diff options
Diffstat (limited to 'fs/gfs2/log.c')
| -rw-r--r-- | fs/gfs2/log.c | 1273 |
1 files changed, 1273 insertions, 0 deletions
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c new file mode 100644 index 000000000..7473b894e --- /dev/null +++ b/fs/gfs2/log.c @@ -0,0 +1,1273 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <linux/gfs2_ondisk.h> +#include <linux/crc32.h> +#include <linux/crc32c.h> +#include <linux/delay.h> +#include <linux/kthread.h> +#include <linux/freezer.h> +#include <linux/bio.h> +#include <linux/blkdev.h> +#include <linux/writeback.h> +#include <linux/list_sort.h> + +#include "gfs2.h" +#include "incore.h" +#include "bmap.h" +#include "glock.h" +#include "log.h" +#include "lops.h" +#include "meta_io.h" +#include "util.h" +#include "dir.h" +#include "trace_gfs2.h" +#include "trans.h" + +static void gfs2_log_shutdown(struct gfs2_sbd *sdp); + +/** + * gfs2_struct2blk - compute stuff + * @sdp: the filesystem + * @nstruct: the number of structures + * + * Compute the number of log descriptor blocks needed to hold a certain number + * of structures of a certain size. + * + * Returns: the number of blocks needed (minimum is always 1) + */ + +unsigned int gfs2_struct2blk(struct gfs2_sbd *sdp, unsigned int nstruct) +{ + unsigned int blks; + unsigned int first, second; + + blks = 1; + first = sdp->sd_ldptrs; + + if (nstruct > first) { + second = sdp->sd_inptrs; + blks += DIV_ROUND_UP(nstruct - first, second); + } + + return blks; +} + +/** + * gfs2_remove_from_ail - Remove an entry from the ail lists, updating counters + * @mapping: The associated mapping (maybe NULL) + * @bd: The gfs2_bufdata to remove + * + * The ail lock _must_ be held when calling this function + * + */ + +void gfs2_remove_from_ail(struct gfs2_bufdata *bd) +{ + bd->bd_tr = NULL; + list_del_init(&bd->bd_ail_st_list); + list_del_init(&bd->bd_ail_gl_list); + atomic_dec(&bd->bd_gl->gl_ail_count); + brelse(bd->bd_bh); +} + +/** + * gfs2_ail1_start_one - Start I/O on a part of the AIL + * @sdp: the filesystem + * @wbc: The writeback control structure + * @ai: The ail structure + * + */ + +static int gfs2_ail1_start_one(struct gfs2_sbd *sdp, + struct writeback_control *wbc, + struct gfs2_trans *tr) +__releases(&sdp->sd_ail_lock) +__acquires(&sdp->sd_ail_lock) +{ + struct gfs2_glock *gl = NULL; + struct address_space *mapping; + struct gfs2_bufdata *bd, *s; + struct buffer_head *bh; + int ret = 0; + + list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, bd_ail_st_list) { + bh = bd->bd_bh; + + gfs2_assert(sdp, bd->bd_tr == tr); + + if (!buffer_busy(bh)) { + if (buffer_uptodate(bh)) { + list_move(&bd->bd_ail_st_list, + &tr->tr_ail2_list); + continue; + } + if (!cmpxchg(&sdp->sd_log_error, 0, -EIO)) { + gfs2_io_error_bh(sdp, bh); + gfs2_withdraw_delayed(sdp); + } + } + + if (gfs2_withdrawn(sdp)) { + gfs2_remove_from_ail(bd); + continue; + } + if (!buffer_dirty(bh)) + continue; + if (gl == bd->bd_gl) + continue; + gl = bd->bd_gl; + list_move(&bd->bd_ail_st_list, &tr->tr_ail1_list); + mapping = bh->b_page->mapping; + if (!mapping) + continue; + spin_unlock(&sdp->sd_ail_lock); + ret = generic_writepages(mapping, wbc); + spin_lock(&sdp->sd_ail_lock); + if (ret == -ENODATA) /* if a jdata write into a new hole */ + ret = 0; /* ignore it */ + if (ret || wbc->nr_to_write <= 0) + break; + return -EBUSY; + } + + return ret; +} + +static void dump_ail_list(struct gfs2_sbd *sdp) +{ + struct gfs2_trans *tr; + struct gfs2_bufdata *bd; + struct buffer_head *bh; + + list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) { + list_for_each_entry_reverse(bd, &tr->tr_ail1_list, + bd_ail_st_list) { + bh = bd->bd_bh; + fs_err(sdp, "bd %p: blk:0x%llx bh=%p ", bd, + (unsigned long long)bd->bd_blkno, bh); + if (!bh) { + fs_err(sdp, "\n"); + continue; + } + fs_err(sdp, "0x%llx up2:%d dirt:%d lkd:%d req:%d " + "map:%d new:%d ar:%d aw:%d delay:%d " + "io err:%d unwritten:%d dfr:%d pin:%d esc:%d\n", + (unsigned long long)bh->b_blocknr, + buffer_uptodate(bh), buffer_dirty(bh), + buffer_locked(bh), buffer_req(bh), + buffer_mapped(bh), buffer_new(bh), + buffer_async_read(bh), buffer_async_write(bh), + buffer_delay(bh), buffer_write_io_error(bh), + buffer_unwritten(bh), + buffer_defer_completion(bh), + buffer_pinned(bh), buffer_escaped(bh)); + } + } +} + +/** + * gfs2_ail1_flush - start writeback of some ail1 entries + * @sdp: The super block + * @wbc: The writeback control structure + * + * Writes back some ail1 entries, according to the limits in the + * writeback control structure + */ + +void gfs2_ail1_flush(struct gfs2_sbd *sdp, struct writeback_control *wbc) +{ + struct list_head *head = &sdp->sd_ail1_list; + struct gfs2_trans *tr; + struct blk_plug plug; + int ret; + unsigned long flush_start = jiffies; + + trace_gfs2_ail_flush(sdp, wbc, 1); + blk_start_plug(&plug); + spin_lock(&sdp->sd_ail_lock); +restart: + ret = 0; + if (time_after(jiffies, flush_start + (HZ * 600))) { + fs_err(sdp, "Error: In %s for ten minutes! t=%d\n", + __func__, current->journal_info ? 