diff options
Diffstat (limited to 'kernel/fs/gfs2/log.c')
| -rw-r--r-- | kernel/fs/gfs2/log.c | 950 |
1 files changed, 950 insertions, 0 deletions
diff --git a/kernel/fs/gfs2/log.c b/kernel/fs/gfs2/log.c new file mode 100644 index 000000000..536e7a625 --- /dev/null +++ b/kernel/fs/gfs2/log.c @@ -0,0 +1,950 @@ +/* + * 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; +} + |