diff options
Diffstat (limited to 'fs/ceph/caps.c')
| -rw-r--r-- | fs/ceph/caps.c | 2955 |
1 files changed, 2955 insertions, 0 deletions
diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c new file mode 100644 index 000000000000..aa2239fa9a3b --- /dev/null +++ b/fs/ceph/caps.c @@ -0,0 +1,2955 @@ +#include "ceph_debug.h" + +#include <linux/fs.h> +#include <linux/kernel.h> +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/vmalloc.h> +#include <linux/wait.h> +#include <linux/writeback.h> + +#include "super.h" +#include "decode.h" +#include "messenger.h" + +/* + * Capability management + * + * The Ceph metadata servers control client access to inode metadata + * and file data by issuing capabilities, granting clients permission + * to read and/or write both inode field and file data to OSDs + * (storage nodes). Each capability consists of a set of bits + * indicating which operations are allowed. + * + * If the client holds a *_SHARED cap, the client has a coherent value + * that can be safely read from the cached inode. + * + * In the case of a *_EXCL (exclusive) or FILE_WR capabilities, the + * client is allowed to change inode attributes (e.g., file size, + * mtime), note its dirty state in the ceph_cap, and asynchronously + * flush that metadata change to the MDS. + * + * In the event of a conflicting operation (perhaps by another + * client), the MDS will revoke the conflicting client capabilities. + * + * In order for a client to cache an inode, it must hold a capability + * with at least one MDS server. When inodes are released, release + * notifications are batched and periodically sent en masse to the MDS + * cluster to release server state. + */ + + +/* + * Generate readable cap strings for debugging output. + */ +#define MAX_CAP_STR 20 +static char cap_str[MAX_CAP_STR][40]; +static DEFINE_SPINLOCK(cap_str_lock); +static int last_cap_str; + +static char *gcap_string(char *s, int c) +{ + if (c & CEPH_CAP_GSHARED) + *s++ = 's'; + if (c & CEPH_CAP_GEXCL) + *s++ = 'x'; + if (c & CEPH_CAP_GCACHE) + *s++ = 'c'; + if (c & CEPH_CAP_GRD) + *s++ = 'r'; + if (c & CEPH_CAP_GWR) + *s++ = 'w'; + if (c & CEPH_CAP_GBUFFER) + *s++ = 'b'; + if (c & CEPH_CAP_GLAZYIO) + *s++ = 'l'; + return s; +} + +const char *ceph_cap_string(int caps) +{ + int i; + char *s; + int c; + + spin_lock(&cap_str_lock); + i = last_cap_str++; + if (last_cap_str == MAX_CAP_STR) + last_cap_str = 0; + spin_unlock(&cap_str_lock); + + s = cap_str[i]; + + if (caps & CEPH_CAP_PIN) + *s++ = 'p'; + + c = (caps >> CEPH_CAP_SAUTH) & 3; + if (c) { + *s++ = 'A'; + s = gcap_string(s, c); + } + + c = (caps >> CEPH_CAP_SLINK) & 3; + if (c) { + *s++ = 'L'; + s = gcap_string(s, c); + } + + c = (caps >> CEPH_CAP_SXATTR) & 3; + if (c) { + *s++ = 'X'; + s = gcap_string(s, c); + } + + c = caps >> CEPH_CAP_SFILE; + if (c) { + *s++ = 'F'; + s = gcap_string(s, c); + } + + if (s == cap_str[i]) + *s++ = '-'; + *s = 0; + return cap_str[i]; +} + +/* + * Cap reservations + * + * Maintain a global pool of preallocated struct ceph_caps, referenced + * by struct ceph_caps_reservations. This ensures that we preallocate + * memory needed to successfully process an MDS response. (If an MDS + * sends us cap information and we fail to process it, we will have + * problems due to the client and MDS being out of sync.) + * + * Reservations are 'owned' by a ceph_cap_reservation context. + */ +static spinlock_t caps_list_lock; +static struct list_head caps_list; /* unused (reserved or unreserved) */ +static int caps_total_count; /* total caps allocated */ +static int caps_use_count; /* in use */ +static int caps_reserve_count; /* unused, reserved */ +static int caps_avail_count; /* unused, unreserved */ +static int caps_min_count; /* keep at least this many (unreserved) */ + +void __init ceph_caps_init(void) +{ + INIT_LIST_HEAD(&caps_list); + spin_lock_init(&caps_list_lock); +} + +void ceph_caps_finalize(void) +{ + struct ceph_cap *cap; + + spin_lock(&caps_list_lock); + while (!list_empty(&caps_list)) { + cap = list_first_entry(&caps_list, struct ceph_cap, caps_item); + list_del(&cap->caps_item); + kmem_cache_free(ceph_cap_cachep, cap); + } + caps_total_count = 0; + caps_avail_count = 0; + caps_use_count = 0; + caps_reserve_count = 0; + caps_min_count = 0; + spin_unlock(&caps_list_lock); +} + +void ceph_adjust_min_caps(int delta) +{ + spin_lock(&caps_list_lock); + caps_min_count += delta; + BUG_ON(caps_min_count < 0); + spin_unlock(&caps_list_lock); +} + +int ceph_reserve_caps(struct ceph_cap_reservation *ctx, int need) +{ + int i; + struct ceph_cap *cap; + int have; + int alloc = 0; + LIST_HEAD(newcaps); + int ret = 0; + + dout("reserve caps ctx=%p need=%d\n", ctx, need); + + /* first reserve any caps that are already allocated */ + spin_lock(&caps_list_lock); + if (caps_avail_count >= need) + have = need; + else + have = caps_avail_count; + caps_avail_count -= have; + caps_reserve_count += have; + BUG_ON(caps_total_count != caps_use_count + caps_reserve_count + + caps_avail_count); + spin_unlock(&caps_list_lock); + + for (i = have; i < need; i++) { + cap = kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS); + if (!cap) { + ret = -ENOMEM; + goto out_alloc_count; + } + list_add(&cap->caps_item, &newcaps); + alloc++; + } + BUG_ON(have + alloc != need); + + spin_lock(&caps_list_lock); + caps_total_count += alloc; + caps_reserve_count += alloc; + list_splice(&newcaps, &caps_list); + + BUG_ON(caps_total_count != caps_use_count + caps_reserve_count + + caps_avail_count); + spin_unlock(&caps_list_lock); + + ctx->count = need; + dout("reserve caps ctx=%p %d = %d used + %d resv + %d avail\n", + ctx, caps_total_count, caps_use_count, caps_reserve_count, + caps_avail_count); + return 0; + +out_alloc_count: + /* we didn't manage to reserve as much as we needed */ + pr_warning("reserve caps ctx=%p ENOMEM need=%d got=%d\n", + ctx, need, have); + return ret; +} + +int ceph_unreserve_caps(struct ceph_cap_reservation *ctx) +{ + dout("unreserve caps ctx=%p count=%d\n", ctx, ctx->count); + if (ctx->count) { + spin_lock(&caps_list_lock); + BUG_ON(caps_reserve_count < ctx->count); + caps_reserve_count -= ctx->count; + caps_avail_count += ctx->count; + ctx->count = 0; + dout("unreserve caps %d = %d used + %d resv + %d avail\n", + caps_total_count, caps_use_count, caps_reserve_count, + caps_avail_count); + BUG_ON(caps_total_count != caps_use_count + caps_reserve_count + + caps_avail_count); + spin_unlock(&caps_list_lock); + } + return 0; +} + +static struct ceph_cap *get_cap(struct ceph_cap_reservation *ctx) +{ + struct ceph_cap *cap = NULL; + + /* temporary, until we do something about cap import/export */ + if (!ctx) + return kmem_cache_alloc(ceph_cap_cachep, GFP_NOFS); + + spin_lock(&caps_list_lock); + dout("get_cap ctx=%p (%d) %d = %d used + %d resv + %d avail\n", + ctx, ctx->count, caps_total_count, caps_use_count, + caps_reserve_count, caps_avail_count); + BUG_ON(!ctx->count); + BUG_ON(ctx->count > caps_reserve_count); + BUG_ON(list_empty(&caps_list)); + + ctx->count--; + caps_reserve_count--; + caps_use_count++; + + cap = list_first_entry(&caps_list, struct ceph_cap, caps_item); + list_del(&cap->caps_item); + + BUG_ON(caps_total_count != caps_use_count + caps_reserve_count + + caps_avail_count); + spin_unlock(&caps_list_lock); + return cap; +} + +void ceph_put_cap(struct ceph_cap *cap) +{ + spin_lock(&caps_list_lock); + dout("put_cap %p %d = %d used + %d resv + %d avail\n", + cap, caps_total_count, caps_use_count, + caps_reserve_count, caps_avail_count); + caps_use_count--; + /* + * Keep some preallocated caps around (ceph_min_count), to + * avoid lots of free/alloc churn. + */ + if (caps_avail_count >= caps_reserve_count + caps_min_count) { + caps_total_count--; + kmem_cache_free(ceph_cap_cachep, cap); + } else { + caps_avail_count++; + list_add(&cap->caps_item, &caps_list); + } + + BUG_ON(caps_total_count != caps_use_count + caps_reserve_count + + caps_avail_count); + spin_unlock(&caps_list_lock); +} + +void ceph_reservation_status(struct ceph_client *client, + int *total, int *avail, int *used, int *reserved, + int *min) +{ + if (total) + *total = caps_total_count; + if (avail) + *avail = caps_avail_count; + if (used) + *used = caps_use_count; + if (reserved) + *reserved = caps_reserve_count; + if (min) + *min = caps_min_count; +} + +/* + * Find ceph_cap for given mds, if any. + * + * Called with i_lock held. + */ +static struct ceph_cap *__get_cap_for_mds(struct ceph_inode_info *ci, int mds) +{ + struct ceph_cap *cap; + struct rb_node *n = ci->i_caps.rb_node; + + while (n) { + cap = rb_entry(n, struct ceph_cap, ci_node); + if (mds < cap->mds) + n = n->rb_left; + else if (mds > cap->mds) + n = n->rb_right; + else + return cap; + } + return NULL; +} + +/* + * Return id of any MDS with a cap, preferably FILE_WR|WRBUFFER|EXCL, else + * -1. + */ +static int __ceph_get_cap_mds(struct ceph_inode_info *ci, u32 *mseq) +{ + struct ceph_cap *cap; + int mds = -1; + struct rb_node *p; + + /* prefer mds with WR|WRBUFFER|EXCL caps */ + for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) { + cap = rb_entry(p, struct ceph_cap, ci_node); + mds = cap->mds; + if (mseq) + *mseq = cap->mseq; + if (cap->issued & (CEPH_CAP_FILE_WR | + CEPH_CAP_FILE_BUFFER | + CEPH_CAP_FILE_EXCL)) + break; + } + return mds; +} + +int ceph_get_cap_mds(struct inode *inode) +{ + int mds; + spin_lock(&inode->i_lock); + mds = __ceph_get_cap_mds(ceph_inode(inode), NULL); + spin_unlock(&inode->i_lock); + return mds; +} + +/* + * Called under i_lock. + */ +static void __insert_cap_node(struct ceph_inode_info *ci, + struct ceph_cap *new) +{ + struct rb_node **p = &ci->i_caps.rb_node; + struct rb_node *parent = NULL; + struct ceph_cap *cap = NULL; + + while (*p) { + parent = *p; + cap = rb_entry(parent, struct ceph_cap, ci_node); + if (new->mds < cap->mds) + p = &(*p)->rb_left; + else if (new->mds > cap->mds) + p = &(*p)->rb_right; + else + BUG(); + } + + rb_link_node(&new->ci_node, parent, p); + rb_insert_color(&new->ci_node, &ci->i_caps); +} + +/* + * (re)set cap hold timeouts, which control the delayed release + * of unused caps back to the MDS. Should be called on cap use. + */ +static void __cap_set_timeouts(struct ceph_mds_client *mdsc, + struct ceph_inode_info *ci) +{ + struct ceph_mount_args *ma = mdsc->client->mount_args; + + ci->i_hold_caps_min = round_jiffies(jiffies + + ma->caps_wanted_delay_min * HZ); + ci->i_hold_caps_max = round_jiffies(jiffies + + ma->caps_wanted_delay_max * HZ); + dout("__cap_set_timeouts %p min %lu max %lu\n", &ci->vfs_inode, + ci->i_hold_caps_min - jiffies, ci->i_hold_caps_max - jiffies); +} + +/* + * (Re)queue cap at the end of the delayed cap release list. + * + * If I_FLUSH is set, leave the inode at the front of the list. + * + * Caller holds i_lock + * -> we take mdsc->cap_delay_lock + */ +static void __cap_delay_requeue(struct ceph_mds_client *mdsc, + struct ceph_inode_info *ci) +{ + __cap_set_timeouts(mdsc, ci); + dout("__cap_delay_requeue %p flags %d at %lu\n", &ci->vfs_inode, + ci->i_ceph_flags, ci->i_hold_caps_max); + if (!mdsc->stopping) { + spin_lock(&mdsc->cap_delay_lock); + if (!list_empty(&ci->i_cap_delay_list)) { + if (ci->i_ceph_flags & CEPH_I_FLUSH) + goto no_change; + list_del_init(&ci->i_cap_delay_list); + } + list_add_tail(&ci->i_cap_delay_list, &mdsc->cap_delay_list); +no_change: + spin_unlock(&mdsc->cap_delay_lock); + } +} + +/* + * Queue an inode for immediate writeback. Mark inode with I_FLUSH, + * indicating we should send a cap message to flush dirty metadata + * asap, and move to the front of the delayed cap list. + */ +static void __cap_delay_requeue_front(struct ceph_mds_client *mdsc, + struct ceph_inode_info *ci) +{ + dout("__cap_delay_requeue_front %p\n", &ci->vfs_inode); + spin_lock(&mdsc->cap_delay_lock); + ci->i_ceph_flags |= CEPH_I_FLUSH; + if (!list_empty(&ci->i_cap_delay_list)) + list_del_init(&ci->i_cap_delay_list); + list_add(&ci->i_cap_delay_list, &mdsc->cap_delay_list); + spin_unlock(&mdsc->cap_delay_lock); +} + +/* + * Cancel delayed work on cap. + * + * Caller must hold i_lock. + */ +static void __cap_delay_cancel(struct ceph_mds_client *mdsc, + struct ceph_inode_info *ci) +{ + dout("__cap_delay_cancel %p\n", &ci->vfs_inode); + if (list_empty(&ci->i_cap_delay_list)) + return; + spin_lock(&mdsc->cap_delay_lock); + list_del_init(&ci->i_cap_delay_list); + spin_unlock(&mdsc->cap_delay_lock); +} + +/* + * Common issue checks for add_cap, handle_cap_grant. + */ +static void __check_cap_issue(struct ceph_inode_info *ci, struct ceph_cap *cap, + unsigned issued) +{ + unsigned had = __ceph_caps_issued(ci, NULL); + + /* + * Each time we receive FILE_CACHE anew, we increment + * i_rdcache_gen. + */ + if ((issued & CEPH_CAP_FILE_CACHE) && + (had & CEPH_CAP_FILE_CACHE) == 0) + ci->i_rdcache_gen++; + + /* + * if we are newly issued FILE_SHARED, clear I_COMPLETE; we + * don't know what happened to this directory while we didn't + * have the cap. + */ + if ((issued & CEPH_CAP_FILE_SHARED) && + (had & CEPH_CAP_FILE_SHARED) == 0) { + ci->i_shared_gen++; + if (S_ISDIR(ci->vfs_inode.i_mode)) { + dout(" marking %p NOT complete\n", &ci->vfs_inode); + ci->i_ceph_flags &= ~CEPH_I_COMPLETE; + } + } +} + +/* + * Add a capability under the given MDS session. + * + * Caller should hold session snap_rwsem (read) and s_mutex. + * + * @fmode is the open file mode, if we are opening a file, otherwise + * it is < 0. (This is so we can atomically add the cap and add an + * open file reference to it.) + */ +int ceph_add_cap(struct inode *inode, + struct ceph_mds_session *session, u64 cap_id, + int fmode, unsigned issued, unsigned wanted, + unsigned seq, unsigned mseq, u64 realmino, int flags, + struct ceph_cap_reservation *caps_reservation) +{ + struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc; + struct ceph_inode_info *ci = ceph_inode(inode); + struct ceph_cap *new_cap = NULL; + struct ceph_cap *cap; + int mds = session->s_mds; + int actual_wanted; + + dout("add_cap %p mds%d cap %llx %s seq %d\n", inode, + session->s_mds, cap_id, ceph_cap_string(issued), seq); + + /* + * If we are opening the file, include file mode wanted bits + * in wanted. + */ + if (fmode >= 0) + wanted |= ceph_caps_for_mode(fmode); + +retry: + spin_lock(&inode->i_lock); + cap = __get_cap_for_mds(ci, mds); + if (!cap) { + if (new_cap) { + cap = new_cap; + new_cap = NULL; + } else { + spin_unlock(&inode->i_lock); + new_cap = get_cap(caps_reservation); + if (new_cap == NULL) + return -ENOMEM; + goto retry; + } + + cap->issued = 0; + cap->implemented = 0; + cap->mds = mds; + cap->mds_wanted = 0; + + cap->ci = ci; + __insert_cap_node(ci, cap); + + /* clear out old exporting info? (i.e. on cap import) */ + if (ci->i_cap_exporting_mds == mds) { + ci->i_cap_exporting_issued = 0; + ci->i_cap_exporting_mseq = 0; + ci->i_cap_exporting_mds = -1; + } + + /* add to session cap list */ + cap->session = session; + spin_lock(&session->s_cap_lock); + list_add_tail(&cap->session_caps, &session->s_caps); + session->s_nr_caps++; + spin_unlock(&session->s_cap_lock); + } + + if (!ci->i_snap_realm) { + /* + * add this inode to the appropriate snap realm + */ + struct ceph_snap_realm *realm = ceph_lookup_snap_realm(mdsc, + realmino); + if (realm) { + ceph_get_snap_realm(mdsc, realm); + spin_lock(&realm->inodes_with_caps_lock); + ci->i_snap_realm = realm; + list_add(&ci->i_snap_realm_item, + &realm->inodes_with_caps); + spin_unlock(&realm->inodes_with_caps_lock); + } else { + pr_err("ceph_add_cap: couldn't find snap realm %llx\n", + realmino); + } + } + + __check_cap_issue(ci, cap, issued); + + /* + * If we are issued caps we don't want, or the mds' wanted + * value appears to be off, queue a check so we'll release + * later and/or update the mds wanted value. + */ + actual_wanted = __ceph_caps_wanted(ci); + if ((wanted & ~actual_wanted) || + (issued & ~actual_wanted & CEPH_CAP_ANY_WR)) { + dout(" issued %s, mds wanted %s, actual %s, queueing\n", + ceph_cap_string(issued), ceph_cap_string(wanted), + ceph_cap_string(actual_wanted)); + __cap_delay_requeue(mdsc, ci); + } + + if (flags & CEPH_CAP_FLAG_AUTH) + ci->i_auth_cap = cap; + else if (ci->i_auth_cap == cap) + ci->i_auth_cap = NULL; + + dout("add_cap inode %p (%llx.%llx) cap %p %s now %s seq %d mds%d\n", + inode, ceph_vinop(inode), cap, ceph_cap_string(issued), + ceph_cap_string(issued|cap->issued), seq, mds); + cap->cap_id = cap_id; + cap->issued = issued; + cap->implemented |= issued; + cap->mds_wanted |= wanted; + cap->seq = seq; + cap->issue_seq = seq; + cap->mseq = mseq; + cap->cap_gen = session->s_cap_gen; + + if (fmode >= 0) + __ceph_get_fmode(ci, fmode); + spin_unlock(&inode->i_lock); + wake_up(&ci->i_cap_wq); + return 0; +} + +/* + * Return true if cap has not timed out and belongs to the current + * generation of the MDS session (i.e. has not gone 'stale' due to + * us losing touch with the mds). + */ +static int __cap_is_valid(struct ceph_cap *cap) +{ + unsigned long ttl; + u32 gen; + + spin_lock(&cap->session->s_cap_lock); + gen = cap->session->s_cap_gen; + ttl = cap->session->s_cap_ttl; + spin_unlock(&cap->session->s_cap_lock); + + if (cap->cap_gen < gen || time_after_eq(jiffies, ttl)) { + dout("__cap_is_valid %p cap %p issued %s " + "but STALE (gen %u vs %u)\n", &cap->ci->vfs_inode, + cap, ceph_cap_string(cap->issued), cap->cap_gen, gen); + return 0; + } + + return 1; +} + +/* + * Return set of valid cap bits issued to us. Note that caps time + * out, and may be invalidated in bulk if the client session times out + * and session->s_cap_gen is bumped. + */ +int __ceph_caps_issued(struct ceph_inode_info *ci, int *implemented) +{ + int have = ci->i_snap_caps | ci->i_cap_exporting_issued; + struct ceph_cap *cap; + struct rb_node *p; + + if (implemented) + *implemented = 0; + for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) { + cap = rb_entry(p, struct ceph_cap, ci_node); + if (!__cap_is_valid(cap)) + continue; + dout("__ceph_caps_issued %p cap %p issued %s\n", + &ci->vfs_inode, cap, ceph_cap_string(cap->issued)); + have |= cap->issued; + if (implemented) + *implemented |= cap->implemented; + } + return have; +} + +/* + * Get cap bits issued by caps other than @ocap + */ +int __ceph_caps_issued_other(struct ceph_inode_info *ci, struct ceph_cap *ocap) +{ + int have = ci->i_snap_caps; + struct ceph_cap *cap; + struct rb_node *p; + + for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) { + cap = rb_entry(p, struct ceph_cap, ci_node); + if (cap == ocap) + continue; + if (!__cap_is_valid(cap)) + continue; + have |= cap->issued; + } + return have; +} + +/* + * Move a cap to the end of the LRU (oldest caps at list head, newest + * at list tail). + */ +static void __touch_cap(struct ceph_cap *cap) +{ + struct ceph_mds_session *s = cap->session; + + spin_lock(&s->s_cap_lock); + if (s->s_cap_iterator == NULL) { + dout("__touch_cap %p cap %p mds%d\n", &cap->ci->vfs_inode, cap, + s->s_mds); + list_move_tail(&cap->session_caps, &s->s_caps); + } else { + dout("__touch_cap %p cap %p mds%d NOP, iterating over caps\n", + &cap->ci->vfs_inode, cap, s->s_mds); + } + spin_unlock(&s->s_cap_lock); +} + +/* + * Check if we hold the given mask. If so, move the cap(s) to the + * front of their respective LRUs. (This is the preferred way for + * callers to check for caps they want.) + */ +int __ceph_caps_issued_mask(struct ceph_inode_info *ci, int mask, int touch) +{ + struct ceph_cap *cap; + struct rb_node *p; + int have = ci->i_snap_caps; + + if ((have & mask) == mask) { + dout("__ceph_caps_issued_mask %p snap issued %s" + " (mask %s)\n", &ci->vfs_inode, + ceph_cap_string(have), + ceph_cap_string(mask)); + return 1; + } + + for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) { + cap = rb_entry(p, struct ceph_cap, ci_node); + if (!__cap_is_valid(cap)) + continue; + if ((cap->issued & mask) == mask) { + dout("__ceph_caps_issued_mask %p cap %p issued %s" + " (mask %s)\n", &ci->vfs_inode, cap, + ceph_cap_string(cap->issued), + ceph_cap_string(mask)); + if (touch) + __touch_cap(cap); + return 1; + } + + /* does a combination of caps satisfy mask? */ + have |= cap->issued; + if ((have & mask) == mask) { + dout("__ceph_caps_issued_mask %p combo issued %s" + " (mask %s)\n", &ci->vfs_inode, + ceph_cap_string(cap->issued), + ceph_cap_string(mask)); + if (touch) { + struct rb_node *q; + + /* touch this + preceeding caps */ + __touch_cap(cap); + for (q = rb_first(&ci->i_caps); q != p; + q = rb_next(q)) { + cap = rb_entry(q, struct ceph_cap, + ci_node); + if (!