diff options
Diffstat (limited to 'fs/gfs2/lock_dlm.c')
| -rw-r--r-- | fs/gfs2/lock_dlm.c | 1352 |
1 files changed, 1352 insertions, 0 deletions
diff --git a/fs/gfs2/lock_dlm.c b/fs/gfs2/lock_dlm.c new file mode 100644 index 000000000..9e90e42c4 --- /dev/null +++ b/fs/gfs2/lock_dlm.c @@ -0,0 +1,1352 @@ +/* + * 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 <linux/fs.h> +#include <linux/dlm.h> +#include <linux/slab.h> +#include <linux/types.h> +#include <linux/delay.h> +#include <linux/gfs2_ondisk.h> +#include <linux/sched/signal.h> + +#include "incore.h" +#include "glock.h" +#include "util.h" +#include "sys.h" +#include "trace_gfs2.h" + +/** + * 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 variance estimate is a bit + * more complicated. We subtract the current variance estimate from + * the abs value of the @delta and add 1/4 of that to the running + * total. That's equivalent to 3/4 of the current variance + * estimate plus 1/4 of the abs of @delta. + * + * 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] += (s64)(abs(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_name.ln_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_name.ln_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_name.ln_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_name.ln_sbd; + struct lm_lockstruct *ls = &sdp->sd_lockstruct; + 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 call dlm if we've unmounted the lock protocol */ + if (test_bit(DFL_UNMOUNT, &ls->ls_recover_flags)) { + gfs2_glock_free(gl); + return; + } + /* don't want to skip dlm_unlock writing the lvb when lock has one */ + + if (test_bit(SDF_SKIP_DLM_UNLOCK, &sdp->sd_flags) && + !gl->gl_lksb.sb_lvbptr) { + 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_name.ln_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; + } + + /** + * If we're a spectator, we don't want to take the lock in EX because + * we cannot do the first-mount responsibility it implies: recovery. + */ + if (sdp->sd_args.ar_spectator) + goto locks_done; + + 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 */ + if (sdp->sd_args.ar_spectator) { + fs_info(sdp, "Recovery is required. Waiting for a " + "non-spectator to mount.\n"); + msleep_interruptible(1000); + } else { + 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; + ls->ls_lvb_bits = NULL; +} + +/* 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\n", + 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\n", + 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); +} + +static 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, +}; + |