/* * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. * Copyright 2004-2011 Red Hat, Inc. * * This copyrighted material is made available to anyone wishing to use, * modify, copy, or redistribute it subject to the terms and conditions * of the GNU General Public License version 2. */ #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt #include #include #include #include #include #include #include "incore.h" #include "glock.h" #include "util.h" #include "sys.h" #include "trace_gfs2.h" extern struct workqueue_struct *gfs2_control_wq; /** * gfs2_update_stats - Update time based stats * @mv: Pointer to mean/variance structure to update * @sample: New data to include * * @delta is the difference between the current rtt sample and the * running average srtt. We add 1/8 of that to the srtt in order to * update the current srtt estimate. The varience estimate is a bit * more complicated. We subtract the abs value of the @delta from * the current variance estimate and add 1/4 of that to the running * total. * * Note that the index points at the array entry containing the smoothed * mean value, and the variance is always in the following entry * * Reference: TCP/IP Illustrated, vol 2, p. 831,832 * All times are in units of integer nanoseconds. Unlike the TCP/IP case, * they are not scaled fixed point. */ static inline void gfs2_update_stats(struct gfs2_lkstats *s, unsigned index, s64 sample) { s64 delta = sample - s->stats[index]; s->stats[index] += (delta >> 3); index++; s->stats[index] += ((abs64(delta) - s->stats[index]) >> 2); } /** * gfs2_update_reply_times - Update locking statistics * @gl: The glock to update * * This assumes that gl->gl_dstamp has been set earlier. * * The rtt (lock round trip time) is an estimate of the time * taken to perform a dlm lock request. We update it on each * reply from the dlm. * * The blocking flag is set on the glock for all dlm requests * which may potentially block due to lock requests from other nodes. * DLM requests where the current lock state is exclusive, the * requested state is null (or unlocked) or where the TRY or * TRY_1CB flags are set are classified as non-blocking. All * other DLM requests are counted as (potentially) blocking. */ static inline void gfs2_update_reply_times(struct gfs2_glock *gl) { struct gfs2_pcpu_lkstats *lks; const unsigned gltype = gl->gl_name.ln_type; unsigned index = test_bit(GLF_BLOCKING, &gl->gl_flags) ? GFS2_LKS_SRTTB : GFS2_LKS_SRTT; s64 rtt; preempt_disable(); rtt = ktime_to_ns(ktime_sub(ktime_get_real(), gl->gl_dstamp)); lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats); gfs2_update_stats(&gl->gl_stats, index, rtt); /* Local */ gfs2_update_stats(&lks->lkstats[gltype], index, rtt); /* Global */ preempt_enable(); trace_gfs2_glock_lock_time(gl, rtt); } /** * gfs2_update_request_times - Update locking statistics * @gl: The glock to update * * The irt (lock inter-request times) measures the average time * between requests to the dlm. It is updated immediately before * each dlm call. */ static inline void gfs2_update_request_times(struct gfs2_glock *gl) { struct gfs2_pcpu_lkstats *lks; const unsigned gltype = gl->gl_name.ln_type; ktime_t dstamp; s64 irt; preempt_disable(); dstamp = gl->gl_dstamp; gl->gl_dstamp = ktime_get_real(); irt = ktime_to_ns(ktime_sub(gl->gl_dstamp, dstamp)); lks = this_cpu_ptr(gl->gl_sbd->sd_lkstats); gfs2_update_stats(&gl->gl_stats, GFS2_LKS_SIRT, irt); /* Local */ gfs2_update_stats(&lks->lkstats[gltype], GFS2_LKS_SIRT, irt); /* Global */ preempt_enable(); } static void gdlm_ast(void *arg) { struct gfs2_glock *gl = arg; unsigned ret = gl->gl_state; gfs2_update_reply_times(gl); BUG_ON(gl->gl_lksb.sb_flags & DLM_SBF_DEMOTED); if ((gl->gl_lksb.sb_flags & DLM_SBF_VALNOTVALID) && gl->gl_lksb.sb_lvbptr) memset(gl->gl_lksb.sb_lvbptr, 0, GDLM_LVB_SIZE); switch (gl->gl_lksb.sb_status) { case -DLM_EUNLOCK: /* Unlocked, so glock can be freed */ gfs2_glock_free(gl); return; case -DLM_ECANCEL: /* Cancel while getting lock */ ret |= LM_OUT_CANCELED; goto out; case -EAGAIN: /* Try lock fails */ case -EDEADLK: /* Deadlock detected */ goto out; case -ETIMEDOUT: /* Canceled due to timeout */ ret |= LM_OUT_ERROR; goto out; case 0: /* Success */ break; default: /* Something unexpected */ BUG(); } ret = gl->gl_req; if (gl->gl_lksb.sb_flags & DLM_SBF_ALTMODE) { if (gl->gl_req == LM_ST_SHARED) ret = LM_ST_DEFERRED; else if (gl->gl_req == LM_ST_DEFERRED) ret = LM_ST_SHARED; else BUG(); } set_bit(GLF_INITIAL, &gl->gl_flags); gfs2_glock_complete(gl, ret); return; out: if (!test_bit(GLF_INITIAL, &gl->gl_flags)) gl->gl_lksb.sb_lkid = 0; gfs2_glock_complete(gl, ret); } static void gdlm_bast(void *arg, int mode) { struct gfs2_glock *gl = arg; switch (mode) { case DLM_LOCK_EX: gfs2_glock_cb(gl, LM_ST_UNLOCKED); break; case DLM_LOCK_CW: gfs2_glock_cb(gl, LM_ST_DEFERRED); break; case DLM_LOCK_PR: gfs2_glock_cb(gl, LM_ST_SHARED); break; default: pr_err("unknown bast mode %d\n", mode); BUG(); } } /* convert gfs lock-state to dlm lock-mode */ static int make_mode(const unsigned int lmstate) { switch (lmstate) { case LM_ST_UNLOCKED: return DLM_LOCK_NL; case LM_ST_EXCLUSIVE: return DLM_LOCK_EX; case LM_ST_DEFERRED: return DLM_LOCK_CW; case LM_ST_SHARED: return DLM_LOCK_PR; } pr_err("unknown LM state %d\n", lmstate); BUG(); return -1; } static u32 make_flags(struct gfs2_glock *gl, const unsigned int gfs_flags, const int req) { u32 lkf = 0; if (gl->gl_lksb.sb_lvbptr) lkf |= DLM_LKF_VALBLK; if (gfs_flags & LM_FLAG_TRY) lkf |= DLM_LKF_NOQUEUE; if (gfs_flags & LM_FLAG_TRY_1CB) { lkf |= DLM_LKF_NOQUEUE; lkf |= DLM_LKF_NOQUEUEBAST; } if (gfs_flags & LM_FLAG_PRIORITY) { lkf |= DLM_LKF_NOORDER; lkf |= DLM_LKF_HEADQUE; } if (gfs_flags & LM_FLAG_ANY) { if (req == DLM_LOCK_PR) lkf |= DLM_LKF_ALTCW; else if (req == DLM_LOCK_CW) lkf |= DLM_LKF_ALTPR; else BUG(); } if (gl->gl_lksb.sb_lkid != 0) { lkf |= DLM_LKF_CONVERT; if (test_bit(GLF_BLOCKING, &gl->gl_flags)) lkf |= DLM_LKF_QUECVT; } return lkf; } static void gfs2_reverse_hex(char *c, u64 value) { *c = '0'; while (value) { *c-- = hex_asc[value & 0x0f]; value >>= 4; } } static int gdlm_lock(struct gfs2_glock *gl, unsigned int req_state, unsigned int flags) { struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; int req; u32 lkf; char strname[GDLM_STRNAME_BYTES] = ""; req = make_mode(req_state); lkf = make_flags(gl, flags, req); gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT); gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT); if (gl->gl_lksb.sb_lkid) { gfs2_update_request_times(gl); } else { memset(strname, ' ', GDLM_STRNAME_BYTES - 1); strname[GDLM_STRNAME_BYTES - 1] = '\0'; gfs2_reverse_hex(strname + 7, gl->gl_name.ln_type); gfs2_reverse_hex(strname + 23, gl->gl_name.ln_number); gl->gl_dstamp = ktime_get_real(); } /* * Submit the actual lock request. */ return dlm_lock(ls->ls_dlm, req, &gl->gl_lksb, lkf, strname, GDLM_STRNAME_BYTES - 1, 0, gdlm_ast, gl, gdlm_bast); } static void gdlm_put_lock(struct gfs2_glock *gl) { struct gfs2_sbd *sdp = gl->gl_sbd; struct lm_lockstruct *ls = &sdp->sd_lockstruct; int lvb_needs_unlock = 0; int error; if (gl->gl_lksb.sb_lkid == 0) { gfs2_glock_free(gl); return; } clear_bit(GLF_BLOCKING, &gl->gl_flags); gfs2_glstats_inc(gl, GFS2_LKS_DCOUNT); gfs2_sbstats_inc(gl, GFS2_LKS_DCOUNT); gfs2_update_request_times(gl); /* don't want to skip dlm_unlock writing the lvb when lock is ex */ if (gl->gl_lksb.sb_lvbptr && (gl->gl_state == LM_ST_EXCLUSIVE)) lvb_needs_unlock = 1; if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) && !lvb_needs_unlock) { gfs2_glock_free(gl); return; } error = dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_VALBLK, NULL, gl); if (error) { pr_err("gdlm_unlock %x,%llx err=%d\n", gl->gl_name.ln_type, (unsigned long long)gl->gl_name.ln_number, error); return; } } static void gdlm_cancel(struct gfs2_glock *gl) { struct lm_lockstruct *ls = &gl->gl_sbd->sd_lockstruct; dlm_unlock(ls->ls_dlm, gl->gl_lksb.sb_lkid, DLM_LKF_CANCEL, NULL, gl); } /* * dlm/gfs2 recovery coordination using dlm_recover callbacks * * 1. dlm_controld sees lockspace members change * 2. dlm_controld blocks dlm-kernel locking activity * 3. dlm_controld within dlm-kernel notifies gfs2 (recover_prep) * 4. dlm_controld starts and finishes its own user level recovery * 5. dlm_controld starts dlm-kernel dlm_recoverd to do kernel recovery * 6. dlm_recoverd notifies gfs2 of failed nodes (recover_slot) * 7. dlm_recoverd does its own lock recovery * 8. dlm_recoverd unblocks dlm-kernel locking activity * 9. dlm_recoverd notifies gfs2 when done (recover_done with new generation) * 10. gfs2_control updates control_lock lvb with new generation and jid bits * 11. gfs2_control enqueues journals for gfs2_recover to recover (maybe none) * 12. gfs2_recover dequeues and recovers journals of failed nodes * 13. gfs2_recover provides recovery results to gfs2_control (recovery_result) * 14. gfs2_control updates control_lock lvb jid bits for recovered journals * 15. gfs2_control unblocks normal locking when all journals are recovered * * - failures during recovery * * recover_prep() may set BLOCK_LOCKS (step 3) again before gfs2_control * clears BLOCK_LOCKS (step 15), e.g. another node fails while still * recovering for a prior failure. gfs2_control needs a way to detect * this so it can leave BLOCK_LOCKS set in step 15. This is managed using * the recover_block and recover_start values. * * recover_done() provides a new lockspace generation number each time it * is called (step 