULL;
/* temporary, until we do something about cap import/export */
if (!ctx)
return kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
spin_lock(&caps_list_lock);
dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n",
ctx, ctx->count, caps_total_count, caps_use_count,
caps_reserve_count, caps_avail_count);
BUG_ON(!ctx->count);
BUG_ON(ctx->count > caps_reserve_count);
BUG_ON(list_empty(&caps_list));
ctx->count--;
caps_reserve_count--;
caps_use_count++;
cap = list_first_entry(&caps_list, struct ceph_cap, caps_item);
list_del(&cap->caps_item);
BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
caps_avail_count);
spin_unlock(&caps_list_lock);
return cap;
}
void ceph_put_cap(struct ceph_cap *cap)
{
spin_lock(&caps_list_lock);
dout("put_cap %p %d = %d used + %d resv + %d avail\n",
cap, caps_total_count, caps_use_count,
caps_reserve_count, caps_avail_count);
caps_use_count--;
/*
* Keep some preallocated caps around (ceph_min_count), to
* avoid lots of free/alloc churn.
*/
if (caps_avail_count >= caps_reserve_count + caps_min_count) {
caps_total_count--;
kmem_cache_free(ceph_cap_cachep, cap);
} else {
caps_avail_count++;
list_add(&cap->caps_item, &caps_list);
}
BUG_ON(caps_total_count != caps_use_count + caps_reserve_count +
caps_avail_count);
spin_unlock(&caps_list_lock);
}
void ceph_reservation_status(struct ceph_client *client,
int *total, int *avail, int *used, int *reserved,
int *min)
{
if (total)
*total = caps_total_count;
if (avail)
*avail = caps_avail_count;
if (used)
*used = caps_use_count;
if (reserved)
*reserved = caps_reserve_count;
if (min)
*min = caps_min_count;
}
/*
* Find ceph_cap for given mds, if any.
*
* Called with i_lock held.
*/
static struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds)
{
struct ceph_cap *cap;
struct rb_node *n = ci->i_caps.rb_node;
while (n) {
cap = rb_entry(n, struct ceph_cap, ci_node);
if (mds < cap->mds)
n = n->rb_left;
else if (mds > cap->mds)
n = n->rb_right;
else
return cap;
}
return NULL;
}
/*
* Return id of any MDS with a cap, preferably FILE_WR|WRBUFFER|EXCL, else
* -1.
*/
static int __ceph_get_cap_mds(struct ceph_inode_info *ci, u32 *mseq)
{
struct ceph_cap *cap;
int mds = -1;
struct rb_node *p;
/* prefer mds with WR|WRBUFFER|EXCL caps */
for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
cap = rb_entry(p, struct ceph_cap, ci_node);
mds = cap->mds;
if (mseq)
*mseq = cap->mseq;
if (cap->issued & (CEPH_CAP_FILE_WR |
CEPH_CAP_FILE_BUFFER |
CEPH_CAP_FILE_EXCL))
break;
}
return mds;
}
int ceph_get_cap_mds(struct inode *inode)
{
int mds;
spin_lock(&inode->i_lock);
mds = __ceph_get_cap_mds(ceph_inode(inode), NULL);
spin_unlock(&inode->i_lock);
return mds;
}
/*
* Called under i_lock.
*/
static void __insert_cap_node(struct ceph_inode_info *ci,
struct ceph_cap *new)
{
struct rb_node **p = &ci->i_caps.rb_node;
struct rb_node *parent = NULL;
struct ceph_cap *cap = NULL;
while (*p) {
parent = *p;
cap = rb_entry(parent, struct ceph_cap, ci_node);
if (new->mds < cap->mds)
p = &(*p)->rb_left;
else if (new->mds > cap->mds)
p = &(*p)->rb_right;
else
BUG();
}
rb_link_node(&new->ci_node, parent, p);
rb_insert_color(&new->ci_node, &ci->i_caps);
}
/*
* (re)set cap hold timeouts, which control the delayed release
* of unused caps back to the MDS. Should be called on cap use.
*/
static void __cap_set_timeouts(struct ceph_mds_client *mdsc,
struct ceph_inode_info *ci)
{
struct ceph_mount_args *ma = mdsc->client->mount_args;
ci->i_hold_caps_min = round_jiffies(jiffies +
ma->caps_wanted_delay_min * HZ);
ci->i_hold_caps_max = round_jiffies(jiffies +
ma->caps_wanted_delay_max * HZ);
dout("__cap_set_timeouts %p min %lu max %lu\n", &ci->vfs_inode,
ci->i_hold_caps_min - jiffies, ci->i_hold_caps_max - jiffies);
}
/*
* (Re)queue cap at the end of the delayed cap release list.
*
* If I_FLUSH is set, leave the inode at the front of the list.
*
* Caller holds i_lock
* -> we take mdsc->cap_delay_lock
*/
static void __cap_delay_requeue(struct ceph_mds_client *mdsc,
struct ceph_inode_info *ci)
{
__cap_set_timeouts(mdsc, ci);
dout("__cap_delay_requeue %p flags %d at %lu\n", &ci->vfs_inode,
ci->i_ceph_flags, ci->i_hold_caps_max);
if (!mdsc->stopping) {
spin_lock(&mdsc->cap_delay_lock);
if (!list_empty(&ci->i_cap_delay_list)) {
if (ci->i_ceph_flags & CEPH_I_FLUSH)
goto no_change;
list_del_init(&ci->i_cap_delay_list);
}
list_add_tail(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
no_change:
spin_unlock(&mdsc->cap_delay_lock);
}
}
/*
* Queue an inode for immediate writeback. Mark inode with I_FLUSH,
* indicating we should send a cap message to flush dirty metadata
* asap, and move to the front of the delayed cap list.
*/
static void __cap_delay_requeue_front(struct ceph_mds_client *mdsc,
struct ceph_inode_info *ci)
{
dout("__cap_delay_requeue_front %p\n", &ci->vfs_inode);
spin_lock(&mdsc->cap_delay_lock);
ci->i_ceph_flags |= CEPH_I_FLUSH;
if (!list_empty(&ci->i_cap_delay_list))
list_del_init(&ci->i_cap_delay_list);
list_add(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
spin_unlock(&mdsc->cap_delay_lock);
}
/*
* Cancel delayed work on cap.
*
* Caller must hold i_lock.
*/
static void __cap_delay_cancel(struct ceph_mds_client *mdsc,
struct ceph_inode_info *ci)
{
dout("__cap_delay_cancel %p\n", &ci->vfs_inode);
if (list_empty(&ci->i_cap_delay_list))
return;
spin_lock(&mdsc->cap_delay_lock);
list_del_init(&ci->i_cap_delay_list);
spin_unlock(&mdsc->cap_delay_lock);
}
/*
* Common issue checks for add_cap, handle_cap_grant.
*/
static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap,
unsigned issued)
{
unsigned had = __ceph_caps_issued(ci, NULL);
/*
* Each time we receive FILE_CACHE anew, we increment
* i_rdcache_gen.
*/
if ((issued & CEPH_CAP_FILE_CACHE) &&
(had & CEPH_CAP_FILE_CACHE) == 0)
ci->i_rdcache_gen++;
/*
* if we are newly issued FILE_SHARED, clear I_COMPLETE; we
* don't know what happened to this directory while we didn't
* have the cap.
*/
if ((issued & CEPH_CAP_FILE_SHARED) &&
(had & CEPH_CAP_FILE_SHARED) == 0) {
ci->i_shared_gen++;
if (S_ISDIR(ci->vfs_inode.i_mode)) {
dout(" marking %p NOT complete\n", &ci->vfs_inode);
ci->i_ceph_flags &= ~CEPH_I_COMPLETE;
}
}
}
/*
* Add a capability under the given MDS session.
*
* Caller should hold session snap_rwsem (read) and s_mutex.
*
* @fmode is the open file mode, if we are opening a file, otherwise
* it is < 0. (This is so we can atomically add the cap and add an
* open file reference to it.)
*/
int ceph_add_cap(struct inode *inode,
struct ceph_mds_session *session, u64 cap_id,
int fmode, unsigned issued, unsigned wanted,
unsigned seq, unsigned mseq, u64 realmino, int flags,
struct ceph_cap_reservation *caps_reservation)
{
struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_cap *new_cap = NULL;
struct ceph_cap *cap;
int mds = session->s_mds;
int actual_wanted;
dout("add_cap %p mds%d cap %llx %s seq %d\n", inode,
session->s_mds, cap_id, ceph_cap_string(issued), seq);
/*
* If we are opening the file, include file mode wanted bits
* in wanted.
*/
if (fmode >= 0)
wanted |= ceph_caps_for_mode(fmode);
retry:
spin_lock(&inode->i_lock);
cap = __get_cap_for_mds(ci, mds);
if (!cap) {
if (new_cap) {
cap = new_cap;
new_cap = NULL;
} else {
spin_unlock(&inode->i_lock);
new_cap = get_cap(caps_reservation);
if (new_cap == NULL)
return -ENOMEM;
goto retry;
}
cap->issued = 0;
cap->implemented = 0;
cap->mds = mds;
cap->mds_wanted = 0;
cap->ci = ci;
__insert_cap_node(ci, cap);
/* clear out old exporting info? (i.e. on cap import) */
if (ci->i_cap_exporting_mds == mds) {
ci->i_cap_exporting_issued = 0;
ci->i_cap_exporting_mseq = 0;
ci->i_cap_exporting_mds = -1;
}
/* add to session cap list */
cap->session = session;
spin_lock(&session->s_cap_lock);
list_add_tail(&cap->session_caps, &session->s_caps);
session->s_nr_caps++;
spin_unlock(&session->s_cap_lock);
}
if (!ci->i_snap_realm) {
/*
* add this inode to the appropriate snap realm
*/
struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc,
realmino);
if (realm) {
ceph_get_snap_realm(mdsc, realm);
spin_lock(&realm->inodes_with_caps_lock);
ci->i_snap_realm = realm;
list_add(&ci->i_snap_realm_item,
&realm->inodes_with_caps);
spin_unlock(&realm->inodes_with_caps_lock);
} else {
pr_err("ceph_add_cap: couldn't find snap realm %llx\n",
realmino);
}
}
__check_cap_issue(ci, cap, issued);
/*
* If we are issued caps we don't want, or the mds' wanted
* value appears to be off, queue a check so we'll release
* later and/or update the mds wanted value.
