Moved, renamed, and deleted files

The original directory structure was scattered and unorganized.
Changes are basically to make it look like kernel structure.

1 files changed, 0 insertions, 3088 deletions

diff --git a/ANDROID_3.4.5/fs/ceph/caps.c b/ANDROID_3.4.5/fs/ceph/caps.c
deleted file mode 100644
index 620daad2..00000000
--- a/ANDROID_3.4.5/fs/ceph/caps.c
+++ /dev/null
@@ -1,3088 +0,0 @@
-#include <linux/ceph/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 "mds_client.h"
-#include <linux/ceph/decode.h>
-#include <linux/ceph/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];
-}
-
-void ceph_caps_init(struct ceph_mds_client *mdsc)
-{
-	INIT_LIST_HEAD(&mdsc->caps_list);
-	spin_lock_init(&mdsc->caps_list_lock);
-}
-
-void ceph_caps_finalize(struct ceph_mds_client *mdsc)
-{
-	struct ceph_cap *cap;
-
-	spin_lock(&mdsc->caps_list_lock);
-	while (!list_empty(&mdsc->caps_list)) {
-		cap = list_first_entry(&mdsc->caps_list,
-				       struct ceph_cap, caps_item);
-		list_del(&cap->caps_item);
-		kmem_cache_free(ceph_cap_cachep, cap);
-	}
-	mdsc->caps_total_count = 0;
-	mdsc->caps_avail_count = 0;
-	mdsc->caps_use_count = 0;
-	mdsc->caps_reserve_count = 0;
-	mdsc->caps_min_count = 0;
-	spin_unlock(&mdsc->caps_list_lock);
-}
-
-void ceph_adjust_min_caps(struct ceph_mds_client *mdsc, int delta)
-{
-	spin_lock(&mdsc->caps_list_lock);
-	mdsc->caps_min_count += delta;
-	BUG_ON(mdsc->caps_min_count < 0);
-	spin_unlock(&mdsc->caps_list_lock);
-}
-
-int ceph_reserve_caps(struct ceph_mds_client *mdsc,
-		      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(&mdsc->caps_list_lock);
-	if (mdsc->caps_avail_count >= need)
-		have = need;
-	else
-		have = mdsc->caps_avail_count;
-	mdsc->caps_avail_count -= have;
-	mdsc->caps_reserve_count += have;
-	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
-					 mdsc->caps_reserve_count +
-					 mdsc->caps_avail_count);
-	spin_unlock(&mdsc->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(&mdsc->caps_list_lock);
-	mdsc->caps_total_count += alloc;
-	mdsc->caps_reserve_count += alloc;
-	list_splice(&newcaps, &mdsc->caps_list);
-
-	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
-					 mdsc->caps_reserve_count +
-					 mdsc->caps_avail_count);
-	spin_unlock(&mdsc->caps_list_lock);
-
-	ctx->count = need;
-	dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n",
-	     ctx, mdsc->caps_total_count, mdsc->caps_use_count,
-	     mdsc->caps_reserve_count, mdsc->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_mds_client *mdsc,
-			struct ceph_cap_reservation *ctx)
-{
-	dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count);
-	if (ctx->count) {
-		spin_lock(&mdsc->caps_list_lock);
-		BUG_ON(mdsc->caps_reserve_count < ctx->count);
-		mdsc->caps_reserve_count -= ctx->count;
-		mdsc->caps_avail_count += ctx->count;
-		ctx->count = 0;
-		dout("unreserve caps %d = %d used + %d resv + %d avail\n",
-		     mdsc->caps_total_count, mdsc->caps_use_count,