9). This generation number is saved as recover_start. * When recover_prep() is called, it sets BLOCK_LOCKS and sets * recover_block = recover_start. So, while recover_block is equal to * recover_start, BLOCK_LOCKS should remain set. (recover_spin must * be held around the BLOCK_LOCKS/recover_block/recover_start logic.) * * - more specific gfs2 steps in sequence above * * 3. recover_prep sets BLOCK_LOCKS and sets recover_block = recover_start * 6. recover_slot records any failed jids (maybe none) * 9. recover_done sets recover_start = new generation number * 10. gfs2_control sets control_lock lvb = new gen + bits for failed jids * 12. gfs2_recover does journal recoveries for failed jids identified above * 14. gfs2_control clears control_lock lvb bits for recovered jids * 15. gfs2_control checks if recover_block == recover_start (step 3 occured * again) then do nothing, otherwise if recover_start > recover_block * then clear BLOCK_LOCKS. * * - parallel recovery steps across all nodes * * All nodes attempt to update the control_lock lvb with the new generation * number and jid bits, but only the first to get the control_lock EX will * do so; others will see that it's already done (lvb already contains new * generation number.) * * . All nodes get the same recover_prep/recover_slot/recover_done callbacks * . All nodes attempt to set control_lock lvb gen + bits for the new gen * . One node gets control_lock first and writes the lvb, others see it's done * . All nodes attempt to recover jids for which they see control_lock bits set * . One node succeeds for a jid, and that one clears the jid bit in the lvb * . All nodes will eventually see all lvb bits clear and unblock locks * * - is there a problem with clearing an lvb bit that should be set * and missing a journal recovery? * * 1. jid fails * 2. lvb bit set for step 1 * 3. jid recovered for step 1 * 4. jid taken again (new mount) * 5. jid fails (for step 4) * 6. lvb bit set for step 5 (will already be set) * 7. lvb bit cleared for step 3 * * This is not a problem because the failure in step 5 does not * require recovery, because the mount in step 4 could not have * progressed far enough to unblock locks and access the fs. The * control_mount() function waits for all recoveries to be complete * for the latest lockspace generation before ever unblocking locks * and returning. The mount in step 4 waits until the recovery in * step 1 is done. * * - special case of first mounter: first node to mount the fs * * The first node to mount a gfs2 fs needs to check all the journals * and recover any that need recovery before other nodes are allowed * to mount the fs. (Others may begin mounting, but they must wait * for the first mounter to be done before taking locks on the fs * or accessing the fs.) This has two parts: * * 1. The mounted_lock tells a node it's the first to mount the fs. * Each node holds the mounted_lock in PR while it's mounted. * Each node tries to acquire the mounted_lock in EX when it mounts. * If a node is granted the mounted_lock EX it means there are no * other mounted nodes (no PR locks exist), and it is the first mounter. * The mounted_lock is demoted to PR when first recovery is done, so * others will fail to get an EX lock, but will get a PR lock. * * 2. The control_lock blocks others in control_mount() while the first * mounter is doing first mount recovery of all journals. * A mounting node needs to acquire control_lock in EX mode before * it can proceed. The first mounter holds control_lock in EX while doing * the first mount recovery, blocking mounts from other nodes, then demotes * control_lock to NL when it's done (others_may_mount/first_done), * allowing other nodes to continue mounting. * * first mounter: * control_lock EX/NOQUEUE success * mounted_lock EX/NOQUEUE success (no other PR, so no other mounters) * set first=1 * do first mounter recovery * mounted_lock EX->PR * control_lock EX->NL, write lvb generation * * other mounter: * control_lock EX/NOQUEUE success (if fail -EAGAIN, retry) * mounted_lock EX/NOQUEUE fail -EAGAIN (expected due to other mounters PR) * mounted_lock PR/NOQUEUE success * read lvb generation * control_lock EX->NL * set first=0 * * - mount during recovery * * If a node mounts while others are doing recovery (not first mounter), * the mounting node will get its initial recover_done() callback without * having seen any previous failures/callbacks. * * It must wait for all recoveries preceding its mount to be finished * before it unblocks locks. It does this by repeating the "other mounter" * steps above until the lvb generation number is >= its mount generation * number (from initial recover_done) and all lvb bits are clear. * * - control_lock lvb format * * 