*/
actual_wanted = __ceph_caps_wanted(ci);
if ((wanted & ~actual_wanted) ||
(issued & ~actual_wanted & CEPH_CAP_ANY_WR)) {
dout(" issued %s, mds wanted %s, actual %s, queueing\n",
ceph_cap_string(issued), ceph_cap_string(wanted),
ceph_cap_string(actual_wanted));
__cap_delay_requeue(mdsc, ci);
}
if (flags & CEPH_CAP_FLAG_AUTH)
ci->i_auth_cap = cap;
else if (ci->i_auth_cap == cap)
ci->i_auth_cap = NULL;
dout("add_cap inode %p (%llx.%llx) cap %p %s now %s seq %d mds%d\n",
inode, ceph_vinop(inode), cap, ceph_cap_string(issued),
ceph_cap_string(issued|cap->issued), seq, mds);
cap->cap_id = cap_id;
cap->issued = issued;
cap->implemented |= issued;
cap->mds_wanted |= wanted;
cap->seq = seq;
cap->issue_seq = seq;
cap->mseq = mseq;
cap->cap_gen = session->s_cap_gen;
if (fmode >= 0)
__ceph_get_fmode(ci, fmode);
spin_unlock(&inode->i_lock);
wake_up(&ci->i_cap_wq);
return 0;
}
/*
* Return true if cap has not timed out and belongs to the current
* generation of the MDS session (i.e. has not gone 'stale' due to
* us losing touch with the mds).
*/
static int __cap_is_valid(struct ceph_cap *cap)
{
unsigned long ttl;
u32 gen;
spin_lock(&cap->session->s_cap_lock);
gen = cap->session->s_cap_gen;
ttl = cap->session->s_cap_ttl;
spin_unlock(&cap->session->s_cap_lock);
if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) {
dout("__cap_is_valid %p cap %p issued %s "
"but STALE (gen %u vs %u)\n", &cap->ci->vfs_inode,
cap, ceph_cap_string(cap->issued), cap->cap_gen, gen);
return 0;
}
return 1;
}
/*
* 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
* and session->s_cap_gen is bumped.
*/
int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented)
{
int have = ci->i_snap_caps | ci->i_cap_exporting_issued;
struct ceph_cap *cap;
struct rb_node *p;
if (implemented)
*implemented = 0;
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;
dout("__ceph_caps_issued %p cap %p issued %s\n",
&ci->vfs_inode, cap, ceph_cap_string(cap->issued));
have |= cap->issued;
if (implemented)
*implemented |= cap->implemented;
}
return have;
}
/*
* Get cap bits issued by caps other than @ocap
*/
int __ceph_caps_issued_other(struct ceph_inode_info *ci, struct ceph_cap *ocap)
{
int have = ci->i_snap_caps;
struct ceph_cap *cap;
struct rb_node *p;
for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
cap = rb_entry(p, struct ceph_cap, ci_node);
if (cap == ocap)
continue;
if (!__cap_is_valid(cap))
continue;
have |= cap->issued;
}
return have;
}
/*
* Move a cap to the end of the LRU (oldest caps at list head, newest
* at list tail).
*/
static void __touch_cap(struct ceph_cap *cap)
{
struct ceph_mds_session *s = cap->session;
spin_lock(&s->s_cap_lock);
if (s->s_cap_iterator == NULL) {
dout("__touch_cap %p cap %p mds%d\n", &cap->ci->vfs_inode, cap,
s->s_mds);
list_move_tail(&cap->session_caps, &s->s_caps);
} else {
dout("__touch_cap %p cap %p mds%d NOP, iterating over caps\n",
&cap->ci->vfs_inode, cap, s->s_mds);
}
spin_unlock(&s->s_cap_lock);
}
/*
* Check if we hold the given mask. If so, move the cap(s) to the
* front of their respective LRUs. (This is the preferred way for
* callers to check for caps they want.)
*/
int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int touch)
{
struct ceph_cap *cap;
struct rb_node *p;
int have = ci->i_snap_caps;
if ((have & mask) == mask) {
dout("__ceph_caps_issued_mask %p snap issued %s"
" (mask %s)\n", &ci->vfs_inode,
ceph_cap_string(have),
ceph_cap_string(mask));
return 1;
}
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 ((cap->issued & mask) == mask) {
dout("__ceph_caps_issued_mask %p cap %p issued %s"
" (mask %s)\n", &ci->vfs_inode, cap,
ceph_cap_string(cap->issued),
ceph_cap_string(mask));
if (touch)
__touch_cap(cap);
return 1;
}
/* does a combination of caps satisfy mask? */
have |= cap->issued;
if ((have & mask) == mask) {
dout("__ceph_caps_issued_mask %p combo issued %s"
" (mask %s)\n", &ci->vfs_inode,
ceph_cap_string(cap->issued),
ceph_cap_string(mask));
if (touch) {
struct rb_node *q;
/* touch this + preceeding caps */
__touch_cap(cap);
for (q = rb_first(&ci->i_caps); q != p;
q = rb_next(q)) {
cap = rb_entry(q, struct ceph_cap,
ci_node);
if (!__cap_is_valid(cap))
continue;
__touch_cap(cap);
}
}
return 1;
}
}
return 0;
}
/*
* Return true if mask caps are currently being revoked by an MDS.
*/
int ceph_caps_revoking(struct ceph_inode_info *ci, int mask)
{
struct inode *inode = &ci->vfs_inode;
struct ceph_cap *cap;
struct rb_node *p;
int ret = 0;
spin_lock(&inode->i_lock);
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) &&
(cap->implemented & ~cap->issued & mask)) {
ret = 1;
break;
}
}
spin_unlock(&inode->i_lock);
dout("ceph_caps_revoking %p %s = %d\n", inode,
ceph_cap_string(mask), ret);
return ret;
}
int __ceph_caps_used(struct ceph_inode_info *ci)
{
int used = 0;
if (ci->i_pin_ref)
used |= CEPH_CAP_PIN;
if (ci->i_rd_ref)
used |= CEPH_CAP_FILE_RD;
if (ci->i_rdcache_ref || ci->i_rdcache_gen)
used |= CEPH_CAP_FILE_CACHE;
if (ci->i_wr_ref)
used |= CEPH_CAP_FILE_WR;
if (ci->i_wrbuffer_ref)
used |= CEPH_CAP_FILE_BUFFER;
return used;
}
/*
* wanted, by virtue of open file modes
*/
int __ceph_caps_file_wanted(struct ceph_inode_info *ci)
{
int want = 0;
int mode;
for (mode = 0; mode < 4; mode++)
if (ci->i_nr_by_mode[mode])
want |= ceph_caps_for_mode(mode);
return want;
}
/*
* Return caps we have registered with the MDS(s) as 'wanted'.
*/
int __ceph_caps_mds_wanted(struct ceph_inode_info *ci)
{
struct ceph_cap *cap;
struct rb_node *p;
int mds_wanted = 0;
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;
mds_wanted |= cap->mds_wanted;
}
return mds_wanted;
}
/*
* called under i_lock
*/
static int __ceph_is_any_caps(struct ceph_inode_info *ci)
{
return !RB_EMPTY_ROOT(&ci->i_caps) || ci->i_cap_exporting_mds >= 0;
}
/*
* Remove a cap. Take steps to deal with a racing iterate_session_caps.
*
* caller should hold i_lock.
* caller will not hold session s_mutex if called from destroy_inode.
*/
void __ceph_remove_cap(struct ceph_cap *cap)
{
struct ceph_mds_session *session = cap->session;
struct ceph_inode_info *ci = cap->ci;
struct ceph_mds_client *mdsc = &ceph_client(ci->vfs_inode.i_sb)->mdsc;
int removed = 0;
dout("__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode);
/* remove from session list */
spin_lock(&session->s_cap_lock);
if (session->s_cap_iterator == cap) {
/* not yet, we are iterating over this very cap */
dout("__ceph_remove_cap delaying %p removal from session %p\n",
cap, cap->session);
} else {
list_del_init(&cap->session_caps);
session->s_nr_caps--;
cap->session = NULL;
removed = 1;
}
/* protect backpointer with s_cap_lock: see iterate_session_caps */
cap->ci = NULL;
spin_unlock(&session->s_cap_lock);
/* remove from inode list */
rb_erase(&cap->ci_node, &ci->i_caps);
if (ci->i_auth_cap == cap)
ci->i_auth_cap = NULL;
if (removed)
ceph_put_cap(cap);
if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) {
struct ceph_snap_realm *realm = ci->i_snap_realm;
spin_lock(&realm->inodes_with_caps_lock);
list_del_init(&ci->i_snap_realm_item);
ci->i_snap_realm_counter++;
ci->i_snap_realm = NULL;
spin_unlock(&realm->inodes_with_caps_lock);
ceph_put_snap_realm(mdsc, realm);
}
if (!__ceph_is_any_real_caps(ci))
__cap_delay_cancel(mdsc, ci);
}
/*
* Build and send a cap message to the given MDS.
*
* Caller should be holding s_mutex.
*/
static int send_cap_msg(struct ceph_mds_session *session,
u64 ino, u64 cid, int op,
int caps, int wanted, int dirty,
u32 seq, u64 flush_tid, u32 issue_seq, u32 mseq,
u64 size, u64 max_size,
struct timespec *mtime, struct timespec *atime,
u64 time_warp_seq,
uid_t uid, gid_t gid, mode_t mode,
u64 xattr_version,
struct ceph_buffer *xattrs_buf,
u64 follows)
{
struct ceph_mds_caps *fc;
struct ceph_msg *msg;
dout("send_cap_msg %s %llx %llx caps %s wanted %s dirty %s"
" seq %u/%u mseq %u follows %lld size %llu/%llu"
" xattr_ver %llu xattr_len %d\n", ceph_cap_op_name(op),
cid, ino, ceph_cap_string(caps), ceph_cap_string(wanted),
ceph_cap_string(dirty),
seq, issue_seq, mseq, follows, size, max_size,
xattr_version, xattrs_buf ? (int)xattrs_buf->vec.iov_len : 0);
msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc), 0, 0, NULL);
if (IS_ERR(msg))
return PTR_ERR(msg);
msg->hdr.tid = cpu_to_le64(flush_tid);
fc = msg->front.iov_base;
memset(fc, 0, sizeof(*fc));
fc->cap_id = cpu_to_le64(cid);
fc->op = cpu_to_le32(op);
fc->seq = cpu_to_le32(seq);
fc->issue_seq = cpu_to_le32(issue_seq);
fc->migrate_seq = cpu_to_le32(mseq);
fc->caps = cpu_to_le32(caps);
fc->wanted = cpu_to_le32(wanted);
fc->dirty = cpu_to_le32(dirty);
fc->ino = cpu_to_le64(ino);
fc->snap_follows = cpu_to_le64(follows);
fc->size = cpu_to_le64(size);
fc->max_size = cpu_to_le64(max_size);
if (mtime)
ceph_encode_timespec(&fc->mtime, mtime);
if (atime)
ceph_encode_timespec(&fc->atime, atime);
fc->time_warp_seq = cpu_to_le32(time_warp_seq);
fc->uid = cpu_to_le32(uid);
fc->gid = cpu_to_le32(gid);
fc->mode = cpu_to_le32(mode);
fc->xattr_version = cpu_to_le64(xattr_version);
if (xattrs_buf) {
msg->middle = ceph_buffer_get(xattrs_buf);
fc->xattr_len = cpu_to_le32(xattrs_buf->vec.iov_len);
msg->hdr.middle_len = cpu_to_le32(xattrs_buf->vec.iov_len);
}
ceph_con_send(&session->s_con, msg);
return 0;
}
/*
* Queue cap releases when an inode is dropped from our cache. Since
* inode is about to be destroyed, there is no need for i_lock.
