/* * Copyright (C) Sistina Software, Inc. 1997-2003 All rights reserved. * Copyright (C) 2004-2006 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/lm_interface.h> #include <linux/delay.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" #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_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) { struct gfs2_bufdata *bd, *s; struct buffer_head *bh; int retry; BUG_ON(!spin_is_locked(&sdp->sd_log_lock)); 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_log_unlock(sdp); gfs2_io_error_bh(sdp, bh); gfs2_log_lock(sdp); } 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); gfs2_log_unlock(sdp); wait_on_buffer(bh); ll_rw_block(WRITE, 1, &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, int flags) { struct list_head *head = &sdp->sd_ail1_list; u64 sync_gen; struct list_head *first; struct gfs2_ail *first_ai, *ai, *tmp; int done = 0; 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); /* This may drop log lock */ if (flags & DIO_ALL) first = NULL; while(!done) { if (first && (head->prev != first || gfs2_ail1_empty_one(sdp, first_ai, 0))) break; done = 1; list_for_each_entry_safe_reverse(ai, tmp, 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); } 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); bd->bd_ail = NULL; list_del(&bd->bd_ail_st_list); list_del(&bd->bd_ail_gl_list); atomic_dec(&bd->bd_gl->gl_ail_count); brelse(bd->bd_bh); } } 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 6 blocks of the journal. Thats * due to the fact that there is are 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. * * Returns: errno */ int gfs2_log_reserve(struct gfs2_sbd *sdp, unsigned int blks) { unsigned int try = 0; if (gfs2_assert_warn(sdp, blks) || gfs2_assert_warn(sdp, blks <= sdp->sd_jdesc->jd_blocks)) return -EINVAL; mutex_lock(&sdp->sd_log_reserve_mutex); gfs2_log_lock(sdp); while(sdp->sd_log_blks_free <= (blks + 6)) { gfs2_log_unlock(sdp); gfs2_ail1_empty(sdp, 0); gfs2_log_flush(sdp, NULL); if (try++) gfs2_ail1_start(sdp, 0); gfs2_log_lock(sdp); } sdp->sd_log_blks_free -= blks; gfs2_log_unlock(sdp); mutex_unlock(&sdp->sd_log_reserve_mutex); down_read(&sdp->sd_log_flush_lock); 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) { 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); up_read(&sdp->sd_log_flush_lock); } static u64 log_bmap(struct gfs2_sbd *sdp, unsigned int lbn) { struct inode *inode = sdp->sd_jdesc->jd_inode; int error; struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 }; bh_map.b_size = 1 << inode->i_blkbits; error = gfs2_block_map(inode, lbn, 0, &bh_map); if (error || !bh_map.b_blocknr) printk(KERN_INFO "error=%d, dbn=%llu lbn=%u", error, (unsigned long long)bh_map.b_blocknr, lbn); gfs2_assert_withdraw(sdp, !error && bh_map.b_blocknr); return bh_map.b_blocknr; } /** * 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) { u64 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_NOFS | __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) { u64 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_NOFS | __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, 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; 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, 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); 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_be32(GFS2_METATYPE_LH); lh->lh_header.mh_format = cpu_to_be32(GFS2_FORMAT_LH); 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); 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; 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 - 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); if (gl) { gfs2_log_lock(sdp); if (list_empty(&gl->gl_le.le_list)) { gfs2_log_unlock(sdp); up_write(&sdp->sd_log_flush_lock); return; } gfs2_log_unlock(sdp); } ai = kzalloc(sizeof(struct gfs2_ail), GFP_NOFS | __GFP_NOFAIL); INIT_LIST_HEAD(&ai->ai_ail1_list); INIT_LIST_HEAD(&ai->ai_ail2_list); 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); 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); gfs2_log_lock(sdp); sdp->sd_log_head = sdp->sd_log_flush_head; sdp->sd_log_blks_free -= sdp->sd_log_num_hdrs; sdp->sd_log_blks_reserved = 0; sdp->sd_log_commited_buf = 0; sdp->sd_log_num_hdrs = 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); sdp->sd_vfs->s_dirt = 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 = 0; 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 += sdp->sd_log_commited_buf; if (sdp->sd_log_commited_revoke) reserved += gfs2_struct2blk(sdp, sdp->sd_log_commited_revoke, sizeof(u64)); if (reserved) reserved++; 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_num_hdrs); 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; up_read(&sdp->sd_log_flush_lock); gfs2_log_lock(sdp); if (sdp->sd_log_num_buf > gfs2_tune_get(sdp, gt_incore_log_blocks)) wake_up_process(sdp->sd_logd_process); 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_write(&sdp->sd_log_flush_lock); 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_jdata); 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, !sdp->sd_log_num_hdrs); 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_warn(sdp, 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, DIO_ALL); if (gfs2_ail1_empty(sdp, DIO_ALL)) break; msleep(10); } }