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author | David Teigland <teigland@redhat.com> | 2006-01-16 17:50:04 +0100 |
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committer | Steven Whitehouse <swhiteho@redhat.com> | 2006-01-16 17:50:04 +0100 |
commit | b3b94faa5fe5968827ba0640ee9fba4b3e7f736e (patch) | |
tree | 70bd6068b050d2c46e338484f8b03fae4365c6c3 /fs/gfs2/log.c | |
parent | [GFS2] Hook GFS2 into the Kbuild system (diff) | |
download | linux-b3b94faa5fe5968827ba0640ee9fba4b3e7f736e.tar.xz linux-b3b94faa5fe5968827ba0640ee9fba4b3e7f736e.zip |
[GFS2] The core of GFS2
This patch contains all the core files for GFS2.
Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Diffstat (limited to 'fs/gfs2/log.c')
-rw-r--r-- | fs/gfs2/log.c | 659 |
1 files changed, 659 insertions, 0 deletions
diff --git a/fs/gfs2/log.c b/fs/gfs2/log.c new file mode 100644 index 000000000000..736d0d33dd1b --- /dev/null +++ b/fs/gfs2/log.c @@ -0,0 +1,659 @@ +/* + * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. + * Copyright (C) 2004-2005 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 v.2. + */ + +#include <linux/sched.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/completion.h> +#include <linux/buffer_head.h> +#include <asm/semaphore.h> + +#include "gfs2.h" +#include "bmap.h" +#include "glock.h" +#include "log.h" +#include "lops.h" +#include "meta_io.h" + +#define PULL 1 + +static inline int is_done(struct gfs2_sbd *sdp, atomic_t *a) +{ + int done; + gfs2_log_lock(sdp); + done = atomic_read(a) ? 0 : 1; + gfs2_log_unlock(sdp); + return done; +} + +static void do_lock_wait(struct gfs2_sbd *sdp, wait_queue_head_t *wq, + atomic_t *a) +{ + gfs2_log_unlock(sdp); + wait_event(*wq, is_done(sdp, a)); + gfs2_log_lock(sdp); +} + +static void lock_for_trans(struct gfs2_sbd *sdp) +{ + gfs2_log_lock(sdp); + do_lock_wait(sdp, &sdp->sd_log_trans_wq, &sdp->sd_log_flush_count); + atomic_inc(&sdp->sd_log_trans_count); + gfs2_log_unlock(sdp); +} + +static void unlock_from_trans(struct gfs2_sbd *sdp) +{ + gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_trans_count)); + if (atomic_dec_and_test(&sdp->sd_log_trans_count)) + wake_up(&sdp->sd_log_flush_wq); +} + +void gfs2_lock_for_flush(struct gfs2_sbd *sdp) +{ + gfs2_log_lock(sdp); + atomic_inc(&sdp->sd_log_flush_count); + do_lock_wait(sdp, &sdp->sd_log_flush_wq, &sdp->sd_log_trans_count); + gfs2_log_unlock(sdp); +} + +void gfs2_unlock_from_flush(struct gfs2_sbd *sdp) +{ + gfs2_assert_warn(sdp, atomic_read(&sdp->sd_log_flush_count)); + if (atomic_dec_and_test(&sdp->sd_log_flush_count)) + wake_up(&sdp->sd_log_trans_wq); +} + +/** + * 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_RU(nstruct - first, second); + } + + return blks; +} + +void gfs2_ail1_start(struct gfs2_sbd *sdp, int flags) +{ + struct list_head *head = &sdp->sd_ail1_list; + uint64_t sync_gen; + struct list_head *first, *tmp; + struct gfs2_ail *first_ai, *ai; + + gfs2_log_lock(sdp); + if (list_empty(head)) { + gfs2_log_unlock(sdp); + return; + } + sync_gen = sdp->sd_ail_sync_gen++; + + first = head->prev; + first_ai = list_entry(first, struct gfs2_ail, ai_list); + first_ai->ai_sync_gen = sync_gen; + gfs2_ail1_start_one(sdp, first_ai); + + if (flags & DIO_ALL) + first = NULL; + + for (;;) { + if (first && + (head->prev != first || + gfs2_ail1_empty_one(sdp, first_ai, 0))) + break; + + for (tmp = head->prev; tmp != head; tmp = tmp->prev) { + ai = list_entry(tmp, struct gfs2_ail, ai_list); + if (ai->ai_sync_gen >= sync_gen) + continue; + ai->ai_sync_gen = sync_gen; + gfs2_ail1_start_one(sdp, ai); + break; + } + + if (tmp == head) + break; + } + + gfs2_log_unlock(sdp); +} + +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; +} + +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 + * + * Returns: errno + */ + +int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) +{ + LIST_HEAD(list); + unsigned int try = 0; + + if (gfs2_assert_warn(sdp, blks) || + gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) + return -EINVAL; + + for (;;) { + gfs2_log_lock(sdp); + + if (list_empty(&list)) { + list_add_tail(&list, &sdp->sd_log_blks_list); + while (sdp->sd_log_blks_list.next != &list) { + DECLARE_WAITQUEUE(__wait_chan, current); + set_current_state(TASK_UNINTERRUPTIBLE); + add_wait_queue(&sdp->sd_log_blks_wait, + &__wait_chan); + gfs2_log_unlock(sdp); + schedule(); + gfs2_log_lock(sdp); + remove_wait_queue(&sdp->sd_log_blks_wait, + &__wait_chan); + set_current_state(TASK_RUNNING); + } + } + + /* Never give away the last block so we can + always pull the tail if we need to. */ + if (sdp->sd_log_blks_free > blks) { + sdp->sd_log_blks_free -= blks; + list_del(&list); + gfs2_log_unlock(sdp); + wake_up(&sdp->sd_log_blks_wait); + break; + } + + gfs2_log_unlock(sdp); + + gfs2_ail1_empty(sdp, 0); + gfs2_log_flush(sdp); + + if (try++) + gfs2_ail1_start(sdp, 0); + } + + lock_for_trans(sdp); + + return 0; +} + +/** + * 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) +{ + unlock_from_trans(sdp); + + gfs2_log_lock(sdp); + sdp->sd_log_blks_free += blks; + gfs2_assert_withdraw(sdp, + sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks); + gfs2_log_unlock(sdp); +} + +static uint64_t log_bmap(struct gfs2_sbd *sdp, unsigned int lbn) +{ + int new = 0; + uint64_t dbn; + int error; + + error = gfs2_block_map(sdp->sd_jdesc->jd_inode, lbn, &new, &dbn, NULL); + gfs2_assert_withdraw(sdp, !error && dbn); + + return dbn; +} + +/** + * 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; +} + +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; +} + +static inline void log_incr_head(struct gfs2_sbd *sdp) +{ + if (sdp->sd_log_flush_head == sdp->sd_log_tail) + gfs2_assert_withdraw(sdp, + 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_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) +{ + uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head); + struct gfs2_log_buf *lb; + struct buffer_head *bh; + + lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_KERNEL | __GFP_NOFAIL); + list_add(&lb->lb_list, &sdp->sd_log_flush_list); + + bh = lb->lb_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); + unlock_buffer(bh); + + log_incr_head(sdp); + + return bh; +} + +/** + * 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) +{ + uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head); + struct gfs2_log_buf *lb; + struct buffer_head *bh; + + lb = kzalloc(sizeof(struct