*/
void ceph_queue_caps_release(struct inode *inode)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct rb_node *p;
p = rb_first(&ci->i_caps);
while (p) {
struct ceph_cap *cap = rb_entry(p, struct ceph_cap, ci_node);
struct ceph_mds_session *session = cap->session;
struct ceph_msg *msg;
struct ceph_mds_cap_release *head;
struct ceph_mds_cap_item *item;
spin_lock(&session->s_cap_lock);
BUG_ON(!session->s_num_cap_releases);
msg = list_first_entry(&session->s_cap_releases,
struct ceph_msg, list_head);
dout(" adding %p release to mds%d msg %p (%d left)\n",
inode, session->s_mds, msg, session->s_num_cap_releases);
BUG_ON(msg->front.iov_len + sizeof(*item) > PAGE_CACHE_SIZE);
head = msg->front.iov_base;
head->num = cpu_to_le32(le32_to_cpu(head->num) + 1);
item = msg->front.iov_base + msg->front.iov_len;
item->ino = cpu_to_le64(ceph_ino(inode));
item->cap_id = cpu_to_le64(cap->cap_id);
item->migrate_seq = cpu_to_le32(cap->mseq);
item->seq = cpu_to_le32(cap->issue_seq);
session->s_num_cap_releases--;
msg->front.iov_len += sizeof(*item);
if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) {
dout(" release msg %p full\n", msg);
list_move_tail(&msg->list_head,
&session->s_cap_releases_done);
} else {
dout(" release msg %p at %d/%d (%d)\n", msg,
(int)le32_to_cpu(head->num),
(int)CEPH_CAPS_PER_RELEASE,
(int)msg->front.iov_len);
}
spin_unlock(&session->s_cap_lock);
p = rb_next(p);
__ceph_remove_cap(cap);
}
}
/*
* Send a cap msg on the given inode. Update our caps state, then
* drop i_lock and send the message.
*
* Make note of max_size reported/requested from mds, revoked caps
* that have now been implemented.
*
* Make half-hearted attempt ot to invalidate page cache if we are
* dropping RDCACHE. Note that this will leave behind locked pages
* that we'll then need to deal with elsewhere.
*
* Return non-zero if delayed release, or we experienced an error
* such that the caller should requeue + retry later.
*
* called with i_lock, then drops it.
* caller should hold snap_rwsem (read), s_mutex.
*/
static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap,
int op, int used, int want, int retain, int flushing,
unsigned *pflush_tid)
__releases(cap->ci->vfs_inode->i_lock)
{
struct ceph_inode_info *ci = cap->ci;
struct inode *inode = &ci->vfs_inode;
u64 cap_id = cap->cap_id;
int held, revoking, dropping, keep;
u64 seq, issue_seq, mseq, time_warp_seq, follows;
u64 size, max_size;
struct timespec mtime, atime;
int wake = 0;
mode_t mode;
uid_t uid;
gid_t gid;
struct ceph_mds_session *session;
u64 xattr_version = 0;
int delayed = 0;
u64 flush_tid = 0;
int i;
int ret;
held = cap->issued | cap->implemented;
revoking = cap->implemented & ~cap->issued;
retain &= ~revoking;
dropping = cap->issued & ~retain;
dout("__send_cap %p cap %p session %p %s -> %s (revoking %s)\n",
inode, cap, cap->session,
ceph_cap_string(held), ceph_cap_string(held & retain),
ceph_cap_string(revoking));
BUG_ON((retain & CEPH_CAP_PIN) == 0);
session = cap->session;
/* don't release wanted unless we've waited a bit. */
if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
time_before(jiffies, ci->i_hold_caps_min)) {
dout(" delaying issued %s -> %s, wanted %s -> %s on send\n",
ceph_cap_string(cap->issued),
ceph_cap_string(cap->issued & retain),
ceph_cap_string(cap->mds_wanted),
ceph_cap_string(want));
want |= cap->mds_wanted;
retain |= cap->issued;
delayed = 1;
}
ci->i_ceph_flags &= ~(CEPH_I_NODELAY | CEPH_I_FLUSH);
cap->issued &= retain; /* drop bits we don't want */
if (cap->implemented & ~cap->issued) {
/*
* Wake up any waiters on wanted -> needed transition.
* This is due to the weird transition from buffered
* to sync IO... we need to flush dirty pages _before_
* allowing sync writes to avoid reordering.
*/
wake = 1;
}
cap->implemented &= cap->issued | used;
cap->mds_wanted = want;
if (flushing) {
/*
* assign a tid for flush operations so we can avoid
* flush1 -> dirty1 -> flush2 -> flushack1 -> mark
* clean type races. track latest tid for every bit
* so we can handle flush AxFw, flush Fw, and have the
* first ack clean Ax.
*/
flush_tid = ++ci->i_cap_flush_last_tid;
if (pflush_tid)
*pflush_tid = flush_tid;
dout(" cap_flush_tid %d\n", (int)flush_tid);
for (i = 0; i < CEPH_CAP_BITS; i++)
if (flushing & (1 << i))
ci->i_cap_flush_tid[i] = flush_tid;
}
keep = cap->implemented;
seq = cap->seq;
issue_seq = cap->issue_seq;
mseq = cap->mseq;
size = inode->i_size;
ci->i_reported_size = size;
max_size = ci->i_wanted_max_size;
ci->i_requested_max_size = max_size;
mtime = inode->i_mtime;
atime = inode->i_atime;
time_warp_seq = ci->i_time_warp_seq;
follows = ci->i_snap_realm->cached_context->seq;
uid = inode->i_uid;
gid = inode->i_gid;
mode = inode->i_mode;
if (dropping & CEPH_CAP_XATTR_EXCL) {
__ceph_build_xattrs_blob(ci);
xattr_version = ci->i_xattrs.version + 1;
}
spin_unlock(&inode->i_lock);
ret = send_cap_msg(session, ceph_vino(inode).ino, cap_id,
op, keep, want, flushing, seq, flush_tid, issue_seq, mseq,
size, max_size, &mtime, &atime, time_warp_seq,
uid, gid, mode,
xattr_version,
(flushing & CEPH_CAP_XATTR_EXCL) ? ci->i_xattrs.blob : NULL,
follows);
if (ret < 0) {
dout("error sending cap msg, must requeue %p\n", inode);
delayed = 1;
}
if (wake)
wake_up(&ci->i_cap_wq);
return delayed;
}
/*
* When a snapshot is taken, clients accumulate dirty metadata on
* inodes with capabilities in ceph_cap_snaps to describe the file
* state at the time the snapshot was taken. This must be flushed
* asynchronously back to the MDS once sync writes complete and dirty
* data is written out.
*
* Called under i_lock. Takes s_mutex as needed.
*/
void __ceph_flush_snaps(struct ceph_inode_info *ci,
struct ceph_mds_session **psession)
{
struct inode *inode = &ci->vfs_inode;
int mds;
struct ceph_cap_snap *capsnap;
u32 mseq;
struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
struct ceph_mds_session *session = NULL; /* if session != NULL, we hold
session->s_mutex */
u64 next_follows = 0; /* keep track of how far we've gotten through the
i_cap_snaps list, and skip these entries next time
around to avoid an infinite loop */
if (psession)
session = *psession;
dout("__flush_snaps %p\n", inode);
retry:
list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
/* avoid an infiniute loop after retry */
if (capsnap->follows < next_follows)
continue;
/*
* we need to wait for sync writes to complete and for dirty
* pages to be written out.
*/
if (capsnap->dirty_pages || capsnap->writing)
continue;
/*
* if cap writeback already occurred, we should have dropped
* the capsnap in ceph_put_wrbuffer_cap_refs.
*/
BUG_ON(capsnap->dirty == 0);
/* pick mds, take s_mutex */
mds = __ceph_get_cap_mds(ci, &mseq);
if (session && session->s_mds != mds) {
dout("oops, wrong session %p mutex\n", session);
mutex_unlock(&session->s_mutex);
ceph_put_mds_session(session);
session = NULL;
}
if (!session) {
spin_unlock(&inode->i_lock);
mutex_lock(&mdsc->mutex);
session = __ceph_lookup_mds_session(mdsc, mds);
mutex_unlock(&mdsc->mutex);
if (session) {
dout("inverting session/ino locks on %p\n",
session);
mutex_lock(&session->s_mutex);
}
/*
* if session == NULL, we raced against a cap
* deletion. retry, and we'll get a better
* @mds value next time.
*/
spin_lock(&inode->i_lock);
goto retry;
}
capsnap->flush_tid = ++ci->i_cap_flush_last_tid;
atomic_inc(&capsnap->nref);
if (!list_empty(&capsnap->flushing_item))
list_del_init(&capsnap->flushing_item);
list_add_tail(&capsnap->flushing_item,
&session->s_cap_snaps_flushing);
spin_unlock(&inode->i_lock);
dout("flush_snaps %p cap_snap %p follows %lld size %llu\n",
inode, capsnap, next_follows, capsnap->size);
send_cap_msg(session, ceph_vino(inode).ino, 0,
CEPH_CAP_OP_FLUSHSNAP, capsnap->issued, 0,
capsnap->dirty, 0, capsnap->flush_tid, 0, mseq,
capsnap->size, 0,
&capsnap->mtime, &capsnap->atime,
capsnap->time_warp_seq,
capsnap->uid, capsnap->gid, capsnap->mode,
0, NULL,
capsnap->follows);
next_follows = capsnap->follows + 1;
ceph_put_cap_snap(capsnap);
spin_lock(&inode->i_lock);
goto retry;
}
/* we flushed them all; remove this inode from the queue */
spin_lock(&mdsc->snap_flush_lock);
list_del_init(&ci->i_snap_flush_item);
spin_unlock(&mdsc->snap_flush_lock);
if (psession)
*psession = session;
else if (session) {
mutex_unlock(&session->s_mutex);
ceph_put_mds_session(session);
}
}
static void ceph_flush_snaps(struct ceph_inode_info *ci)
{
struct inode *inode = &ci->vfs_inode;
spin_lock(&inode->i_lock);
__ceph_flush_snaps(ci, NULL);
spin_unlock(&inode->i_lock);
}
/*
* Mark caps dirty. If inode is newly dirty, add to the global dirty
* list.