1 : 0); + dump_ail_list(sdp); + goto out; + } + list_for_each_entry_reverse(tr, head, tr_list) { + if (wbc->nr_to_write <= 0) + break; + ret = gfs2_ail1_start_one(sdp, wbc, tr); + if (ret) { + if (ret == -EBUSY) + goto restart; + break; + } + } +out: + spin_unlock(&sdp->sd_ail_lock); + blk_finish_plug(&plug); + if (ret) { + gfs2_lm(sdp, "gfs2_ail1_start_one (generic_writepages) " + "returned: %d\n", ret); + gfs2_withdraw(sdp); + } + trace_gfs2_ail_flush(sdp, wbc, 0); +} + +/** + * gfs2_ail1_start - start writeback of all ail1 entries + * @sdp: The superblock + */ + +static void gfs2_ail1_start(struct gfs2_sbd *sdp) +{ + struct writeback_control wbc = { + .sync_mode = WB_SYNC_NONE, + .nr_to_write = LONG_MAX, + .range_start = 0, + .range_end = LLONG_MAX, + }; + + return gfs2_ail1_flush(sdp, &wbc); +} + +/** + * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced + * @sdp: the filesystem + * @tr: the transaction + * @max_revokes: If nonzero, issue revokes for the bd items for written buffers + * + * returns: the transaction's count of remaining active items + */ + +static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr, + int *max_revokes) +{ + struct gfs2_bufdata *bd, *s; + struct buffer_head *bh; + int active_count = 0; + + list_for_each_entry_safe_reverse(bd, s, &tr->tr_ail1_list, + bd_ail_st_list) { + bh = bd->bd_bh; + gfs2_assert(sdp, bd->bd_tr == tr); + /* + * If another process flagged an io error, e.g. writing to the + * journal, error all other bhs and move them off the ail1 to + * prevent a tight loop when unmount tries to flush ail1, + * regardless of whether they're still busy. If no outside + * errors were found and the buffer is busy, move to the next. + * If the ail buffer is not busy and caught an error, flag it + * for others. + */ + if (!sdp->sd_log_error && buffer_busy(bh)) { + active_count++; + continue; + } + if (!buffer_uptodate(bh) && + !cmpxchg(&sdp->sd_log_error, 0, -EIO)) { + gfs2_io_error_bh(sdp, bh); + gfs2_withdraw_delayed(sdp); + } + /* + * If we have space for revokes and the bd is no longer on any + * buf list, we can just add a revoke for it immediately and + * avoid having to put it on the ail2 list, where it would need + * to be revoked later. + */ + if (*max_revokes && list_empty(&bd->bd_list)) { + gfs2_add_revoke(sdp, bd); + (*max_revokes)--; + continue; + } + list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list); + } + return active_count; +} + +/** + * gfs2_ail1_empty - Try to empty the ail1 lists + * @sdp: The superblock + * @max_revokes: If non-zero, add revokes where appropriate + * + * Tries to empty the ail1 lists, starting with the oldest first + */ + +static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int max_revokes) +{ + struct gfs2_trans *tr, *s; + int oldest_tr = 1; + int ret; + + spin_lock(&sdp->sd_ail_lock); + list_for_each_entry_safe_reverse(tr, s, &sdp->sd_ail1_list, tr_list) { + if (!gfs2_ail1_empty_one(sdp, tr, &max_revokes) && oldest_tr) + list_move(&tr->tr_list, &sdp->sd_ail2_list); + else + oldest_tr = 0; + } + ret = list_empty(&sdp->sd_ail1_list); + spin_unlock(&sdp->sd_ail_lock); + + if (test_bit(SDF_WITHDRAWING, &sdp->sd_flags)) { + gfs2_lm(sdp, "fatal: I/O error(s)\n"); + gfs2_withdraw(sdp); + } + + return ret; +} + +static void gfs2_ail1_wait(struct gfs2_sbd *sdp) +{ + struct gfs2_trans *tr; + struct gfs2_bufdata *bd; + struct buffer_head *bh; + + spin_lock(&sdp->sd_ail_lock); + list_for_each_entry_reverse(tr, &sdp->sd_ail1_list, tr_list) { + list_for_each_entry(bd, &tr->tr_ail1_list, bd_ail_st_list) { + bh = bd->bd_bh; + if (!buffer_locked(bh)) + continue; + get_bh(bh); + spin_unlock(&sdp->sd_ail_lock); + wait_on_buffer(bh); + brelse(bh); + return; + } + } + spin_unlock(&sdp->sd_ail_lock); +} + +/** + * gfs2_ail_empty_tr - empty one of the ail lists for a transaction + */ + +static void gfs2_ail_empty_tr(struct gfs2_sbd *sdp, struct gfs2_trans *tr, + struct list_head *head) +{ + struct gfs2_bufdata *bd; + + while (!list_empty(head)) { + bd = list_first_entry(head, struct gfs2_bufdata, + bd_ail_st_list); + gfs2_assert(sdp, bd->bd_tr == tr); + gfs2_remove_from_ail(bd); + } +} + +static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail) +{ + struct gfs2_trans *tr, *safe; + unsigned int old_tail = sdp->sd_log_tail; + int wrap = (new_tail < old_tail); + int a, b, rm; + + spin_lock(&sdp->sd_ail_lock); + + list_for_each_entry_safe(tr, safe, &sdp->sd_ail2_list, tr_list) { + a = (old_tail <= tr->tr_first); + b = (tr->tr_first < new_tail); + rm = (wrap) ? (a || b) : (a && b); + if (!rm) + continue; + + gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list); + list_del(&tr->tr_list); + gfs2_assert_warn(sdp, list_empty(&tr->tr_ail1_list)); + gfs2_assert_warn(sdp, list_empty(&tr->tr_ail2_list)); + gfs2_trans_free(sdp, tr); + } + + spin_unlock(&sdp->sd_ail_lock); +} + +/** + * gfs2_log_release - Release a given number of log blocks + * @sdp: The GFS2 superblock + * @blks: The number of blocks + * + */ + +void gfs2_log_release(struct gfs2_sbd *sdp, unsigned int blks) +{ + + atomic_add(blks, &sdp->sd_log_blks_free); + trace_gfs2_log_blocks(sdp, blks); + gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= + sdp->sd_jdesc->jd_blocks); + up_read(&sdp->sd_log_flush_lock); +} + +/** + * gfs2_log_reserve - Make a log reservation + * @sdp: The GFS2 superblock + * @blks: The number of blocks to reserve + * + * Note that we never give out the last few blocks of the journal. Thats + * due to the fact that there is a small number of header blocks + * associated with each log flush. The exact number can't be known until + * flush time, so we ensure that we have just enough free blocks at all + * times to avoid running out during a log flush. + * + * We no longer flush the log here, instead we wake up logd to do that + * for us. To avoid the thundering herd and to ensure that we deal fairly + * with queued waiters, we use an exclusive wait. This means that when we + * get woken with enough journal space to get our reservation, we need to + * wake the next waiter on the list. + * + * Returns: errno + */ + +int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) +{ + int ret = 0; + unsigned reserved_blks = 7 * (4096 / sdp->sd_vfs->s_blocksize); + unsigned wanted = blks + reserved_blks; + DEFINE_WAIT(wait); + int did_wait = 0; + unsigned int free_blocks; + + if (gfs2_assert_warn(sdp, blks) || + gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) + return -EINVAL; + atomic_add(blks, &sdp->sd_log_blks_needed); +retry: + free_blocks = atomic_read(&sdp->sd_log_blks_free); + if (unlikely(free_blocks <= wanted)) { + do { + prepare_to_wait_exclusive(&sdp->sd_log_waitq, &wait, + TASK_UNINTERRUPTIBLE); + wake_up(&sdp->sd_logd_waitq); + did_wait = 1; + if (atomic_read(&sdp->sd_log_blks_free) <= wanted) + io_schedule(); + free_blocks = atomic_read(&sdp->sd_log_blks_free); + } while(free_blocks <= wanted); + finish_wait(&sdp->sd_log_waitq, &wait); + } + atomic_inc(&sdp->sd_reserving_log); + if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks, + free_blocks - blks) != free_blocks) { + if (atomic_dec_and_test(&sdp->sd_reserving_log)) + wake_up(&sdp->sd_reserving_log_wait); + goto retry; + } + atomic_sub(blks, &sdp->sd_log_blks_needed); + trace_gfs2_log_blocks(sdp, -blks); + + /* + * If we waited, then so might others, wake them up _after_ we get + * our share of the log. + */ + if (unlikely(did_wait)) + wake_up(&sdp->sd_log_waitq); + + down_read(&sdp->sd_log_flush_lock); + if (unlikely(!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))) { + gfs2_log_release(sdp, blks); + ret = -EROFS; + } + if (atomic_dec_and_test(&sdp->sd_reserving_log)) + wake_up(&sdp->sd_reserving_log_wait); + return ret; +} + +/** + * log_distance - Compute distance between two journal blocks + * @sdp: The GFS2 superblock + * @newer: The most recent journal block of the pair + * @older: The older journal block of the pair + * + * Compute the distance (in the journal direction) between two + * blocks in the journal + * + * Returns: the distance in blocks + */ + +static inline unsigned int log_distance(struct gfs2_sbd *sdp, unsigned int newer, + unsigned int older) +{ + int dist; + + dist = newer - older; + if (dist < 0) + dist += sdp->sd_jdesc->jd_blocks; + + return dist; +} + +/** + * calc_reserved - Calculate the number of blocks to reserve when + * refunding a transaction's unused buffers. + * @sdp: The GFS2 superblock + * + * This is complex. We need to