4 bytes generation number: the latest dlm lockspace generation number * from recover_done callback. Indicates the jid bitmap has been updated * to reflect all slot failures through that generation. * 4 bytes unused. * GDLM_LVB_SIZE-8 bytes of jid bit map. If bit N is set, it indicates * that jid N needs recovery. */ #define JID_BITMAP_OFFSET 8 /* 4 byte generation number + 4 byte unused */ static void control_lvb_read(struct lm_lockstruct *ls, uint32_t *lvb_gen, char *lvb_bits) { __le32 gen; memcpy(lvb_bits, ls->ls_control_lvb, GDLM_LVB_SIZE); memcpy(&gen, lvb_bits, sizeof(__le32)); *lvb_gen = le32_to_cpu(gen); } static void control_lvb_write(struct lm_lockstruct *ls, uint32_t lvb_gen, char *lvb_bits) { __le32 gen; memcpy(ls->ls_control_lvb, lvb_bits, GDLM_LVB_SIZE); gen = cpu_to_le32(lvb_gen); memcpy(ls->ls_control_lvb, &gen, sizeof(__le32)); } static int all_jid_bits_clear(char *lvb) { return !memchr_inv(lvb + JID_BITMAP_OFFSET, 0, GDLM_LVB_SIZE - JID_BITMAP_OFFSET); } static void sync_wait_cb(void *arg) { struct lm_lockstruct *ls = arg; complete(&ls->ls_sync_wait); } static int sync_unlock(struct gfs2_sbd *sdp, struct dlm_lksb *lksb, char *name) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; int error; error = dlm_unlock(ls->ls_dlm, lksb->sb_lkid, 0, lksb, ls); if (error) { fs_err(sdp, "%s lkid %x error %d\n", name, lksb->sb_lkid, error); return error; } wait_for_completion(&ls->ls_sync_wait); if (lksb->sb_status != -DLM_EUNLOCK) { fs_err(sdp, "%s lkid %x status %d\n", name, lksb->sb_lkid, lksb->sb_status); return -1; } return 0; } static int sync_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags, unsigned int num, struct dlm_lksb *lksb, char *name) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; char strname[GDLM_STRNAME_BYTES]; int error, status; memset(strname, 0, GDLM_STRNAME_BYTES); snprintf(strname, GDLM_STRNAME_BYTES, "%8x%16x", LM_TYPE_NONDISK, num); error = dlm_lock(ls->ls_dlm, mode, lksb, flags, strname, GDLM_STRNAME_BYTES - 1, 0, sync_wait_cb, ls, NULL); if (error) { fs_err(sdp, "%s lkid %x flags %x mode %d error %d\n", name, lksb->sb_lkid, flags, mode, error); return error; } wait_for_completion(&ls->ls_sync_wait); status = lksb->sb_status; if (status && status != -EAGAIN) { fs_err(sdp, "%s lkid %x flags %x mode %d status %d\n", name, lksb->sb_lkid, flags, mode, status); } return status; } static int mounted_unlock(struct gfs2_sbd *sdp) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; return sync_unlock(sdp, &ls->ls_mounted_lksb, "mounted_lock"); } static int mounted_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; return sync_lock(sdp, mode, flags, GFS2_MOUNTED_LOCK, &ls->ls_mounted_lksb, "mounted_lock"); } static int control_unlock(struct gfs2_sbd *sdp) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; return sync_unlock(sdp, &ls->ls_control_lksb, "control_lock"); } static int control_lock(struct gfs2_sbd *sdp, int mode, uint32_t flags) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; return sync_lock(sdp, mode, flags, GFS2_CONTROL_LOCK, &ls->ls_control_lksb, "control_lock"); } static void gfs2_control_func(struct work_struct *work) { struct gfs2_sbd *sdp = container_of(work, struct gfs2_sbd, sd_control_work.work); struct lm_lockstruct *ls = &sdp->sd_lockstruct; uint32_t block_gen, start_gen, lvb_gen, flags; int recover_set = 0; int write_lvb = 0; int recover_size; int i, error; spin_lock(&ls->ls_recover_spin); /* * No MOUNT_DONE means we're still mounting; control_mount() * will set this flag, after which this thread will take over * all further clearing of BLOCK_LOCKS. * * FIRST_MOUNT means this node is doing first mounter recovery, * for which recovery control is handled by * control_mount()/control_first_done(), not this thread. */ if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) || test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) { spin_unlock(&ls->ls_recover_spin); return; } block_gen = ls->ls_recover_block; start_gen = ls->ls_recover_start; spin_unlock(&ls->ls_recover_spin); /* * Equal block_gen and start_gen implies we are between * recover_prep and recover_done callbacks, which means * dlm recovery is in progress and dlm locking is blocked. * There's no point trying to do any work until recover_done. */ if (block_gen == start_gen) return; /* * Propagate recover_submit[] and recover_result[] to lvb: * dlm_recoverd adds to recover_submit[] jids needing recovery * gfs2_recover adds to recover_result[] journal recovery results * * set lvb bit for jids in recover_submit[] if the lvb has not * yet been updated for the generation of the failure * * clear lvb bit for jids in recover_result[] if the result of * the journal recovery is SUCCESS */ error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_VALBLK); if (error) { fs_err(sdp, "control lock EX error %d\n", error); return; } control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits); spin_lock(&ls->ls_recover_spin); if (block_gen != ls->ls_recover_block || start_gen != ls->ls_recover_start) { fs_info(sdp, "recover generation %u block1 %u %u\n", start_gen, block_gen, ls->ls_recover_block); spin_unlock(&ls->ls_recover_spin); control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT); return; } recover_size = ls->ls_recover_size; if (lvb_gen <= start_gen) { /* * Clear lvb bits for jids we've successfully recovered. * Because all nodes attempt to recover failed journals, * a journal can be recovered multiple times successfully * in succession. Only the first will really do recovery, * the others find it clean, but still report a successful * recovery. So, another node may have already recovered * the jid and cleared the lvb bit for it. */ for (i = 0; i < recover_size; i++) { if (ls->ls_recover_result[i] != LM_RD_SUCCESS) continue; ls->ls_recover_result[i] = 0; if (!test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) continue; __clear_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET); write_lvb = 1; } } if (lvb_gen == start_gen) { /* * Failed slots before start_gen are already set in lvb. */ for (i = 0; i < recover_size; i++) { if (!ls->ls_recover_submit[i]) continue; if (ls->ls_recover_submit[i] < lvb_gen) ls->ls_recover_submit[i] = 0; } } else if (lvb_gen < start_gen) { /* * Failed slots before start_gen are not yet set in lvb. */ for (i = 0; i < recover_size; i++) { if (!ls->ls_recover_submit[i]) continue; if (ls->ls_recover_submit[i] < start_gen) { ls->ls_recover_submit[i] = 0; __set_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET); } } /* even if there are no bits to set, we need to write the latest generation to the lvb */ write_lvb = 1; } else { /* * we should be getting a recover_done() for lvb_gen soon */ } spin_unlock(&ls->ls_recover_spin); if (write_lvb) { control_lvb_write(ls, start_gen, ls->ls_lvb_bits); flags = DLM_LKF_CONVERT | DLM_LKF_VALBLK; } else { flags = DLM_LKF_CONVERT; } error = control_lock(sdp, DLM_LOCK_NL, flags); if (error) { fs_err(sdp, "control lock NL error %d\n", error); return; } /* * Everyone will see jid bits set in the lvb, run gfs2_recover_set(), * and clear a jid bit in the lvb if the recovery is a success. * Eventually all journals will be recovered, all jid bits will * be cleared in the lvb, and everyone will clear BLOCK_LOCKS. */ for (i = 0; i < recover_size; i++) { if (test_bit_le(i, ls->ls_lvb_bits + JID_BITMAP_OFFSET)) { fs_info(sdp, "recover generation %u jid %d\n", start_gen, i); gfs2_recover_set(sdp, i); recover_set++; } } if (recover_set) return; /* * No more jid bits set in lvb, all recovery is done, unblock locks * (unless a new recover_prep callback has occured blocking locks * again while working above) */ spin_lock(&ls->ls_recover_spin); if (ls->ls_recover_block == block_gen && ls->ls_recover_start == start_gen) { clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags); spin_unlock(&ls->ls_recover_spin); fs_info(sdp, "recover generation %u done\n", start_gen); gfs2_glock_thaw(sdp); } else { fs_info(sdp, "recover generation %u block2 %u %u\n", start_gen, block_gen, ls->ls_recover_block); spin_unlock(&ls->ls_recover_spin); } } static int control_mount(struct gfs2_sbd *sdp) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; uint32_t start_gen, block_gen, mount_gen, lvb_gen; int mounted_mode; int retries = 0; int error; memset(&ls->ls_mounted_lksb, 0, sizeof(struct dlm_lksb)); memset(&ls->ls_control_lksb, 0, sizeof(struct dlm_lksb)); memset(&ls->ls_control_lvb, 0, GDLM_LVB_SIZE); ls->ls_control_lksb.sb_lvbptr = ls->ls_control_lvb; init_completion(&ls->ls_sync_wait); set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags); error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_VALBLK); if (error) { fs_err(sdp, "control_mount control_lock NL error %d\n", error); return error; } error = mounted_lock(sdp, DLM_LOCK_NL, 0); if (error) { fs_err(sdp, "control_mount mounted_lock NL error %d\n", error); control_unlock(sdp); return error; } mounted_mode = DLM_LOCK_NL; restart: if (retries++ && signal_pending(current)) { error = -EINTR; goto fail; } /* * We always start with both locks in NL. control_lock is * demoted to NL below so we don't need to do it here. */ if (mounted_mode != DLM_LOCK_NL) { error = mounted_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT); if (error) goto fail; mounted_mode = DLM_LOCK_NL; } /* * Other nodes need to do some work in dlm recovery and gfs2_control * before the recover_done and control_lock will be ready for us below. * A delay here is not required but