*/
void __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
{
struct ceph_mds_client *mdsc = &ceph_client(ci->vfs_inode.i_sb)->mdsc;
struct inode *inode = &ci->vfs_inode;
int was = ci->i_dirty_caps;
int dirty = 0;
dout("__mark_dirty_caps %p %s dirty %s -> %s\n", &ci->vfs_inode,
ceph_cap_string(mask), ceph_cap_string(was),
ceph_cap_string(was | mask));
ci->i_dirty_caps |= mask;
if (was == 0) {
dout(" inode %p now dirty\n", &ci->vfs_inode);
BUG_ON(!list_empty(&ci->i_dirty_item));
spin_lock(&mdsc->cap_dirty_lock);
list_add(&ci->i_dirty_item, &mdsc->cap_dirty);
spin_unlock(&mdsc->cap_dirty_lock);
if (ci->i_flushing_caps == 0) {
igrab(inode);
dirty |= I_DIRTY_SYNC;
}
}
BUG_ON(list_empty(&ci->i_dirty_item));
if (((was | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) &&
(mask & CEPH_CAP_FILE_BUFFER))
dirty |= I_DIRTY_DATASYNC;
if (dirty)
__mark_inode_dirty(inode, dirty);
__cap_delay_requeue(mdsc, ci);
}
/*
* Add dirty inode to the flushing list. Assigned a seq number so we
* can wait for caps to flush without starving.
*
* Called under i_lock.
*/
static int __mark_caps_flushing(struct inode *inode,
struct ceph_mds_session *session)
{
struct ceph_mds_client *mdsc = &ceph_client(inode->i_sb)->mdsc;
struct ceph_inode_info *ci = ceph_inode(inode);
int flushing;
BUG_ON(ci->i_dirty_caps == 0);
BUG_ON(list_empty(&ci->i_dirty_item));
flushing = ci->i_dirty_caps;
dout("__mark_caps_flushing flushing %s, flushing_caps %s -> %s\n",
ceph_cap_string(flushing),
ceph_cap_string(ci->i_flushing_caps),
ceph_cap_string(ci->i_flushing_caps | flushing));
ci->i_flushing_caps |= flushing;
ci->i_dirty_caps = 0;
dout(" inode %p now !dirty\n", inode);
spin_lock(&mdsc->cap_dirty_lock);
list_del_init(&ci->i_dirty_item);
ci->i_cap_flush_seq = ++mdsc->cap_flush_seq;
if (list_empty(&ci->i_flushing_item)) {
list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing);
mdsc->num_cap_flushing++;
dout(" inode %p now flushing seq %lld\n", inode,
ci->i_cap_flush_seq);
} else {
list_move_tail(&ci->i_flushing_item, &session->s_cap_flushing);
dout(" inode %p now flushing (more) seq %lld\n", inode,
ci->i_cap_flush_seq);
}
spin_unlock(&mdsc->cap_dirty_lock);
return flushing;
}
/*
* try to invalidate mapping pages without blocking.
*/
static int mapping_is_empty(struct address_space *mapping)
{
struct page *page = find_get_page(mapping, 0);
if (!page)
return 1;
put_page(page);
return 0;
}
static int try_nonblocking_invalidate(struct inode *inode)
{
struct ceph_inode_info *ci = ceph_inode(inode);
u32 invalidating_gen = ci->i_rdcache_gen;
spin_unlock(&inode->i_lock);
invalidate_mapping_pages(&inode->i_data, 0, -1);
spin_lock(&inode->i_lock);
if (mapping_is_empty(&inode->i_data) &&
invalidating_gen == ci->i_rdcache_gen) {
/* success. */
dout("try_nonblocking_invalidate %p success\n", inode);
ci->i_rdcache_gen = 0;
ci->i_rdcache_revoking = 0;
return 0;
}
dout("try_nonblocking_invalidate %p failed\n", inode);
return -1;
}
/*
* Swiss army knife function to examine currently used and wanted
* versus held caps. Release, flush, ack revoked caps to mds as
* appropriate.
*
* CHECK_CAPS_NODELAY - caller is delayed work and we should not delay
* cap release further.
* CHECK_CAPS_AUTHONLY - we should only check the auth cap
* CHECK_CAPS_FLUSH - we should flush any dirty caps immediately, without
* further delay.
*/
void ceph_check_caps(struct ceph_inode_info *ci, int flags,
struct ceph_mds_session *session)
__releases(session->s_mutex)
{
struct ceph_client *client = ceph_inode_to_client(&ci->vfs_inode);
struct ceph_mds_client *mdsc = &client->mdsc;
struct inode *inode = &ci->vfs_inode;
struct ceph_cap *cap;
int file_wanted, used;
int took_snap_rwsem = 0; /* true if mdsc->snap_rwsem held */
int issued, implemented, want, retain, revoking, flushing = 0;
int mds = -1; /* keep track of how far we've gone through i_caps list
to avoid an infinite loop on retry */
struct rb_node *p;
int tried_invalidate = 0;
int delayed = 0, sent = 0, force_requeue = 0, num;
int queue_invalidate = 0;
int is_delayed = flags & CHECK_CAPS_NODELAY;
/* if we are unmounting, flush any unused caps immediately. */
if (mdsc->stopping)
is_delayed = 1;
spin_lock(&inode->i_lock);
if (ci->i_ceph_flags & CEPH_I_FLUSH)
flags |= CHECK_CAPS_FLUSH;
/* flush snaps first time around only */
if (!list_empty(&ci->i_cap_snaps))
__ceph_flush_snaps(ci, &session);
goto retry_locked;
retry:
spin_lock(&inode->i_lock);
retry_locked:
file_wanted = __ceph_caps_file_wanted(ci);
used = __ceph_caps_used(ci);
want = file_wanted | used;
issued = __ceph_caps_issued(ci, &implemented);
revoking = implemented & ~issued;
retain = want | CEPH_CAP_PIN;
if (!mdsc->stopping && inode->i_nlink > 0) {
if (want) {
retain |= CEPH_CAP_ANY; /* be greedy */
} else {
retain |= CEPH_CAP_ANY_SHARED;
/*
* keep RD only if we didn't have the file open RW,
* because then the mds would revoke it anyway to
* journal max_size=0.
*/
if (ci->i_max_size == 0)
retain |= CEPH_CAP_ANY_RD;
}
}
dout("check_caps %p file_want %s used %s dirty %s flushing %s"
" issued %s revoking %s retain %s %s%s%s\n", inode,
ceph_cap_string(file_wanted),
ceph_cap_string(used), ceph_cap_string(ci->i_dirty_caps),
ceph_cap_string(ci->i_flushing_caps),
ceph_cap_string(issued), ceph_cap_string(revoking),
ceph_cap_string(retain),
(flags & CHECK_CAPS_AUTHONLY) ? " AUTHONLY" : "",
(flags & CHECK_CAPS_NODELAY) ? " NODELAY" : "",
(flags & CHECK_CAPS_FLUSH) ? " FLUSH" : "");
/*
* If we no longer need to hold onto old our caps, and we may
* have cached pages, but don't want them, then try to invalidate.
* If we fail, it's because pages are locked.... try again later.
*/
if ((!is_delayed || mdsc->stopping) &&
ci->i_wrbuffer_ref == 0 && /* no dirty pages... */
ci->i_rdcache_gen && /* may have cached pages */
(file_wanted == 0 || /* no open files */
(revoking & CEPH_CAP_FILE_CACHE)) && /* or revoking cache */
!tried_invalidate) {
dout("check_caps trying to invalidate on %p\n", inode);
if (try_nonblocking_invalidate(inode) < 0) {
if (revoking & CEPH_CAP_FILE_CACHE) {
dout("check_caps queuing invalidate\n");
queue_invalidate = 1;
ci->i_rdcache_revoking = ci->i_rdcache_gen;
} else {
dout("check_caps failed to invalidate pages\n");
/* we failed to invalidate pages. check these
caps again later. */
force_requeue = 1;
__cap_set_timeouts(mdsc, ci);
}
}
tried_invalidate = 1;
goto retry_locked;
}
num = 0;
for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
cap = rb_entry(p, struct ceph_cap, ci_node);
num++;
/* avoid looping forever */
if (mds >= cap->mds ||
((flags & CHECK_CAPS_AUTHONLY) && cap != ci->i_auth_cap))
continue;
/* NOTE: no side-effects allowed, until we take s_mutex */
revoking = cap->implemented & ~cap->issued;
if (revoking)
dout(" mds%d revoking %s\n", cap->mds,
ceph_cap_string(revoking));
if (cap == ci->i_auth_cap &&
(cap->issued & CEPH_CAP_FILE_WR)) {
/* request larger max_size from MDS? */
if (ci->i_wanted_max_size > ci->i_max_size &&
ci->i_wanted_max_size > ci->i_requested_max_size) {
dout("requesting new max_size\n");
goto ack;
}
/* approaching file_max? */
if ((inode->i_size << 1) >= ci->i_max_size &&
(ci->i_reported_size << 1) < ci->i_max_size) {
dout("i_size approaching max_size\n");
goto ack;
}
}
/* flush anything dirty? */
if (cap == ci->i_auth_cap && (flags & CHECK_CAPS_FLUSH) &&
ci->i_dirty_caps) {
dout("flushing dirty caps\n");
goto ack;
}
/* completed revocation? going down and there are no caps? */
if (revoking && (revoking & used) == 0) {
dout("completed revocation of %s\n",
ceph_cap_string(cap->implemented & ~cap->issued));
goto ack;
}
/* want more caps from mds? */
if (want & ~(cap->mds_wanted | cap->issued))
goto ack;
/* things we might delay */
if ((cap->issued & ~retain) == 0 &&
cap->mds_wanted == want)
continue; /* nope, all good */
if (is_delayed)
goto ack;
/* delay? */
if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 &&
time_before(jiffies, ci->i_hold_caps_max)) {
dout(" delaying issued %s -> %s, wanted %s -> %s\n",
ceph_cap_string(cap->issued),
ceph_cap_string(cap->issued & retain),
ceph_cap_string(cap->mds_wanted),
ceph_cap_string(want));
delayed++;
continue;
}
ack:
if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
dout(" skipping %p I_NOFLUSH set\n", inode);
continue;
}
if (session && session != cap->session) {
dout("oops, wrong session %p mutex\n", session);
mutex_unlock(&session->s_mutex);
session = NULL;
}
if (!session) {
session = cap->session;
if (mutex_trylock(&session->s_mutex) == 0) {
dout("inverting session/ino locks on %p\n",
session);
spin_unlock(&inode->i_lock);
if (took_snap_rwsem) {
up_read(&mdsc->snap_rwsem);
took_snap_rwsem = 0;
}
mutex_lock(&session->s_mutex);
goto retry;
}
}
/* take snap_rwsem after session mutex */
if (!took_snap_rwsem) {
if (down_read_trylock(&mdsc->snap_rwsem) == 0) {
dout("inverting snap/in locks on %p\n",
inode);
spin_unlock(&inode->i_lock);
down_read(&mdsc->snap_rwsem);
took_snap_rwsem = 1;
goto retry;
}
took_snap_rwsem = 1;
}
if (cap == ci->i_auth_cap && ci->i_dirty_caps)
flushing = __mark_caps_flushing(inode, session);
mds = cap->mds; /* remember mds, so we don't repeat */
sent++;
/* __send_cap drops i_lock */
delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, used, want,
retain, flushing, NULL);
goto retry; /* retake i_lock and restart our cap scan. */
}
/*
* Reschedule delayed caps release if we delayed anything,
* otherwise cancel.