-		     mdsc->caps_reserve_count, mdsc->caps_avail_count);
-		BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
-						 mdsc->caps_reserve_count +
-						 mdsc->caps_avail_count);
-		spin_unlock(&mdsc->caps_list_lock);
-	}
-	return 0;
-}
-
-static struct ceph_cap *get_cap(struct ceph_mds_client *mdsc,
-				struct ceph_cap_reservation *ctx)
-{
-	struct ceph_cap *cap = NULL;
-
-	/* temporary, until we do something about cap import/export */
-	if (!ctx) {
-		cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS);
-		if (cap) {
-			mdsc->caps_use_count++;
-			mdsc->caps_total_count++;
-		}
-		return cap;
-	}
-
-	spin_lock(&mdsc->caps_list_lock);
-	dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n",
-	     ctx, ctx->count, mdsc->caps_total_count, mdsc->caps_use_count,
-	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
-	BUG_ON(!ctx->count);
-	BUG_ON(ctx->count > mdsc->caps_reserve_count);
-	BUG_ON(list_empty(&mdsc->caps_list));
-
-	ctx->count--;
-	mdsc->caps_reserve_count--;
-	mdsc->caps_use_count++;
-
-	cap = list_first_entry(&mdsc->caps_list, struct ceph_cap, caps_item);
-	list_del(&cap->caps_item);
-
-	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
-	       mdsc->caps_reserve_count + mdsc->caps_avail_count);
-	spin_unlock(&mdsc->caps_list_lock);
-	return cap;
-}
-
-void ceph_put_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap)
-{
-	spin_lock(&mdsc->caps_list_lock);
-	dout("put_cap %p %d = %d used + %d resv + %d avail\n",
-	     cap, mdsc->caps_total_count, mdsc->caps_use_count,
-	     mdsc->caps_reserve_count, mdsc->caps_avail_count);
-	mdsc->caps_use_count--;
-	/*
-	 * Keep some preallocated caps around (ceph_min_count), to
-	 * avoid lots of free/alloc churn.
-	 */
-	if (mdsc->caps_avail_count >= mdsc->caps_reserve_count +
-				      mdsc->caps_min_count) {
-		mdsc->caps_total_count--;
-		kmem_cache_free(ceph_cap_cachep, cap);
-	} else {
-		mdsc->caps_avail_count++;
-		list_add(&cap->caps_item, &mdsc->caps_list);
-	}
-
-	BUG_ON(mdsc->caps_total_count != mdsc->caps_use_count +
-	       mdsc->caps_reserve_count + mdsc->caps_avail_count);
-	spin_unlock(&mdsc->caps_list_lock);
-}
-
-void ceph_reservation_status(struct ceph_fs_client *fsc,
-			     int *total, int *avail, int *used, int *reserved,
-			     int *min)
-{
-	struct ceph_mds_client *mdsc = fsc->mdsc;
-
-	if (total)
-		*total = mdsc->caps_total_count;
-	if (avail)
-		*avail = mdsc->caps_avail_count;
-	if (used)
-		*used = mdsc->caps_use_count;
-	if (reserved)
-		*reserved = mdsc->caps_reserve_count;
-	if (min)
-		*min = mdsc->caps_min_count;
-}
-
-/*
- * Find ceph_cap for given mds, if any.
- *
- * Called with i_ceph_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;
-}
-
-struct ceph_cap *ceph_get_cap_for_mds(struct ceph_inode_info *ci, int mds)
-{
-	struct ceph_cap *cap;
-
-	spin_lock(&ci->i_ceph_lock);
-	cap = __get_cap_for_mds(ci, mds);
-	spin_unlock(&ci->i_ceph_lock);
-	return cap;
-}
-
-/*
- * Return id of any MDS with a cap, preferably FILE_WR|BUFFER|EXCL, else -1.
