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Message-Id: <1236638439-6753-14-git-send-email-sage@newdream.net>
Date: Mon, 9 Mar 2009 15:40:32 -0700
From: Sage Weil <sage@...dream.net>
To: linux-kernel@...r.kernel.org, linux-fsdevel@...r.kernel.org
Cc: Sage Weil <sage@...dream.net>
Subject: [PATCH 13/20] ceph: capability management
The Ceph metadata servers control client access to data by issuing
capabilities granting clients permission to read and/or write to OSDs
(storage nodes). Each capability consists of a set of bits indicating
which operations are allowed.
In the case of an EXCL (exclusive) or WR capabilities, the client is
allowed to change inode attributes (e.g., file size, mtime), noting
it's 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.
A subset of capabilities (termed 'rdcaps') are opportunistically
issued by the MDS to grant the a client read lease on metadata, and
time out automatically. Other capabilities (write capabilities, and
those that are "wanted" due to an open file) are explicitly released.
Signed-off-by: Sage Weil <sage@...dream.net>
---
fs/ceph/caps.c | 1900 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 1900 insertions(+), 0 deletions(-)
create mode 100644 fs/ceph/caps.c
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c
new file mode 100644
index 0000000..8682c6a
--- /dev/null
+++ b/fs/ceph/caps.c
@@ -0,0 +1,1900 @@
+#include <linux/fs.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+
+#include "ceph_debug.h"
+
+int ceph_debug_caps __read_mostly = -1;
+#define DOUT_MASK DOUT_MASK_CAPS
+#define DOUT_VAR ceph_debug_caps
+#include "super.h"
+
+#include "decode.h"
+#include "messenger.h"
+
+/*
+ * Generate readable cap strings for debugging output.
+ */
+#define MAX_CAP_STR 20
+static char cap_str[MAX_CAP_STR][40];
+static spinlock_t cap_str_lock = SPIN_LOCK_UNLOCKED;
+static int last_cap_str;
+
+static char *gcap_string(char *s, int c)
+{
+ if (c & CEPH_CAP_GRDCACHE)
+ *s++ = 'c';
+ if (c & CEPH_CAP_GEXCL)
+ *s++ = 'x';
+ if (c & CEPH_CAP_GRD)
+ *s++ = 'r';
+ if (c & CEPH_CAP_GWR)
+ *s++ = 'w';
+ if (c & CEPH_CAP_GWRBUFFER)
+ *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];
+}
+
+/*
+ * Find ceph_cap for given mds, if any.
+ *
+ * Called with i_lock held.
+ */
+static struct ceph_cap *__get_cap_for_mds(struct inode *inode, int mds)
+{
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ 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 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_WRBUFFER |
+ 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);
+}
+
+/*
+ * Remove or place the given cap on the session 'rdcaps' list (or
+ * read-only, expireable caps). A cap belongs on the rdcaps list IFF
+ * it does not include any non-expireable caps and wanted == 0.
+ *
+ * The rdcaps list is protected by a separate spinlock because
+ * ceph_put_fmode may need to add caps to it when wanted goes to 0.
+ */
+static void __adjust_cap_rdcaps_listing(struct ceph_inode_info *ci,
+ struct ceph_cap *cap,
+ int wanted)
+{
+ int caps = cap->issued | cap->flushing | ci->i_dirty_caps;
+
+ spin_lock(&cap->session->s_rdcaps_lock);
+ if ((caps & ~CEPH_CAP_EXPIREABLE) == 0 && wanted == 0) {
+ /* move to tail of session rdcaps lru? */
+ if (!list_empty(&cap->session_rdcaps))
+ list_del_init(&cap->session_rdcaps);
+ else
+ dout(20, "adjust_cap_rdcaps_listing %p added %p\n",
+ &ci->vfs_inode, cap);
+ list_add_tail(&cap->session_rdcaps, &cap->session->s_rdcaps);
+ } else {
+ if (!list_empty(&cap->session_rdcaps)) {
+ dout(20, "adjust_cap_rdcaps_listing %p removed %p\n",
+ &ci->vfs_inode, cap);
+ list_del_init(&cap->session_rdcaps);
+ }
+ }
+ spin_unlock(&cap->session->s_rdcaps_lock);
+}
+
+/*
+ * Add a capability under the given MDS session.
+ *
+ * Bump i_count when adding the first cap.
+ *
+ * Caller should hold session snap_rwsem (read), s_mutex.
+ *
+ * @fmode is the open file mode, if we are opening a file,
+ * otherwise it is < 0.
+ */
+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,
+ unsigned ttl_ms, unsigned long ttl_from,
+ struct ceph_cap *new_cap)
+{
+ struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc;
+ struct ceph_inode_info *ci = ceph_inode(inode);
+ struct ceph_cap *cap;
+ int mds = session->s_mds;
+ int is_first = 0;
+
+ dout(10, "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. Needed by adjust_cap_rdcaps_listing.