*/
if (delayed && is_delayed)
force_requeue = 1; /* __send_cap delayed release; requeue */
if (!delayed && !is_delayed)
__cap_delay_cancel(mdsc, ci);
else if (!is_delayed || force_requeue)
__cap_delay_requeue(mdsc, ci);
spin_unlock(&inode->i_lock);
if (queue_invalidate)
ceph_queue_invalidate(inode);
if (session)
mutex_unlock(&session->s_mutex);
if (took_snap_rwsem)
up_read(&mdsc->snap_rwsem);
}
/*
* Try to flush dirty caps back to the auth mds.
*/
static int try_flush_caps(struct inode *inode, struct ceph_mds_session *session,
unsigned *flush_tid)
{
struct ceph_mds_client *mdsc = &ceph_client(inode->i_sb)->mdsc;
struct ceph_inode_info *ci = ceph_inode(inode);
int unlock_session = session ? 0 : 1;
int flushing = 0;
retry:
spin_lock(&inode->i_lock);
if (ci->i_ceph_flags & CEPH_I_NOFLUSH) {
dout("try_flush_caps skipping %p I_NOFLUSH set\n", inode);
goto out;
}
if (ci->i_dirty_caps && ci->i_auth_cap) {
struct ceph_cap *cap = ci->i_auth_cap;
int used = __ceph_caps_used(ci);
int want = __ceph_caps_wanted(ci);
int delayed;
if (!session) {
spin_unlock(&inode->i_lock);
session = cap->session;
mutex_lock(&session->s_mutex);
goto retry;
}
BUG_ON(session != cap->session);
if (cap->session->s_state < CEPH_MDS_SESSION_OPEN)
goto out;
flushing = __mark_caps_flushing(inode, session);
/* __send_cap drops i_lock */
delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH, used, want,
cap->issued | cap->implemented, flushing,
flush_tid);
if (!delayed)
goto out_unlocked;
spin_lock(&inode->i_lock);
__cap_delay_requeue(mdsc, ci);
}
out:
spin_unlock(&inode->i_lock);
out_unlocked:
if (session && unlock_session)
mutex_unlock(&session->s_mutex);
return flushing;
}
/*
* Return true if we've flushed caps through the given flush_tid.
*/
static int caps_are_flushed(struct inode *inode, unsigned tid)
{
struct ceph_inode_info *ci = ceph_inode(inode);
int dirty, i, ret = 1;
spin_lock(&inode->i_lock);
dirty = __ceph_caps_dirty(ci);
for (i = 0; i < CEPH_CAP_BITS; i++)
if ((ci->i_flushing_caps & (1 << i)) &&
ci->i_cap_flush_tid[i] <= tid) {
/* still flushing this bit */
ret = 0;
break;
}
spin_unlock(&inode->i_lock);
return ret;
}
/*
* Wait on any unsafe replies for the given inode. First wait on the
* newest request, and make that the upper bound. Then, if there are
* more requests, keep waiting on the oldest as long as it is still older
* than the original request.
*/
static void sync_write_wait(struct inode *inode)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct list_head *head = &ci->i_unsafe_writes;
struct ceph_osd_request *req;
u64 last_tid;
spin_lock(&ci->i_unsafe_lock);
if (list_empty(head))
goto out;
/* set upper bound as _last_ entry in chain */
req = list_entry(head->prev, struct ceph_osd_request,
r_unsafe_item);
last_tid = req->r_tid;
do {
ceph_osdc_get_request(req);
spin_unlock(&ci->i_unsafe_lock);
dout("sync_write_wait on tid %llu (until %llu)\n",
req->r_tid, last_tid);
wait_for_completion(&req->r_safe_completion);
spin_lock(&ci->i_unsafe_lock);
ceph_osdc_put_request(req);
/*
* from here on look at first entry in chain, since we
* only want to wait for anything older than last_tid
*/
if (list_empty(head))
break;
req = list_entry(head->next, struct ceph_osd_request,
r_unsafe_item);
} while (req->r_tid < last_tid);
out:
spin_unlock(&ci->i_unsafe_lock);
}
int ceph_fsync(struct file *file, struct dentry *dentry, int datasync)
{
struct inode *inode = dentry->d_inode;
struct ceph_inode_info *ci = ceph_inode(inode);
unsigned flush_tid;
int ret;
int dirty;
dout("fsync %p%s\n", inode, datasync ? " datasync" : "");
sync_write_wait(inode);
ret = filemap_write_and_wait(inode->i_mapping);
if (ret < 0)
return ret;
dirty = try_flush_caps(inode, NULL, &flush_tid);
dout("fsync dirty caps are %s\n", ceph_cap_string(dirty));
/*
* only wait on non-file metadata writeback (the mds
* can recover size and mtime, so we don't need to
* wait for that)
*/
if (!datasync && (dirty & ~CEPH_CAP_ANY_FILE_WR)) {
dout("fsync waiting for flush_tid %u\n", flush_tid);
ret = wait_event_interruptible(ci->i_cap_wq,
caps_are_flushed(inode, flush_tid));
}
dout("fsync %p%s done\n", inode, datasync ? " datasync" : "");
return ret;
}
/*
* Flush any dirty caps back to the mds. If we aren't asked to wait,
* queue inode for flush but don't do so immediately, because we can
* get by with fewer MDS messages if we wait for data writeback to
* complete first.
*/
int ceph_write_inode(struct inode *inode, struct writeback_control *wbc)
{
struct ceph_inode_info *ci = ceph_inode(inode);
unsigned flush_tid;
int err = 0;
int dirty;
int wait = wbc->sync_mode == WB_SYNC_ALL;
dout("write_inode %p wait=%d\n", inode, wait);
if (wait) {
dirty = try_flush_caps(inode, NULL, &flush_tid);
if (dirty)
err = wait_event_interruptible(ci->i_cap_wq,
caps_are_flushed(inode, flush_tid));
} else {
struct ceph_mds_client *mdsc = &ceph_client(inode->i_sb)->mdsc;
spin_lock(&inode->i_lock);
if (__ceph_caps_dirty(ci))
__cap_delay_requeue_front(mdsc, ci);
spin_unlock(&inode->i_lock);
}
return err;
}
/*
* After a recovering MDS goes active, we need to resend any caps
* we were flushing.
*
* Caller holds session->s_mutex.
*/
static void kick_flushing_capsnaps(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_cap_snap *capsnap;
dout("kick_flushing_capsnaps mds%d\n", session->s_mds);
list_for_each_entry(capsnap, &session->s_cap_snaps_flushing,
flushing_item) {
struct ceph_inode_info *ci = capsnap->ci;
struct inode *inode = &ci->vfs_inode;
struct ceph_cap *cap;
spin_lock(&inode->i_lock);
cap = ci->i_auth_cap;
if (cap && cap->session == session) {
dout("kick_flushing_caps %p cap %p capsnap %p\n", inode,
cap, capsnap);
__ceph_flush_snaps(ci, &session);
} else {
pr_err("%p auth cap %p not mds%d ???\n", inode,
cap, session->s_mds);
}
spin_unlock(&inode->i_lock);
}
}
void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc,
struct ceph_mds_session *session)
{
struct ceph_inode_info *ci;
kick_flushing_capsnaps(mdsc, session);
dout("kick_flushing_caps mds%d\n", session->s_mds);
list_for_each_entry(ci, &session->s_cap_flushing, i_flushing_item) {
struct inode *inode = &ci->vfs_inode;
struct ceph_cap *cap;
int delayed = 0;
spin_lock(&inode->i_lock);
cap = ci->i_auth_cap;
if (cap && cap->session == session) {
dout("kick_flushing_caps %p cap %p %s\n", inode,
cap, ceph_cap_string(ci->i_flushing_caps));
delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH,
__ceph_caps_used(ci),
__ceph_caps_wanted(ci),
cap->issued | cap->implemented,
ci->i_flushing_caps, NULL);
if (delayed) {
spin_lock(&inode->i_lock);
__cap_delay_requeue(mdsc, ci);
spin_unlock(&inode->i_lock);
}
} else {
pr_err("%p auth cap %p not mds%d ???\n", inode,
cap, session->s_mds);
spin_unlock(&inode->i_lock);
}
}
}
/*
* Take references to capabilities we hold, so that we don't release
* them to the MDS prematurely.
*
* Protected by i_lock.
*/
static void __take_cap_refs(struct ceph_inode_info *ci, int got)
{
if (got & CEPH_CAP_PIN)
ci->i_pin_ref++;
if (got & CEPH_CAP_FILE_RD)
ci->i_rd_ref++;
if (got & CEPH_CAP_FILE_CACHE)
ci->i_rdcache_ref++;
if (got & CEPH_CAP_FILE_WR)
ci->i_wr_ref++;
if (got & CEPH_CAP_FILE_BUFFER) {
if (ci->i_wrbuffer_ref == 0)
igrab(&ci->vfs_inode);
ci->i_wrbuffer_ref++;
dout("__take_cap_refs %p wrbuffer %d -> %d (?)\n",
&ci->vfs_inode, ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref);
}
}
/*
* Try to grab cap references. Specify those refs we @want, and the
* minimal set we @need. Also include the larger offset we are writing
* to (when applicable), and check against max_size here as well.
* Note that caller is responsible for ensuring max_size increases are
* requested from the MDS.
*/
static int try_get_cap_refs(struct ceph_inode_info *ci, int need, int want,
int *got, loff_t endoff, int *check_max, int *err)
{
struct inode *inode = &ci->vfs_inode;
int ret = 0;
int have, implemented;
int file_wanted;
dout("get_cap_refs %p need %s want %s\n", inode,
ceph_cap_string(need), ceph_cap_string(want));
spin_lock(&inode->i_lock);
/* make sure file is actually open */
file_wanted = __ceph_caps_file_wanted(ci);
if ((file_wanted & need) == 0) {
dout("try_get_cap_refs need %s file_wanted %s, EBADF\n",
ceph_cap_string(need), ceph_cap_string(file_wanted));
*err = -EBADF;
ret = 1;
goto out;
}
if (need & CEPH_CAP_FILE_WR) {
if (endoff >= 0 && endoff > (loff_t)ci->i_max_size) {
dout("get_cap_refs %p endoff %llu > maxsize %llu\n",
inode, endoff, ci->i_max_size);
if (endoff > ci->i_wanted_max_size) {
*check_max = 1;
ret = 1;
}
goto out;
}
/*
* If a sync write is in progress, we must wait, so that we
* can get a final snapshot value for size+mtime.
