/* * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. * Copyright (C) 2004-2007 Red Hat, Inc. All rights reserved. * * 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. */ #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/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" /** * gfs2_struct2blk - compute stuff * @sdp: the filesystem * @nstruct: the number of structures * @ssize: the size of the 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 ssize) { unsigned int blks; unsigned int first, second; blks = 1; first = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / ssize; if (nstruct > first) { second = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_meta_header)) / ssize; 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; 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)) gfs2_io_error_bh(sdp, bh); list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list); 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); generic_writepages(mapping, wbc); spin_lock(&sdp->sd_ail_lock); if (wbc->nr_to_write <= 0) break; return 1; } return 0; } /** * 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; trace_gfs2_ail_flush(sdp, wbc, 1); blk_start_plug(&plug); spin_lock(&sdp->sd_ail_lock); restart: list_for_each_entry_reverse(tr, head, tr_list) { if (wbc->nr_to_write <= 0) break; if (gfs2_ail1_start_one(sdp, wbc, tr)) goto restart; } spin_unlock(&sdp->sd_ail_lock); blk_finish_plug(&plug); 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 * @ai: the AIL entry * */ static void gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr) { struct gfs2_bufdata *bd, *s; struct buffer_head *bh; 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)) continue; if (!buffer_uptodate(bh)) gfs2_io_error_bh(sdp, bh); list_move(&bd->bd_ail_st_list, &tr->tr_ail2_list); } } /** * gfs2_ail1_empty - Try to empty the ail1 lists * @sdp: The superblock * * Tries to empty the ail1 lists, starting with the oldest first */ static int gfs2_ail1_empty(struct gfs2_sbd *sdp) { 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) { gfs2_ail1_empty_one(sdp, tr); if (list_empty(&tr->tr_ail1_list) && 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); 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_ail2_empty_one - Check whether or not a trans in the AIL has been synced * @sdp: the filesystem * @ai: the AIL entry * */ static void gfs2_ail2_empty_one(struct gfs2_sbd *sdp, struct gfs2_trans *tr) { struct list_head *head = &tr->tr_ail2_list; struct gfs2_bufdata *bd; while (!list_empty(head)) { bd = list_entry(head->prev, 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_ail2_empty_one(sdp, tr); 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)); kfree(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; 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; } 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_commited_revoke > 0) reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, sizeof(u64)); /* 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_entry(sdp->sd_ail1_list.prev, 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; } static 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, struct list_head *a, 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 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_le_ordered, &ip_cmp); while (!list_empty(&sdp->sd_log_le_ordered)) { ip = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_inode, i_ordered); list_move(&ip->i_ordered, &written); if (ip->i_inode.i_mapping->nrpages == 0) continue; 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_le_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_le_ordered)) { ip = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_inode, i_ordered); list_del(&ip->i_ordered); WARN_ON(!test_and_clear_bit(GIF_ORDERED, &ip->i_flags)); 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); if (test_and_clear_bit(GIF_ORDERED, &ip->i_flags)) list_del(&ip->i_ordered); 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; bh->b_private = NULL; bd->bd_blkno = bh->b_blocknr; gfs2_remove_from_ail(bd); /* drops ref on bh */ bd->bd_bh = NULL; bd->bd_ops = &gfs2_revoke_lops; sdp->sd_log_num_revoke++; atomic_inc(&gl->gl_revokes); set_bit(GLF_LFLUSH, &gl->gl_flags); list_add(&bd->bd_list, &sdp->sd_log_le_revoke); } void gfs2_write_revokes(struct gfs2_sbd *sdp) { struct gfs2_trans *tr; struct gfs2_bufdata *bd, *tmp; int have_revokes = 0; int max_revokes = (sdp->sd_sb.sb_bsize - sizeof(struct gfs2_log_descriptor)) / sizeof(u64); gfs2_ail1_empty(sdp); spin_lock(&sdp->sd_ail_lock); list_for_each_entry(tr, &sdp->sd_ail1_list, tr_list) { list_for_each_entry(bd, &tr->tr_ail2_list, bd_ail_st_list) { if (list_empty(&bd->bd_list)) { have_revokes = 1; goto done; } } } done: spin_unlock(&sdp->sd_ail_lock); if (have_revokes == 0) return; 