+ */
+ if (fmode >= 0)
+ wanted |= ceph_caps_for_mode(fmode);
+
+retry:
+ spin_lock(&inode->i_lock);
+ cap = __get_cap_for_mds(inode, mds);
+ if (!cap) {
+ if (new_cap) {
+ cap = new_cap;
+ new_cap = NULL;
+ } else {
+ spin_unlock(&inode->i_lock);
+ new_cap = kmalloc(sizeof(*cap), GFP_NOFS);
+ if (new_cap == NULL)
+ return -ENOMEM;
+ goto retry;
+ }
+
+ cap->issued = 0;
+ cap->implemented = 0;
+ cap->flushing = 0;
+ cap->mds_wanted = wanted;
+ cap->mds = mds;
+
+ is_first = RB_EMPTY_ROOT(&ci->i_caps); /* grab inode later */
+ 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;
+ list_add(&cap->session_caps, &session->s_caps);
+ session->s_nr_caps++;
+ INIT_LIST_HEAD(&cap->session_rdcaps);
+ }
+
+ __adjust_cap_rdcaps_listing(ci, cap, __ceph_caps_wanted(ci) | wanted);
+
+ if (!ci->i_snap_realm) {
+ struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc,
+ realmino);
+ if (realm) {
+ ceph_get_snap_realm(mdsc, realm);
+ ci->i_snap_realm = realm;
+ list_add(&ci->i_snap_realm_item,
+ &realm->inodes_with_caps);
+ } else {
+ derr(0, "couldn't find snap realm realmino=%llu\n",
+ realmino);
+ }
+ }
+
+ /*
+ * if we are newly issued FILE_RDCACHE, clear I_COMPLETE; we
+ * don't know what happened to this directory while we didn't
+ * have the cap.
+ */
+ if (S_ISDIR(inode->i_mode) &&
+ (issued & CEPH_CAP_FILE_RDCACHE) &&
+ (cap->issued & CEPH_CAP_FILE_RDCACHE) == 0) {
+ dout(10, " marking %p NOT complete\n", inode);
+ ci->i_ceph_flags &= ~CEPH_I_COMPLETE;
+ }
+
+ dout(10, "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->seq = seq;
+ cap->mseq = mseq;
+ cap->gen = session->s_cap_gen;
+ cap->expires = ttl_from + (ttl_ms * HZ / 1000);
+ if (fmode >= 0)
+ __ceph_get_fmode(ci, fmode);
+ spin_unlock(&inode->i_lock);
+ if (is_first)
+ igrab(inode);
+ wake_up(&ci->i_cap_wq);
+ kfree(new_cap);
+ return 0;
+}
+
+/*
+ * Return true if cap has not timed out and belongs to the current
+ * generation of the MDS session.
+ */
+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->gen < gen || time_after_eq(jiffies, ttl)) {
+ dout(30, "__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->gen, gen);
+ return 0;
+ }
+
+ if (time_after_eq(jiffies, cap->expires) &&
+ !list_empty(&cap->session_rdcaps)) {
+ dout(30, "__cap_is_valid %p cap %p issued %s "
+ "but rdcap and expired\n", &cap->ci->vfs_inode,
+ cap, ceph_cap_string(cap->issued));
+ 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;
+ 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(30, "__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;
+}
+
+/*
+ * Return mask of fields dirtied while holding *_EXCL or FILE_WR caps.
+ * Include both per-inode 'dirty' fields and 'flushing' caps.
+ */
+int __ceph_caps_dirty(struct ceph_inode_info *ci)
+{
+ struct inode *inode = &ci->vfs_inode;
+ int dirty = ci->i_dirty_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_is_valid(cap))
+ continue;
+ dout(30, "__ceph_caps_dirty %p cap %p flushing %s\n",
+ inode, cap, ceph_cap_string(cap->flushing));
+ dirty |= cap->flushing;
+ }
+ dout(30, "__ceph_caps_dirty %p dirty %s\n", inode,
+ ceph_cap_string(dirty));
+ return dirty;
+}
+
+/*
+ * Return mask of caps 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(30, "ceph_caps_revoking %p %s = %d\n", inode,
+ ceph_cap_string(mask), ret);
+ return ret;
+}
+
+/*
+ * 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;
+}
+
+/*
+ * caller should hold i_lock, and session s_mutex.
+ * returns true if this is the last cap. if so, caller should iput.
+ */
+static int __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;
+
+ dout(20, "__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode);
+
+ /* remove from session list */
+ list_del_init(&cap->session_caps);
+ if (!list_empty(&cap->session_rdcaps))
+ list_del_init(&cap->session_rdcaps);
+ session->s_nr_caps--;
+
+ /* remove from inode list */
+ rb_erase(&cap->ci_node, &ci->i_caps);
+ cap->session = NULL;
+
+ kfree(cap);
+
+ if (!__ceph_is_any_caps(ci)) {
+ list_del_init(&ci->i_snap_realm_item);
+ ceph_put_snap_realm(mdsc, ci->i_snap_realm);
+ ci->i_snap_realm = NULL;
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * caller should hold session s_mutex.