*/
if (__ceph_have_pending_cap_snap(ci)) {
dout("get_cap_refs %p cap_snap_pending\n", inode);
goto out;
}
}
have = __ceph_caps_issued(ci, &implemented);
/*
* disallow writes while a truncate is pending
*/
if (ci->i_truncate_pending)
have &= ~CEPH_CAP_FILE_WR;
if ((have & need) == need) {
/*
* Look at (implemented & ~have & not) so that we keep waiting
* on transition from wanted -> needed caps. This is needed
* for WRBUFFER|WR -> WR to avoid a new WR sync write from
* going before a prior buffered writeback happens.
*/
int not = want & ~(have & need);
int revoking = implemented & ~have;
dout("get_cap_refs %p have %s but not %s (revoking %s)\n",
inode, ceph_cap_string(have), ceph_cap_string(not),
ceph_cap_string(revoking));
if ((revoking & not) == 0) {
*got = need | (have & want);
__take_cap_refs(ci, *got);
ret = 1;
}
} else {
dout("get_cap_refs %p have %s needed %s\n", inode,
ceph_cap_string(have), ceph_cap_string(need));
}
out:
spin_unlock(&inode->i_lock);
dout("get_cap_refs %p ret %d got %s\n", inode,
ret, ceph_cap_string(*got));
return ret;
}
/*
* Check the offset we are writing up to against our current
* max_size. If necessary, tell the MDS we want to write to
* a larger offset.
*/
static void check_max_size(struct inode *inode, loff_t endoff)
{
struct ceph_inode_info *ci = ceph_inode(inode);
int check = 0;
/* do we need to explicitly request a larger max_size? */
spin_lock(&inode->i_lock);
if ((endoff >= ci->i_max_size ||
endoff > (inode->i_size << 1)) &&
endoff > ci->i_wanted_max_size) {
dout("write %p at large endoff %llu, req max_size\n",
inode, endoff);
ci->i_wanted_max_size = endoff;
check = 1;
}
spin_unlock(&inode->i_lock);
if (check)
ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
}
/*
* Wait for caps, and take cap references. If we can't get a WR cap
* due to a small max_size, make sure we check_max_size (and possibly
* ask the mds) so we don't get hung up indefinitely.
*/
int ceph_get_caps(struct ceph_inode_info *ci, int need, int want, int *got,
loff_t endoff)
{
int check_max, ret, err;
retry:
if (endoff > 0)
check_max_size(&ci->vfs_inode, endoff);
check_max = 0;
err = 0;
ret = wait_event_interruptible(ci->i_cap_wq,
try_get_cap_refs(ci, need, want,
got, endoff,
&check_max, &err));
if (err)
ret = err;
if (check_max)
goto retry;
return ret;
}
/*
* Take cap refs. Caller must already know we hold at least one ref
* on the caps in question or we don't know this is safe.
*/
void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps)
{
spin_lock(&ci->vfs_inode.i_lock);
__take_cap_refs(ci, caps);
spin_unlock(&ci->vfs_inode.i_lock);
}
/*
* Release cap refs.
*
* If we released the last ref on any given cap, call ceph_check_caps
* to release (or schedule a release).
*
* If we are releasing a WR cap (from a sync write), finalize any affected
* cap_snap, and wake up any waiters.
*/
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;
struct ceph_cap_snap *capsnap;
spin_lock(&inode->i_lock);
if (had & CEPH_CAP_PIN)
--ci->i_pin_ref;
if (had & CEPH_CAP_FILE_RD)
if (--ci->i_rd_ref == 0)
last++;
if (had & CEPH_CAP_FILE_CACHE)
if (--ci->i_rdcache_ref == 0)
last++;
if (had & CEPH_CAP_FILE_BUFFER) {
if (--ci->i_wrbuffer_ref == 0) {
last++;
put++;
}
dout("put_cap_refs %p wrbuffer %d -> %d (?)\n",
inode, ci->i_wrbuffer_ref+1, ci->i_wrbuffer_ref);
}
if (had & CEPH_CAP_FILE_WR)
if (--ci->i_wr_ref == 0) {
last++;
if (!list_empty(&ci->i_cap_snaps)) {
capsnap = list_first_entry(&ci->i_cap_snaps,
struct ceph_cap_snap,
ci_item);
if (capsnap->writing) {
capsnap->writing = 0;
flushsnaps =
__ceph_finish_cap_snap(ci,
capsnap);
wake = 1;
}
}
}
spin_unlock(&inode->i_lock);
dout("put_cap_refs %p had %s%s%s\n", inode, ceph_cap_string(had),
last ? " last" : "", put ? " put" : "");
if (last && !flushsnaps)
ceph_check_caps(ci, 0, NULL);
else if (flushsnaps)
ceph_flush_snaps(ci);
if (wake)
wake_up(&ci->i_cap_wq);
if (put)
iput(inode);
}
/*
* Release @nr WRBUFFER refs on dirty pages for the given @snapc snap
* context. Adjust per-snap dirty page accounting as appropriate.
* Once all dirty data for a cap_snap is flushed, flush snapped file
* metadata back to the MDS. If we dropped the last ref, call
* ceph_check_caps.
*/
void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr,
struct ceph_snap_context *snapc)
{
struct inode *inode = &ci->vfs_inode;
int last = 0;
int complete_capsnap = 0;
int drop_capsnap = 0;
int found = 0;
struct ceph_cap_snap *capsnap = NULL;
spin_lock(&inode->i_lock);
ci->i_wrbuffer_ref -= nr;
last = !ci->i_wrbuffer_ref;
if (ci->i_head_snapc == snapc) {
ci->i_wrbuffer_ref_head -= nr;
if (!ci->i_wrbuffer_ref_head) {
ceph_put_snap_context(ci->i_head_snapc);
ci->i_head_snapc = NULL;
}
dout("put_wrbuffer_cap_refs on %p head %d/%d -> %d/%d %s\n",
inode,
ci->i_wrbuffer_ref+nr, ci->i_wrbuffer_ref_head+nr,
ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head,
last ? " LAST" : "");
} else {
list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
if (capsnap->context == snapc) {
found = 1;
break;
}
}
BUG_ON(!found);
capsnap->dirty_pages -= nr;
if (capsnap->dirty_pages == 0) {
complete_capsnap = 1;
if (capsnap->dirty == 0)
/* cap writeback completed before we created
* the cap_snap; no FLUSHSNAP is needed */
drop_capsnap = 1;
}
dout("put_wrbuffer_cap_refs on %p cap_snap %p "
" snap %lld %d/%d -> %d/%d %s%s%s\n",
inode, capsnap, capsnap->context->seq,
ci->i_wrbuffer_ref+nr, capsnap->dirty_pages + nr,
ci->i_wrbuffer_ref, capsnap->dirty_pages,
last ? " (wrbuffer last)" : "",
complete_capsnap ? " (complete capsnap)" : "",
drop_capsnap ? " (drop capsnap)" : "");
if (drop_capsnap) {
ceph_put_snap_context(capsnap->context);
list_del(&capsnap->ci_item);
list_del(&capsnap->flushing_item);
ceph_put_cap_snap(capsnap);
}
}
spin_unlock(&inode->i_lock);
if (last) {
ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
iput(inode);
} else if (complete_capsnap) {
ceph_flush_snaps(ci);
wake_up(&ci->i_cap_wq);
}
if (drop_capsnap)
iput(inode);
}
/*
* Handle a cap GRANT message from the MDS. (Note that a GRANT may
* actually be a revocation if it specifies a smaller cap set.)
*
* caller holds s_mutex and i_lock, we drop both.
*
* return value:
* 0 - ok
* 1 - check_caps on auth cap only (writeback)
* 2 - check_caps (ack revoke)
*/
static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
struct ceph_mds_session *session,
struct ceph_cap *cap,
struct ceph_buffer *xattr_buf)
__releases(inode->i_lock)
__releases(session->s_mutex)
{
struct ceph_inode_info *ci = ceph_inode(inode);
int mds = session->s_mds;
int seq = le32_to_cpu(grant->seq);
int newcaps = le32_to_cpu(grant->caps);
int issued, implemented, used, wanted, dirty;
u64 size = le64_to_cpu(grant->size);
u64 max_size = le64_to_cpu(grant->max_size);
struct timespec mtime, atime, ctime;
int check_caps = 0;
int wake = 0;
int writeback = 0;
int revoked_rdcache = 0;
int queue_invalidate = 0;
dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
inode, cap, mds, seq, ceph_cap_string(newcaps));
dout(" size %llu max_size %llu, i_size %llu\n", size, max_size,
inode->i_size);
/*
* If CACHE is being revoked, and we have no dirty buffers,
* try to invalidate (once). (If there are dirty buffers, we
* will invalidate _after_ writeback.)