- */
-static int __ceph_get_cap_mds(struct ceph_inode_info *ci)
-{
-	struct ceph_cap *cap;
-	int mds = -1;
-	struct rb_node *p;
-
-	/* prefer mds with WR|BUFFER|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 (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)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	int mds;
-	spin_lock(&ci->i_ceph_lock);
-	mds = __ceph_get_cap_mds(ceph_inode(inode));
-	spin_unlock(&ci->i_ceph_lock);
-	return mds;
-}
-
-/*
- * Called under i_ceph_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_options *ma = mdsc->fsc->mount_options;
-
-	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_ceph_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_ceph_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|CEPH_CAP_FILE_LAZYIO)) &&
-	    (had & (CEPH_CAP_FILE_CACHE|CEPH_CAP_FILE_LAZYIO)) == 0)
-		ci->i_rdcache_gen++;
-
-	/*
-	 * if we are newly issued FILE_SHARED, clear D_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))
-			ceph_dir_clear_complete(&ci->vfs_inode);
-	}
-}
-
-/*
- * 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(&ci->i_ceph_lock);
-	cap = __get_cap_for_mds(ci, mds);
-	if (!cap) {
-		if (new_cap) {
-			cap = new_cap;
-			new_cap = NULL;
-		} else {
-			spin_unlock(&ci->i_ceph_lock);
-			new_cap = get_cap(mdsc, 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);
-	} else if (new_cap)
-		ceph_put_cap(mdsc, new_cap);
-
-	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);
-			WARN_ON(!realm);
-		}
-	}
-
-	__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(&ci->i_ceph_lock);
-	wake_up_all(&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_gen_ttl_lock);
-	gen = cap->session->s_cap_gen;
-	ttl = cap->session->s_cap_ttl;
-	spin_unlock(&cap->session->s_gen_ttl_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 + preceding 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(&ci->i_ceph_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(&ci->i_ceph_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->vfs_inode.i_data.nrpages)
-		used |= CEPH_CAP_FILE_CACHE;
-	if (ci->i_wr_ref)
-		used |= CEPH_CAP_FILE_WR;
-	if (ci->i_wb_ref || 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 < CEPH_FILE_MODE_NUM; 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_ceph_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_ceph_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_sb_to_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(mdsc, 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, umode_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), GFP_NOFS, false);
-	if (!msg)
-		return -ENOMEM;
-
-	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;
-}
-
-static void __queue_cap_release(struct ceph_mds_session *session,
-				u64 ino, u64 cap_id, u32 migrate_seq,
-				u32 issue_seq)
-{
-	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 %llx release to mds%d msg %p (%d left)\n",
-	     ino, 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(ino);
-	item->cap_id = cpu_to_le64(cap_id);
-	item->migrate_seq = cpu_to_le32(migrate_seq);
-	item->seq = cpu_to_le32(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);
-}
-
-/*
- * Queue cap releases when an inode is dropped from our cache.  Since
- * inode is about to be destroyed, there is no need for i_ceph_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;
-
-		__queue_cap_release(session, ceph_ino(inode), cap->cap_id,
-				    cap->mseq, cap->issue_seq);
-		p = rb_next(p);
-		__ceph_remove_cap(cap);
-	}
-}
-
-/*
- * Send a cap msg on the given inode.  Update our caps state, then
- * drop i_ceph_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_ceph_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->i_ceph_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;
-	umode_t mode;
-	uid_t uid;
-	gid_t gid;
-	struct ceph_mds_session *session;
-	u64 xattr_version = 0;
-	struct ceph_buffer *xattr_blob = NULL;
-	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;
-
-		follows = ci->i_head_snapc->seq;
-	} else {
-		follows = 0;
-	}
-
-	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;
-	uid = inode->i_uid;
-	gid = inode->i_gid;
-	mode = inode->i_mode;
-
-	if (flushing & CEPH_CAP_XATTR_EXCL) {
-		__ceph_build_xattrs_blob(ci);
-		xattr_blob = ci->i_xattrs.blob;
-		xattr_version = ci->i_xattrs.version;
-	}
-
-	spin_unlock(&ci->i_ceph_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, xattr_blob,
-		follows);
-	if (ret < 0) {
-		dout("error sending cap msg, must requeue %p\n", inode);
-		delayed = 1;
-	}
-
-	if (wake)
-		wake_up_all(&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.
- *
- * Unless @again is true, skip cap_snaps that were already sent to
- * the MDS (i.e., during this session).
- *
- * Called under i_ceph_lock.  Takes s_mutex as needed.