+ */
+void ceph_remove_cap(struct ceph_cap *cap)
+{
+ struct inode *inode = &cap->ci->vfs_inode;
+ int was_last;
+
+ spin_lock(&inode->i_lock);
+ was_last = __ceph_remove_cap(cap);
+ spin_unlock(&inode->i_lock);
+ if (was_last)
+ iput(inode);
+}
+
+/*
+ *
+ * (Re)queue cap at the end of the delayed cap release 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)
+{
+ ci->i_hold_caps_until = round_jiffies(jiffies + CEPH_CAP_DELAY);
+ dout(10, "__cap_delay_requeue %p at %lu\n", &ci->vfs_inode,
+ ci->i_hold_caps_until);
+ if (!mdsc->stopping) {
+ spin_lock(&mdsc->cap_delay_lock);
+ if (list_empty(&ci->i_cap_delay_list))
+ igrab(&ci->vfs_inode);
+ else
+ list_del_init(&ci->i_cap_delay_list);
+ list_add_tail(&ci->i_cap_delay_list, &mdsc->cap_delay_list);
+ spin_unlock(&mdsc->cap_delay_lock);
+ }
+}
+
+/*
+ * Cancel delayed work on cap.
+ *
+ * Caller hold i_lock.
+ */
+static void __cap_delay_cancel(struct ceph_mds_client *mdsc,
+ struct ceph_inode_info *ci)
+{
+ dout(10, "__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);
+ iput(&ci->vfs_inode);
+}
+
+/*
+ * Build and send a cap message to the given MDS.
+ *
+ * Caller should be holding s_mutex.
+ */
+static void send_cap_msg(struct ceph_mds_client *mdsc, u64 ino, u64 cid, int op,
+ int caps, int wanted, int dirty, u64 seq, u64 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 follows, int mds)
+{
+ struct ceph_mds_caps *fc;
+ struct ceph_msg *msg;
+
+ dout(10, "send_cap_msg %s %llx %llx caps %s wanted %s dirty %s"
+ " seq %llu/%llu follows %lld size %llu\n", ceph_cap_op_name(op),
+ cid, ino, ceph_cap_string(caps), ceph_cap_string(wanted),
+ ceph_cap_string(dirty),
+ seq, mseq, follows, size);
+
+ msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc), 0, 0, NULL);
+ if (IS_ERR(msg))
+ return;
+
+ 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->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);
+
+ ceph_send_msg_mds(mdsc, msg, mds);
+}
+
+/*
+ * 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.
+ *
+ * called with i_lock, then drops it.
+ * caller should hold snap_rwsem (read), s_mutex.
+ */
+static void __send_cap(struct ceph_mds_client *mdsc,
+ struct ceph_mds_session *session,
+ struct ceph_cap *cap,
+ int used, int want, int retain)
+ __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 = cap->issued | cap->implemented;
+ int revoking = cap->implemented & ~cap->issued;
+ int dropping = cap->issued & ~retain;
+ int op = (retain == 0) ? CEPH_CAP_OP_RELEASE : CEPH_CAP_OP_UPDATE;
+ int keep;
+ u64 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;
+ int dirty;
+ int flushing;
+ int last_cap = 0;
+
+ dout(10, "__send_cap cap %p session %p %s -> %s (revoking %s)\n",
+ cap, cap->session,
+ ceph_cap_string(held), ceph_cap_string(held & retain),
+ ceph_cap_string(revoking));
+
+ dirty = __ceph_caps_dirty(ci);
+ cap->flushing |= dirty & held;
+ if (cap->flushing) {
+ ci->i_dirty_caps &= ~cap->flushing;
+ dout(10, "__send_cap flushing %s, dirty_caps now %s\n",
+ ceph_cap_string(cap->flushing),
+ ceph_cap_string(ci->i_dirty_caps));
+ }
+
+ cap->issued &= retain; /* drop bits we don't want */
+
+ if (revoking && (revoking & used) == 0) {
+ 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->mds_wanted = want;
+
+ keep = cap->issued;
+ flushing = cap->flushing;
+ seq = cap->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;
+
+ /* close out cap? */
+ if (flushing == 0 && keep == 0)
+ last_cap = __ceph_remove_cap(cap);
+ else
+ __adjust_cap_rdcaps_listing(ci, cap, __ceph_caps_wanted(ci));
+ spin_unlock(&inode->i_lock);
+
+ if (dropping & CEPH_CAP_FILE_RDCACHE) {
+ /* invalidate what we can */
+ dout(20, "invalidating pages on %p\n", inode);
+ invalidate_mapping_pages(&inode->i_data, 0, -1);
+ }
+
+ send_cap_msg(mdsc, ceph_vino(inode).ino, cap_id,
+ op, keep, want, flushing, seq, mseq,
+ size, max_size, &mtime, &atime, time_warp_seq,
+ uid, gid, mode,
+ follows, session->s_mds);
+
+ if (wake)
+ wake_up(&ci->i_cap_wq);
+ if (last_cap)
+ iput(inode);
+}
+
+/*
+ * 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 list_head *p;
+ 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(10, "__flush_snaps %p\n", inode);
+retry:
+ list_for_each(p, &ci->i_cap_snaps) {
+ capsnap = list_entry(p, struct ceph_cap_snap, 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;
+
+ /* pick mds, take s_mutex */
+ mds = __ceph_get_cap_mds(ci, &mseq);
+ if (session && session->s_mds != mds) {
+ dout(30, "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(10, "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;
+ }
+
+ atomic_inc(&capsnap->nref);
+ spin_unlock(&inode->i_lock);
+
+ dout(10, "flush_snaps %p cap_snap %p follows %lld size %llu\n",
+ inode, capsnap, next_follows, capsnap->size);
+ send_cap_msg(mdsc, ceph_vino(inode).ino, 0,
+ CEPH_CAP_OP_FLUSHSNAP, capsnap->issued, 0,
+ capsnap->dirty, 0, mseq,
+ capsnap->size, 0,
+ &capsnap->mtime, &capsnap->atime,
+ capsnap->time_warp_seq,
+ capsnap->uid, capsnap->gid, capsnap->mode,
+ capsnap->follows, mds);
+
+ 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);
+}
+
+/*
+ * Swiss army knife function to examine currently used, wanted versus
+ * held caps. Release, flush, ack revoked caps to mds as appropriate.