__cap_is_valid(cap)) + continue; + __touch_cap(cap); + } + } + return 1; + } + } + + return 0; +} + +/* + * Return true if mask caps are currently being revoked by an MDS. + */ +int ceph_caps_revoking(struct ceph_inode_info *ci, int mask) +{ + struct inode *inode = &ci->vfs_inode; + struct ceph_cap *cap; + struct rb_node *p; + int ret = 0; + + spin_lock(&inode->i_lock); + for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) { + cap = rb_entry(p, struct ceph_cap, ci_node); + if (__cap_is_valid(cap) && + (cap->implemented & ~cap->issued & mask)) { + ret = 1; + break; + } + } + spin_unlock(&inode->i_lock); + dout("ceph_caps_revoking %p %s = %d\n", inode, + ceph_cap_string(mask), ret); + return ret; +} + +int __ceph_caps_used(struct ceph_inode_info *ci) +{ + int used = 0; + if (ci->i_pin_ref) + used |= CEPH_CAP_PIN; + if (ci->i_rd_ref) + used |= CEPH_CAP_FILE_RD; + if (ci->i_rdcache_ref || ci->i_rdcache_gen) + used |= CEPH_CAP_FILE_CACHE; + if (ci->i_wr_ref) + used |= CEPH_CAP_FILE_WR; + if (ci->i_wrbuffer_ref) + used |= CEPH_CAP_FILE_BUFFER; + return used; +} + +/* + * wanted, by virtue of open file modes + */ +int __ceph_caps_file_wanted(struct ceph_inode_info *ci) +{ + int want = 0; + int mode; + for (mode = 0; mode < 4; mode++) + if (ci->i_nr_by_mode[mode]) + want |= ceph_caps_for_mode(mode); + return want; +} + +/* + * Return caps we have registered with the MDS(s) as 'wanted'. + */ +int __ceph_caps_mds_wanted(struct ceph_inode_info *ci) +{ + struct ceph_cap *cap; + struct rb_node *p; + int mds_wanted = 0; + + for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) { + cap = rb_entry(p, struct ceph_cap, ci_node); + if (!__cap_is_valid(cap)) + continue; + mds_wanted |= cap->mds_wanted; + } + return mds_wanted; +} + +/* + * called under i_lock + */ +static int __ceph_is_any_caps(struct ceph_inode_info *ci) +{ + return !RB_EMPTY_ROOT(&ci->i_caps) || ci->i_cap_exporting_mds >= 0; +} + +/* + * caller should hold i_lock. + * caller will not hold session s_mutex if called from destroy_inode. + */ +void __ceph_remove_cap(struct ceph_cap *cap) +{ + struct ceph_mds_session *session = cap->session; + struct ceph_inode_info *ci = cap->ci; + struct ceph_mds_client *mdsc = &ceph_client(ci->vfs_inode.i_sb)->mdsc; + + dout("__ceph_remove_cap %p from %p\n", cap, &ci->vfs_inode); + + /* remove from inode list */ + rb_erase(&cap->ci_node, &ci->i_caps); + cap->ci = NULL; + if (ci->i_auth_cap == cap) + ci->i_auth_cap = NULL; + + /* 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; + } + spin_unlock(&session->s_cap_lock); + + if (cap->session == NULL) + ceph_put_cap(cap); + + if (!__ceph_is_any_caps(ci) && ci->i_snap_realm) { + struct ceph_snap_realm *realm = ci->i_snap_realm; + spin_lock(&realm->inodes_with_caps_lock); + list_del_init(&ci->i_snap_realm_item); + ci->i_snap_realm_counter++; + ci->i_snap_realm = NULL; + spin_unlock(&realm->inodes_with_caps_lock); + ceph_put_snap_realm(mdsc, realm); + } + if (!__ceph_is_any_real_caps(ci)) + __cap_delay_cancel(mdsc, ci); +} + +/* + * Build and send a cap message to the given MDS. + * + * Caller should be holding s_mutex. + */ +static int send_cap_msg(struct ceph_mds_session *session, + u64 ino, u64 cid, int op, + int caps, int wanted, int dirty, + u32 seq, u64 flush_tid, u32 issue_seq, u32 mseq, + u64 size, u64 max_size, + struct timespec *mtime, struct timespec *atime, + u64 time_warp_seq, + uid_t uid, gid_t gid, mode_t mode, + u64 xattr_version, + struct ceph_buffer *xattrs_buf, + u64 follows) +{ + struct ceph_mds_caps *fc; + struct ceph_msg *msg; + + dout("send_cap_msg %s %llx %llx caps %s wanted %s dirty %s" + " seq %u/%u mseq %u follows %lld size %llu/%llu" + " xattr_ver %llu xattr_len %d\n", ceph_cap_op_name(op), + cid, ino, ceph_cap_string(caps), ceph_cap_string(wanted), + ceph_cap_string(dirty), + seq, issue_seq, mseq, follows, size, max_size, + xattr_version, xattrs_buf ? (int)xattrs_buf->vec.iov_len : 0); + + msg = ceph_msg_new(CEPH_MSG_CLIENT_CAPS, sizeof(*fc), 0, 0, NULL); + if (IS_ERR(msg)) + return PTR_ERR(msg); + + msg->hdr.tid = cpu_to_le64(flush_tid); + + fc = msg->front.iov_base; + memset(fc, 0, sizeof(*fc)); + + fc->cap_id = cpu_to_le64(cid); + fc->op = cpu_to_le32(op); + fc->seq = cpu_to_le32(seq); + fc->issue_seq = cpu_to_le32(issue_seq); + fc->migrate_seq = cpu_to_le32(mseq); + fc->caps = cpu_to_le32(caps); + fc->wanted = cpu_to_le32(wanted); + fc->dirty = cpu_to_le32(dirty); + fc->ino = cpu_to_le64(ino); + fc->snap_follows = cpu_to_le64(follows); + + fc->size = cpu_to_le64(size); + fc->max_size = cpu_to_le64(max_size); + if (mtime) + ceph_encode_timespec(&fc->mtime, mtime); + if (atime) + ceph_encode_timespec(&fc->atime, atime); + fc->time_warp_seq = cpu_to_le32(time_warp_seq); + + fc->uid = cpu_to_le32(uid); + fc->gid = cpu_to_le32(gid); + fc->mode = cpu_to_le32(mode); + + fc->xattr_version = cpu_to_le64(xattr_version); + if (xattrs_buf) { + msg->middle = ceph_buffer_get(xattrs_buf); + fc->xattr_len = cpu_to_le32(xattrs_buf->vec.iov_len); + msg->hdr.middle_len = cpu_to_le32(xattrs_buf->vec.iov_len); + } + + ceph_con_send(&session->s_con, msg); + return 0; +} + +/* + * Queue cap releases when an inode is dropped from our cache. Since + * inode is about to be destroyed, there is no need for i_lock. + */ +void ceph_queue_caps_release(struct inode *inode) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + struct rb_node *p; + + p = rb_first(&ci->i_caps); + while (p) { + struct ceph_cap *cap = rb_entry(p, struct ceph_cap, ci_node); + struct ceph_mds_session *session = cap->session; + struct ceph_msg *msg; + struct ceph_mds_cap_release *head; + struct ceph_mds_cap_item *item; + + spin_lock(&session->s_cap_lock); + BUG_ON(!session->s_num_cap_releases); + msg = list_first_entry(&session->s_cap_releases, + struct ceph_msg, list_head); + + dout(" adding %p release to mds%d msg %p (%d left)\n", + inode, session->s_mds, msg, session->s_num_cap_releases); + + BUG_ON(msg->front.iov_len + sizeof(*item) > PAGE_CACHE_SIZE); + head = msg->front.iov_base; + head->num = cpu_to_le32(le32_to_cpu(head->num) + 1); + item = msg->front.iov_base + msg->front.iov_len; + item->ino = cpu_to_le64(ceph_ino(inode)); + item->cap_id = cpu_to_le64(cap->cap_id); + item->migrate_seq = cpu_to_le32(cap->mseq); + item->seq = cpu_to_le32(cap->issue_seq); + + session->s_num_cap_releases--; + + msg->front.iov_len += sizeof(*item); + if (le32_to_cpu(head->num) == CEPH_CAPS_PER_RELEASE) { + dout(" release msg %p full\n", msg); + list_move_tail(&msg->list_head, + &session->s_cap_releases_done); + } else { + dout(" release msg %p at %d/%d (%d)\n", msg, + (int)le32_to_cpu(head->num), + (int)CEPH_CAPS_PER_RELEASE, + (int)msg->front.iov_len); + } + spin_unlock(&session->s_cap_lock); + p = rb_next(p); + __ceph_remove_cap(cap); + } +} + +/* + * Send a cap msg on the given inode. Update our caps state, then + * drop i_lock and send the message. + * + * Make note of max_size reported/requested from mds, revoked caps + * that have now been implemented. + * + * Make half-hearted attempt ot to invalidate page cache if we are + * dropping RDCACHE. Note that this will leave behind locked pages + * that we'll then need to deal with elsewhere. + * + * Return non-zero if delayed release, or we experienced an error + * such that the caller should requeue + retry later. + * + * called with i_lock, then drops it. + * caller should hold snap_rwsem (read), s_mutex. + */ +static int __send_cap(struct ceph_mds_client *mdsc, struct ceph_cap *cap, + int op, int used, int want, int retain, int flushing, + unsigned *pflush_tid) + __releases(cap->ci->vfs_inode->i_lock) +{ + struct ceph_inode_info *ci = cap->ci; + struct inode *inode = &ci->vfs_inode; + u64 cap_id = cap->cap_id; + int held, revoking, dropping, keep; + u64 seq, issue_seq, mseq, time_warp_seq, follows; + u64 size, max_size; + struct timespec mtime, atime; + int wake = 0; + mode_t mode; + uid_t uid; + gid_t gid; + struct ceph_mds_session *session; + u64 xattr_version = 0; + int delayed = 0; + u64 flush_tid = 0; + int i; + int ret; + + held = cap->issued | cap->implemented; + revoking = cap->implemented & ~cap->issued; + retain &= ~revoking; + dropping = cap->issued & ~retain; + + dout("__send_cap %p cap %p session %p %s -> %s (revoking %s)\n", + inode, cap, cap->session, + ceph_cap_string(held), ceph_cap_string(held & retain), + ceph_cap_string(revoking)); + BUG_ON((retain & CEPH_CAP_PIN) == 0); + + session = cap->session; + + /* don't release wanted unless we've waited a bit. */ + if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 && + time_before(jiffies, ci->i_hold_caps_min)) { + dout(" delaying issued %s -> %s, wanted %s -> %s on send\n", + ceph_cap_string(cap->issued), + ceph_cap_string(cap->issued & retain), + ceph_cap_string(cap->mds_wanted), + ceph_cap_string(want)); + want |= cap->mds_wanted; + retain |= cap->issued; + delayed = 1; + } + ci->i_ceph_flags &= ~(CEPH_I_NODELAY | CEPH_I_FLUSH); + + cap->issued &= retain; /* drop bits we don't want */ + if (cap->implemented & ~cap->issued) { + /* + * Wake up any waiters on wanted -> needed transition. + * This is due to the weird transition from buffered + * to sync IO... we need to flush dirty pages _before_ + * allowing sync writes to avoid reordering. + */ + wake = 1; + } + cap->implemented &= cap->issued | used; + cap->mds_wanted = want; + + if (flushing) { + /* + * assign a tid for flush operations so we can avoid + * flush1 -> dirty1 -> flush2 -> flushack1 -> mark + * clean type races. track latest tid for every bit + * so we can handle flush AxFw, flush Fw, and have the + * first ack clean Ax. + */ + flush_tid = ++ci->i_cap_flush_last_tid; + if (pflush_tid) + *pflush_tid = flush_tid; + dout(" cap_flush_tid %d\n", (int)flush_tid); + for (i = 0; i < CEPH_CAP_BITS; i++) + if (flushing & (1 << i)) + ci->i_cap_flush_tid[i] = flush_tid; + } + + keep = cap->implemented; + seq = cap->seq; + issue_seq = cap->issue_seq; + mseq = cap->mseq; + size = inode->i_size; + ci->i_reported_size = size; + max_size = ci->i_wanted_max_size; + ci->i_requested_max_size = max_size; + mtime = inode->i_mtime; + atime = inode->i_atime; + time_warp_seq = ci->i_time_warp_seq; + follows = ci->i_snap_realm->cached_context->seq; + uid = inode->i_uid; + gid = inode->i_gid; + mode = inode->i_mode; + + if (dropping & CEPH_CAP_XATTR_EXCL) { + __ceph_build_xattrs_blob(ci); + xattr_version = ci->i_xattrs.version + 1; + } + + spin_unlock(&inode->i_lock); + + ret = send_cap_msg(session, ceph_vino(inode).ino, cap_id, + op, keep, want, flushing, seq, flush_tid, issue_seq, mseq, + size, max_size, &mtime, &atime, time_warp_seq, + uid, gid, mode, + xattr_version, + (flushing & CEPH_CAP_XATTR_EXCL) ? ci->i_xattrs.blob : NULL, + follows); + if (ret < 0) { + dout("error sending cap msg, must requeue %p\n", inode); + delayed = 1; + } + + if (wake) + wake_up(&ci->i_cap_wq); + + return delayed; +} + +/* + * When a snapshot is taken, clients accumulate dirty metadata on + * inodes with capabilities in ceph_cap_snaps to describe the file + * state at the time the snapshot was taken. This must be flushed + * asynchronously back to the MDS once sync writes complete and dirty + * data is written out. + * + * Called under i_lock. Takes s_mutex as needed. + */ +void __ceph_flush_snaps(struct ceph_inode_info *ci, + struct ceph_mds_session **psession) +{ + struct inode *inode = &ci->vfs_inode; + int mds; + struct ceph_cap_snap *capsnap; + u32 mseq; + struct ceph_mds_client *mdsc = &ceph_inode_to_client(inode)->mdsc; + struct ceph_mds_session *session = NULL; /* if session != NULL, we hold + session->s_mutex */ + u64 next_follows = 0; /* keep track of how far we've gotten through the + i_cap_snaps list, and skip these entries next time + around to avoid an infinite loop */ + + if (psession) + session = *psession; + + dout("__flush_snaps %p\n", inode); +retry: + list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { + /* avoid an infiniute loop after retry */ + if (capsnap->follows < next_follows) + continue; + /* + * we need to wait for sync writes to complete and for dirty + * pages to be written out. + */ + if (capsnap->dirty_pages || capsnap->writing) + continue; + + /* + * if cap writeback already occurred, we should have dropped + * the capsnap in ceph_put_wrbuffer_cap_refs. + */ + BUG_ON(capsnap->dirty == 0); + + /* pick mds, take s_mutex */ + mds = __ceph_get_cap_mds(ci, &mseq); + if (session && session->s_mds != mds) { + dout("oops, wrong session %p mutex\n", session); + mutex_unlock(&session->s_mutex); + ceph_put_mds_session(session); + session = NULL; + } + if (!session) { + spin_unlock(&inode->i_lock); + mutex_lock(&mdsc->mutex); + session = __ceph_lookup_mds_session(mdsc, mds); + mutex_unlock(&mdsc->mutex); + if (session) { + dout("inverting session/ino locks on %p\n", + session); + mutex_lock(&session->s_mutex); + } + /* + * if session == NULL, we raced against a cap + * deletion. retry, and we'll get a better + * @mds value next time. + */ + spin_lock(&inode->i_lock); + goto retry; + } + + capsnap->flush_tid = ++ci->i_cap_flush_last_tid; + atomic_inc(&capsnap->nref); + if (!list_empty(&capsnap->flushing_item)) + list_del_init(&capsnap->flushing_item); + list_add_tail(&capsnap->flushing_item, + &session->s_cap_snaps_flushing); + spin_unlock(&inode->i_lock); + + dout("flush_snaps %p cap_snap %p follows %lld size %llu\n", + inode, capsnap, next_follows, capsnap->size); + send_cap_msg(session, ceph_vino(inode).ino, 0, + CEPH_CAP_OP_FLUSHSNAP, capsnap->issued, 0, + capsnap->dirty, 0, capsnap->flush_tid, 0, mseq, + capsnap->size, 0, + &capsnap->mtime, &capsnap->atime, + capsnap->time_warp_seq, + capsnap->uid, capsnap->gid, capsnap->mode, + 0, NULL, + capsnap->follows); + + next_follows = capsnap->follows + 1; + ceph_put_cap_snap(capsnap); + + spin_lock(&inode->i_lock); + goto retry; + } + + /* we flushed them all; remove this inode from the queue */ + spin_lock(&mdsc->snap_flush_lock); + list_del_init(&ci->i_snap_flush_item); + spin_unlock(&mdsc->snap_flush_lock); + + if (psession) + *psession = session; + else if (session) { + mutex_unlock(&session->s_mutex); + ceph_put_mds_session(session); + } +} + +static void ceph_flush_snaps(struct ceph_inode_info *ci) +{ + struct inode *inode = &ci->vfs_inode; + + spin_lock(&inode->i_lock); + __ceph_flush_snaps(ci, NULL); + spin_unlock(&inode->i_lock); +} + +/* + * Mark caps dirty. If inode is newly dirty, add to the global dirty + * list. + */ +void __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask) +{ + struct ceph_mds_client *mdsc = &ceph_client(ci->vfs_inode.i_sb)->mdsc; + struct inode *inode = &ci->vfs_inode; + int was = ci->i_dirty_caps; + int dirty = 0; + + dout("__mark_dirty_caps %p %s dirty %s -> %s\n", &ci->vfs_inode, + ceph_cap_string(mask), ceph_cap_string(was), + ceph_cap_string(was | mask)); + ci->i_dirty_caps |= mask; + if (was == 0) { + dout(" inode %p now dirty\n", &ci->vfs_inode); + BUG_ON(!list_empty(&ci->i_dirty_item)); + spin_lock(&mdsc->cap_dirty_lock); + list_add(&ci->i_dirty_item, &mdsc->cap_dirty); + spin_unlock(&mdsc->cap_dirty_lock); + if (ci->i_flushing_caps == 0) { + igrab(inode); + dirty |= I_DIRTY_SYNC; + } + } + BUG_ON(list_empty(&ci->i_dirty_item)); + if (((was | ci->i_flushing_caps) & CEPH_CAP_FILE_BUFFER) && + (mask & CEPH_CAP_FILE_BUFFER)) + dirty |= I_DIRTY_DATASYNC; + if (dirty) + __mark_inode_dirty(inode, dirty); + __cap_delay_requeue(mdsc, ci); +} + +/* + * Add dirty inode to the flushing list. Assigned a seq number so we + * can wait for caps to flush without starving. + * + * Called under i_lock. + */ +static int __mark_caps_flushing(struct inode *inode, + struct ceph_mds_session *session) +{ + struct ceph_mds_client *mdsc = &ceph_client(inode->i_sb)->mdsc; + struct ceph_inode_info *ci = ceph_inode(inode); + int flushing; + + BUG_ON(ci->i_dirty_caps == 0); + BUG_ON(list_empty(&ci->i_dirty_item)); + + flushing = ci->i_dirty_caps; + dout("__mark_caps_flushing flushing %s, flushing_caps %s -> %s\n", + ceph_cap_string(flushing), + ceph_cap_string(ci->i_flushing_caps), + ceph_cap_string(ci->i_flushing_caps | flushing)); + ci->i_flushing_caps |= flushing; + ci->i_dirty_caps = 0; + dout(" inode %p now !dirty\n", inode); + + spin_lock(&mdsc->cap_dirty_lock); + list_del_init(&ci->i_dirty_item); + + ci->i_cap_flush_seq = ++mdsc->cap_flush_seq; + if (list_empty(&ci->i_flushing_item)) { + list_add_tail(&ci->i_flushing_item, &session->s_cap_flushing); + mdsc->num_cap_flushing++; + dout(" inode %p now flushing seq %lld\n", inode, + ci->i_cap_flush_seq); + } else { + list_move_tail(&ci->i_flushing_item, &session->s_cap_flushing); + dout(" inode %p now flushing (more) seq %lld\n", inode, + ci->i_cap_flush_seq); + } + spin_unlock(&mdsc->cap_dirty_lock); + + return flushing; +} + +/* + * try to invalidate mapping pages without blocking. + */ +static int mapping_is_empty(struct address_space *mapping) +{ + struct page *page = find_get_page(mapping, 0); + + if (!page) + return 1; + + put_page(page); + return 0; +} + +static int try_nonblocking_invalidate(struct inode *inode) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + u32 invalidating_gen = ci->i_rdcache_gen; + + spin_unlock(&inode->i_lock); + invalidate_mapping_pages(&inode->i_data, 0, -1); + spin_lock(&inode->i_lock); + + if (mapping_is_empty(&inode->i_data) && + invalidating_gen == ci->i_rdcache_gen) { + /* success. */ + dout("try_nonblocking_invalidate %p success\n", inode); + ci->i_rdcache_gen = 0; + ci->i_rdcache_revoking = 0; + return 0; + } + dout("try_nonblocking_invalidate %p failed\n", inode); + return -1; +} + +/* + * Swiss army knife function to examine currently used and wanted + * versus held caps. Release, flush, ack revoked caps to mds as + * appropriate. + * + * CHECK_CAPS_NODELAY - caller is delayed work and we should not delay + * cap release further. + * CHECK_CAPS_AUTHONLY - we should only check the auth cap + * CHECK_CAPS_FLUSH - we should flush any dirty caps immediately, without + * further delay. + */ +void ceph_check_caps(struct ceph_inode_info *ci, int flags, + struct ceph_mds_session *session) + __releases(session->s_mutex) +{ + struct ceph_client *client = ceph_inode_to_client(&ci->vfs_inode); + struct ceph_mds_client *mdsc = &client->mdsc; + struct inode *inode = &ci->vfs_inode; + struct ceph_cap *cap; + int file_wanted, used; + int took_snap_rwsem = 0; /* true if mdsc->snap_rwsem held */ + int issued, implemented, want, retain, revoking, flushing = 0; + int mds = -1; /* keep track of how far we've gone through i_caps list + to avoid an infinite loop on retry */ + struct rb_node *p; + int tried_invalidate = 0; + int delayed = 0, sent = 0, force_requeue = 0, num; + int queue_invalidate = 0; + int is_delayed = flags & CHECK_CAPS_NODELAY; + + /* if we are unmounting, flush any unused caps immediately. */ + if (mdsc->stopping) + is_delayed = 1; + + spin_lock(&inode->i_lock); + + if (ci->i_ceph_flags & CEPH_I_FLUSH) + flags |= CHECK_CAPS_FLUSH; + + /* flush snaps first time around only */ + if (!list_empty(&ci->i_cap_snaps)) + __ceph_flush_snaps(ci, &session); + goto retry_locked; +retry: + spin_lock(&inode->i_lock); +retry_locked: + file_wanted = __ceph_caps_file_wanted(ci); + used = __ceph_caps_used(ci); + want = file_wanted | used; + issued = __ceph_caps_issued(ci, &implemented); + revoking = implemented & ~issued; + + retain = want | CEPH_CAP_PIN; + if (!mdsc->stopping && inode->i_nlink > 0) { + if (want) { + retain |= CEPH_CAP_ANY; /* be greedy */ + } else { + retain |= CEPH_CAP_ANY_SHARED; + /* + * keep RD only if we didn't have the file open RW, + * because then the mds would revoke it anyway to + * journal max_size=0. + */ + if (ci->i_max_size == 0) + retain |= CEPH_CAP_ANY_RD; + } + } + + dout("check_caps %p file_want %s used %s dirty %s flushing %s" + " issued %s revoking %s retain %s %s%s%s\n", inode, + ceph_cap_string(file_wanted), + ceph_cap_string(used), ceph_cap_string(ci->i_dirty_caps), + ceph_cap_string(ci->i_flushing_caps), + ceph_cap_string(issued), ceph_cap_string(revoking), + ceph_cap_string(retain), + (flags & CHECK_CAPS_AUTHONLY) ? " AUTHONLY" : "", + (flags & CHECK_CAPS_NODELAY) ? " NODELAY" : "", + (flags & CHECK_CAPS_FLUSH) ? " FLUSH" : ""); + + /* + * If we no longer need to hold