- */
-void __ceph_flush_snaps(struct ceph_inode_info *ci,
-			struct ceph_mds_session **psession,
-			int again)
-		__releases(ci->i_ceph_lock)
-		__acquires(ci->i_ceph_lock)
-{
-	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)
-			break;
-
-		/*
-		 * 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 */
-		if (ci->i_auth_cap == NULL) {
-			dout("no auth cap (migrating?), doing nothing\n");
-			goto out;
-		}
-
-		/* only flush each capsnap once */
-		if (!again && !list_empty(&capsnap->flushing_item)) {
-			dout("already flushed %p, skipping\n", capsnap);
-			continue;
-		}
-
-		mds = ci->i_auth_cap->session->s_mds;
-		mseq = ci->i_auth_cap->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(&ci->i_ceph_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 or migration.  retry, and we'll
-			 * get a better @mds value next time.
-			 */
-			spin_lock(&ci->i_ceph_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(&ci->i_ceph_lock);
-
-		dout("flush_snaps %p cap_snap %p follows %lld tid %llu\n",
-		     inode, capsnap, capsnap->follows, capsnap->flush_tid);
-		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,
-			     capsnap->xattr_version, capsnap->xattr_blob,
-			     capsnap->follows);
-
-		next_follows = capsnap->follows + 1;
-		ceph_put_cap_snap(capsnap);
-
-		spin_lock(&ci->i_ceph_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);
-
-out:
-	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)
-{
-	spin_lock(&ci->i_ceph_lock);
-	__ceph_flush_snaps(ci, NULL, 0);
-	spin_unlock(&ci->i_ceph_lock);
-}
-
-/*
- * Mark caps dirty.  If inode is newly dirty, return the dirty flags.
- * Caller is then responsible for calling __mark_inode_dirty with the
- * returned flags value.
- */
-int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask)
-{
-	struct ceph_mds_client *mdsc =
-		ceph_sb_to_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) {
-		if (!ci->i_head_snapc)
-			ci->i_head_snapc = ceph_get_snap_context(
-				ci->i_snap_realm->cached_context);
-		dout(" inode %p now dirty snapc %p\n", &ci->vfs_inode,
-			ci->i_head_snapc);
-		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) {
-			ihold(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;
-	__cap_delay_requeue(mdsc, ci);
-	return dirty;
-}
-
-/*
- * Add dirty inode to the flushing list.  Assigned a seq number so we
- * can wait for caps to flush without starving.
- *
- * Called under i_ceph_lock.
- */
-static int __mark_caps_flushing(struct inode *inode,
-				 struct ceph_mds_session *session)
-{
-	struct ceph_mds_client *mdsc = ceph_sb_to_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 try_nonblocking_invalidate(struct inode *inode)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	u32 invalidating_gen = ci->i_rdcache_gen;
-
-	spin_unlock(&ci->i_ceph_lock);
-	invalidate_mapping_pages(&inode->i_data, 0, -1);
-	spin_lock(&ci->i_ceph_lock);
-
-	if (inode->i_data.nrpages == 0 &&
-	    invalidating_gen == ci->i_rdcache_gen) {
-		/* success. */
-		dout("try_nonblocking_invalidate %p success\n", inode);
-		/* save any racing async invalidate some trouble */
-		ci->i_rdcache_revoking = ci->i_rdcache_gen - 1;
-		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)
-{
-	struct ceph_fs_client *fsc = ceph_inode_to_client(&ci->vfs_inode);
-	struct ceph_mds_client *mdsc = fsc->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(&ci->i_ceph_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, 0);
-	goto retry_locked;
-retry:
-	spin_lock(&ci->i_ceph_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... */
-	    inode->i_data.nrpages &&                 /* have cached pages */
-	    (file_wanted == 0 ||                     /* no open files */
-	     (revoking & (CEPH_CAP_FILE_CACHE|
-			  CEPH_CAP_FILE_LAZYIO))) && /*  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|
-					CEPH_CAP_FILE_LAZYIO)) {
-				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;
-		dout(" mds%d cap %p issued %s implemented %s revoking %s\n",