+ *
+ * @is_delayed indicates caller is delayed work and we should not
+ * delay further.
+ */
+void ceph_check_caps(struct ceph_inode_info *ci, int is_delayed, int drop,
+ struct ceph_mds_session *session)
+{
+ 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 want, retain, revoking;
+ 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;
+
+ /* if we are unmounting, flush any unused caps immediately. */
+ if (mdsc->stopping)
+ is_delayed = 1;
+
+ spin_lock(&inode->i_lock);
+
+ /* 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;
+
+ retain = want;
+ if (!mdsc->stopping && inode->i_nlink > 0) {
+ /*
+ * we cannot retain anything outside of
+ * (wanted|EXPIREABLE), or else we run the risk of the
+ * MDS' wanted value getting out of sync, and we have
+ * no mechanism to adjust that (besides open()).
+ */
+ retain |= CEPH_CAP_EXPIREABLE;
+
+ /* keep any EXCL bits too, while we are holding caps anyway */
+ if (want || S_ISDIR(inode->i_mode))
+ retain |= CEPH_CAP_ANY_EXCL;
+ }
+ retain &= ~drop;
+
+ dout(10, "check_caps %p file_wanted %s used %s retain %s issued %s\n",
+ inode, ceph_cap_string(file_wanted), ceph_cap_string(used),
+ ceph_cap_string(retain),
+ ceph_cap_string(__ceph_caps_issued(ci, NULL)));
+
+ /*
+ * Reschedule delayed caps release, unless we are called from
+ * the delayed work handler (i.e. this _is_ the delayed release)
+ */
+ if (!is_delayed)
+ __cap_delay_requeue(mdsc, ci);
+
+ /*
+ * 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 ((!time_before(jiffies, ci->i_hold_caps_until) || mdsc->stopping) &&
+ ci->i_wrbuffer_ref == 0 && /* no dirty pages... */
+ ci->i_rdcache_gen && /* may have cached pages */
+ file_wanted == 0 && /* no open files */
+ !tried_invalidate) {
+ u32 invalidating_gen = ci->i_rdcache_gen;
+ int ret;
+
+ dout(10, "check_caps trying to invalidate on %p\n", inode);
+ spin_unlock(&inode->i_lock);
+ ret = invalidate_inode_pages2(&inode->i_data);
+ spin_lock(&inode->i_lock);
+ if (ret == 0 && invalidating_gen == ci->i_rdcache_gen) {
+ /* success. */
+ ci->i_rdcache_gen = 0;
+ ci->i_rdcache_revoking = 0;
+ } else {
+ dout(10, "check_caps failed to invalidate pages\n");
+ /* we failed to invalidate pages. check these
+ caps again later. */
+ if (is_delayed)
+ __cap_delay_requeue(mdsc, ci);
+ }
+ tried_invalidate = 1;
+ goto retry_locked;
+ }
+
+ for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
+ cap = rb_entry(p, struct ceph_cap, ci_node);
+
+ /* avoid looping forever */
+ if (mds >= cap->mds)
+ continue;
+
+ /* NOTE: no side-effects allowed, until we take s_mutex */
+
+ revoking = cap->implemented & ~cap->issued;
+ if (revoking)
+ dout(10, "mds%d revoking %s\n", cap->mds,
+ ceph_cap_string(revoking));
+
+ /* request larger max_size from MDS& ~drop;? */
+ if (ci->i_wanted_max_size > ci->i_max_size &&
+ ci->i_wanted_max_size > ci->i_requested_max_size)
+ goto ack;
+
+ /* approaching file_max? */
+ if ((cap->issued & CEPH_CAP_FILE_WR) &&
+ (inode->i_size << 1) >= ci->i_max_size &&
+ (ci->i_reported_size << 1) < ci->i_max_size) {
+ dout(10, "i_size approaching max_size\n");
+ goto ack;
+ }
+
+ /* completed revocation? going down and there are no caps? */
+ if (revoking && (revoking & used) == 0) {
+ dout(10, "completed revocation of %s\n",
+ ceph_cap_string(cap->implemented & ~cap->issued));
+ goto ack;
+ }
+
+ /* shutting down? */
+ if (!revoking && mdsc->stopping && (used == 0))
+ goto ack;
+
+ if ((cap->issued & ~retain) == 0 &&
+ cap->mds_wanted == want)
+ continue; /* nothing extra, wanted is correct */
+
+ /* delay cap release for a bit? */
+ if (!is_delayed &&
+ time_before(jiffies, ci->i_hold_caps_until)) {
+ dout(30, "delaying cap release\n");
+ continue;
+ }
+
+ack:
+ if (session && session != cap->session) {