onto old our caps, and we may + * have cached pages, but don't want them, then try to invalidate. + * If we fail, it's because pages are locked.... try again later. + */ + if ((!is_delayed || mdsc->stopping) && + ci->i_wrbuffer_ref == 0 && /* no dirty pages... */ + ci->i_rdcache_gen && /* may have cached pages */ + (file_wanted == 0 || /* no open files */ + (revoking & CEPH_CAP_FILE_CACHE)) && /* or revoking cache */ + !tried_invalidate) { + dout("check_caps trying to invalidate on %p\n", inode); + if (try_nonblocking_invalidate(inode) < 0) { + if (revoking & CEPH_CAP_FILE_CACHE) { + dout("check_caps queuing invalidate\n"); + queue_invalidate = 1; + ci->i_rdcache_revoking = ci->i_rdcache_gen; + } else { + dout("check_caps failed to invalidate pages\n"); + /* we failed to invalidate pages. check these + caps again later. */ + force_requeue = 1; + __cap_set_timeouts(mdsc, ci); + } + } + tried_invalidate = 1; + goto retry_locked; + } + + num = 0; + for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) { + cap = rb_entry(p, struct ceph_cap, ci_node); + num++; + + /* avoid looping forever */ + if (mds >= cap->mds || + ((flags & CHECK_CAPS_AUTHONLY) && cap != ci->i_auth_cap)) + continue; + + /* NOTE: no side-effects allowed, until we take s_mutex */ + + revoking = cap->implemented & ~cap->issued; + if (revoking) + dout(" mds%d revoking %s\n", cap->mds, + ceph_cap_string(revoking)); + + if (cap == ci->i_auth_cap && + (cap->issued & CEPH_CAP_FILE_WR)) { + /* request larger max_size from MDS? */ + if (ci->i_wanted_max_size > ci->i_max_size && + ci->i_wanted_max_size > ci->i_requested_max_size) { + dout("requesting new max_size\n"); + goto ack; + } + + /* approaching file_max? */ + if ((inode->i_size << 1) >= ci->i_max_size && + (ci->i_reported_size << 1) < ci->i_max_size) { + dout("i_size approaching max_size\n"); + goto ack; + } + } + /* flush anything dirty? */ + if (cap == ci->i_auth_cap && (flags & CHECK_CAPS_FLUSH) && + ci->i_dirty_caps) { + dout("flushing dirty caps\n"); + goto ack; + } + + /* completed revocation? going down and there are no caps? */ + if (revoking && (revoking & used) == 0) { + dout("completed revocation of %s\n", + ceph_cap_string(cap->implemented & ~cap->issued)); + goto ack; + } + + /* want more caps from mds? */ + if (want & ~(cap->mds_wanted | cap->issued)) + goto ack; + + /* things we might delay */ + if ((cap->issued & ~retain) == 0 && + cap->mds_wanted == want) + continue; /* nope, all good */ + + if (is_delayed) + goto ack; + + /* delay? */ + if ((ci->i_ceph_flags & CEPH_I_NODELAY) == 0 && + time_before(jiffies, ci->i_hold_caps_max)) { + dout(" delaying issued %s -> %s, wanted %s -> %s\n", + ceph_cap_string(cap->issued), + ceph_cap_string(cap->issued & retain), + ceph_cap_string(cap->mds_wanted), + ceph_cap_string(want)); + delayed++; + continue; + } + +ack: + if (ci->i_ceph_flags & CEPH_I_NOFLUSH) { + dout(" skipping %p I_NOFLUSH set\n", inode); + continue; + } + + if (session && session != cap->session) { + dout("oops, wrong session %p mutex\n", session); + mutex_unlock(&session->s_mutex); + session = NULL; + } + if (!session) { + session = cap->session; + if (mutex_trylock(&session->s_mutex) == 0) { + dout("inverting session/ino locks on %p\n", + session); + spin_unlock(&inode->i_lock); + if (took_snap_rwsem) { + up_read(&mdsc->snap_rwsem); + took_snap_rwsem = 0; + } + mutex_lock(&session->s_mutex); + goto retry; + } + } + /* take snap_rwsem after session mutex */ + if (!took_snap_rwsem) { + if (down_read_trylock(&mdsc->snap_rwsem) == 0) { + dout("inverting snap/in locks on %p\n", + inode); + spin_unlock(&inode->i_lock); + down_read(&mdsc->snap_rwsem); + took_snap_rwsem = 1; + goto retry; + } + took_snap_rwsem = 1; + } + + if (cap == ci->i_auth_cap && ci->i_dirty_caps) + flushing = __mark_caps_flushing(inode, session); + + mds = cap->mds; /* remember mds, so we don't repeat */ + sent++; + + /* __send_cap drops i_lock */ + delayed += __send_cap(mdsc, cap, CEPH_CAP_OP_UPDATE, used, want, + retain, flushing, NULL); + goto retry; /* retake i_lock and restart our cap scan. */ + } + + /* + * Reschedule delayed caps release if we delayed anything, + * otherwise cancel. + */ + if (delayed && is_delayed) + force_requeue = 1; /* __send_cap delayed release; requeue */ + if (!delayed && !is_delayed) + __cap_delay_cancel(mdsc, ci); + else if (!is_delayed || force_requeue) + __cap_delay_requeue(mdsc, ci); + + spin_unlock(&inode->i_lock); + + if (queue_invalidate) + ceph_queue_invalidate(inode); + + if (session) + mutex_unlock(&session->s_mutex); + if (took_snap_rwsem) + up_read(&mdsc->snap_rwsem); +} + +/* + * Try to flush dirty caps back to the auth mds. + */ +static int try_flush_caps(struct inode *inode, struct ceph_mds_session *session, + unsigned *flush_tid) +{ + struct ceph_mds_client *mdsc = &ceph_client(inode->i_sb)->mdsc; + struct ceph_inode_info *ci = ceph_inode(inode); + int unlock_session = session ? 0 : 1; + int flushing = 0; + +retry: + spin_lock(&inode->i_lock); + if (ci->i_ceph_flags & CEPH_I_NOFLUSH) { + dout("try_flush_caps skipping %p I_NOFLUSH set\n", inode); + goto out; + } + if (ci->i_dirty_caps && ci->i_auth_cap) { + struct ceph_cap *cap = ci->i_auth_cap; + int used = __ceph_caps_used(ci); + int want = __ceph_caps_wanted(ci); + int delayed; + + if (!session) { + spin_unlock(&inode->i_lock); + session = cap->session; + mutex_lock(&session->s_mutex); + goto retry; + } + BUG_ON(session != cap->session); + if (cap->session->s_state < CEPH_MDS_SESSION_OPEN) + goto out; + + flushing = __mark_caps_flushing(inode, session); + + /* __send_cap drops i_lock */ + delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH, used, want, + cap->issued | cap->implemented, flushing, + flush_tid); + if (!delayed) + goto out_unlocked; + + spin_lock(&inode->i_lock); + __cap_delay_requeue(mdsc, ci); + } +out: + spin_unlock(&inode->i_lock); +out_unlocked: + if (session && unlock_session) + mutex_unlock(&session->s_mutex); + return flushing; +} + +/* + * Return true if we've flushed caps through the given flush_tid. + */ +static int caps_are_flushed(struct inode *inode, unsigned tid) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + int dirty, i, ret = 1; + + spin_lock(&inode->i_lock); + dirty = __ceph_caps_dirty(ci); + for (i = 0; i < CEPH_CAP_BITS; i++) + if ((ci->i_flushing_caps & (1 << i)) && + ci->i_cap_flush_tid[i] <= tid) { + /* still flushing this bit */ + ret = 0; + break; + } + spin_unlock(&inode->i_lock); + return ret; +} + +/* + * Wait on any unsafe replies for the given inode. First wait on the + * newest request, and make that the upper bound. Then, if there are + * more requests, keep waiting on the oldest as long as it is still older + * than the original request. + */ +static void sync_write_wait(struct inode *inode) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + struct list_head *head = &ci->i_unsafe_writes; + struct ceph_osd_request *req; + u64 last_tid; + + spin_lock(&ci->i_unsafe_lock); + if (list_empty(head)) + goto out; + + /* set upper bound as _last_ entry in chain */ + req = list_entry(head->prev, struct ceph_osd_request, + r_unsafe_item); + last_tid = req->r_tid; + + do { + ceph_osdc_get_request(req); + spin_unlock(&ci->i_unsafe_lock); + dout("sync_write_wait on tid %llu (until %llu)\n", + req->r_tid, last_tid); + wait_for_completion(&req->r_safe_completion); + spin_lock(&ci->i_unsafe_lock); + ceph_osdc_put_request(req); + + /* + * from here on look at first entry in chain, since we + * only want to wait for anything older than last_tid + */ + if (list_empty(head)) + break; + req = list_entry(head->next, struct ceph_osd_request, + r_unsafe_item); + } while (req->r_tid < last_tid); +out: + spin_unlock(&ci->i_unsafe_lock); +} + +int ceph_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + struct inode *inode = dentry->d_inode; + struct ceph_inode_info *ci = ceph_inode(inode); + unsigned flush_tid; + int ret; + int dirty; + + dout("fsync %p%s\n", inode, datasync ? " datasync" : ""); + sync_write_wait(inode); + + ret = filemap_write_and_wait(inode->i_mapping); + if (ret < 0) + return ret; + + dirty = try_flush_caps(inode, NULL, &flush_tid); + dout("fsync dirty caps are %s\n", ceph_cap_string(dirty)); + + /* + * only wait on non-file metadata writeback (the mds + * can recover size and mtime, so we don't need to + * wait for that) + */ + if (!datasync && (dirty & ~CEPH_CAP_ANY_FILE_WR)) { + dout("fsync waiting for flush_tid %u\n", flush_tid); + ret = wait_event_interruptible(ci->i_cap_wq, + caps_are_flushed(inode, flush_tid)); + } + + dout("fsync %p%s done\n", inode, datasync ? " datasync" : ""); + return ret; +} + +/* + * Flush any dirty caps back to the mds. If we aren't asked to wait, + * queue inode for flush but don't do so immediately, because we can + * get by with fewer MDS messages if we wait for data writeback to + * complete first. + */ +int ceph_write_inode(struct inode *inode, struct writeback_control *wbc) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + unsigned flush_tid; + int err = 0; + int dirty; + int wait = wbc->sync_mode == WB_SYNC_ALL; + + dout("write_inode %p wait=%d\n", inode, wait); + if (wait) { + dirty = try_flush_caps(inode, NULL, &flush_tid); + if (dirty) + err = wait_event_interruptible(ci->i_cap_wq, + caps_are_flushed(inode, flush_tid)); + } else { + struct ceph_mds_client *mdsc = &ceph_client(inode->i_sb)->mdsc; + + spin_lock(&inode->i_lock); + if (__ceph_caps_dirty(ci)) + __cap_delay_requeue_front(mdsc, ci); + spin_unlock(&inode->i_lock); + } + return err; +} + +/* + * After a recovering MDS goes active, we need to resend any caps + * we were flushing. + * + * Caller holds session->s_mutex. + */ +static void kick_flushing_capsnaps(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session) +{ + struct ceph_cap_snap *capsnap; + + dout("kick_flushing_capsnaps mds%d\n", session->s_mds); + list_for_each_entry(capsnap, &session->s_cap_snaps_flushing, + flushing_item) { + struct ceph_inode_info *ci = capsnap->ci; + struct inode *inode = &ci->vfs_inode; + struct ceph_cap *cap; + + spin_lock(&inode->i_lock); + cap = ci->i_auth_cap; + if (cap && cap->session == session) { + dout("kick_flushing_caps %p cap %p capsnap %p\n", inode, + cap, capsnap); + __ceph_flush_snaps(ci, &session); + } else { + pr_err("%p auth cap %p not mds%d ???