*/
if (((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) &&
!ci->i_wrbuffer_ref) {
if (try_nonblocking_invalidate(inode) == 0) {
revoked_rdcache = 1;
} else {
/* there were locked pages.. invalidate later
in a separate thread. */
if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
queue_invalidate = 1;
ci->i_rdcache_revoking = ci->i_rdcache_gen;
}
}
}
/* side effects now are allowed */
issued = __ceph_caps_issued(ci, &implemented);
issued |= implemented | __ceph_caps_dirty(ci);
cap->cap_gen = session->s_cap_gen;
__check_cap_issue(ci, cap, newcaps);
if ((issued & CEPH_CAP_AUTH_EXCL) == 0) {
inode->i_mode = le32_to_cpu(grant->mode);
inode->i_uid = le32_to_cpu(grant->uid);
inode->i_gid = le32_to_cpu(grant->gid);
dout("%p mode 0%o uid.gid %d.%d\n", inode, inode->i_mode,
inode->i_uid, inode->i_gid);
}
if ((issued & CEPH_CAP_LINK_EXCL) == 0)
inode->i_nlink = le32_to_cpu(grant->nlink);
if ((issued & CEPH_CAP_XATTR_EXCL) == 0 && grant->xattr_len) {
int len = le32_to_cpu(grant->xattr_len);
u64 version = le64_to_cpu(grant->xattr_version);
if (version > ci->i_xattrs.version) {
dout(" got new xattrs v%llu on %p len %d\n",
version, inode, len);
if (ci->i_xattrs.blob)
ceph_buffer_put(ci->i_xattrs.blob);
ci->i_xattrs.blob = ceph_buffer_get(xattr_buf);
ci->i_xattrs.version = version;
}
}
/* size/ctime/mtime/atime? */
ceph_fill_file_size(inode, issued,
le32_to_cpu(grant->truncate_seq),
le64_to_cpu(grant->truncate_size), size);
ceph_decode_timespec(&mtime, &grant->mtime);
ceph_decode_timespec(&atime, &grant->atime);
ceph_decode_timespec(&ctime, &grant->ctime);
ceph_fill_file_time(inode, issued,
le32_to_cpu(grant->time_warp_seq), &ctime, &mtime,
&atime);
/* max size increase? */
if (max_size != ci->i_max_size) {
dout("max_size %lld -> %llu\n", ci->i_max_size, max_size);
ci->i_max_size = max_size;
if (max_size >= ci->i_wanted_max_size) {
ci->i_wanted_max_size = 0; /* reset */
ci->i_requested_max_size = 0;
}
wake = 1;
}
/* check cap bits */
wanted = __ceph_caps_wanted(ci);
used = __ceph_caps_used(ci);
dirty = __ceph_caps_dirty(ci);
dout(" my wanted = %s, used = %s, dirty %s\n",
ceph_cap_string(wanted),
ceph_cap_string(used),
ceph_cap_string(dirty));
if (wanted != le32_to_cpu(grant->wanted)) {
dout("mds wanted %s -> %s\n",
ceph_cap_string(le32_to_cpu(grant->wanted)),
ceph_cap_string(wanted));
grant->wanted = cpu_to_le32(wanted);
}
cap->seq = seq;
/* file layout may have changed */
ci->i_layout = grant->layout;
/* revocation, grant, or no-op? */
if (cap->issued & ~newcaps) {
dout("revocation: %s -> %s\n", ceph_cap_string(cap->issued),
ceph_cap_string(newcaps));
if ((used & ~newcaps) & CEPH_CAP_FILE_BUFFER)
writeback = 1; /* will delay ack */
else if (dirty & ~newcaps)
check_caps = 1; /* initiate writeback in check_caps */
else if (((used & ~newcaps) & CEPH_CAP_FILE_CACHE) == 0 ||
revoked_rdcache)
check_caps = 2; /* send revoke ack in check_caps */
cap->issued = newcaps;
cap->implemented |= newcaps;
} else if (cap->issued == newcaps) {
dout("caps unchanged: %s -> %s\n",
ceph_cap_string(cap->issued), ceph_cap_string(newcaps));
} else {
dout("grant: %s -> %s\n", ceph_cap_string(cap->issued),
ceph_cap_string(newcaps));
cap->issued = newcaps;
cap->implemented |= newcaps; /* add bits only, to
* avoid stepping on a
* pending revocation */
wake = 1;
}
BUG_ON(cap->issued & ~cap->implemented);
spin_unlock(&inode->i_lock);
if (writeback)
/*
* queue inode for writeback: we can't actually call
* filemap_write_and_wait, etc. from message handler
* context.
*/
ceph_queue_writeback(inode);
if (queue_invalidate)
ceph_queue_invalidate(inode);
if (wake)
wake_up(&ci->i_cap_wq);
if (check_caps == 1)
ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY,
session);
else if (check_caps == 2)
ceph_check_caps(ci, CHECK_CAPS_NODELAY, session);
else
mutex_unlock(&session->s_mutex);
}
/*
* Handle FLUSH_ACK from MDS, indicating that metadata we sent to the
* MDS has been safely committed.
*/
static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid,
struct ceph_mds_caps *m,
struct ceph_mds_session *session,
struct ceph_cap *cap)
__releases(inode->i_lock)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_mds_client *mdsc = &ceph_client(inode->i_sb)->mdsc;
unsigned seq = le32_to_cpu(m->seq);
int dirty = le32_to_cpu(m->dirty);
int cleaned = 0;
int drop = 0;
int i;
for (i = 0; i < CEPH_CAP_BITS; i++)
if ((dirty & (1 << i)) &&
flush_tid == ci->i_cap_flush_tid[i])
cleaned |= 1 << i;
dout("handle_cap_flush_ack inode %p mds%d seq %d on %s cleaned %s,"
" flushing %s -> %s\n",
inode, session->s_mds, seq, ceph_cap_string(dirty),
ceph_cap_string(cleaned), ceph_cap_string(ci->i_flushing_caps),
ceph_cap_string(ci->i_flushing_caps & ~cleaned));
if (ci->i_flushing_caps == (ci->i_flushing_caps & ~cleaned))
goto out;
ci->i_flushing_caps &= ~cleaned;
spin_lock(&mdsc->cap_dirty_lock);
if (ci->i_flushing_caps == 0) {
list_del_init(&ci->i_flushing_item);
if (!list_empty(&session->s_cap_flushing))
dout(" mds%d still flushing cap on %p\n",
session->s_mds,
&list_entry(session->s_cap_flushing.next,
struct ceph_inode_info,
i_flushing_item)->vfs_inode);
mdsc->num_cap_flushing--;
wake_up(&mdsc->cap_flushing_wq);
dout(" inode %p now !flushing\n", inode);
if (ci->i_dirty_caps == 0) {
dout(" inode %p now clean\n", inode);
BUG_ON(!list_empty(&ci->i_dirty_item));
drop = 1;
} else {
BUG_ON(list_empty(&ci->i_dirty_item));
}
}
spin_unlock(&mdsc->cap_dirty_lock);
wake_up(&ci->i_cap_wq);
out:
spin_unlock(&inode->i_lock);
if (drop)
iput(inode);
}
/*
* Handle FLUSHSNAP_ACK. MDS has flushed snap data to disk and we can
* throw away our cap_snap.
*
* Caller hold s_mutex.
*/
static void handle_cap_flushsnap_ack(struct inode *inode, u64 flush_tid,
struct ceph_mds_caps *m,
struct ceph_mds_session *session)
{
struct ceph_inode_info *ci = ceph_inode(inode);
u64 follows = le64_to_cpu(m->snap_follows);
struct ceph_cap_snap *capsnap;
int drop = 0;
dout("handle_cap_flushsnap_ack inode %p ci %p mds%d follows %lld\n",
inode, ci, session->s_mds, follows);
spin_lock(&inode->i_lock);
list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) {
if (capsnap->follows == follows) {
if (capsnap->flush_tid != flush_tid) {
dout(" cap_snap %p follows %lld tid %lld !="
" %lld\n", capsnap, follows,
flush_tid, capsnap->flush_tid);
break;
}
WARN_ON(capsnap->dirty_pages || capsnap->writing);
dout(" removing %p cap_snap %p follows %lld\n",
inode, capsnap, follows);
ceph_put_snap_context(capsnap->context);
list_del(&capsnap->ci_item);
list_del(&capsnap->flushing_item);
ceph_put_cap_snap(capsnap);
drop = 1;
break;
} else {
dout(" skipping cap_snap %p follows %lld\n",
capsnap, capsnap->follows);
}
}
spin_unlock(&inode->i_lock);
if (drop)
iput(inode);
}
/*
* Handle TRUNC from MDS, indicating file truncation.
*
* caller hold s_mutex.
*/
static void handle_cap_trunc(struct inode *inode,
struct ceph_mds_caps *trunc,
struct ceph_mds_session *session)
__releases(inode->i_lock)
{
struct ceph_inode_info *ci = ceph_inode(inode);
int mds = session->s_mds;
int seq = le32_to_cpu(trunc->seq);
u32 truncate_seq = le32_to_cpu(trunc->truncate_seq);
u64 truncate_size = le64_to_cpu(trunc->truncate_size);
u64 size = le64_to_cpu(trunc->size);
int implemented = 0;
int dirty = __ceph_caps_dirty(ci);
int issued = __ceph_caps_issued(ceph_inode(inode), &implemented);
int queue_trunc = 0;
issued |= implemented | dirty;
dout("handle_cap_trunc inode %p mds%d seq %d to %lld seq %d\n",
inode, mds, seq, truncate_size, truncate_seq);
queue_trunc = ceph_fill_file_size(inode, issued,
truncate_seq, truncate_size, size);
spin_unlock(&inode->i_lock);
if (queue_trunc)
ceph_queue_vmtruncate(inode);
}
/*
* Handle EXPORT from MDS. Cap is being migrated _from_ this mds to a
* different one. If we are the most recent migration we've seen (as
* indicated by mseq), make note of the migrating cap bits for the
* duration (until we see the corresponding IMPORT).
*
* caller holds s_mutex
*/
static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex,
struct ceph_mds_session *session)
{
struct ceph_inode_info *ci = ceph_inode(inode);
int mds = session->s_mds;
unsigned mseq = le32_to_cpu(ex->migrate_seq);
struct ceph_cap *cap = NULL, *t;
struct rb_node *p;
int remember = 1;
dout("handle_cap_export inode %p ci %p mds%d mseq %d\n",
inode, ci, mds, mseq);
spin_lock(&inode->i_lock);
/* make sure we haven't seen a higher mseq */
for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
t = rb_entry(p, struct ceph_cap, ci_node);
if (ceph_seq_cmp(t->mseq, mseq) > 0) {
dout(" higher mseq on cap from mds%d\n",
t->session->s_mds);
remember = 0;
}
if (t->session->s_mds == mds)
cap = t;
}
if (cap) {
if (remember) {
/* make note */
ci->i_cap_exporting_mds = mds;
ci->i_cap_exporting_mseq = mseq;
ci->i_cap_exporting_issued = cap->issued;
}
__ceph_remove_cap(cap);
}
/* else, we already released it */
spin_unlock(&inode->i_lock);
}
/*
* Handle cap IMPORT. If there are temp bits from an older EXPORT,
* clean them up.
*
* caller holds s_mutex.
*/
static void handle_cap_import(struct ceph_mds_client *mdsc,
struct inode *inode, struct ceph_mds_caps *im,
struct ceph_mds_session *session,
void *snaptrace, int snaptrace_len)
{
struct ceph_inode_info *ci = ceph_inode(inode);
int mds = session->s_mds;
unsigned issued = le32_to_cpu(im->caps);
unsigned wanted = le32_to_cpu(im->wanted);
unsigned seq = le32_to_cpu(im->seq);
unsigned mseq = le32_to_cpu(im->migrate_seq);
u64 realmino = le64_to_cpu(im->realm);
u64 cap_id = le64_to_cpu(im->cap_id);
if (ci->i_cap_exporting_mds >= 0 &&
ceph_seq_cmp(ci->i_cap_exporting_mseq, mseq) < 0) {
dout("handle_cap_import inode %p ci %p mds%d mseq %d"
" - cleared exporting from mds%d\n",
inode, ci, mds, mseq,
ci->i_cap_exporting_mds);
ci->i_cap_exporting_issued = 0;
ci->i_cap_exporting_mseq = 0;
ci->i_cap_exporting_mds = -1;
} else {
dout("handle_cap_import inode %p ci %p mds%d mseq %d\n",
inode, ci, mds, mseq);
}
down_write(&mdsc->snap_rwsem);
ceph_update_snap_trace(mdsc, snaptrace, snaptrace+snaptrace_len,
false);
downgrade_write(&mdsc->snap_rwsem);
ceph_add_cap(inode, session, cap_id, -1,
issued, wanted, seq, mseq, realmino, CEPH_CAP_FLAG_AUTH,
NULL /* no caps context */);
try_flush_caps(inode, session, NULL);
up_read(&mdsc->snap_rwsem);
}
/*
* Handle a caps message from the MDS.