+ dout(30, "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(10, "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(10, "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;
+ }
+
+ mds = cap->mds; /* remember mds, so we don't repeat */
+
+ /* __send_cap drops i_lock */
+ __send_cap(mdsc, session, cap, used, want, retain);
+
+ goto retry; /* retake i_lock and restart our cap scan. */
+ }
+ spin_unlock(&inode->i_lock);
+
+ if (session)
+ mutex_unlock(&session->s_mutex);
+ if (took_snap_rwsem)
+ up_read(&mdsc->snap_rwsem);
+}
+
+/*
+ * 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_FILE_RD)
+ ci->i_rd_ref++;
+ if (got & CEPH_CAP_FILE_RDCACHE)
+ ci->i_rdcache_ref++;
+ if (got & CEPH_CAP_FILE_WR)
+ ci->i_wr_ref++;
+ if (got & CEPH_CAP_FILE_WRBUFFER) {
+ ci->i_wrbuffer_ref++;
+ dout(30, "__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 ceph_get_cap_refs(struct ceph_inode_info *ci, int need, int want,
+ int *got,
+ loff_t endoff)
+{
+ struct inode *inode = &ci->vfs_inode;
+ int ret = 0;
+ int have, implemented;
+
+ dout(30, "get_cap_refs %p need %s want %s\n", inode,
+ ceph_cap_string(need), ceph_cap_string(want));
+ spin_lock(&inode->i_lock);
+ if (need & CEPH_CAP_FILE_WR) {
+ if (endoff >= 0 && endoff > (loff_t)ci->i_max_size) {
+ dout(20, "get_cap_refs %p endoff %llu > maxsize %llu\n",
+ inode, endoff, ci->i_max_size);
+ goto sorry;
+ }
+ /*
+ * 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(20, "get_cap_refs %p cap_snap_pending\n", inode);
+ goto sorry;
+ }
+ }
+ 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(30, "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(30, "get_cap_refs %p have %s needed %s\n", inode,
+ ceph_cap_string(have), ceph_cap_string(need));
+ }
+sorry:
+ spin_unlock(&inode->i_lock);
+ dout(30, "get_cap_refs %p ret %d got %s\n", inode,
+ ret, ceph_cap_string(*got));
+ return ret;
+}
+
+/*
+ * Wait for caps, and take cap references.
+ */
+int ceph_get_caps(struct ceph_inode_info *ci, int need, int want, int *got,
+ loff_t endoff)
+{
+ return wait_event_interruptible(ci->i_cap_wq,
+ ceph_get_cap_refs(ci, need, want, got, endoff));
+}
+
+/*
+ * 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, flushsnaps = 0, wake = 0;
+ struct ceph_cap_snap *capsnap;
+
+ spin_lock(&inode->i_lock);
+ if (had & CEPH_CAP_FILE_RD)
+ if (--ci->i_rd_ref == 0)
+ last++;
+ if (had & CEPH_CAP_FILE_RDCACHE)
+ if (--ci->i_rdcache_ref == 0)
+ last++;
+ if (had & CEPH_CAP_FILE_WRBUFFER) {
+ if (--ci->i_wrbuffer_ref == 0)
+ last++;
+ dout(30, "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_entry(ci->i_cap_snaps.next,
+ 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(30, "put_cap_refs %p had %s %s\n", inode, ceph_cap_string(had),
+ last ? "last" : "");
+
+ if (last && !flushsnaps)
+ ceph_check_caps(ci, 0, 0, NULL);
+ else if (flushsnaps)
+ ceph_flush_snaps(ci);
+ if (wake)
+ wake_up(&ci->i_cap_wq);
+}
+
+/*
+ * 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 last_snap = 0;
+ int found = 0;
+ struct list_head *p;
+ 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(30, "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(p, &ci->i_cap_snaps) {
+ capsnap = list_entry(p, struct ceph_cap_snap, ci_item);
+ if (capsnap->context == snapc) {
+ found = 1;
+ capsnap->dirty_pages -= nr;
+ last_snap = !capsnap->dirty_pages;
+ break;
+ }
+ }
+ BUG_ON(!found);
+ dout(30, "put_wrbuffer_cap_refs on %p cap_snap %p "
+ " snap %lld %d/%d -> %d/%d %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)" : "",
+ last_snap ? " (capsnap last)" : "");
+ }
+
+ spin_unlock(&inode->i_lock);
+
+ if (last) {
+ ceph_check_caps(ci, 0, 0, NULL);
+ } else if (last_snap) {
+ ceph_flush_snaps(ci);
+ wake_up(&ci->i_cap_wq);
+ }
+}
+
+/*
+ * 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.