\n", inode, + cap, session->s_mds); + spin_unlock(&inode->i_lock); + } + } +} + +void ceph_kick_flushing_caps(struct ceph_mds_client *mdsc, + struct ceph_mds_session *session) +{ + struct ceph_inode_info *ci; + + kick_flushing_capsnaps(mdsc, session); + + dout("kick_flushing_caps mds%d\n", session->s_mds); + list_for_each_entry(ci, &session->s_cap_flushing, i_flushing_item) { + struct inode *inode = &ci->vfs_inode; + struct ceph_cap *cap; + int delayed = 0; + + spin_lock(&inode->i_lock); + cap = ci->i_auth_cap; + if (cap && cap->session == session) { + dout("kick_flushing_caps %p cap %p %s\n", inode, + cap, ceph_cap_string(ci->i_flushing_caps)); + delayed = __send_cap(mdsc, cap, CEPH_CAP_OP_FLUSH, + __ceph_caps_used(ci), + __ceph_caps_wanted(ci), + cap->issued | cap->implemented, + ci->i_flushing_caps, NULL); + if (delayed) { + spin_lock(&inode->i_lock); + __cap_delay_requeue(mdsc, ci); + spin_unlock(&inode->i_lock); + } + } else { + pr_err("%p auth cap %p not mds%d ???\n", inode, + cap, session->s_mds); + spin_unlock(&inode->i_lock); + } + } +} + + +/* + * Take references to capabilities we hold, so that we don't release + * them to the MDS prematurely. + * + * Protected by i_lock. + */ +static void __take_cap_refs(struct ceph_inode_info *ci, int got) +{ + if (got & CEPH_CAP_PIN) + ci->i_pin_ref++; + if (got & CEPH_CAP_FILE_RD) + ci->i_rd_ref++; + if (got & CEPH_CAP_FILE_CACHE) + ci->i_rdcache_ref++; + if (got & CEPH_CAP_FILE_WR) + ci->i_wr_ref++; + if (got & CEPH_CAP_FILE_BUFFER) { + if (ci->i_wrbuffer_ref == 0) + igrab(&ci->vfs_inode); + ci->i_wrbuffer_ref++; + dout("__take_cap_refs %p wrbuffer %d -> %d (?)\n", + &ci->vfs_inode, ci->i_wrbuffer_ref-1, ci->i_wrbuffer_ref); + } +} + +/* + * Try to grab cap references. Specify those refs we @want, and the + * minimal set we @need. Also include the larger offset we are writing + * to (when applicable), and check against max_size here as well. + * Note that caller is responsible for ensuring max_size increases are + * requested from the MDS. + */ +static int try_get_cap_refs(struct ceph_inode_info *ci, int need, int want, + int *got, loff_t endoff, int *check_max, int *err) +{ + struct inode *inode = &ci->vfs_inode; + int ret = 0; + int have, implemented; + int file_wanted; + + dout("get_cap_refs %p need %s want %s\n", inode, + ceph_cap_string(need), ceph_cap_string(want)); + spin_lock(&inode->i_lock); + + /* make sure file is actually open */ + file_wanted = __ceph_caps_file_wanted(ci); + if ((file_wanted & need) == 0) { + dout("try_get_cap_refs need %s file_wanted %s, EBADF\n", + ceph_cap_string(need), ceph_cap_string(file_wanted)); + *err = -EBADF; + ret = 1; + goto out; + } + + if (need & CEPH_CAP_FILE_WR) { + if (endoff >= 0 && endoff > (loff_t)ci->i_max_size) { + dout("get_cap_refs %p endoff %llu > maxsize %llu\n", + inode, endoff, ci->i_max_size); + if (endoff > ci->i_wanted_max_size) { + *check_max = 1; + ret = 1; + } + goto out; + } + /* + * If a sync write is in progress, we must wait, so that we + * can get a final snapshot value for size+mtime. + */ + if (__ceph_have_pending_cap_snap(ci)) { + dout("get_cap_refs %p cap_snap_pending\n", inode); + goto out; + } + } + have = __ceph_caps_issued(ci, &implemented); + + /* + * disallow writes while a truncate is pending + */ + if (ci->i_truncate_pending) + have &= ~CEPH_CAP_FILE_WR; + + if ((have & need) == need) { + /* + * Look at (implemented & ~have & not) so that we keep waiting + * on transition from wanted -> needed caps. This is needed + * for WRBUFFER|WR -> WR to avoid a new WR sync write from + * going before a prior buffered writeback happens. + */ + int not = want & ~(have & need); + int revoking = implemented & ~have; + dout("get_cap_refs %p have %s but not %s (revoking %s)\n", + inode, ceph_cap_string(have), ceph_cap_string(not), + ceph_cap_string(revoking)); + if ((revoking & not) == 0) { + *got = need | (have & want); + __take_cap_refs(ci, *got); + ret = 1; + } + } else { + dout("get_cap_refs %p have %s needed %s\n", inode, + ceph_cap_string(have), ceph_cap_string(need)); + } +out: + spin_unlock(&inode->i_lock); + dout("get_cap_refs %p ret %d got %s\n", inode, + ret, ceph_cap_string(*got)); + return ret; +} + +/* + * Check the offset we are writing up to against our current + * max_size. If necessary, tell the MDS we want to write to + * a larger offset. + */ +static void check_max_size(struct inode *inode, loff_t endoff) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + int check = 0; + + /* do we need to explicitly request a larger max_size? */ + spin_lock(&inode->i_lock); + if ((endoff >= ci->i_max_size || + endoff > (inode->i_size << 1)) && + endoff > ci->i_wanted_max_size) { + dout("write %p at large endoff %llu, req max_size\n", + inode, endoff); + ci->i_wanted_max_size = endoff; + check = 1; + } + spin_unlock(&inode->i_lock); + if (check) + ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL); +} + +/* + * Wait for caps, and take cap references. If we can't get a WR cap + * due to a small max_size, make sure we check_max_size (and possibly + * ask the mds) so we don't get hung up indefinitely. + */ +int ceph_get_caps(struct ceph_inode_info *ci, int need, int want, int *got, + loff_t endoff) +{ + int check_max, ret, err; + +retry: + if (endoff > 0) + check_max_size(&ci->vfs_inode, endoff); + check_max = 0; + err = 0; + ret = wait_event_interruptible(ci->i_cap_wq, + try_get_cap_refs(ci, need, want, + got, endoff, + &check_max, &err)); + if (err) + ret = err; + if (check_max) + goto retry; + return ret; +} + +/* + * Take cap refs. Caller must already know we hold at least one ref + * on the caps in question or we don't know this is safe. + */ +void ceph_get_cap_refs(struct ceph_inode_info *ci, int caps) +{ + spin_lock(&ci->vfs_inode.i_lock); + __take_cap_refs(ci, caps); + spin_unlock(&ci->vfs_inode.i_lock); +} + +/* + * Release cap refs. + * + * If we released the last ref on any given cap, call ceph_check_caps + * to release (or schedule a release). + * + * If we are releasing a WR cap (from a sync write), finalize any affected + * cap_snap, and wake up any waiters. + */ +void ceph_put_cap_refs(struct ceph_inode_info *ci, int had) +{ + struct inode *inode = &ci->vfs_inode; + int last = 0, put = 0, flushsnaps = 0, wake = 0; + struct ceph_cap_snap *capsnap; + + spin_lock(&inode->i_lock); + if (had & CEPH_CAP_PIN) + --ci->i_pin_ref; + if (had & CEPH_CAP_FILE_RD) + if (--ci->i_rd_ref == 0) + last++; + if (had & CEPH_CAP_FILE_CACHE) + if (--ci->i_rdcache_ref == 0) + last++; + if (had & CEPH_CAP_FILE_BUFFER) { + if (--ci->i_wrbuffer_ref == 0) { + last++; + put++; + } + dout("put_cap_refs %p wrbuffer %d -> %d (?)\n", + inode, ci->i_wrbuffer_ref+1, ci->i_wrbuffer_ref); + } + if (had & CEPH_CAP_FILE_WR) + if (--ci->i_wr_ref == 0) { + last++; + if (!list_empty(&ci->i_cap_snaps)) { + capsnap = list_first_entry(&ci->i_cap_snaps, + struct ceph_cap_snap, + ci_item); + if (capsnap->writing) { + capsnap->writing = 0; + flushsnaps = + __ceph_finish_cap_snap(ci, + capsnap); + wake = 1; + } + } + } + spin_unlock(&inode->i_lock); + + dout("put_cap_refs %p had %s%s%s\n", inode, ceph_cap_string(had), + last ? " last" : "", put ? " put" : ""); + + if (last && !flushsnaps) + ceph_check_caps(ci, 0, NULL); + else if (flushsnaps) + ceph_flush_snaps(ci); + if (wake) + wake_up(&ci->i_cap_wq); + if (put) + iput(inode); +} + +/* + * Release @nr WRBUFFER refs on dirty pages for the given @snapc snap + * context. Adjust per-snap dirty page accounting as appropriate. + * Once all dirty data for a cap_snap is flushed, flush snapped file + * metadata back to the MDS. If we dropped the last ref, call + * ceph_check_caps. + */ +void ceph_put_wrbuffer_cap_refs(struct ceph_inode_info *ci, int nr, + struct ceph_snap_context *snapc) +{ + struct inode *inode = &ci->vfs_inode; + int last = 0; + int complete_capsnap = 0; + int drop_capsnap = 0; + int found = 0; + struct ceph_cap_snap *capsnap = NULL; + + spin_lock(&inode->i_lock); + ci->i_wrbuffer_ref -= nr; + last = !ci->i_wrbuffer_ref; + + if (ci->i_head_snapc == snapc) { + ci->i_wrbuffer_ref_head -= nr; + if (!ci->i_wrbuffer_ref_head) { + ceph_put_snap_context(ci->i_head_snapc); + ci->i_head_snapc = NULL; + } + dout("put_wrbuffer_cap_refs on %p head %d/%d -> %d/%d %s\n", + inode, + ci->i_wrbuffer_ref+nr, ci->i_wrbuffer_ref_head+nr, + ci->i_wrbuffer_ref, ci->i_wrbuffer_ref_head, + last ? " LAST" : ""); + } else { + list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { + if (capsnap->context == snapc) { + found = 1; + break; + } + } + BUG_ON(!found); + capsnap->dirty_pages -= nr; + if (capsnap->dirty_pages == 0) { + complete_capsnap = 1; + if (capsnap->dirty == 0) + /* cap writeback completed before we created + * the cap_snap; no FLUSHSNAP is needed */ + drop_capsnap = 1; + } + dout("put_wrbuffer_cap_refs on %p cap_snap %p " + " snap %lld %d/%d -> %d/%d %s%s%s\n", + inode, capsnap, capsnap->context->seq, + ci->i_wrbuffer_ref+nr, capsnap->dirty_pages + nr, + ci->i_wrbuffer_ref, capsnap->dirty_pages, + last ? " (wrbuffer last)" : "", + complete_capsnap ? " (complete capsnap)" : "", + drop_capsnap ? " (drop capsnap)" : ""); + if (drop_capsnap) { + ceph_put_snap_context(capsnap->context); + list_del(&capsnap->ci_item); + list_del(&capsnap->flushing_item); + ceph_put_cap_snap(capsnap); + } + } + + spin_unlock(&inode->i_lock); + + if (last) { + ceph_check_caps(ci, CHECK_CAPS_AUTHONLY, NULL); + iput(inode); + } else if (complete_capsnap) { + ceph_flush_snaps(ci); + wake_up(&ci->i_cap_wq); + } + if (drop_capsnap) + iput(inode); +} + +/* + * Handle a cap GRANT message from the MDS. (Note that a GRANT may + * actually be a revocation if it specifies a smaller cap set.) + * + * caller holds s_mutex and i_lock, we drop both. + * + * return value: + * 0 - ok + * 1 - check_caps on auth cap only (writeback) + * 2 - check_caps (ack revoke) + */ +static void handle_cap_grant(struct inode *inode, struct ceph_mds_caps *grant, + struct ceph_mds_session *session, + struct ceph_cap *cap, + struct ceph_buffer *xattr_buf) + __releases(inode->i_lock) + __releases(session->s_mutex) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + int mds = session->s_mds; + int seq = le32_to_cpu(grant->seq); + int newcaps = le32_to_cpu(grant->caps); + int issued, implemented, used, wanted, dirty; + u64 size = le64_to_cpu(grant->size); + u64 max_size = le64_to_cpu(grant->max_size); + struct timespec mtime, atime, ctime; + int check_caps = 0; + int wake = 0; + int writeback = 0; + int revoked_rdcache = 0; + int queue_invalidate = 0; + + dout("handle_cap_grant inode %p cap %p mds%d seq %d %s\n", + inode, cap, mds, seq, ceph_cap_string(newcaps)); + dout(" size %llu max_size %llu, i_size %llu\n", size, max_size, + inode->i_size); + + /* + * If CACHE is being revoked, and we have no dirty buffers, + * try to invalidate (once). (If there are dirty buffers, we + * will invalidate _after_ writeback.) + */ + if (((cap->issued & ~newcaps) & CEPH_CAP_FILE_CACHE) && + !ci->i_wrbuffer_ref) { + if (try_nonblocking_invalidate(inode) == 0) { + revoked_rdcache = 1; + } else { + /* there were locked pages.. invalidate later + in a separate thread. */ + if (ci->i_rdcache_revoking != ci->i_rdcache_gen) { + queue_invalidate = 1; + ci->i_rdcache_revoking = ci->i_rdcache_gen; + } + } + } + + /* side effects now are allowed */ + + issued = __ceph_caps_issued(ci, &implemented); + issued |= implemented | __ceph_caps_dirty(ci); + + cap->cap_gen = session->s_cap_gen; + + __check_cap_issue(ci, cap, newcaps); + + if ((issued & CEPH_CAP_AUTH_EXCL) == 0) { + inode->i_mode = le32_to_cpu(grant->mode); + inode->i_uid = le32_to_cpu(grant->uid); + inode->i_gid = le32_to_cpu(grant->gid); + dout("%p mode 0%o uid.gid %d.%d\n", inode, inode->i_mode, + inode->i_uid, inode->i_gid); + } + + if ((issued & CEPH_CAP_LINK_EXCL) == 0) + inode->i_nlink = le32_to_cpu(grant->nlink); + + if ((issued & CEPH_CAP_XATTR_EXCL) == 0 && grant->xattr_len) { + int len = le32_to_cpu(grant->xattr_len); + u64 version = le64_to_cpu(grant->xattr_version); + + if (version > ci->i_xattrs.version) { + dout(" got new xattrs v%llu on %p len %d\n", + version, inode, len); + if (ci->i_xattrs.blob) + ceph_buffer_put(ci->i_xattrs.blob); + ci->i_xattrs.blob = ceph_buffer_get(xattr_buf); + ci->i_xattrs.version = version; + } + } + + /* size/ctime/mtime/atime? */ + ceph_fill_file_size(inode, issued, + le32_to_cpu(grant->truncate_seq), + le64_to_cpu(grant->truncate_size), size); + ceph_decode_timespec(&mtime, &grant->mtime); + ceph_decode_timespec(&atime, &grant->atime); + ceph_decode_timespec(&ctime, &grant->ctime); + ceph_fill_file_time(inode, issued, + le32_to_cpu(grant->time_warp_seq), &ctime, &mtime, + &atime); + + /* max size increase? */ + if (max_size != ci->i_max_size) { + dout("max_size %lld -> %llu\n", ci->i_max_size, max_size); + ci->i_max_size = max_size; + if (max_size >= ci->i_wanted_max_size) { + ci->i_wanted_max_size = 0; /* reset */ + ci->i_requested_max_size = 0; + } + wake = 1; + } + + /* check cap bits */ + wanted = __ceph_caps_wanted(ci); + used = __ceph_caps_used(ci); + dirty = __ceph_caps_dirty(ci); + dout(" my wanted = %s, used = %s, dirty %s\n", + ceph_cap_string(wanted), + ceph_cap_string(used), + ceph_cap_string(dirty)); + if (wanted != le32_to_cpu(grant->wanted)) { + dout("mds wanted %s -> %s\n", + ceph_cap_string(le32_to_cpu(grant->wanted)), + ceph_cap_string(wanted)); + grant->wanted = cpu_to_le32(wanted); + } + + cap->seq = seq; + + /* file layout may have changed */ + ci->i_layout = grant->layout; + + /* revocation, grant, or no-op? */ + if (cap->issued & ~newcaps) { + dout("revocation: %s -> %s\n", ceph_cap_string(cap->issued), + ceph_cap_string(newcaps)); + if ((used & ~newcaps) & CEPH_CAP_FILE_BUFFER) + writeback = 1; /* will delay ack */ + else if (dirty & ~newcaps) + check_caps = 1; /* initiate writeback in check_caps */ + else if (((used & ~newcaps) & CEPH_CAP_FILE_CACHE) == 0 || + revoked_rdcache) + check_caps = 2; /* send revoke ack in check_caps */ + cap->issued = newcaps; + cap->implemented |= newcaps; + } else if (cap->issued == newcaps) { + dout("caps unchanged: %s -> %s\n", + ceph_cap_string(cap->issued), ceph_cap_string(newcaps)); + } else { + dout("grant: %s -> %s\n", ceph_cap_string(cap->issued), + ceph_cap_string(newcaps)); + cap->issued = newcaps; + cap->implemented |= newcaps; /* add bits only, to + * avoid stepping on a + * pending revocation */ + wake = 1; + } + BUG_ON(cap->issued & ~cap->implemented); + + spin_unlock(&inode->i_lock); + if (writeback) + /* + * queue inode for writeback: we can't actually call + * filemap_write_and_wait, etc. from message handler + * context. + */ + ceph_queue_writeback(inode); + if (queue_invalidate) + ceph_queue_invalidate(inode); + if (wake) + wake_up(&ci->i_cap_wq); + + if (check_caps == 1) + ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_AUTHONLY, + session); + else if (check_caps == 2) + ceph_check_caps(ci, CHECK_CAPS_NODELAY, session); + else + mutex_unlock(&session->s_mutex); +} + +/* + * Handle FLUSH_ACK from MDS, indicating that metadata we sent to the + * MDS has been safely committed. + */ +static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid, + struct ceph_mds_caps *m, + struct ceph_mds_session *session, + struct ceph_cap *cap) + __releases(inode->i_lock) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + struct ceph_mds_client *mdsc = &ceph_client(inode->i_sb)->mdsc; + unsigned seq = le32_to_cpu(m->seq); + int dirty = le32_to_cpu(m->dirty); + int cleaned = 0; + int drop = 0; + int i; + + for (i = 0; i < CEPH_CAP_BITS; i++) + if ((dirty & (1 << i)) && + flush_tid == ci->i_cap_flush_tid[i]) + cleaned |= 1 << i; + + dout("handle_cap_flush_ack inode %p mds%d seq %d on %s cleaned %s," + " flushing %s -> %s\n", + inode, session->s_mds, seq, ceph_cap_string(dirty), + ceph_cap_string(cleaned), ceph_cap_string(ci->i_flushing_caps), + ceph_cap_string(ci->i_flushing_caps & ~cleaned)); + + if (ci->i_flushing_caps == (ci->i_flushing_caps & ~cleaned)) + goto out; + + ci->i_flushing_caps &= ~cleaned; + + spin_lock(&mdsc->cap_dirty_lock); + if (ci->i_flushing_caps == 0) { + list_del_init(&ci->i_flushing_item); + if (!list_empty(&session->s_cap_flushing)) + dout(" mds%d still flushing cap on %p\n", + session->s_mds, + &list_entry(session->s_cap_flushing.next, + struct ceph_inode_info, + i_flushing_item)->vfs_inode); + mdsc->num_cap_flushing--; + wake_up(&mdsc->cap_flushing_wq); + dout(" inode %p now !flushing\n", inode); + + if (ci->i_dirty_caps == 0) { + dout(" inode %p now clean\n", inode); + BUG_ON(!list_empty(&ci->i_dirty_item)); + drop = 1; + } else { + BUG_ON(list_empty(&ci->i_dirty_item)); + } + } + spin_unlock(&mdsc->cap_dirty_lock); + wake_up(&ci->i_cap_wq); + +out: + spin_unlock(&inode->i_lock); + if (drop) + iput(inode); +} + +/* + * Handle FLUSHSNAP_ACK. MDS has flushed snap data to disk and we can + * throw away our cap_snap. + * + * Caller hold s_mutex. + */ +static void handle_cap_flushsnap_ack(struct inode *inode, u64 flush_tid, + struct ceph_mds_caps *m, + struct ceph_mds_session *session) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + u64 follows = le64_to_cpu(m->snap_follows); + struct ceph_cap_snap *capsnap; + int drop = 0; + + dout("handle_cap_flushsnap_ack inode %p ci %p mds%d follows %lld\n", + inode, ci, session->s_mds, follows); + + spin_lock(&inode->i_lock); + list_for_each_entry(capsnap, &ci->i_cap_snaps, ci_item) { + if (capsnap->follows == follows) { + if (capsnap->flush_tid != flush_tid) { + dout(" cap_snap %p follows %lld tid %lld !=" + " %lld\n", capsnap, follows, + flush_tid, capsnap->flush_tid); + break; + } + WARN_ON(capsnap->dirty_pages || capsnap->writing); + dout(" removing %p cap_snap %p follows %lld\n", + inode, capsnap, follows); + ceph_put_snap_context(capsnap->context); + list_del(&capsnap->ci_item); + list_del(&capsnap->flushing_item); + ceph_put_cap_snap(capsnap); + drop = 1; + break; + } else { + dout(" skipping cap_snap %p follows %lld\n", + capsnap, capsnap->follows); + } + } + spin_unlock(&inode->i_lock); + if (drop) + iput(inode); +} + +/* + * Handle TRUNC from MDS, indicating file truncation. + * + * caller hold s_mutex. + */ +static void handle_cap_trunc(struct inode *inode, + struct ceph_mds_caps *trunc, + struct ceph_mds_session *session) + __releases(inode->i_lock) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + int mds = session->s_mds; + int seq = le32_to_cpu(trunc->seq); + u32 truncate_seq = le32_to_cpu(trunc->truncate_seq); + u64 truncate_size = le64_to_cpu(trunc->truncate_size); + u64 size = le64_to_cpu(trunc->size); + int implemented = 0; + int dirty = __ceph_caps_dirty(ci); + int issued = __ceph_caps_issued(ceph_inode(inode), &implemented); + int queue_trunc = 0; + + issued |= implemented | dirty; + + dout("handle_cap_trunc inode %p mds%d seq %d to %lld seq %d\n", + inode, mds, seq, truncate_size, truncate_seq); + queue_trunc = ceph_fill_file_size(inode, issued, + truncate_seq, truncate_size, size); + spin_unlock(&inode->i_lock); + + if (queue_trunc) + ceph_queue_vmtruncate(inode); +} + +/* + * Handle EXPORT from MDS. Cap is being migrated _from_ this mds to a + * different one. If we are the most recent migration we've seen (as + * indicated by mseq), make note of the migrating cap bits for the + * duration (until we see the corresponding IMPORT). + * + * caller holds s_mutex + */ +static void handle_cap_export(struct inode *inode, struct ceph_mds_caps *ex, + struct ceph_mds_session *session) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + int mds = session->s_mds; + unsigned mseq = le32_to_cpu(ex->migrate_seq); + struct ceph_cap *cap = NULL, *t; + struct rb_node *p; + int remember = 1; + + dout("handle_cap_export inode %p ci %p mds%d mseq %d\n", + inode, ci, mds, mseq); + + spin_lock(&inode->i_lock); + + /* make sure we haven't seen a higher mseq */ + for (p = rb_first(&ci->i_caps); p; p = rb_next(p)) { + t = rb_entry(p, struct ceph_cap, ci_node); + if (ceph_seq_cmp(t->mseq, mseq) > 0) { + dout(" higher mseq on cap from mds%d\n", + t->session->s_mds); + remember = 0; + } + if (t->session->s_mds == mds) + cap = t; + } + + if (cap) { + if (remember) { + /* make note */ + ci->i_cap_exporting_mds = mds; + ci->i_cap_exporting_mseq = mseq; + ci->i_cap_exporting_issued = cap->issued; + } + __ceph_remove_cap(cap); + } + /* else, we already released it */ + + spin_unlock(&inode->i_lock); +} + +/* + * Handle cap IMPORT. If there are temp bits from an older EXPORT, + * clean them up. + * + * caller holds s_mutex. + */ +static void handle_cap_import(struct ceph_mds_client *mdsc, + struct inode *inode, struct ceph_mds_caps *im, + struct ceph_mds_session *session, + void *snaptrace, int snaptrace_len) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + int mds = session->s_mds; + unsigned issued = le32_to_cpu(im->caps); + unsigned wanted = le32_to_cpu(im->wanted); + unsigned seq = le32_to_cpu(im->seq); + unsigned mseq = le32_to_cpu(im->migrate_seq); + u64 realmino = le64_to_cpu(im->realm); + u64 cap_id = le64_to_cpu(im->cap_id); + + if (ci->i_cap_exporting_mds >= 0 && + ceph_seq_cmp(ci->i_cap_exporting_mseq, mseq) < 0) { + dout("handle_cap_import inode %p ci %p mds%d mseq %d" + " - cleared exporting from mds%d\n", + inode, ci, mds, mseq, + ci->i_cap_exporting_mds); + ci->i_cap_exporting_issued = 0; + ci->i_cap_exporting_mseq = 0; + ci->i_cap_exporting_mds = -1; + } else { + dout("handle_cap_import inode %p ci %p mds%d mseq %d\n", + inode, ci, mds, mseq); + } + + down_write(&mdsc->snap_rwsem); + ceph_update_snap_trace(mdsc, snaptrace, snaptrace+snaptrace_len, + false); + downgrade_write(&mdsc->snap_rwsem); + ceph_add_cap(inode, session, cap_id, -1, + issued, wanted, seq, mseq, realmino, CEPH_CAP_FLAG_AUTH, + NULL /* no caps context */); + try_flush_caps(inode, session, NULL); + up_read(&mdsc->snap_rwsem); +} + +/* + * Handle a caps message from the MDS. + * + * Identify the appropriate session, inode, and call the right handler + * based on the cap op. + */ +void ceph_handle_caps(struct ceph_mds_session *session, + struct ceph_msg *msg) +{ + struct ceph_mds_client *mdsc = session->s_mdsc; + struct super_block *sb = mdsc->client->sb; + struct inode *inode; + struct ceph_cap *cap; + struct ceph_mds_caps *h; + int mds = session->s_mds; + int op; + u32 seq; + struct ceph_vino vino; + u64 cap_id; + u64 size, max_size; + u64 tid; + void *snaptrace; + + dout("handle_caps from mds%d\n", mds); + + /* decode */ + tid = le64_to_cpu(msg->hdr.tid); + if (msg->front.iov_len < sizeof(*h)) + goto bad; + h = msg->front.iov_base; + snaptrace = h + 1; + op = le32_to_cpu(h->op); + vino.ino = le64_to_cpu(h->ino); + vino.snap = CEPH_NOSNAP; + cap_id = le64_to_cpu(h->cap_id); + seq = le32_to_cpu(h->seq); + size = le64_to_cpu(h->size); + max_size = le64_to_cpu(h->max_size); + + mutex_lock(&session->s_mutex); + session->s_seq++; + dout(" mds%d seq %lld cap seq %u\n", session->s_mds, session->s_seq, + (unsigned)seq); + + /* lookup ino */ + inode = ceph_find_inode(sb, vino); + dout(" op %s ino %llx.%llx inode %p\n", ceph_cap_op_name(op), vino.ino, + vino.snap, inode); + if (!inode) { + dout(" i don't have ino %llx\n", vino.ino); + goto done; + } + + /* these will work even if we don't have a cap yet */ + switch (op) { + case CEPH_CAP_OP_FLUSHSNAP_ACK: + handle_cap_flushsnap_ack(inode, tid, h, session); + goto done; + + case CEPH_CAP_OP_EXPORT: + handle_cap_export(inode, h, session); + goto done; + + case CEPH_CAP_OP_IMPORT: + handle_cap_import(mdsc, inode, h, session, + snaptrace, le32_to_cpu(h->snap_trace_len)); + ceph_check_caps(ceph_inode(inode), CHECK_CAPS_NODELAY, + session); + goto done_unlocked; + } + + /* the rest require a cap */ + spin_lock(&inode->i_lock); + cap = __get_cap_for_mds(ceph_inode(inode), mds); + if (!cap) { + dout("no cap on %p ino %llx.%llx from mds%d, releasing\n", + inode, ceph_ino(inode), ceph_snap(inode), mds); + spin_unlock(&inode->i_lock); + goto done; + } + + /* note that each of these drops i_lock for us */ + switch (op) { + case CEPH_CAP_OP_REVOKE: + case CEPH_CAP_OP_GRANT: + handle_cap_grant(inode, h, session, cap, msg->middle); + goto done_unlocked; + + case CEPH_CAP_OP_FLUSH_ACK: + handle_cap_flush_ack(inode, tid, h, session, cap); + break; + + case CEPH_CAP_OP_TRUNC: + handle_cap_trunc(inode, h, session); + break; + + default: + spin_unlock(&inode->i_lock); + pr_err("ceph_handle_caps: unknown cap op %d %s\n", op, + ceph_cap_op_name(op)); + } + +done: + mutex_unlock(&session->s_mutex); +done_unlocked: + if (inode) + iput(inode); + return; + +bad: + pr_err("ceph_handle_caps: corrupt message\n"); + ceph_msg_dump(msg); + return; +} + +/* + * Delayed work handler to process end of delayed cap release LRU list. + */ +void ceph_check_delayed_caps(struct ceph_mds_client *mdsc) +{ + struct ceph_inode_info *ci; + int flags = CHECK_CAPS_NODELAY; + + dout("check_delayed_caps\n"); + while (1) { + spin_lock(&mdsc->cap_delay_lock); + if (list_empty(&mdsc->cap_delay_list)) + break; + ci = list_first_entry(&mdsc->cap_delay_list, + struct ceph_inode_info, + i_cap_delay_list); + if ((ci->i_ceph_flags & CEPH_I_FLUSH) == 0 && + time_before(jiffies, ci->i_hold_caps_max)) + break; + list_del_init(&ci->i_cap_delay_list); + spin_unlock(&mdsc->cap_delay_lock); + dout("check_delayed_caps on %p\n", &ci->vfs_inode); + ceph_check_caps(ci, flags, NULL); + } + spin_unlock(&mdsc->cap_delay_lock); +} + +/* + * Flush all dirty caps to the mds + */ +void ceph_flush_dirty_caps(struct ceph_mds_client *mdsc) +{ + struct ceph_inode_info *ci, *nci = NULL; + struct inode *inode, *ninode = NULL; + struct list_head *p, *n; + + dout("flush_dirty_caps\n"); + spin_lock(&mdsc->cap_dirty_lock); + list_for_each_safe(p, n, &mdsc->cap_dirty) { + if (nci) { + ci = nci; + inode = ninode; + ci->i_ceph_flags &= ~CEPH_I_NOFLUSH; + dout("flush_dirty_caps inode %p (was next inode)\n", + inode); + } else { + ci = list_entry(p, struct ceph_inode_info, + i_dirty_item); + inode = igrab(&ci->vfs_inode); + BUG_ON(!inode); + dout("flush_dirty_caps inode %p\n", inode); + } + if (n != &mdsc->cap_dirty) { + nci = list_entry(n, struct ceph_inode_info, + i_dirty_item); + ninode = igrab(&nci->vfs_inode); + BUG_ON(!ninode); + nci->i_ceph_flags |= CEPH_I_NOFLUSH; + dout("flush_dirty_caps next inode %p, noflush\n", + ninode); + } else { + nci = NULL; + ninode = NULL; + } + spin_unlock(&mdsc->cap_dirty_lock); + if (inode) { + ceph_check_caps(ci, CHECK_CAPS_NODELAY|CHECK_CAPS_FLUSH, + NULL); + iput(inode); + } + spin_lock(&mdsc->cap_dirty_lock); + } + spin_unlock(&mdsc->cap_dirty_lock); +} + +/* + * Drop open file reference. If we were the last open file, + * we may need to release capabilities to the MDS (or schedule + * their delayed release). + */ +void ceph_put_fmode(struct ceph_inode_info *ci, int fmode) +{ + struct inode *inode = &ci->vfs_inode; + int last = 0; + + spin_lock(&inode->i_lock); + dout("put_fmode %p fmode %d %d -> %d\n", inode, fmode, + ci->i_nr_by_mode[fmode], ci->i_nr_by_mode[fmode]-1); + BUG_ON(ci->i_nr_by_mode[fmode] == 0); + if (--ci->i_nr_by_mode[fmode] == 0) + last++; + spin_unlock(&inode->i_lock); + + if (last && ci->i_vino.snap == CEPH_NOSNAP) + ceph_check_caps(ci, 0, NULL); +} + +/* + * Helpers for embedding cap and dentry lease releases into mds + * requests. + * + * @force is used by dentry_release (below) to force inclusion of a + * record for the directory inode, even when there aren't any caps to + * drop. + */ +int ceph_encode_inode_release(void **p, struct inode *inode, + int mds, int drop, int unless, int force) +{ + struct ceph_inode_info *ci = ceph_inode(inode); + struct ceph_cap *cap; + struct ceph_mds_request_release *rel = *p; + int ret = 0; + int used = 0; + + spin_lock(&inode->i_lock); + used = __ceph_caps_used(ci); + + dout("encode_inode_release %p mds%d used %s drop %s unless %s\n", inode, + mds, ceph_cap_string(used), ceph_cap_string(drop), + ceph_cap_string(unless)); + + /* only drop unused caps */ + drop &= ~used; + + cap = __get_cap_for_mds(ci, mds); + if (cap && __cap_is_valid(cap)) { + if (force || + ((cap->issued & drop) && + (cap->issued & unless) == 0)) { + if ((cap->issued & drop) && + (cap->issued & unless) == 0) { + dout("encode_inode_release %p cap %p %s -> " + "%s\n", inode, cap, + ceph_cap_string(cap->issued), + ceph_cap_string(cap->issued & ~drop)); + cap->issued &= ~drop; + cap->implemented &= ~drop; + if (ci->i_ceph_flags & CEPH_I_NODELAY) { + int wanted = __ceph_caps_wanted(ci); + dout(" wanted %s -> %s (act %s)\n", + ceph_cap_string(cap->mds_wanted), + ceph_cap_string(cap->mds_wanted & + ~wanted), + ceph_cap_string(wanted)); + cap->mds_wanted &= wanted; + } + } else { + dout("encode_inode_release %p cap %p %s" + " (force)\n", inode, cap, + ceph_cap_string(cap->issued)); + } + + rel->ino = cpu_to_le64(ceph_ino(inode)); + rel->cap_id = cpu_to_le64(cap->cap_id); + rel->seq = cpu_to_le32(cap->seq); + rel->issue_seq = cpu_to_le32(cap->issue_seq), + rel->mseq = cpu_to_le32(cap->mseq); + rel->caps = cpu_to_le32(cap->issued); + rel->wanted = cpu_to_le32(cap->mds_wanted); + rel->dname_len = 0; + rel->dname_seq = 0; + *p += sizeof(*rel); + ret = 1; + } else { + dout("encode_inode_release %p cap %p %s\n", + inode, cap, ceph_cap_string(cap->issued)); + } + } + spin_unlock(&inode->i_lock); + return ret; +} + +int ceph_encode_dentry_release(void **p, struct dentry *dentry, + int mds, int drop, int unless) +{ + struct inode *dir = dentry->d_parent->d_inode; + struct ceph_mds_request_release *rel = *p; + struct ceph_dentry_info *di = ceph_dentry(dentry); + int force = 0; + int ret; + + /* + * force an record for the directory caps if we have a dentry lease. + * this is racy (can't take i_lock and d_lock together), but it + * doesn't have to be perfect; the mds will revoke anything we don't + * release. + */ + spin_lock(&dentry->d_lock); + if (di->lease_session && di->lease_session->s_mds == mds) + force = 1; + spin_unlock(&dentry->d_lock); + + ret = ceph_encode_inode_release(p, dir, mds, drop, unless, force); + + spin_lock(&dentry->d_lock); + if (ret && di->lease_session && di->lease_session->s_mds == mds) { + dout("encode_dentry_release %p mds%d seq %d\n", + dentry, mds, (int)di->lease_seq); + rel->dname_len = cpu_to_le32(dentry->d_name.len); + memcpy(*p, dentry->d_name.name, dentry->d_name.len); + *p += dentry->d_name.len; + rel->dname_seq = cpu_to_le32(di->lease_seq); + } + spin_unlock(&dentry->d_lock); + return ret; +} |