reserve room for all our currently used + * metadata buffers (e.g. normal file I/O rewriting file time stamps) and + * all our journaled data buffers for journaled files (e.g. files in the + * meta_fs like rindex, or files for which chattr +j was done.) + * If we don't reserve enough space, gfs2_log_refund and gfs2_log_flush + * will count it as free space (sd_log_blks_free) and corruption will follow. + * + * We can have metadata bufs and jdata bufs in the same journal. So each + * type gets its own log header, for which we need to reserve a block. + * In fact, each type has the potential for needing more than one header + * in cases where we have more buffers than will fit on a journal page. + * Metadata journal entries take up half the space of journaled buffer entries. + * Thus, metadata entries have buf_limit (502) and journaled buffers have + * databuf_limit (251) before they cause a wrap around. + * + * Also, we need to reserve blocks for revoke journal entries and one for an + * overall header for the lot. + * + * Returns: the number of blocks reserved + */ +static unsigned int calc_reserved(struct gfs2_sbd *sdp) +{ + unsigned int reserved = 0; + unsigned int mbuf; + unsigned int dbuf; + struct gfs2_trans *tr = sdp->sd_log_tr; + + if (tr) { + mbuf = tr->tr_num_buf_new - tr->tr_num_buf_rm; + dbuf = tr->tr_num_databuf_new - tr->tr_num_databuf_rm; + reserved = mbuf + dbuf; + /* Account for header blocks */ + reserved += DIV_ROUND_UP(mbuf, buf_limit(sdp)); + reserved += DIV_ROUND_UP(dbuf, databuf_limit(sdp)); + } + + if (sdp->sd_log_committed_revoke > 0) + reserved += gfs2_struct2blk(sdp, sdp->sd_log_committed_revoke); + /* One for the overall header */ + if (reserved) + reserved++; + return reserved; +} + +static unsigned int current_tail(struct gfs2_sbd *sdp) +{ + struct gfs2_trans *tr; + unsigned int tail; + + spin_lock(&sdp->sd_ail_lock); + + if (list_empty(&sdp->sd_ail1_list)) { + tail = sdp->sd_log_head; + } else { + tr = list_last_entry(&sdp->sd_ail1_list, struct gfs2_trans, + tr_list); + tail = tr->tr_first; + } + + spin_unlock(&sdp->sd_ail_lock); + + return tail; +} + +static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail) +{ + unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail); + + ail2_empty(sdp, new_tail); + + atomic_add(dist, &sdp->sd_log_blks_free); + trace_gfs2_log_blocks(sdp, dist); + gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= + sdp->sd_jdesc->jd_blocks); + + sdp->sd_log_tail = new_tail; +} + + +void log_flush_wait(struct gfs2_sbd *sdp) +{ + DEFINE_WAIT(wait); + + if (atomic_read(&sdp->sd_log_in_flight)) { + do { + prepare_to_wait(&sdp->sd_log_flush_wait, &wait, + TASK_UNINTERRUPTIBLE); + if (atomic_read(&sdp->sd_log_in_flight)) + io_schedule(); + } while(atomic_read(&sdp->sd_log_in_flight)); + finish_wait(&sdp->sd_log_flush_wait, &wait); + } +} + +static int ip_cmp(void *priv, const struct list_head *a, const struct list_head *b) +{ + struct gfs2_inode *ipa, *ipb; + + ipa = list_entry(a, struct gfs2_inode, i_ordered); + ipb = list_entry(b, struct gfs2_inode, i_ordered); + + if (ipa->i_no_addr < ipb->i_no_addr) + return -1; + if (ipa->i_no_addr > ipb->i_no_addr) + return 1; + return 0; +} + +static void __ordered_del_inode(struct gfs2_inode *ip) +{ + if (!list_empty(&ip->i_ordered)) + list_del_init(&ip->i_ordered); +} + +static void gfs2_ordered_write(struct gfs2_sbd *sdp) +{ + struct gfs2_inode *ip; + LIST_HEAD(written); + + spin_lock(&sdp->sd_ordered_lock); + list_sort(NULL, &sdp->sd_log_ordered, &ip_cmp); + while (!list_empty(&sdp->sd_log_ordered)) { + ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered); + if (ip->i_inode.i_mapping->nrpages == 0) { + __ordered_del_inode(ip); + continue; + } + list_move(&ip->i_ordered, &written); + spin_unlock(&sdp->sd_ordered_lock); + filemap_fdatawrite(ip->i_inode.i_mapping); + spin_lock(&sdp->sd_ordered_lock); + } + list_splice(&written, &sdp->sd_log_ordered); + spin_unlock(&sdp->sd_ordered_lock); +} + +static void gfs2_ordered_wait(struct gfs2_sbd *sdp) +{ + struct gfs2_inode *ip; + + spin_lock(&sdp->sd_ordered_lock); + while (!list_empty(&sdp->sd_log_ordered)) { + ip = list_first_entry(&sdp->sd_log_ordered, struct gfs2_inode, i_ordered); + __ordered_del_inode(ip); + if (ip->i_inode.i_mapping->nrpages == 0) + continue; + spin_unlock(&sdp->sd_ordered_lock); + filemap_fdatawait(ip->i_inode.i_mapping); + spin_lock(&sdp->sd_ordered_lock); + } + spin_unlock(&sdp->sd_ordered_lock); +} + +void gfs2_ordered_del_inode(struct