+ * return value:
+ * 0 - ok
+ * 1 - send the msg back to mds
+ * 2 - check_caps
+ */
+static int handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant,
+ struct ceph_mds_session *session,
+ struct ceph_cap *cap,
+ void **xattr_data)
+ __releases(inode->i_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 reply = 0;
+ int wake = 0;
+ int writeback = 0;
+ int revoked_rdcache = 0;
+ int invalidate_async = 0;
+ int tried_invalidate = 0;
+ int ret;
+
+ dout(10, "handle_cap_grant inode %p cap %p mds%d seq %d %s\n",
+ inode, cap, mds, seq, ceph_cap_string(newcaps));
+ dout(10, " size %llu max_size %llu, i_size %llu\n", size, max_size,
+ inode->i_size);
+start:
+
+ cap->gen = session->s_cap_gen;
+
+ /*
+ * Each time we receive RDCACHE anew, we increment i_rdcache_gen.
+ * Also clear I_COMPLETE: we don't know what happened to this directory
+ */
+ if ((newcaps & CEPH_CAP_FILE_RDCACHE) && /* got RDCACHE */
+ (cap->issued & CEPH_CAP_FILE_RDCACHE) == 0 && /* but not before */
+ (__ceph_caps_issued(ci, NULL) & CEPH_CAP_FILE_RDCACHE) == 0) {
+ ci->i_rdcache_gen++;
+
+ if (S_ISDIR(inode->i_mode)) {
+ dout(10, " marking %p NOT complete\n", inode);
+ ci->i_ceph_flags &= ~CEPH_I_COMPLETE;
+ }
+ }
+
+ /*
+ * If RDCACHE 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_RDCACHE) &&
+ !ci->i_wrbuffer_ref && !tried_invalidate) {
+ dout(10, "RDCACHE invalidation\n");
+ spin_unlock(&inode->i_lock);
+ tried_invalidate = 1;
+
+ ret = invalidate_inode_pages2(&inode->i_data);
+ spin_lock(&inode->i_lock);
+ if (ret < 0) {
+ /* there were locked pages.. invalidate later
+ in a separate thread. */
+ if (ci->i_rdcache_revoking != ci->i_rdcache_gen) {
+ invalidate_async = 1;
+ ci->i_rdcache_revoking = ci->i_rdcache_gen;
+ }
+ } else {
+ /* we successfully invalidated those pages */
+ revoked_rdcache = 1;
+ ci->i_rdcache_gen = 0;
+ ci->i_rdcache_revoking = 0;
+ }
+ goto start;
+ }
+
+ issued = __ceph_caps_issued(ci, &implemented);
+ issued |= implemented | __ceph_caps_dirty(ci);
+
+ 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(20, "%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 (!(len > 4 && *xattr_data == NULL) && /* ENOMEM in caller */
+ version > ci->i_xattr_version) {
+ dout(20, " got new xattrs v%llu on %p len %d\n",
+ version, inode, len);
+ kfree(ci->i_xattr_data);
+ ci->i_xattr_len = len;
+ ci->i_xattr_version = version;
+ ci->i_xattr_data = *xattr_data;
+ *xattr_data = NULL;
+ }
+ }
+
+ /* 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(10, "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(10, " 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(10, "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(10, "revocation: %s -> %s\n", ceph_cap_string(cap->issued),
+ ceph_cap_string(newcaps));
+ if ((used & ~newcaps) & CEPH_CAP_FILE_WRBUFFER) {
+ writeback = 1; /* will delay ack */
+ } else if (dirty & ~newcaps) {
+ reply = 2; /* initiate writeback in check_caps */
+ } else if (((used & ~newcaps) & CEPH_CAP_FILE_RDCACHE) == 0 ||
+ revoked_rdcache) {
+ /*
+ * we're not using revoked caps.. ack now.
+ * re-use incoming message.
+ */
+ cap->implemented = newcaps;
+
+ grant->size = cpu_to_le64(inode->i_size);
+ grant->max_size = 0; /* don't re-request */
+ ceph_encode_timespec(&grant->mtime, &inode->i_mtime);
+ ceph_encode_timespec(&grant->atime, &inode->i_atime);
+ grant->time_warp_seq = cpu_to_le32(ci->i_time_warp_seq);
+ grant->snap_follows =
+ cpu_to_le64(ci->i_snap_realm->cached_context->seq);
+ reply = 1;
+ wake = 1;
+ }
+ cap->issued = newcaps;
+ } else if (cap->issued == newcaps) {
+ dout(10, "caps unchanged: %s -> %s\n",
+ ceph_cap_string(cap->issued), ceph_cap_string(newcaps));
+ } else {
+ dout(10, "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;
+ }
+
+ 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.
+ */
+ dout(10, "queueing %p for writeback\n", inode);
+ if (ceph_queue_writeback(inode))
+ igrab(inode);
+ }
+ if (invalidate_async) {
+ dout(10, "queueing %p for page invalidation\n", inode);
+ if (ceph_queue_page_invalidation(inode))
+ igrab(inode);
+ }
+ if (wake)
+ wake_up(&ci->i_cap_wq);
+ return reply;
+}
+
+/*
+ * Handle FLUSH_ACK from MDS, indicating that metadata we sent to the
+ * MDS has been safely recorded.