often avoids having to retry. */ msleep_interruptible(500); /* * Acquire control_lock in EX and mounted_lock in either EX or PR. * control_lock lvb keeps track of any pending journal recoveries. * mounted_lock indicates if any other nodes have the fs mounted. */ error = control_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE|DLM_LKF_VALBLK); if (error == -EAGAIN) { goto restart; } else if (error) { fs_err(sdp, "control_mount control_lock EX error %d\n", error); goto fail; } error = mounted_lock(sdp, DLM_LOCK_EX, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE); if (!error) { mounted_mode = DLM_LOCK_EX; goto locks_done; } else if (error != -EAGAIN) { fs_err(sdp, "control_mount mounted_lock EX error %d\n", error); goto fail; } error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_NOQUEUE); if (!error) { mounted_mode = DLM_LOCK_PR; goto locks_done; } else { /* not even -EAGAIN should happen here */ fs_err(sdp, "control_mount mounted_lock PR error %d\n", error); goto fail; } locks_done: /* * If we got both locks above in EX, then we're the first mounter. * If not, then we need to wait for the control_lock lvb to be * updated by other mounted nodes to reflect our mount generation. * * In simple first mounter cases, first mounter will see zero lvb_gen, * but in cases where all existing nodes leave/fail before mounting * nodes finish control_mount, then all nodes will be mounting and * lvb_gen will be non-zero. */ control_lvb_read(ls, &lvb_gen, ls->ls_lvb_bits); if (lvb_gen == 0xFFFFFFFF) { /* special value to force mount attempts to fail */ fs_err(sdp, "control_mount control_lock disabled\n"); error = -EINVAL; goto fail; } if (mounted_mode == DLM_LOCK_EX) { /* first mounter, keep both EX while doing first recovery */ spin_lock(&ls->ls_recover_spin); clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags); set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags); set_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags); spin_unlock(&ls->ls_recover_spin); fs_info(sdp, "first mounter control generation %u\n", lvb_gen); return 0; } error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT); if (error) goto fail; /* * We are not first mounter, now we need to wait for the control_lock * lvb generation to be >= the generation from our first recover_done * and all lvb bits to be clear (no pending journal recoveries.) */ if (!all_jid_bits_clear(ls->ls_lvb_bits)) { /* journals need recovery, wait until all are clear */ fs_info(sdp, "control_mount wait for journal recovery\n"); goto restart; } spin_lock(&ls->ls_recover_spin); block_gen = ls->ls_recover_block; start_gen = ls->ls_recover_start; mount_gen = ls->ls_recover_mount; if (lvb_gen < mount_gen) { /* wait for mounted nodes to update control_lock lvb to our generation, which might include new recovery bits set */ fs_info(sdp, "control_mount wait1 block %u start %u mount %u " "lvb %u flags %lx\n", block_gen, start_gen, mount_gen, lvb_gen, ls->ls_recover_flags); spin_unlock(&ls->ls_recover_spin); goto restart; } if (lvb_gen != start_gen) { /* wait for mounted nodes to update control_lock lvb to the latest recovery generation */ fs_info(sdp, "control_mount wait2 block %u start %u mount %u " "lvb %u flags %lx\n", block_gen, start_gen, mount_gen, lvb_gen, ls->ls_recover_flags); spin_unlock(&ls->ls_recover_spin); goto restart; } if (block_gen == start_gen) { /* dlm recovery in progress, wait for it to finish */ fs_info(sdp, "control_mount wait3 block %u start %u mount %u " "lvb %u flags %lx\n", block_gen, start_gen, mount_gen, lvb_gen, ls->ls_recover_flags); spin_unlock(&ls->ls_recover_spin); goto restart; } clear_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags); set_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags); memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t)); memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t)); spin_unlock(&ls->ls_recover_spin); return 0; fail: mounted_unlock(sdp); control_unlock(sdp); return error; } static int control_first_done(struct gfs2_sbd *sdp) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; uint32_t start_gen, block_gen; int error; restart: spin_lock(&ls->ls_recover_spin); start_gen = ls->ls_recover_start; block_gen = ls->ls_recover_block; if (test_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags) || !test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) || !test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) { /* sanity check, should not happen */ fs_err(sdp, "control_first_done start %u block %u flags %lx\n", start_gen, block_gen, ls->ls_recover_flags); spin_unlock(&ls->ls_recover_spin); control_unlock(sdp); return -1; } if (start_gen == block_gen) { /* * Wait for the end of a dlm recovery cycle