gfs2_inode *ip) +{ + struct gfs2_sbd *sdp = GFS2_SB(&ip->i_inode); + + spin_lock(&sdp->sd_ordered_lock); + __ordered_del_inode(ip); + spin_unlock(&sdp->sd_ordered_lock); +} + +void gfs2_add_revoke(struct gfs2_sbd *sdp, struct gfs2_bufdata *bd) +{ + struct buffer_head *bh = bd->bd_bh; + struct gfs2_glock *gl = bd->bd_gl; + + sdp->sd_log_num_revoke++; + if (atomic_inc_return(&gl->gl_revokes) == 1) + gfs2_glock_hold(gl); + bh->b_private = NULL; + bd->bd_blkno = bh->b_blocknr; + gfs2_remove_from_ail(bd); /* drops ref on bh */ + bd->bd_bh = NULL; + set_bit(GLF_LFLUSH, &gl->gl_flags); + list_add(&bd->bd_list, &sdp->sd_log_revokes); +} + +void gfs2_glock_remove_revoke(struct gfs2_glock *gl) +{ + if (atomic_dec_return(&gl->gl_revokes) == 0) { + clear_bit(GLF_LFLUSH, &gl->gl_flags); + gfs2_glock_queue_put(gl); + } +} + +/** + * gfs2_write_revokes - Add as many revokes to the system transaction as we can + * @sdp: The GFS2 superblock + * + * Our usual strategy is to defer writing revokes as much as we can in the hope + * that we'll eventually overwrite the journal, which will make those revokes + * go away. This changes when we flush the log: at that point, there will + * likely be some left-over space in the last revoke block of that transaction. + * We can fill that space with additional revokes for blocks that have already + * been written back. This will basically come at no cost now, and will save + * us from having to keep track of those blocks on the AIL2 list later. + */ +void gfs2_write_revokes(struct gfs2_sbd *sdp) +{ + /* number of revokes we still have room for */ + int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64); + + gfs2_log_lock(sdp); + while (sdp->sd_log_num_revoke > max_revokes) + max_revokes += (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / sizeof(u64); + max_revokes -= sdp->sd_log_num_revoke; + if (!sdp->sd_log_num_revoke) { + atomic_dec(&sdp->sd_log_blks_free); + /* If no blocks have been reserved, we need to also + * reserve a block for the header */ + if (!sdp->sd_log_blks_reserved) { + atomic_dec(&sdp->sd_log_blks_free); + trace_gfs2_log_blocks(sdp, -2); + } else { + trace_gfs2_log_blocks(sdp, -1); + } + } + gfs2_ail1_empty(sdp, max_revokes); + gfs2_log_unlock(sdp); + + if (!sdp->sd_log_num_revoke) { + atomic_inc(&sdp->sd_log_blks_free); + if (!sdp->sd_log_blks_reserved) { + atomic_inc(&sdp->sd_log_blks_free); + trace_gfs2_log_blocks(sdp, 2); + } else { + trace_gfs2_log_blocks(sdp, 1); + } + } +} + +/** + * gfs2_write_log_header - Write a journal log header buffer at lblock + * @sdp: The GFS2 superblock + * @jd: journal descriptor of the journal to which we are writing + * @seq: sequence number + * @tail: tail of the log + * @lblock: value for lh_blkno (block number relative to start of journal) + * @flags: log header flags GFS2_LOG_HEAD_* + * @op_flags: flags to pass to the bio + * + * Returns: the initialized log buffer descriptor + */ + +void gfs2_write_log_header(struct gfs2_sbd *sdp, struct gfs2_jdesc *jd, + u64 seq, u32 tail, u32 lblock, u32 flags, + int op_flags) +{ + struct gfs2_log_header *lh; + u32 hash, crc; + struct page *page; + struct gfs2_statfs_change_host *l_sc = &sdp->sd_statfs_local; + struct timespec64 tv; + struct super_block *sb = sdp->sd_vfs; + u64 dblock; + + if (gfs2_withdrawn(sdp)) + goto out; + + page = mempool_alloc(gfs2_page_pool, GFP_NOIO); + lh = page_address(page); + clear_page(lh); + + lh->lh_header.mh_magic = cpu_to_be32(GFS2_MAGIC); + lh->lh_header.mh_type = cpu_to_be32(GFS2_METATYPE_LH); + lh->lh_header.__pad0 = cpu_to_be64(0); + lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH); + lh->lh_header.mh_jid = cpu_to_be32(sdp->sd_jdesc->jd_jid); + lh->lh_sequence = cpu_to_be64(seq); + lh->lh_flags = cpu_to_be32(flags); + lh->lh_tail = cpu_to_be32(tail); + lh->lh_blkno = cpu_to_be32(lblock); + hash = ~crc32(~0, lh, LH_V1_SIZE); + lh->lh_hash = cpu_to_be32(hash); + + ktime_get_coarse_real_ts64(&tv); + lh->lh_nsec = cpu_to_be32(tv.tv_nsec); + lh->lh_sec = cpu_to_be64(tv.tv_sec); + if (!list_empty(&jd->extent_list)) + dblock = gfs2_log_bmap(jd, lblock); + else { + int ret = gfs2_lblk_to_dblk(jd->jd_inode, lblock, &dblock); + if (gfs2_assert_withdraw(sdp, ret == 0)) + return; + } + lh->lh_addr = cpu_to_be64(dblock); + lh->lh_jinode = cpu_to_be64(GFS2_I(jd->jd_inode)->i_no_addr); + + /* We may only write local statfs, quota, etc., when writing to our + own journal. The values are left 0 when recovering a journal + different from our own. */ + if (!