/* * 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 "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" #define PULL 1 /** * 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 log lock _must_ be held when calling this function * */ void gfs2_remove_from_ail(struct gfs2_bufdata *bd) { bd->bd_ail = 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 * @tr: the part of the AIL * */ static void gfs2_ail1_start_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai) __releases(&sdp->sd_log_lock) __acquires(&sdp->sd_log_lock) { struct gfs2_bufdata *bd, *s; struct buffer_head *bh; int retry; do { retry = 0; list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) { bh = bd->bd_bh; gfs2_assert(sdp, bd->bd_ail == ai); if (!buffer_busy(bh)) { if (!buffer_uptodate(bh)) gfs2_io_error_bh(sdp, bh); list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); continue; } if (!buffer_dirty(bh)) continue; list_move(&bd->bd_ail_st_list, &ai->ai_ail1_list); get_bh(bh); gfs2_log_unlock(sdp); lock_buffer(bh); if (test_clear_buffer_dirty(bh)) { bh->b_end_io = end_buffer_write_sync; submit_bh(WRITE_SYNC_PLUG, bh); } else { unlock_buffer(bh); brelse(bh); } gfs2_log_lock(sdp); retry = 1; break; } } while (retry); } /** * gfs2_ail1_empty_one - Check whether or not a trans in the AIL has been synced * @sdp: the filesystem * @ai: the AIL entry * */ static int gfs2_ail1_empty_one(struct gfs2_sbd *sdp, struct gfs2_ail *ai, int flags) { struct gfs2_bufdata *bd, *s; struct buffer_head *bh; list_for_each_entry_safe_reverse(bd, s, &ai->ai_ail1_list, bd_ail_st_list) { bh = bd->bd_bh; gfs2_assert(sdp, bd->bd_ail == ai); if (buffer_busy(bh)) { if (flags & DIO_ALL) continue; else break; } if (!buffer_uptodate(bh)) gfs2_io_error_bh(sdp, bh); list_move(&bd->bd_ail_st_list, &ai->ai_ail2_list); } return list_empty(&ai->ai_ail1_list); } static void gfs2_ail1_start(struct gfs2_sbd *sdp) { struct list_head *head; u64 sync_gen; struct gfs2_ail *ai; int done = 0; gfs2_log_lock(sdp); head = &sdp->sd_ail1_list; if (list_empty(head)) { gfs2_log_unlock(sdp); return; } sync_gen = sdp->sd_ail_sync_gen++; while(!done) { done = 1; list_for_each_entry_reverse(ai, head, ai_list) { if (ai->ai_sync_gen >= sync_gen) continue; ai->ai_sync_gen = sync_gen; gfs2_ail1_start_one(sdp, ai); /* This may drop log lock */ done = 0; break; } } gfs2_log_unlock(sdp); } static int gfs2_ail1_empty(struct gfs2_sbd *sdp, int flags) { struct gfs2_ail *ai, *s; int ret; gfs2_log_lock(sdp); list_for_each_entry_safe_reverse(ai, s, &sdp->sd_ail1_list, ai_list) { if (gfs2_ail1_empty_one(sdp, ai, flags)) list_move(&ai->ai_list, &sdp->sd_ail2_list); else if (!(flags & DIO_ALL)) break; } ret = list_empty(&sdp->sd_ail1_list); gfs2_log_unlock(sdp); return ret; } /** * 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_ail *ai) { struct list_head *head = &ai->ai_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_ail == ai); gfs2_remove_from_ail(bd); } } static void ail2_empty(struct gfs2_sbd *sdp, unsigned int new_tail) { struct gfs2_ail *ai, *safe; unsigned int old_tail = sdp->sd_log_tail; int wrap = (new_tail < old_tail); int a, b, rm; gfs2_log_lock(sdp); list_for_each_entry_safe(ai, safe, &sdp->sd_ail2_list, ai_list) { a = (old_tail <= ai->ai_first); b = (ai->ai_first < new_tail); rm = (wrap) ? (a || b) : (a && b); if (!rm) continue; gfs2_ail2_empty_one(sdp, ai); list_del(&ai->ai_list); gfs2_assert_warn(sdp, list_empty(&ai->ai_ail1_list)); gfs2_assert_warn(sdp, list_empty(&ai->ai_ail2_list)); kfree(ai); } gfs2_log_unlock(sdp); } /** * 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) { unsigned reserved_blks = 6 * (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); } if (atomic_cmpxchg(&sdp->sd_log_blks_free, free_blocks, free_blocks - blks) != free_blocks) 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); return 0; } static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn) { struct gfs2_journal_extent *je; list_for_each_entry(je, &sdp->sd_jdesc->extent_list, extent_list) { if (lbn >= je->lblock && lbn < je->lblock + je->blocks) return je->dblock + lbn - je->lblock; } return -1; } /** * 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_limit, metabufhdrs_needed; unsigned int dbuf_limit, databufhdrs_needed; unsigned int revokes = 0; mbuf_limit = buf_limit(sdp); metabufhdrs_needed = (sdp->sd_log_commited_buf + (mbuf_limit - 1)) / mbuf_limit; dbuf_limit = databuf_limit(sdp); databufhdrs_needed = (sdp->sd_log_commited_databuf + (dbuf_limit - 1)) / dbuf_limit; if (sdp->sd_log_commited_revoke > 0) revokes = gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, sizeof(u64)); reserved = sdp->sd_log_commited_buf + metabufhdrs_needed + sdp->sd_log_commited_databuf + databufhdrs_needed + revokes; /* One for the overall header */ if (reserved) reserved++; return reserved; } static unsigned int current_tail(struct gfs2_sbd *sdp) { struct gfs2_ail *ai; unsigned int tail; gfs2_log_lock(sdp); if (list_empty(&sdp->sd_ail1_list)) { tail = sdp->sd_log_head; } else { ai = list_entry(sdp->sd_ail1_list.prev, struct gfs2_ail, ai_list); tail = ai->ai_first; } gfs2_log_unlock(sdp); return tail; } void gfs2_log_incr_head(struct gfs2_sbd *sdp) { if (sdp->sd_log_flush_head == sdp->sd_log_tail) BUG_ON(sdp->sd_log_flush_head != sdp->sd_log_head); if (++sdp->sd_log_flush_head == sdp->sd_jdesc->jd_blocks) { sdp->sd_log_flush_head = 0; sdp->sd_log_flush_wrapped = 1; } } /** * gfs2_log_write_endio - End of I/O for a log buffer * @bh: The buffer head * @uptodate: I/O Status * */ static void gfs2_log_write_endio(struct buffer_head *bh, int uptodate) { struct gfs2_sbd *sdp = bh->b_private; bh->b_private = NULL; end_buffer_write_sync(bh, uptodate); if (atomic_dec_and_test(&sdp->sd_log_in_flight)) wake_up(&sdp->sd_log_flush_wait); } /** * gfs2_log_get_buf - Get and initialize a buffer to use for log control data * @sdp: The GFS2 superblock * * Returns: the buffer_head */ struct buffer_head *gfs2_log_get_buf(struct gfs2_sbd *sdp) { u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); struct buffer_head *bh; bh = sb_getblk(sdp->sd_vfs, blkno); lock_buffer(bh); memset(bh->b_data, 0, bh->b_size); set_buffer_uptodate(bh); clear_buffer_dirty(bh); gfs2_log_incr_head(sdp); atomic_inc(&sdp->sd_log_in_flight); bh->b_private = sdp; bh->b_end_io = gfs2_log_write_endio; return bh; } /** * gfs2_fake_write_endio - * @bh: The buffer head * @uptodate: The I/O Status * */ static void gfs2_fake_write_endio(struct buffer_head *bh, int uptodate) { struct buffer_head *real_bh = bh->b_private; struct gfs2_bufdata *bd = real_bh->b_private; struct gfs2_sbd *sdp = bd->bd_gl->gl_sbd; end_buffer_write_sync(bh, uptodate); free_buffer_head(bh); unlock_buffer(real_bh); brelse(real_bh); if (atomic_dec_and_test(&sdp->sd_log_in_flight)) wake_up(&sdp->sd_log_flush_wait); } /** * gfs2_log_fake_buf - Build a fake buffer head to write metadata buffer to log * @sdp: the filesystem * @data: the data the buffer_head should point to * * Returns: the log buffer descriptor */ struct buffer_head *gfs2_log_fake_buf(struct gfs2_sbd *sdp, struct buffer_head *real) { u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); struct buffer_head *bh; bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL); atomic_set(&bh->b_count, 1); bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate) | (1 << BH_Lock); set_bh_page(bh, real->b_page, bh_offset(real)); bh->b_blocknr = blkno; bh->b_size = sdp->sd_sb.sb_bsize; bh->b_bdev = sdp->sd_vfs->s_bdev; bh->b_private = real; bh->b_end_io = gfs2_fake_write_endio; gfs2_log_incr_head(sdp); atomic_inc(&sdp->sd_log_in_flight); return bh; } 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; } /** * 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, int pull) { u64 blkno = log_bmap(sdp, sdp->sd_log_flush_head); struct buffer_head *bh; struct gfs2_log_header *lh; unsigned int tail; u32 hash; bh = sb_getblk(sdp->sd_vfs, blkno); lock_buffer(bh); memset(bh->b_data, 0, bh->b_size); set_buffer_uptodate(bh); clear_buffer_dirty(bh); gfs2_ail1_empty(sdp, 0); tail = current_tail(sdp); lh = (struct gfs2_log_header *)bh->b_data; memset(lh, 0, sizeof(struct gfs2_log_header)); 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(bh->b_data, sizeof(struct gfs2_log_header)); lh->lh_hash = cpu_to_be32(hash); bh->b_end_io = end_buffer_write_sync; if (test_bit(SDF_NOBARRIERS, &sdp->sd_flags)) goto skip_barrier; get_bh(bh); submit_bh(WRITE_BARRIER | REQ_META, bh); wait_on_buffer(bh); if (buffer_eopnotsupp(bh)) { clear_buffer_eopnotsupp(bh); set_buffer_uptodate(bh); fs_info(sdp, "barrier sync failed - disabling barriers\n"); set_bit(SDF_NOBARRIERS, &sdp->sd_flags); lock_buffer(bh); skip_barrier: get_bh(bh); submit_bh(WRITE_SYNC | REQ_META, bh); wait_on_buffer(bh); } if (!buffer_uptodate(bh)) gfs2_io_error_bh(sdp, bh); brelse(bh); if (sdp->sd_log_tail != tail) log_pull_tail(sdp, tail); else gfs2_assert_withdraw(sdp, !pull); sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); gfs2_log_incr_head(sdp); } static void log_flush_commit(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); } log_write_header(sdp, 0, 0); } static void gfs2_ordered_write(struct gfs2_sbd *sdp) { struct gfs2_bufdata *bd; struct buffer_head *bh; LIST_HEAD(written); gfs2_log_lock(sdp); while (!list_empty(&sdp->sd_log_le_ordered)) { bd = list_entry(sdp->sd_log_le_ordered.next, struct gfs2_bufdata, bd_le.le_list); list_move(&bd->bd_le.le_list, &written); bh = bd->bd_bh; if (!buffer_dirty(bh)) continue; get_bh(bh); gfs2_log_unlock(sdp); lock_buffer(bh); if (buffer_mapped(bh) && test_clear_buffer_dirty(bh)) { bh->b_end_io = end_buffer_write_sync; submit_bh(WRITE_SYNC_PLUG, bh); } else { unlock_buffer(bh); brelse(bh); } gfs2_log_lock(sdp); } list_splice(&written, &sdp->sd_log_le_ordered); gfs2_log_unlock(sdp); } static void gfs2_ordered_wait(struct gfs2_sbd *sdp) { struct gfs2_bufdata *bd; struct buffer_head *bh; gfs2_log_lock(sdp); while (!list_empty(&sdp->sd_log_le_ordered)) { bd = list_entry(sdp->sd_log_le_ordered.prev, struct gfs2_bufdata, bd_le.le_list); bh = bd->bd_bh; if (buffer_locked(bh)) { get_bh(bh); gfs2_log_unlock(sdp); wait_on_buffer(bh); brelse(bh); gfs2_log_lock(sdp); continue; } list_del_init(&bd->bd_le.le_list); } gfs2_log_unlock(sdp); } /** * 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) { struct gfs2_ail *ai; 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); ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL); INIT_LIST_HEAD(&ai->ai_ail1_list); INIT_LIST_HEAD(&ai->ai_ail2_list); if (sdp->sd_log_num_buf != sdp->sd_log_commited_buf) { printk(KERN_INFO "GFS2: log buf %u %u\n", sdp->sd_log_num_buf, sdp->sd_log_commited_buf); gfs2_assert_withdraw(sdp, 0); } if (sdp->sd_log_num_databuf != sdp->sd_log_commited_databuf) { printk(KERN_INFO "GFS2: log databuf %u %u\n", sdp->sd_log_num_databuf, sdp->sd_log_commited_databuf); gfs2_assert_withdraw(sdp, 0); } gfs2_assert_withdraw(sdp, sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); sdp->sd_log_flush_head = sdp->sd_log_head; sdp->sd_log_flush_wrapped = 0; ai->ai_first = sdp->sd_log_flush_head; gfs2_ordered_write(sdp); lops_before_commit(sdp); gfs2_ordered_wait(sdp); if (sdp->sd_log_head != sdp->sd_log_flush_head) log_flush_commit(sdp); else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle){ gfs2_log_lock(sdp); atomic_dec(&sdp->sd_log_blks_free); /* Adjust for unreserved buffer */ trace_gfs2_log_blocks(sdp, -1); gfs2_log_unlock(sdp); log_write_header(sdp, 0, PULL); } lops_after_commit(sdp, ai); gfs2_log_lock(sdp); sdp->sd_log_head = sdp->sd_log_flush_head; sdp->sd_log_blks_reserved = 0; sdp->sd_log_commited_buf = 0; sdp->sd_log_commited_databuf = 0; sdp->sd_log_commited_revoke = 0; if (!list_empty(&ai->ai_ail1_list)) { list_add(&ai->ai_list, &sdp->sd_ail1_list); ai = NULL; } gfs2_log_unlock(sdp); trace_gfs2_log_flush(sdp, 0); up_write(&sdp->sd_log_flush_lock); kfree(ai); } static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) { unsigned int reserved; unsigned int unused; gfs2_log_lock(sdp); sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm; sdp->sd_log_commited_databuf += tr->tr_num_databuf_new - tr->tr_num_databuf_rm; gfs2_assert_withdraw(sdp, (((int)sdp->sd_log_commited_buf) >= 0) || (((int)sdp->sd_log_commited_databuf) >= 0)); sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; reserved = calc_reserved(sdp); gfs2_assert_withdraw(sdp, sdp->sd_log_blks_reserved + tr->tr_reserved >= reserved); unused = sdp->sd_log_blks_reserved - reserved + tr->tr_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); } static void buf_lo_incore_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) { struct list_head *head = &tr->tr_list_buf; struct gfs2_bufdata *bd; gfs2_log_lock(sdp); while (!list_empty(head)) { bd = list_entry(head->next, struct gfs2_bufdata, bd_list_tr); list_del_init(&bd->bd_list_tr); tr->tr_num_buf--; } gfs2_log_unlock(sdp); gfs2_assert_warn(sdp, !tr->tr_num_buf); } /** * 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); buf_lo_incore_commit(sdp, tr); up_read(&sdp->sd_log_flush_lock); 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) { down_write(&sdp->sd_log_flush_lock); gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); gfs2_assert_withdraw(sdp, !sdp->sd_log_num_buf); gfs2_assert_withdraw(sdp, !sdp->sd_log_num_revoke); gfs2_assert_withdraw(sdp, !sdp->sd_log_num_rg); gfs2_assert_withdraw(sdp, !sdp->sd_log_num_databuf); 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, (sdp->sd_log_tail == current_tail(sdp)) ? 0 : PULL); gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_blks_free) == sdp->sd_jdesc->jd_blocks); 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; up_write(&sdp->sd_log_flush_lock); } /** * gfs2_meta_syncfs - sync all the buffers in a filesystem * @sdp: the filesystem * */ void gfs2_meta_syncfs(struct gfs2_sbd *sdp) { gfs2_log_flush(sdp, NULL); for (;;) { gfs2_ail1_start(sdp); if (gfs2_ail1_empty(sdp, DIO_ALL)) break; msleep(10); } } 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); unsigned preflush; while (!kthread_should_stop()) { preflush = atomic_read(&sdp->sd_log_pinned); if (gfs2_jrnl_flush_reqd(sdp) || t == 0) { gfs2_ail1_empty(sdp, DIO_ALL); gfs2_log_flush(sdp, NULL); gfs2_ail1_empty(sdp, DIO_ALL); } if (gfs2_ail_flush_reqd(sdp)) { gfs2_ail1_start(sdp); io_schedule(); gfs2_ail1_empty(sdp, 0); gfs2_log_flush(sdp, NULL); gfs2_ail1_empty(sdp, DIO_ALL); } wake_up(&sdp->sd_log_waitq); t = gfs2_tune_get(sdp, gt_logd_secs) * HZ; if (freezing(current)) refrigerator(); do { prepare_to_wait(&sdp->sd_logd_waitq, &wait, TASK_UNINTERRUPTIBLE); 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; }