to switch from * first mounter recovery. We can ignore any recover_slot * callbacks between the recover_prep and next recover_done * because we are still the first mounter and any failed nodes * have not fully mounted, so they don't need recovery. */ spin_unlock(&ls->ls_recover_spin); fs_info(sdp, "control_first_done wait gen %u\n", start_gen); wait_on_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY, TASK_UNINTERRUPTIBLE); goto restart; } clear_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags); set_bit(DFL_FIRST_MOUNT_DONE, &ls->ls_recover_flags); memset(ls->ls_recover_submit, 0, ls->ls_recover_size*sizeof(uint32_t)); memset(ls->ls_recover_result, 0, ls->ls_recover_size*sizeof(uint32_t)); spin_unlock(&ls->ls_recover_spin); memset(ls->ls_lvb_bits, 0, GDLM_LVB_SIZE); control_lvb_write(ls, start_gen, ls->ls_lvb_bits); error = mounted_lock(sdp, DLM_LOCK_PR, DLM_LKF_CONVERT); if (error) fs_err(sdp, "control_first_done mounted PR error %d\n", error); error = control_lock(sdp, DLM_LOCK_NL, DLM_LKF_CONVERT|DLM_LKF_VALBLK); if (error) fs_err(sdp, "control_first_done control NL error %d\n", error); return error; } /* * Expand static jid arrays if necessary (by increments of RECOVER_SIZE_INC) * to accomodate the largest slot number. (NB dlm slot numbers start at 1, * gfs2 jids start at 0, so jid = slot - 1) */ #define RECOVER_SIZE_INC 16 static int set_recover_size(struct gfs2_sbd *sdp, struct dlm_slot *slots, int num_slots) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; uint32_t *submit = NULL; uint32_t *result = NULL; uint32_t old_size, new_size; int i, max_jid; if (!ls->ls_lvb_bits) { ls->ls_lvb_bits = kzalloc(GDLM_LVB_SIZE, GFP_NOFS); if (!ls->ls_lvb_bits) return -ENOMEM; } max_jid = 0; for (i = 0; i < num_slots; i++) { if (max_jid < slots[i].slot - 1) max_jid = slots[i].slot - 1; } old_size = ls->ls_recover_size; if (old_size >= max_jid + 1) return 0; new_size = old_size + RECOVER_SIZE_INC; submit = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS); result = kcalloc(new_size, sizeof(uint32_t), GFP_NOFS); if (!submit || !result) { kfree(submit); kfree(result); return -ENOMEM; } spin_lock(&ls->ls_recover_spin); memcpy(submit, ls->ls_recover_submit, old_size * sizeof(uint32_t)); memcpy(result, ls->ls_recover_result, old_size * sizeof(uint32_t)); kfree(ls->ls_recover_submit); kfree(ls->ls_recover_result); ls->ls_recover_submit = submit; ls->ls_recover_result = result; ls->ls_recover_size = new_size; spin_unlock(&ls->ls_recover_spin); return 0; } static void free_recover_size(struct lm_lockstruct *ls) { kfree(ls->ls_lvb_bits); kfree(ls->ls_recover_submit); kfree(ls->ls_recover_result); ls->ls_recover_submit = NULL; ls->ls_recover_result = NULL; ls->ls_recover_size = 0; } /* dlm calls before it does lock recovery */ static void gdlm_recover_prep(void *arg) { struct gfs2_sbd *sdp = arg; struct lm_lockstruct *ls = &sdp->sd_lockstruct; spin_lock(&ls->ls_recover_spin); ls->ls_recover_block = ls->ls_recover_start; set_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags); if (!test_bit(DFL_MOUNT_DONE, &ls->ls_recover_flags) || test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) { spin_unlock(&ls->ls_recover_spin); return; } set_bit(DFL_BLOCK_LOCKS, &ls->ls_recover_flags); spin_unlock(&ls->ls_recover_spin); } /* dlm calls after recover_prep has been completed on all lockspace members; identifies slot/jid of failed member */ static void gdlm_recover_slot(void *arg, struct dlm_slot *slot) { struct gfs2_sbd *sdp = arg; struct lm_lockstruct *ls = &sdp->sd_lockstruct; int jid = slot->slot - 1; spin_lock(&ls->ls_recover_spin); if (ls->ls_recover_size < jid + 1) { fs_err(sdp, "recover_slot jid %d gen %u short size %d", jid, ls->ls_recover_block, ls->ls_recover_size); spin_unlock(&ls->ls_recover_spin); return; } if (ls->ls_recover_submit[jid]) { fs_info(sdp, "recover_slot jid %d gen %u prev %u\n", jid, ls->ls_recover_block, ls->ls_recover_submit[jid]); } ls->ls_recover_submit[jid] = ls->ls_recover_block; spin_unlock(&ls->ls_recover_spin); } /* dlm calls after recover_slot and after it completes lock recovery */ static void gdlm_recover_done(void *arg, struct dlm_slot *slots, int num_slots, int our_slot, uint32_t generation) { struct gfs2_sbd *sdp = arg; struct lm_lockstruct *ls = &sdp->sd_lockstruct; /* ensure the ls jid arrays are large enough */ set_recover_size(sdp, slots, num_slots); spin_lock(&ls->ls_recover_spin); ls->ls_recover_start = generation; if (!ls->ls_recover_mount) { ls->ls_recover_mount = generation; ls->ls_jid = our_slot - 1; } if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags)) queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work, 