gfs2_log_buf), GFP_KERNEL | __GFP_NOFAIL); + list_add(&lb->lb_list, &sdp->sd_log_flush_list); + lb->lb_real = real; + + bh = lb->lb_bh = alloc_buffer_head(GFP_NOFS | __GFP_NOFAIL); + atomic_set(&bh->b_count, 1); + bh->b_state = (1 << BH_Mapped) | (1 << BH_Uptodate); + set_bh_page(bh, virt_to_page(real->b_data), + ((unsigned long)real->b_data) & (PAGE_SIZE - 1)); + bh->b_blocknr = blkno; + bh->b_size = sdp->sd_sb.sb_bsize; + bh->b_bdev = sdp->sd_vfs->s_bdev; + + log_incr_head(sdp); + + return bh; +} + +static void log_pull_tail(struct gfs2_sbd *sdp, unsigned int new_tail, int pull) +{ + unsigned int dist = log_distance(sdp, new_tail, sdp->sd_log_tail); + + ail2_empty(sdp, new_tail); + + gfs2_log_lock(sdp); + sdp->sd_log_blks_free += dist - ((pull) ? 1 : 0); + gfs2_assert_withdraw(sdp, + sdp->sd_log_blks_free <= sdp->sd_jdesc->jd_blocks); + gfs2_log_unlock(sdp); + + 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, uint32_t flags, int pull) +{ + uint64_t blkno = log_bmap(sdp, sdp->sd_log_flush_head); + struct buffer_head *bh; + struct gfs2_log_header *lh; + unsigned int tail; + uint32_t hash; + + atomic_inc(&sdp->sd_log_flush_ondisk); + + 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); + unlock_buffer(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_be16(GFS2_METATYPE_LH); + lh->lh_header.mh_format = cpu_to_be16(GFS2_FORMAT_LH); + lh->lh_sequence = be64_to_cpu(sdp->sd_log_sequence++); + lh->lh_flags = be32_to_cpu(flags); + lh->lh_tail = be32_to_cpu(tail); + lh->lh_blkno = be32_to_cpu(sdp->sd_log_flush_head); + hash = gfs2_disk_hash(bh->b_data, sizeof(struct gfs2_log_header)); + lh->lh_hash = cpu_to_be32(hash); + + set_buffer_dirty(bh); + if (sync_dirty_buffer(bh)) + gfs2_io_error_bh(sdp, bh); + brelse(bh); + + if (sdp->sd_log_tail != tail) + log_pull_tail(sdp, tail, pull); + else + gfs2_assert_withdraw(sdp, !pull); + + sdp->sd_log_idle = (tail == sdp->sd_log_flush_head); + log_incr_head(sdp); +} + +static void log_flush_commit(struct gfs2_sbd *sdp) +{ + struct list_head *head = &sdp->sd_log_flush_list; + struct gfs2_log_buf *lb; + struct buffer_head *bh; + unsigned int d; + + d = log_distance(sdp, sdp->sd_log_flush_head, sdp->sd_log_head); + + gfs2_assert_withdraw(sdp, d + 1 == sdp->sd_log_blks_reserved); + + while (!list_empty(head)) { + lb = list_entry(head->next, struct gfs2_log_buf, lb_list); + list_del(&lb->lb_list); + bh = lb->lb_bh; + + wait_on_buffer(bh); + if (!buffer_uptodate(bh)) + gfs2_io_error_bh(sdp, bh); + if (lb->lb_real) { + while (atomic_read(&bh->b_count) != 1) /* Grrrr... */ + schedule(); + free_buffer_head(bh); + } else + brelse(bh); + kfree(lb); + } + + log_write_header(sdp, 0, 0); +} + +/** + * gfs2_log_flush_i - flush incore transaction(s) + * @sdp: the filesystem + * @gl: The glock structure to flush. If NULL, flush the whole incore log + * + */ + +void gfs2_log_flush_i(struct gfs2_sbd *sdp, struct gfs2_glock *gl) +{ + struct gfs2_ail *ai; + + atomic_inc(&sdp->sd_log_flush_incore); + + ai = kzalloc(sizeof(struct gfs2_ail), GFP_KERNEL | __GFP_NOFAIL); + INIT_LIST_HEAD(&ai->ai_ail1_list); + INIT_LIST_HEAD(&ai->ai_ail2_list); + + gfs2_lock_for_flush(sdp); + down(&sdp->sd_log_flush_lock); + + gfs2_assert_withdraw(sdp, + sdp->sd_log_num_buf == sdp->sd_log_commited_buf); + gfs2_assert_withdraw(sdp, + sdp->sd_log_num_revoke == sdp->sd_log_commited_revoke); + + if (gl && list_empty(&gl->gl_le.le_list)) { + up(&sdp->sd_log_flush_lock); + gfs2_unlock_from_flush(sdp); + kfree(ai); + return; + } + + sdp->sd_log_flush_head = sdp->sd_log_head; + sdp->sd_log_flush_wrapped = 0; + ai->ai_first = sdp->sd_log_flush_head; + + lops_before_commit(sdp); + if (!list_empty(&sdp->sd_log_flush_list)) + log_flush_commit(sdp); + else if (sdp->sd_log_tail != current_tail(sdp) && !sdp->sd_log_idle) + log_write_header(sdp, 0, PULL); + lops_after_commit(sdp, ai); + + sdp->sd_log_head = sdp->sd_log_flush_head; + if (sdp->sd_log_flush_wrapped) + sdp->sd_log_wraps++; + + sdp->sd_log_blks_reserved = + sdp->sd_log_commited_buf = + sdp->sd_log_commited_revoke = 0; + + gfs2_log_lock(sdp); + if (!list_empty(&ai->ai_ail1_list)) { + list_add(&ai->ai_list, &sdp->sd_ail1_list); + ai = NULL; + } + gfs2_log_unlock(sdp); + + up(&sdp->sd_log_flush_lock); + sdp->sd_vfs->s_dirt = 0; + gfs2_unlock_from_flush(sdp); + + kfree(ai); +} + +static void log_refund(struct gfs2_sbd *sdp, struct gfs2_trans *tr) +{ + unsigned int reserved = 1; + unsigned int old; + + gfs2_log_lock(sdp); + + sdp->sd_log_commited_buf += tr->tr_num_buf_new - tr->tr_num_buf_rm; + gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_buf) >= 0); + sdp->sd_log_commited_revoke += tr->tr_num_revoke - tr->tr_num_revoke_rm; + gfs2_assert_withdraw(sdp, ((int)sdp->sd_log_commited_revoke) >= 0); + + if (sdp->sd_log_commited_buf) + reserved += 1 + sdp->sd_log_commited_buf + sdp->sd_log_commited_buf/503; + if (sdp->sd_log_commited_revoke) + reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, + sizeof(uint64_t)); + + old = sdp->sd_log_blks_free; + sdp->sd_log_blks_free += tr->tr_reserved - + (reserved - sdp->sd_log_blks_reserved); + + gfs2_assert_withdraw(sdp, + sdp->sd_log_blks_free >= old); + gfs2_assert_withdraw(sdp, + 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 + * + * Returns: errno + */ + +void gfs2_log_commit(struct gfs2_sbd *sdp, struct gfs2_trans *tr) +{ + log_refund(sdp, tr); + lops_incore_commit(sdp, tr); + + sdp->sd_vfs->s_dirt = 1; + unlock_from_trans(sdp); + + kfree(tr); + + gfs2_log_lock(sdp); + if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) { + gfs2_log_unlock(sdp); + gfs2_log_flush(sdp); + } else + gfs2_log_unlock(sdp); +} + +/** + * gfs2_log_shutdown - write a shutdown header into a journal + * @sdp: the filesystem + * + */ + +void gfs2_log_shutdown(struct gfs2_sbd *sdp) +{ + down(&sdp->sd_log_flush_lock); + + gfs2_assert_withdraw(sdp, !atomic_read(&sdp->sd_log_trans_count)); + gfs2_assert_withdraw(sdp, !sdp->sd_log_blks_reserved); + gfs2_assert_withdraw(sdp, !sdp->sd_log_num_gl); + 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, 0); + + gfs2_assert_withdraw(sdp, sdp->sd_log_blks_free == + sdp->sd_jdesc->jd_blocks); + gfs2_assert_withdraw(sdp, sdp->sd_log_head == sdp->sd_log_tail); + gfs2_assert_withdraw(sdp, list_empty(&sdp->sd_ail2_list)); + + sdp->sd_log_head = sdp->sd_log_flush_head; + if (sdp->sd_log_flush_wrapped) + sdp->sd_log_wraps++; + sdp->sd_log_tail = sdp->sd_log_head; + + up(&sdp->sd_log_flush_lock); +} + |