(flags & GFS2_LOG_HEAD_RECOVERY)) { + lh->lh_statfs_addr = + cpu_to_be64(GFS2_I(sdp->sd_sc_inode)->i_no_addr); + lh->lh_quota_addr = + cpu_to_be64(GFS2_I(sdp->sd_qc_inode)->i_no_addr); + + spin_lock(&sdp->sd_statfs_spin); + lh->lh_local_total = cpu_to_be64(l_sc->sc_total); + lh->lh_local_free = cpu_to_be64(l_sc->sc_free); + lh->lh_local_dinodes = cpu_to_be64(l_sc->sc_dinodes); + spin_unlock(&sdp->sd_statfs_spin); + } + + BUILD_BUG_ON(offsetof(struct gfs2_log_header, lh_crc) != LH_V1_SIZE); + + crc = crc32c(~0, (void *)lh + LH_V1_SIZE + 4, + sb->s_blocksize - LH_V1_SIZE - 4); + lh->lh_crc = cpu_to_be32(crc); + + gfs2_log_write(sdp, page, sb->s_blocksize, 0, dblock); + gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE | op_flags); +out: + log_flush_wait(sdp); +} + +/** + * log_write_header - Get and initialize a journal header buffer + * @sdp: The GFS2 superblock + * @flags: The log header flags, including log header origin + * + * Returns: the initialized log buffer descriptor + */ + +static void log_write_header(struct gfs2_sbd *sdp, u32 flags) +{ + unsigned int tail; + int op_flags = REQ_PREFLUSH | REQ_FUA | REQ_META | REQ_SYNC; + enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state); + + gfs2_assert_withdraw(sdp, (state != SFS_FROZEN)); + tail = current_tail(sdp); + + if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) { + gfs2_ordered_wait(sdp); + log_flush_wait(sdp); + op_flags = REQ_SYNC | REQ_META | REQ_PRIO; + } + sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); + gfs2_write_log_header(sdp, sdp->sd_jdesc, sdp->sd_log_sequence++, tail, + sdp->sd_log_flush_head, flags, op_flags); + gfs2_log_incr_head(sdp); + + if (sdp->sd_log_tail != tail) + log_pull_tail(sdp, tail); +} + +/** + * ail_drain - drain the ail lists after a withdraw + * @sdp: Pointer to GFS2 superblock + */ +static void ail_drain(struct gfs2_sbd *sdp) +{ + struct gfs2_trans *tr; + + spin_lock(&sdp->sd_ail_lock); + /* + * For transactions on the sd_ail1_list we need to drain both the + * ail1 and ail2 lists. That's because function gfs2_ail1_start_one + * (temporarily) moves items from its tr_ail1 list to tr_ail2 list + * before revokes are sent for that block. Items on the sd_ail2_list + * should have already gotten beyond that point, so no need. + */ + while (!list_empty(&sdp->sd_ail1_list)) { + tr = list_first_entry(&sdp->sd_ail1_list, struct gfs2_trans, + tr_list); + gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail1_list); + gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list); + list_del(&tr->tr_list); + gfs2_trans_free(sdp, tr); + } + while (!list_empty(&sdp->sd_ail2_list)) { + tr = list_first_entry(&sdp->sd_ail2_list, struct gfs2_trans, + tr_list); + gfs2_ail_empty_tr(sdp, tr, &tr->tr_ail2_list); + list_del(&tr->tr_list); + gfs2_trans_free(sdp, tr); + } + spin_unlock(&sdp->sd_ail_lock); +} + +/** + * empty_ail1_list - try to start IO and empty the ail1 list + * @sdp: Pointer to GFS2 superblock + */ +static void empty_ail1_list(struct gfs2_sbd *sdp) +{ + unsigned long start = jiffies; + + for (;;) { + if (time_after(jiffies, start + (HZ * 600))) { + fs_err(sdp, "Error: In %s for 10 minutes! t=%d\n", + __func__, current->journal_info ? 1 : 0); + dump_ail_list(sdp); + return; + } + gfs2_ail1_start(sdp); + gfs2_ail1_wait(sdp); + if (gfs2_ail1_empty(sdp, 0)) + return; + } +} + +/** + * trans_drain - drain the buf and databuf queue for a failed transaction + * @tr: the transaction to drain + * + * When this is called, we're taking an error exit for a log write that failed + * but since we bypassed the after_commit functions, we need to remove the + * items from the buf and databuf queue. + */ +static void trans_drain(struct gfs2_trans *tr) +{ + struct gfs2_bufdata *bd; + struct list_head *head; + + if (!tr) + return; + + head = &tr->tr_buf; + while (!list_empty(head)) { + bd = list_first_entry(head, struct gfs2_bufdata, bd_list); + list_del_init(&bd->bd_list); + if (!list_empty(&bd->bd_ail_st_list)) + gfs2_remove_from_ail(bd); + kmem_cache_free(gfs2_bufdata_cachep, bd); + } + head = &tr->tr_databuf; + while (!list_empty(head)) { + bd = list_first_entry(head, struct gfs2_bufdata, bd_list); + list_del_init(&bd->bd_list); + if (!list_empty(&bd->bd_ail_st_list)) + gfs2_remove_from_ail(bd); + kmem_cache_free(gfs2_bufdata_cachep, bd); + } +} + +/** + * gfs2_log_flush - flush incore transaction(s) + * @sdp: the filesystem + * @gl: The glock structure to flush. If NULL, flush the whole incore log + * @flags: The