0); clear_bit(DFL_DLM_RECOVERY, &ls->ls_recover_flags); smp_mb__after_atomic(); wake_up_bit(&ls->ls_recover_flags, DFL_DLM_RECOVERY); spin_unlock(&ls->ls_recover_spin); } /* gfs2_recover thread has a journal recovery result */ static void gdlm_recovery_result(struct gfs2_sbd *sdp, unsigned int jid, unsigned int result) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags)) return; /* don't care about the recovery of own journal during mount */ if (jid == ls->ls_jid) return; spin_lock(&ls->ls_recover_spin); if (test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags)) { spin_unlock(&ls->ls_recover_spin); return; } if (ls->ls_recover_size < jid + 1) { fs_err(sdp, "recovery_result jid %d short size %d", jid, ls->ls_recover_size); spin_unlock(&ls->ls_recover_spin); return; } fs_info(sdp, "recover jid %d result %s\n", jid, result == LM_RD_GAVEUP ? "busy" : "success"); ls->ls_recover_result[jid] = result; /* GAVEUP means another node is recovering the journal; delay our next attempt to recover it, to give the other node a chance to finish before trying again */ if (!test_bit(DFL_UNMOUNT, &ls->ls_recover_flags)) queue_delayed_work(gfs2_control_wq, &sdp->sd_control_work, result == LM_RD_GAVEUP ? HZ : 0); spin_unlock(&ls->ls_recover_spin); } const struct dlm_lockspace_ops gdlm_lockspace_ops = { .recover_prep = gdlm_recover_prep, .recover_slot = gdlm_recover_slot, .recover_done = gdlm_recover_done, }; static int gdlm_mount(struct gfs2_sbd *sdp, const char *table) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; char cluster[GFS2_LOCKNAME_LEN]; const char *fsname; uint32_t flags; int error, ops_result; /* * initialize everything */ INIT_DELAYED_WORK(&sdp->sd_control_work, gfs2_control_func); spin_lock_init(&ls->ls_recover_spin); ls->ls_recover_flags = 0; ls->ls_recover_mount = 0; ls->ls_recover_start = 0; ls->ls_recover_block = 0; ls->ls_recover_size = 0; ls->ls_recover_submit = NULL; ls->ls_recover_result = NULL; ls->ls_lvb_bits = NULL; error = set_recover_size(sdp, NULL, 0); if (error) goto fail; /* * prepare dlm_new_lockspace args */ fsname = strchr(table, ':'); if (!fsname) { fs_info(sdp, "no fsname found\n"); error = -EINVAL; goto fail_free; } memset(cluster, 0, sizeof(cluster)); memcpy(cluster, table, strlen(table) - strlen(fsname)); fsname++; flags = DLM_LSFL_FS | DLM_LSFL_NEWEXCL; /* * create/join lockspace */ error = dlm_new_lockspace(fsname, cluster, flags, GDLM_LVB_SIZE, &gdlm_lockspace_ops, sdp, &ops_result, &ls->ls_dlm); if (error) { fs_err(sdp, "dlm_new_lockspace error %d\n", error); goto fail_free; } if (ops_result < 0) { /* * dlm does not support ops callbacks, * old dlm_controld/gfs_controld are used, try without ops. */ fs_info(sdp, "dlm lockspace ops not used\n"); free_recover_size(ls); set_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags); return 0; } if (!test_bit(SDF_NOJOURNALID, &sdp->sd_flags)) { fs_err(sdp, "dlm lockspace ops disallow jid preset\n"); error = -EINVAL; goto fail_release; } /* * control_mount() uses control_lock to determine first mounter, * and for later mounts, waits for any recoveries to be cleared. */ error = control_mount(sdp); if (error) { fs_err(sdp, "mount control error %d\n", error); goto fail_release; } ls->ls_first = !!test_bit(DFL_FIRST_MOUNT, &ls->ls_recover_flags); clear_bit(SDF_NOJOURNALID, &sdp->sd_flags); smp_mb__after_atomic(); wake_up_bit(&sdp->sd_flags, SDF_NOJOURNALID); return 0; fail_release: dlm_release_lockspace(ls->ls_dlm, 2); fail_free: free_recover_size(ls); fail: return error; } static void gdlm_first_done(struct gfs2_sbd *sdp) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; int error; if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags)) return; error = control_first_done(sdp); if (error) fs_err(sdp, "mount first_done error %d\n", error); } static void gdlm_unmount(struct gfs2_sbd *sdp) { struct lm_lockstruct *ls = &sdp->sd_lockstruct; if (test_bit(DFL_NO_DLM_OPS, &ls->ls_recover_flags)) goto release; /* wait for gfs2_control_wq to be done with this mount */ spin_lock(&ls->ls_recover_spin); set_bit(DFL_UNMOUNT, &ls->ls_recover_flags); spin_unlock(&ls->ls_recover_spin); flush_delayed_work(&sdp->sd_control_work); /* mounted_lock and control_lock will be purged in dlm recovery */ release: if (ls->ls_dlm) { dlm_release_lockspace(ls->ls_dlm, 2); ls->ls_dlm = NULL; } free_recover_size(ls); } static const match_table_t dlm_tokens = { { Opt_jid, "jid=%d"}, { Opt_id, "id=%d"}, { Opt_first, "first=%d"}, { Opt_nodir, "nodir=%d"}, { Opt_err, NULL }, }; const struct lm_lockops gfs2_dlm_ops = { .lm_proto_name = "lock_dlm", .lm_mount = gdlm_mount, .lm_first_done = gdlm_first_done, .lm_recovery_result = gdlm_recovery_result, .lm_unmount = gdlm_unmount, .lm_put_lock = gdlm_put_lock, .lm_lock = gdlm_lock, .lm_cancel = gdlm_cancel, .lm_tokens = &dlm_tokens, };