+ */
+static void handle_cap_flush_ack(struct inode *inode,
+ 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);
+ unsigned seq = le32_to_cpu(m->seq);
+ int caps = le32_to_cpu(m->caps);
+ int dirty = le32_to_cpu(m->dirty);
+ int cleaned = dirty & ~caps;
+ int removed_last = 0;
+
+ dout(10, "handle_cap_flush_ack inode %p mds%d seq %d cleaned %s,"
+ " flushing %s -> %s\n",
+ inode, session->s_mds, seq, ceph_cap_string(cleaned),
+ ceph_cap_string(cap->flushing),
+ ceph_cap_string(cap->flushing & ~cleaned));
+ cap->flushing &= ~cleaned;
+
+ /* did we release this cap, too? */
+ if (caps == 0 && seq == cap->seq) {
+ BUG_ON(cap->flushing);
+ removed_last = __ceph_remove_cap(cap);
+ if (removed_last)
+ __cap_delay_cancel(&ceph_inode_to_client(inode)->mdsc,
+ ci);
+ } else {
+ __adjust_cap_rdcaps_listing(ci, cap, __ceph_caps_wanted(ci));
+ }
+ spin_unlock(&inode->i_lock);
+ if (removed_last)
+ 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,
+ 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 list_head *p;
+ struct ceph_cap_snap *capsnap;
+ int drop = 0;
+
+ dout(10, "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(p, &ci->i_cap_snaps) {
+ capsnap = list_entry(p, struct ceph_cap_snap, ci_item);
+ if (capsnap->follows == follows) {
+ WARN_ON(capsnap->dirty_pages || capsnap->writing);
+ dout(10, " removing cap_snap %p follows %lld\n",
+ capsnap, follows);
+ ceph_put_snap_context(capsnap->context);
+ list_del(&capsnap->ci_item);
+ ceph_put_cap_snap(capsnap);
+ drop = 1;
+ break;
+ } else {
+ dout(10, " 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(10, "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)
+ if (queue_work(ceph_client(inode->i_sb)->trunc_wq,
+ &ci->i_vmtruncate_work))
+ igrab(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 was_last = 0;
+ int remember = 1;
+
+ dout(10, "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(10, " 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;
+ }
+ was_last = __ceph_remove_cap(cap);
+ } else {
+ WARN_ON(!cap);
+ }
+
+ spin_unlock(&inode->i_lock);
+ if (was_last)
+ iput(inode);
+}
+
+/*
+ * 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);
+ unsigned long ttl_ms = le32_to_cpu(im->ttl_ms);
+ 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(10, "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(10, "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,
+ ttl_ms, jiffies - ttl_ms/2, 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_client *mdsc,
+ struct ceph_msg *msg)
+{
+ struct super_block *sb = mdsc->client->sb;
+ struct ceph_mds_session *session;
+ struct inode *inode;
+ struct ceph_cap *cap;
+ struct ceph_mds_caps *h;
+ int mds = le32_to_cpu(msg->hdr.src.name.num);
+ int op;
+ u32 seq;
+ struct ceph_vino vino;
+ u64 cap_id;
+ u64 size, max_size;
+ int check_caps = 0;
+ void *xattr_data = NULL;
+ int r;
+
+ dout(10, "handle_caps from mds%d\n", mds);
+
+ /* decode */
+ 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);
+ size = le64_to_cpu(h->size);
+ max_size = le64_to_cpu(h->max_size);
+
+ /* find session */
+ mutex_lock(&mdsc->mutex);
+ session = __ceph_lookup_mds_session(mdsc, mds);
+ mutex_unlock(&mdsc->mutex);
+ if (!session) {
+ dout(10, "WTF, got cap but no session for mds%d\n", mds);
+ return;
+ }
+
+ mutex_lock(&session->s_mutex);
+ session->s_seq++;
+ dout(20, " mds%d seq %lld\n", session->s_mds, session->s_seq);
+
+ /* lookup ino */
+ inode = ceph_find_inode(sb, vino);
+ dout(20, " op %s ino %llx inode %p\n", ceph_cap_op_name(op), vino.ino,
+ inode);
+ if (!inode) {
+ dout(10, " i don't have ino %llx, sending release\n", vino.ino);
+ goto release;
+ }
+
+ /* 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, h, session);
+ goto done;
+
+ case CEPH_CAP_OP_EXPORT:
+ handle_cap_export(inode, h, session);
+ if (list_empty(&session->s_caps))
+ ceph_mdsc_flushed_all_caps(mdsc, session);
+ goto done;
+
+ case CEPH_CAP_OP_IMPORT:
+ handle_cap_import(mdsc, inode, h, session,
+ msg->front.iov_base + sizeof(*h),
+ le32_to_cpu(h->snap_trace_len));
+ check_caps = 1; /* we may have sent a RELEASE to the old auth */
+ goto done;
+ }
+
+ /* preallocate space for xattrs? */
+ if (le32_to_cpu(h->xattr_len) > 4)
+ xattr_data = kmalloc(le32_to_cpu(h->xattr_len), GFP_NOFS);
+
+ /* the rest require a cap */
+ spin_lock(&inode->i_lock);
+ cap = __get_cap_for_mds(inode, mds);
+ if (!cap) {
+ dout(10, "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 release;
+ }
+
+ /* note that each of these drops i_lock for us */
+ switch (op) {
+ case CEPH_CAP_OP_GRANT:
+ r = handle_cap_grant(inode, h, session, cap,&xattr_data);
+ if (r == 1) {
+ dout(10, " sending reply back to mds%d\n", mds);
+ ceph_msg_get(msg);
+ ceph_send_msg_mds(mdsc, msg, mds);
+ } else if (r == 2) {
+ ceph_check_caps(ceph_inode(inode), 1, 0, session);
+ goto done_unlocked;
+ }
+ break;
+
+ case CEPH_CAP_OP_FLUSH_ACK:
+ handle_cap_flush_ack(inode, h, session, cap);
+ if (list_empty(&session->s_caps))
+ ceph_mdsc_flushed_all_caps(mdsc, session);
+ break;
+
+ case CEPH_CAP_OP_TRUNC:
+ handle_cap_trunc(inode, h, session);
+ break;
+
+ default:
+ spin_unlock(&inode->i_lock);
+ derr(10, " unknown cap op %d %s\n", op, ceph_cap_op_name(op));
+ }
+
+done:
+ mutex_unlock(&session->s_mutex);
+done_unlocked:
+ ceph_put_mds_session(session);
+
+ kfree(xattr_data);
+ if (check_caps)
+ ceph_check_caps(ceph_inode(inode), 1, 0, NULL);
+ if (inode)
+ iput(inode);
+ return;
+
+bad:
+ derr(10, "corrupt caps message\n");
+ return;
+
+release:
+ send_cap_msg(mdsc, vino.ino, cap_id, CEPH_CAP_OP_RELEASE,
+ 0, 0, 0,
+ seq, 0,
+ size, 0, NULL, NULL, 0,
+ 0, 0, 0,
+ 0, mds);
+ goto done;
+}
+
+/*
+ * 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;
+
+ dout(10, "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 (time_before(jiffies, ci->i_hold_caps_until))
+ break;
+ list_del_init(&ci->i_cap_delay_list);
+ spin_unlock(&mdsc->cap_delay_lock);
+ dout(10, "check_delayed_caps on %p\n", &ci->vfs_inode);
+ ceph_check_caps(ci, 1, 0, NULL);
+ iput(&ci->vfs_inode);
+ }
+ spin_unlock(&mdsc->cap_delay_lock);
+}
+
+/*
+ * Caller must hold session s_mutex.
+ *
+ * Note that _removals_ to s_rdcaps are protected by s_mutex and
+ * s_rdcaps_lock spinlock, but additions are protected only by
+ * s_rdcaps_lock (see ceph_put_fmode).
+ */
+void ceph_trim_session_rdcaps(struct ceph_mds_session *session)
+{
+ struct inode *inode;
+ struct ceph_cap *cap;
+ struct list_head *p, *n;
+
+ dout(10, "trim_rdcaps for mds%d\n", session->s_mds);
+ spin_lock(&session->s_rdcaps_lock);
+ list_for_each_safe(p, n, &session->s_rdcaps) {
+ int last_cap = 0;
+
+ cap = list_entry(p, struct ceph_cap, session_rdcaps);
+ spin_unlock(&session->s_rdcaps_lock);
+
+ inode = &cap->ci->vfs_inode;
+ spin_lock(&inode->i_lock);
+
+ if (time_before(jiffies, cap->expires)) {
+ dout(20, " stopping at %p cap %p expires %lu > %lu\n",
+ inode, cap, cap->expires, jiffies);
+ spin_unlock(&inode->i_lock);
+ } else {
+ dout(20, " dropping %p cap %p %s\n", inode, cap,
+ ceph_cap_string(cap->issued));
+ BUG_ON(__ceph_caps_wanted(cap->ci));
+ last_cap = __ceph_remove_cap(cap);
+ spin_unlock(&inode->i_lock);
+ if (last_cap)
+ iput(inode);
+ }
+
+ spin_lock(&session->s_rdcaps_lock);
+ }
+ spin_unlock(&session->s_rdcaps_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(20, "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++;
+
+ /* maybe turn caps into rdcaps? */
+ if (__ceph_caps_wanted(ci) == 0) {
+ struct rb_node *p;
+ struct ceph_cap *cap;
+
+ for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) {
+ cap = rb_entry(p, struct ceph_cap, ci_node);
+ __adjust_cap_rdcaps_listing(ci, cap, 0);
+ }
+ }
+ }
+ spin_unlock(&inode->i_lock);
+
+ if (last && ci->i_vino.snap == CEPH_NOSNAP)
+ ceph_check_caps(ci, 0, 0, NULL);
+}
--
1.5.6.5
--
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