log header flags: GFS2_LOG_HEAD_FLUSH_* and debug flags + * + */ + +void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, u32 flags) +{ + struct gfs2_trans *tr = NULL; + enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state); + + down_write(&sdp->sd_log_flush_lock); + + /* + * Do this check while holding the log_flush_lock to prevent new + * buffers from being added to the ail via gfs2_pin() + */ + if (gfs2_withdrawn(sdp)) + goto out; + + /* Log might have been flushed while we waited for the flush lock */ + if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) + goto out; + trace_gfs2_log_flush(sdp, 1, flags); + + if (flags & GFS2_LOG_HEAD_FLUSH_SHUTDOWN) + clear_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags); + + sdp->sd_log_flush_head = sdp->sd_log_head; + tr = sdp->sd_log_tr; + if (tr) { + sdp->sd_log_tr = NULL; + tr->tr_first = sdp->sd_log_flush_head; + if (unlikely (state == SFS_FROZEN)) + if (gfs2_assert_withdraw_delayed(sdp, + !tr->tr_num_buf_new && !tr->tr_num_databuf_new)) + goto out_withdraw; + } + + if (unlikely(state == SFS_FROZEN)) + if (gfs2_assert_withdraw_delayed(sdp, !sdp->sd_log_num_revoke)) + goto out_withdraw; + if (gfs2_assert_withdraw_delayed(sdp, + sdp->sd_log_num_revoke == sdp->sd_log_committed_revoke)) + goto out_withdraw; + + gfs2_ordered_write(sdp); + if (gfs2_withdrawn(sdp)) + goto out_withdraw; + lops_before_commit(sdp, tr); + if (gfs2_withdrawn(sdp)) + goto out_withdraw; + gfs2_log_submit_bio(&sdp->sd_log_bio, REQ_OP_WRITE); + if (gfs2_withdrawn(sdp)) + goto out_withdraw; + + if (sdp->sd_log_head != sdp->sd_log_flush_head) { + log_flush_wait(sdp); + log_write_header(sdp, flags); + } else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){ + atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ + trace_gfs2_log_blocks(sdp, -1); + log_write_header(sdp, flags); + } + if (gfs2_withdrawn(sdp)) + goto out_withdraw; + lops_after_commit(sdp, tr); + + gfs2_log_lock(sdp); + sdp->sd_log_head = sdp->sd_log_flush_head; + sdp->sd_log_blks_reserved = 0; + sdp->sd_log_committed_revoke = 0; + + spin_lock(&sdp->sd_ail_lock); + if (tr && !list_empty(&tr->tr_ail1_list)) { + list_add(&tr->tr_list, &sdp->sd_ail1_list); + tr = NULL; + } + spin_unlock(&sdp->sd_ail_lock); + gfs2_log_unlock(sdp); + + if (!(flags & GFS2_LOG_HEAD_FLUSH_NORMAL)) { + if (!sdp->sd_log_idle) { + empty_ail1_list(sdp); + if (gfs2_withdrawn(sdp)) + goto out_withdraw; + atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ + trace_gfs2_log_blocks(sdp, -1); + log_write_header(sdp, flags); + sdp->sd_log_head = sdp->sd_log_flush_head; + } + if (flags & (GFS2_LOG_HEAD_FLUSH_SHUTDOWN | + GFS2_LOG_HEAD_FLUSH_FREEZE)) + gfs2_log_shutdown(sdp); + if (flags & GFS2_LOG_HEAD_FLUSH_FREEZE) + atomic_set(&sdp->sd_freeze_state, SFS_FROZEN); + } + +out_end: + trace_gfs2_log_flush(sdp, 0, flags); +out: + up_write(&sdp->sd_log_flush_lock); + gfs2_trans_free(sdp, tr); + if (gfs2_withdrawing(sdp)) + gfs2_withdraw(sdp); + return; + +out_withdraw: + trans_drain(tr); + /** + * If the tr_list is empty, we're withdrawing during a log + * flush that targets a transaction, but the transaction was + * never queued onto any of the ail lists. Here we add it to + * ail1 just so that ail_drain() will find and free it. + */ + spin_lock(&sdp->sd_ail_lock); + if (tr && list_empty(&tr->tr_list)) + list_add(&tr->tr_list, &sdp->sd_ail1_list); + spin_unlock(&sdp->sd_ail_lock); + ail_drain(sdp); /* frees all transactions */ + tr = NULL; + goto out_end; +} + +/** + * gfs2_merge_trans - Merge a new transaction into a cached transaction + * @old: Original transaction to be expanded + * @new: New transaction to be merged + */ + +static void gfs2_merge_trans(struct gfs2_sbd *sdp, struct gfs2_trans *new) +{ + struct gfs2_trans *old = sdp->sd_log_tr; + + WARN_ON_ONCE(!test_bit(TR_ATTACHED, &old->tr_flags)); + + old->tr_num_buf_new += new->tr_num_buf_new; + old->tr_num_databuf_new += new->tr_num_databuf_new; + old->tr_num_buf_rm += new->tr_num_buf_rm; + old->tr_num_databuf_rm += new->tr_num_databuf_rm; + old->tr_num_revoke += new->tr_num_revoke; + old->tr_num_revoke_rm += new->tr_num_revoke_rm; + + list_splice_tail_init(&new->tr_databuf, &old->tr_databuf); + list_splice_tail_init(&new->tr_buf, &old->tr_buf); + + spin_lock(&sdp->sd_ail_lock); + list_splice_tail_init(&new->tr_ail1_list, &old->tr_ail1_list); + list_splice_tail_init(&new->tr_ail2_list, &old->tr_ail2_list); + spin_unlock(&sdp->sd_ail_lock); +} + +static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) +{ + unsigned int reserved; + unsigned int unused; + unsigned int maxres; + + gfs2_log_lock(sdp); + + if (sdp->sd_log_tr) { + gfs2_merge_trans(sdp, tr); + } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) { + gfs2_assert_withdraw(sdp, test_bit(TR_ALLOCED, &tr->tr_flags)); + sdp->sd_log_tr = tr; + set_bit(TR_ATTACHED, &tr->tr_flags); + } + + sdp->sd_log_committed_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; + reserved = calc_reserved(sdp); + maxres = sdp->sd_log_blks_reserved + tr->tr_reserved; + gfs2_assert_withdraw(sdp, maxres >= reserved); + unused = maxres - reserved; + atomic_add(unused, &sdp->sd_log_blks_free); + trace_gfs2_log_blocks(sdp, unused); + gfs2_assert_withdraw(sdp, atomic_read(&sdp->sd_log_blks_free) <= + sdp->sd_jdesc->jd_blocks); + sdp->sd_log_blks_reserved = reserved; + + gfs2_log_unlock(sdp); +} + +/** + * gfs2_log_commit - Commit a transaction to the log + * @sdp: the filesystem + * @tr: the transaction + * + * We wake up gfs2_logd if the number of pinned blocks exceed thresh1 + * or the total number of used blocks (pinned blocks plus AIL blocks) + * is greater than thresh2. + * + * At mount time thresh1 is 2/5ths of journal size, thresh2 is 4/5ths of + * journal size. + * + * Returns: errno + */ + +void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) +{ + log_refund(sdp, tr); + + if (atomic_read(&sdp->sd_log_pinned) > atomic_read(&sdp->sd_log_thresh1) || + ((sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free)) > + atomic_read(&sdp->sd_log_thresh2))) + wake_up(&sdp->sd_logd_waitq); +} + +/** + * gfs2_log_shutdown - write a shutdown header into a journal + * @sdp: the filesystem + * + */ + +static void gfs2_log_shutdown(struct gfs2_sbd *sdp) +{ + gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); + gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); + gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail1_list)); + + sdp->sd_log_flush_head = sdp->sd_log_head; + + log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT | GFS2_LFC_SHUTDOWN); + + gfs2_assert_warn(sdp, sdp->sd_log_head == sdp->sd_log_tail); + gfs2_assert_warn(sdp, list_empty(&sdp->sd_ail2_list)); + + sdp->sd_log_head = sdp->sd_log_flush_head; + sdp->sd_log_tail = sdp->sd_log_head; +} + +static inline int gfs2_jrnl_flush_reqd(struct gfs2_sbd *sdp) +{ + return (atomic_read(&sdp->sd_log_pinned) + + atomic_read(&sdp->sd_log_blks_needed) >= + atomic_read(&sdp->sd_log_thresh1)); +} + +static inline int gfs2_ail_flush_reqd(struct gfs2_sbd *sdp) +{ + unsigned int used_blocks = sdp->sd_jdesc->jd_blocks - atomic_read(&sdp->sd_log_blks_free); + + if (test_and_clear_bit(SDF_FORCE_AIL_FLUSH, &sdp->sd_flags)) + return 1; + + return used_blocks + atomic_read(&sdp->sd_log_blks_needed) >= + atomic_read(&sdp->sd_log_thresh2); +} + +/** + * gfs2_logd - Update log tail as Active Items get flushed to in-place blocks + * @sdp: Pointer to GFS2 superblock + * + * Also, periodically check to make sure that we're using the most recent + * journal index. + */ + +int gfs2_logd(void *data) +{ + struct gfs2_sbd *sdp = data; + unsigned long t = 1; + DEFINE_WAIT(wait); + bool did_flush; + + while (!kthread_should_stop()) { + + if (gfs2_withdrawn(sdp)) { + msleep_interruptible(HZ); + continue; + } + /* Check for errors writing to the journal */ + if (sdp->sd_log_error) { + gfs2_lm(sdp, + "GFS2: fsid=%s: error %d: " + "withdrawing the file system to " + "prevent further damage.\n", + sdp->sd_fsname, sdp->sd_log_error); + gfs2_withdraw(sdp); + continue; + } + + did_flush = false; + if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { + gfs2_ail1_empty(sdp, 0); + gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL | + GFS2_LFC_LOGD_JFLUSH_REQD); + did_flush = true; + } + + if (gfs2_ail_flush_reqd(sdp)) { + gfs2_ail1_start(sdp); + gfs2_ail1_wait(sdp); + gfs2_ail1_empty(sdp, 0); + gfs2_log_flush(sdp, NULL, GFS2_LOG_HEAD_FLUSH_NORMAL | + GFS2_LFC_LOGD_AIL_FLUSH_REQD); + did_flush = true; + } + + if (!gfs2_ail_flush_reqd(sdp) || did_flush) + wake_up(&sdp->sd_log_waitq); + + t = gfs2_tune_get(sdp, gt_logd_secs) * HZ; + + try_to_freeze(); + + do { + prepare_to_wait(&sdp->sd_logd_waitq, &wait, + TASK_INTERRUPTIBLE); + if (!gfs2_ail_flush_reqd(sdp) && + !gfs2_jrnl_flush_reqd(sdp) && + !kthread_should_stop()) + t = schedule_timeout(t); + } while(t && !gfs2_ail_flush_reqd(sdp) && + !gfs2_jrnl_flush_reqd(sdp) && + !kthread_should_stop()); + finish_wait(&sdp->sd_logd_waitq, &wait); + } + + return 0; +} + |