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); } gfs2_log_lock(sdp); spin_lock(&sdp->sd_ail_lock); list_for_each_entry(tr, &sdp->sd_ail1_list, tr_list) { list_for_each_entry_safe(bd, tmp, &tr->tr_ail2_list, bd_ail_st_list) { if (max_revokes == 0) goto out_of_blocks; if (!list_empty(&bd->bd_list)) continue; gfs2_add_revoke(sdp, bd); max_revokes--; } } out_of_blocks: spin_unlock(&sdp->sd_ail_lock); 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); } } /** * log_write_header - Get and initialize a journal header buffer * @sdp: The GFS2 superblock * * Returns: the initialized log buffer descriptor */ static void log_write_header(struct gfs2_sbd *sdp, u32 flags) { struct gfs2_log_header *lh; unsigned int tail; u32 hash; int rw = WRITE_FLUSH_FUA | REQ_META; struct page *page = mempool_alloc(gfs2_page_pool, GFP_NOIO); enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state); lh = page_address(page); clear_page(lh); gfs2_assert_withdraw(sdp, (state != SFS_FROZEN)); tail = current_tail(sdp); 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(sdp->sd_log_sequence++); lh->lh_flags = cpu_to_be32(flags); lh->lh_tail = cpu_to_be32(tail); lh->lh_blkno = cpu_to_be32(sdp->sd_log_flush_head); hash = gfs2_disk_hash(page_address(page), sizeof(struct gfs2_log_header)); lh->lh_hash = cpu_to_be32(hash); if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) { gfs2_ordered_wait(sdp); log_flush_wait(sdp); rw = WRITE_SYNC | REQ_META | REQ_PRIO; } sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); gfs2_log_write_page(sdp, page); gfs2_log_flush_bio(sdp, rw); log_flush_wait(sdp); if (sdp->sd_log_tail != tail) log_pull_tail(sdp, tail); } /** * gfs2_log_flush - flush incore transaction(s) * @sdp: the filesystem * @gl: The glock structure to flush. If NULL, flush the whole incore log * */ void gfs2_log_flush(struct gfs2_sbd *sdp, struct gfs2_glock *gl, enum gfs2_flush_type type) { struct gfs2_trans *tr; enum gfs2_freeze_state state = atomic_read(&sdp->sd_freeze_state); down_write(&sdp->sd_log_flush_lock); /* Log might have been flushed while we waited for the flush lock */ if (gl && !test_bit(GLF_LFLUSH, &gl->gl_flags)) { up_write(&sdp->sd_log_flush_lock); return; } trace_gfs2_log_flush(sdp, 1); sdp->sd_log_flush_head = sdp->sd_log_head; sdp->sd_log_flush_wrapped = 0; tr = sdp->sd_log_tr; if (tr) { sdp->sd_log_tr = NULL; INIT_LIST_HEAD(&tr->tr_ail1_list); INIT_LIST_HEAD(&tr->tr_ail2_list); tr->tr_first = sdp->sd_log_flush_head; if (unlikely (state == SFS_FROZEN)) gfs2_assert_withdraw(sdp, !tr->tr_num_buf_new && !tr->tr_num_databuf_new); } if (unlikely(state == SFS_FROZEN)) gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); gfs2_ordered_write(sdp); lops_before_commit(sdp, tr); gfs2_log_flush_bio(sdp, WRITE); if (sdp->sd_log_head != sdp->sd_log_flush_head) { log_flush_wait(sdp); log_write_header(sdp, 0); } 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, 0); } 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_commited_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 (type != NORMAL_FLUSH) { if (!sdp->sd_log_idle) { for (;;) { gfs2_ail1_start(sdp); gfs2_ail1_wait(sdp); if (gfs2_ail1_empty(sdp)) break; } atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ trace_gfs2_log_blocks(sdp, -1); sdp->sd_log_flush_wrapped = 0; log_write_header(sdp, 0); sdp->sd_log_head = sdp->sd_log_flush_head; } if (type == SHUTDOWN_FLUSH || type == FREEZE_FLUSH) gfs2_log_shutdown(sdp); if (type == FREEZE_FLUSH) atomic_set(&sdp->sd_freeze_state, SFS_FROZEN); } trace_gfs2_log_flush(sdp, 0); up_write(&sdp->sd_log_flush_lock); kfree(tr); } /** * 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_trans *old, struct gfs2_trans *new) { WARN_ON_ONCE(old->tr_attached != 1); 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); } 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->sd_log_tr, tr); } else if (tr->tr_num_buf_new || tr->tr_num_databuf_new) { gfs2_assert_withdraw(sdp, tr->tr_alloced); sdp->sd_log_tr = tr; tr->tr_attached = 1; } sdp->sd_log_commited_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 1/3rd of journal size, thresh2 is 2/3rd 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 * */ 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; sdp->sd_log_flush_wrapped = 0; log_write_header(sdp, GFS2_LOG_HEAD_UNMOUNT); 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_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); return used_blocks >= 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); while (!kthread_should_stop()) { if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { gfs2_ail1_empty(sdp); gfs2_log_flush(sdp, NULL, NORMAL_FLUSH); } if (gfs2_ail_flush_reqd(sdp)) { gfs2_ail1_start(sdp); gfs2_ail1_wait(sdp); gfs2_ail1_empty(sdp); gfs2_log_flush(sdp, NULL, NORMAL_FLUSH); } if (!gfs2_ail_flush_reqd(sdp)) 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; }