-		     cap->mds, cap, ceph_cap_string(cap->issued),
-		     ceph_cap_string(cap->implemented),
-		     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(&ci->i_ceph_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(&ci->i_ceph_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);
-		else
-			flushing = 0;
-
-		mds = cap->mds;  /* remember mds, so we don't repeat */
-		sent++;
-
-		/* __send_cap drops i_ceph_lock */
-		delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, used, want,
-				      retain, flushing, NULL);
-		goto retry; /* retake i_ceph_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(&ci->i_ceph_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_sb_to_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(&ci->i_ceph_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(&ci->i_ceph_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_ceph_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(&ci->i_ceph_lock);
-		__cap_delay_requeue(mdsc, ci);
-	}
-out:
-	spin_unlock(&ci->i_ceph_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 i, ret = 1;
-
-	spin_lock(&ci->i_ceph_lock);
-	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(&ci->i_ceph_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, loff_t start, loff_t end, int datasync)
-{
-	struct inode *inode = file->f_mapping->host;
-	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_range(inode->i_mapping, start, end);
-	if (ret < 0)
-		return ret;
-	mutex_lock(&inode->i_mutex);
-
-	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" : "");
-	mutex_unlock(&inode->i_mutex);
-	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_sb_to_client(inode->i_sb)->mdsc;
-
-		spin_lock(&ci->i_ceph_lock);
-		if (__ceph_caps_dirty(ci))
-			__cap_delay_requeue_front(mdsc, ci);
-		spin_unlock(&ci->i_ceph_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(&ci->i_ceph_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, 1);
-		} else {
-			pr_err("%p auth cap %p not mds%d ???\n", inode,
-			       cap, session->s_mds);
-		}
-		spin_unlock(&ci->i_ceph_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(&ci->i_ceph_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(&ci->i_ceph_lock);
-				__cap_delay_requeue(mdsc, ci);
-				spin_unlock(&ci->i_ceph_lock);
-			}
-		} else {
-			pr_err("%p auth cap %p not mds%d ???\n", inode,
-			       cap, session->s_mds);
-			spin_unlock(&ci->i_ceph_lock);
-		}
-	}
-}
-
-static void kick_flushing_inode_caps(struct ceph_mds_client *mdsc,
-				     struct ceph_mds_session *session,
-				     struct inode *inode)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct ceph_cap *cap;
-	int delayed = 0;
-
-	spin_lock(&ci->i_ceph_lock);
-	cap = ci->i_auth_cap;
-	dout("kick_flushing_inode_caps %p flushing %s flush_seq %lld\n", inode,
-	     ceph_cap_string(ci->i_flushing_caps), ci->i_cap_flush_seq);
-	__ceph_flush_snaps(ci, &session, 1);
-	if (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(&ci->i_ceph_lock);
-			__cap_delay_requeue(mdsc, ci);
-			spin_unlock(&ci->i_ceph_lock);
-		}
-	} else {
-		spin_unlock(&ci->i_ceph_lock);
-	}
-}
-
-
-/*
- * Take references to capabilities we hold, so that we don't release
- * them to the MDS prematurely.
- *
- * Protected by i_ceph_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_wb_ref == 0)
-			ihold(&ci->vfs_inode);
-		ci->i_wb_ref++;
-		dout("__take_cap_refs %p wb %d -> %d (?)\n",
-		     &ci->vfs_inode, ci->i_wb_ref-1, ci->i_wb_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(&ci->i_ceph_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(&ci->i_ceph_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(&ci->i_ceph_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(&ci->i_ceph_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->i_ceph_lock);
-	__take_cap_refs(ci, caps);
-	spin_unlock(&ci->i_ceph_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(&ci->i_ceph_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_wb_ref == 0) {
-			last++;
-			put++;
-		}