*
* Identify the appropriate session, inode, and call the right handler
* based on the cap op.
*/
void ceph_handle_caps(struct ceph_mds_session *session,
struct ceph_msg *msg)
{
struct ceph_mds_client *mdsc = session->s_mdsc;
struct super_block *sb = mdsc->client->sb;
struct inode *inode;
struct ceph_cap *cap;
struct ceph_mds_caps *h;
int mds = session->s_mds;
int op;
u32 seq;
struct ceph_vino vino;
u64 cap_id;
u64 size, max_size;
u64 tid;
void *snaptrace;
dout("handle_caps from mds%d\n", mds);
/* decode */
tid = le64_to_cpu(msg->hdr.tid);
if (msg->front.iov_len < sizeof(*h))
goto bad;
h = msg->front.iov_base;
snaptrace = h + 1;
op = le32_to_cpu(h->op);
vino.ino = le64_to_cpu(h->ino);
vino.snap = CEPH_NOSNAP;
cap_id = le64_to_cpu(h->cap_id);
seq = le32_to_cpu(h->seq);
size = le64_to_cpu(h->size);
max_size = le64_to_cpu(h->max_size);
mutex_lock(&session->s_mutex);
session->s_seq++;
dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq,
(unsigned)seq);
/* lookup ino */
inode = ceph_find_inode(sb, vino);
dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino,
vino.snap, inode);
if (!inode) {
dout(" i don't have ino %llx\n", vino.ino);
goto done;
}
/* these will work even if we don't have a cap yet */
switch (op) {
case CEPH_CAP_OP_FLUSHSNAP_ACK:
handle_cap_flushsnap_ack(inode, tid, h, session);
goto done;
case CEPH_CAP_OP_EXPORT:
handle_cap_export(inode, h, session);
goto done;
case CEPH_CAP_OP_IMPORT:
handle_cap_import(mdsc, inode, h, session,
snaptrace, le32_to_cpu(h->snap_trace_len));
ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY,
session);
goto done_unlocked;
}
/* the rest require a cap */
spin_lock(&inode->i_lock);
cap = __get_cap_for_mds(ceph_inode(inode), mds);
if (!cap) {
dout("no cap on %p ino %llx.%llx from mds%d, releasing\n",
inode, ceph_ino(inode), ceph_snap(inode), mds);
spin_unlock(&inode->i_lock);
goto done;
}
/* note that each of these drops i_lock for us */
switch (op) {
case CEPH_CAP_OP_REVOKE:
case CEPH_CAP_OP_GRANT:
handle_cap_grant(inode, h, session, cap, msg->middle);
goto done_unlocked;
case CEPH_CAP_OP_FLUSH_ACK:
handle_cap_flush_ack(inode, tid, h, session, cap);
break;
case CEPH_CAP_OP_TRUNC:
handle_cap_trunc(inode, h, session);
break;
default:
spin_unlock(&inode->i_lock);
pr_err("ceph_handle_caps: unknown cap op %d %s\n", op,
ceph_cap_op_name(op));
}
done:
mutex_unlock(&session->s_mutex);
done_unlocked:
if (inode)
iput(inode);
return;
bad:
pr_err("ceph_handle_caps: corrupt message\n");
ceph_msg_dump(msg);
return;
}
/*
* Delayed work handler to process end of delayed cap release LRU list.
*/
void ceph_check_delayed_caps(struct ceph_mds_client *mdsc)
{
struct ceph_inode_info *ci;
int flags = CHECK_CAPS_NODELAY;
dout("check_delayed_caps\n");
while (1) {
spin_lock(&mdsc->cap_delay_lock);
if (list_empty(&mdsc->cap_delay_list))
break;
ci = list_first_entry(&mdsc->cap_delay_list,
struct ceph_inode_info,
i_cap_delay_list);
if ((ci->i_ceph_flags & CEPH_I_FLUSH) == 0 &&
time_before(jiffies, ci->i_hold_caps_max))
break;
list_del_init(&ci->i_cap_delay_list);
spin_unlock(&mdsc->cap_delay_lock);
dout("check_delayed_caps on %p\n", &ci->vfs_inode);
ceph_check_caps(ci, flags, NULL);
}
spin_unlock(&mdsc->cap_delay_lock);
}
/*
* Flush all dirty caps to the mds
*/
void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc)
{
struct ceph_inode_info *ci, *nci = NULL;
struct inode *inode, *ninode = NULL;
struct list_head *p, *n;
dout("flush_dirty_caps\n");
spin_lock(&mdsc->cap_dirty_lock);
list_for_each_safe(p, n, &mdsc->cap_dirty) {
if (nci) {
ci = nci;
inode = ninode;
ci->i_ceph_flags &= ~CEPH_I_NOFLUSH;
dout("flush_dirty_caps inode %p (was next inode)\n",
inode);
} else {
ci = list_entry(p, struct ceph_inode_info,
i_dirty_item);
inode = igrab(&ci->vfs_inode);
BUG_ON(!inode);
dout("flush_dirty_caps inode %p\n", inode);
}
if (n != &mdsc->cap_dirty) {
nci = list_entry(n, struct ceph_inode_info,
i_dirty_item);
ninode = igrab(&nci->vfs_inode);
BUG_ON(!ninode);
nci->i_ceph_flags |= CEPH_I_NOFLUSH;
dout("flush_dirty_caps next inode %p, noflush\n",
ninode);
} else {
nci = NULL;
ninode = NULL;
}
spin_unlock(&mdsc->cap_dirty_lock);
if (inode) {
ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH,
NULL);
iput(inode);
}
spin_lock(&mdsc->cap_dirty_lock);
}
spin_unlock(&mdsc->cap_dirty_lock);
}
/*
* Drop open file reference. If we were the last open file,
* 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)
{
struct inode *inode = &ci->vfs_inode;
int last = 0;
spin_lock(&inode->i_lock);
dout("put_fmode %p fmode %d %d -> %d\n", inode, fmode,
ci->i_nr_by_mode[fmode], ci->i_nr_by_mode[fmode]-1);
BUG_ON(ci->i_nr_by_mode[fmode] == 0);
if (--ci->i_nr_by_mode[fmode] == 0)
last++;
spin_unlock(&inode->i_lock);
if (last && ci->i_vino.snap == CEPH_NOSNAP)
ceph_check_caps(ci, 0, NULL);
}
/*
* Helpers for embedding cap and dentry lease releases into mds
* requests.
*
* @force is used by dentry_release (below) to force inclusion of a
* record for the directory inode, even when there aren't any caps to
* drop.
*/
int ceph_encode_inode_release(void **p, struct inode *inode,
int mds, int drop, int unless, int force)
{
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_cap *cap;
struct ceph_mds_request_release *rel = *p;
int ret = 0;
int used = 0;
spin_lock(&inode->i_lock);
used = __ceph_caps_used(ci);
dout("encode_inode_release %p mds%d used %s drop %s unless %s\n", inode,
mds, ceph_cap_string(used), ceph_cap_string(drop),
ceph_cap_string(unless));
/* only drop unused caps */
drop &= ~used;
cap = __get_cap_for_mds(ci, mds);
if (cap && __cap_is_valid(cap)) {
if (force ||
((cap->issued & drop) &&
(cap->issued & unless) == 0)) {
if ((cap->issued & drop) &&
(cap->issued & unless) == 0) {
dout("encode_inode_release %p cap %p %s -> "
"%s\n", inode, cap,
ceph_cap_string(cap->issued),
ceph_cap_string(cap->issued & ~drop));
cap->issued &= ~drop;
cap->implemented &= ~drop;
if (ci->i_ceph_flags & CEPH_I_NODELAY) {
int wanted = __ceph_caps_wanted(ci);
dout(" wanted %s -> %s (act %s)\n",
ceph_cap_string(cap->mds_wanted),
ceph_cap_string(cap->mds_wanted &
~wanted),
ceph_cap_string(wanted));
cap->mds_wanted &= wanted;
}
} else {
dout("encode_inode_release %p cap %p %s"
" (force)\n", inode, cap,
ceph_cap_string(cap->issued));
}
rel->ino = cpu_to_le64(ceph_ino(inode));
rel->cap_id = cpu_to_le64(cap->cap_id);
rel->seq = cpu_to_le32(cap->seq);
rel->issue_seq = cpu_to_le32(cap->issue_seq),
rel->mseq = cpu_to_le32(cap->mseq);
rel->caps = cpu_to_le32(cap->issued);
rel->wanted = cpu_to_le32(cap->mds_wanted);
rel->dname_len = 0;
rel->dname_seq = 0;
*p += sizeof(*rel);
ret = 1;
} else {
dout("encode_inode_release %p cap %p %s\n",
inode, cap, ceph_cap_string(cap->issued));
}
}
spin_unlock(&inode->i_lock);
return ret;
}
int ceph_encode_dentry_release(void **p, struct dentry *dentry,
int mds, int drop, int unless)
{
struct inode *dir = dentry->d_parent->d_inode;
struct ceph_mds_request_release *rel = *p;
struct ceph_dentry_info *di = ceph_dentry(dentry);
int force = 0;
int ret;
/*
* force an record for the directory caps if we have a dentry lease.
* this is racy (can't take i_lock and d_lock together), but it
* doesn't have to be perfect; the mds will revoke anything we don't
* release.
*/
spin_lock(&dentry->d_lock);
if (di->lease_session && di->lease_session->s_mds == mds)
force = 1;
spin_unlock(&dentry->d_lock);
ret = ceph_encode_inode_release(p, dir, mds, drop, unless, force);
spin_lock(&dentry->d_lock);
if (ret && di->lease_session && di->lease_session->s_mds == mds) {
dout("encode_dentry_release %p mds%d seq %d\n",
dentry, mds, (int)di->lease_seq);
rel->dname_len = cpu_to_le32(dentry->d_name.len);
memcpy(*p, dentry->d_name.name, dentry->d_name.len);
*p += dentry->d_name.len;
rel->dname_seq = cpu_to_le32(di->lease_seq);
}
spin_unlock(&dentry->d_lock);
return ret;
}
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