-		dout("put_cap_refs %p wb %d -> %d (?)\n",
-		     inode, ci->i_wb_ref+1, ci->i_wb_ref);
-	}
-	if (had & CEPH_CAP_FILE_WR)
-		if (--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(&ci->i_ceph_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_all(&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(&ci->i_ceph_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 == 0 &&
-		    ci->i_dirty_caps == 0 && ci->i_flushing_caps == 0) {
-			BUG_ON(!ci->i_head_snapc);
-			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(&ci->i_ceph_lock);
-
-	if (last) {
-		ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL);
-		iput(inode);
-	} else if (complete_capsnap) {
-		ceph_flush_snaps(ci);
-		wake_up_all(&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_ceph_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(ci->i_ceph_lock)
-{
-	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) &&
-	    (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
-	    !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)
-		set_nlink(inode, 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) {
-		int revoking = cap->issued & ~newcaps;
-
-		dout("revocation: %s -> %s (revoking %s)\n",
-		     ceph_cap_string(cap->issued),
-		     ceph_cap_string(newcaps),
-		     ceph_cap_string(revoking));
-		if (revoking & used & CEPH_CAP_FILE_BUFFER)
-			writeback = 1;  /* initiate writeback; will delay ack */
-		else if (revoking == CEPH_CAP_FILE_CACHE &&
-			 (newcaps & CEPH_CAP_FILE_LAZYIO) == 0 &&
-			 queue_invalidate)
-			; /* do nothing yet, invalidation will be queued */
-		else if (cap == ci->i_auth_cap)
-			check_caps = 1; /* check auth cap only */
-		else
-			check_caps = 2; /* check all 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(&ci->i_ceph_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_all(&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(ci->i_ceph_lock)
-{
-	struct ceph_inode_info *ci = ceph_inode(inode);
-	struct ceph_mds_client *mdsc = ceph_sb_to_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_all(&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;
-			if (ci->i_wrbuffer_ref_head == 0) {
-				BUG_ON(!ci->i_head_snapc);
-				ceph_put_snap_context(ci->i_head_snapc);
-				ci->i_head_snapc = NULL;
-			}
-		} else {
-			BUG_ON(list_empty(&ci->i_dirty_item));
-		}
-	}
-	spin_unlock(&mdsc->cap_dirty_lock);
-	wake_up_all(&ci->i_cap_wq);
-
-out:
-	spin_unlock(&ci->i_ceph_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(&ci->i_ceph_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(&ci->i_ceph_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(ci->i_ceph_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(&ci->i_ceph_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,
-			      int *open_target_sessions)
-{
-	struct ceph_mds_client *mdsc = ceph_inode_to_client(inode)->mdsc;
-	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(&ci->i_ceph_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;
-
-			/*
-			 * make sure we have open sessions with all possible
-			 * export targets, so that we get the matching IMPORT
-			 */
-			*open_target_sessions = 1;
-
-			/*
-			 * we can't flush dirty caps that we've seen the
-			 * EXPORT but no IMPORT for
-			 */
-			spin_lock(&mdsc->cap_dirty_lock);
-			if (!list_empty(&ci->i_dirty_item)) {
-				dout(" moving %p to cap_dirty_migrating\n",
-				     inode);
-				list_move(&ci->i_dirty_item,
-					  &mdsc->cap_dirty_migrating);
-			}
-			spin_unlock(&mdsc->cap_dirty_lock);
-		}
-		__ceph_remove_cap(cap);
-	}
-	/* else, we already released it */
-
-	spin_unlock(&ci->i_ceph_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;
-
-		spin_lock(&mdsc->cap_dirty_lock);
-		if (!list_empty(&ci->i_dirty_item)) {
-			dout(" moving %p back to cap_dirty\n", inode);
-			list_move(&ci->i_dirty_item, &mdsc->cap_dirty);
-		}
-		spin_unlock(&mdsc->cap_dirty_lock);
-	} 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 */);
-	kick_flushing_inode_caps(mdsc, session, inode);
-	up_read(&mdsc->snap_rwsem);
-
-	/* make sure we re-request max_size, if necessary */
-	spin_lock(&ci->i_ceph_lock);
-	ci->i_requested_max_size = 0;
-	spin_unlock(&ci->i_ceph_lock);
-}
-
-/*
- * 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->fsc->sb;
-	struct inode *inode;
-	struct ceph_inode_info *ci;
-	struct ceph_cap *cap;
-	struct ceph_mds_caps *h;
-	int mds = session->s_mds;
-	int op;
-	u32 seq, mseq;
-	struct ceph_vino vino;
-	u64 cap_id;
-	u64 size, max_size;
-	u64 tid;
-	void *snaptrace;
-	size_t snaptrace_len;
-	void *flock;
-	u32 flock_len;
-	int open_target_sessions = 0;
-
-	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;
-	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);
-	mseq = le32_to_cpu(h->migrate_seq);
-	size = le64_to_cpu(h->size);
-	max_size = le64_to_cpu(h->max_size);
-
-	snaptrace = h + 1;
-	snaptrace_len = le32_to_cpu(h->snap_trace_len);
-
-	if (le16_to_cpu(msg->hdr.version) >= 2) {
-		void *p, *end;
-
-		p = snaptrace + snaptrace_len;
-		end = msg->front.iov_base + msg->front.iov_len;
-		ceph_decode_32_safe(&p, end, flock_len, bad);
-		flock = p;
-	} else {
-		flock = NULL;
-		flock_len = 0;
-	}
-
-	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);
-	ci = ceph_inode(inode);
-	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);
-
-		if (op == CEPH_CAP_OP_IMPORT)
-			__queue_cap_release(session, vino.ino, cap_id,
-					    mseq, seq);
-		goto flush_cap_releases;
-	}
-
-	/* 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, &open_target_sessions);
-		goto done;
-
-	case CEPH_CAP_OP_IMPORT:
-		handle_cap_import(mdsc, inode, h, session,
-				  snaptrace, snaptrace_len);
-		ceph_check_caps(ceph_inode(inode), 0, session);
-		goto done_unlocked;
-	}
-
-	/* the rest require a cap */
-	spin_lock(&ci->i_ceph_lock);
-	cap = __get_cap_for_mds(ceph_inode(inode), mds);
-	if (!cap) {
-		dout(" no cap on %p ino %llx.%llx from mds%d\n",
-		     inode, ceph_ino(inode), ceph_snap(inode), mds);
-		spin_unlock(&ci->i_ceph_lock);
-		goto flush_cap_releases;
-	}
-
-	/* note that each of these drops i_ceph_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(&ci->i_ceph_lock);
-		pr_err("ceph_handle_caps: unknown cap op %d %s\n", op,
-		       ceph_cap_op_name(op));
-	}
-
-	goto done;
-
-flush_cap_releases:
-	/*
-	 * send any full release message to try to move things
-	 * along for the mds (who clearly thinks we still have this
-	 * cap).
-	 */
-	ceph_add_cap_releases(mdsc, session);
-	ceph_send_cap_releases(mdsc, session);
-
-done:
-	mutex_unlock(&session->s_mutex);
-done_unlocked:
-	if (inode)
-		iput(inode);
-	if (open_target_sessions)
-		ceph_mdsc_open_export_target_sessions(mdsc, session);
-	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;
-	struct inode *inode;
-
-	dout("flush_dirty_caps\n");
-	spin_lock(&mdsc->cap_dirty_lock);
-	while (!list_empty(&mdsc->cap_dirty)) {
-		ci = list_first_entry(&mdsc->cap_dirty, struct ceph_inode_info,
-				      i_dirty_item);
-		inode = &ci->vfs_inode;
-		ihold(inode);
-		dout("flush_dirty_caps %p\n", inode);
-		spin_unlock(&mdsc->cap_dirty_lock);
-		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);
-	dout("flush_dirty_caps done\n");
-}
-
-/*
- * 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(&ci->i_ceph_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(&ci->i_ceph_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 used, dirty;
-	int ret = 0;
-
-	spin_lock(&ci->i_ceph_lock);
-	used = __ceph_caps_used(ci);
-	dirty = __ceph_caps_dirty(ci);
-
-	dout("encode_inode_release %p mds%d used|dirty %s drop %s unless %s\n",
-	     inode, mds, ceph_cap_string(used|dirty), ceph_cap_string(drop),
-	     ceph_cap_string(unless));
-
-	/* only drop unused, clean caps */
-	drop &= ~(used | dirty);
-
-	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(&ci->i_ceph_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_ceph_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);
-		__ceph_mdsc_drop_dentry_lease(dentry);
-	}
-	spin_unlock(&dentry->d_lock);
-	return ret;
-}