[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>

1 files changed, 570 insertions, 0 deletions

diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
new file mode 100644
index 00000000000..15cd26fbcff
--- /dev/null
+++ b/fs/gfs2/recovery.c
@@ -0,0 +1,570 @@
+/*
+ * 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 "glops.h"
+#include "lm.h"
+#include "lops.h"
+#include "meta_io.h"
+#include "recovery.h"
+#include "super.h"
+
+int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
+			   struct buffer_head **bh)
+{
+	struct gfs2_glock *gl = jd->jd_inode->i_gl;
+	int new = 0;
+	uint64_t dblock;
+	uint32_t extlen;
+	int error;
+
+	error = gfs2_block_map(jd->jd_inode, blk, &new, &dblock, &extlen);
+	if (error)
+		return error;
+	if (!dblock) {
+		gfs2_consist_inode(jd->jd_inode);
+		return -EIO;
+	}
+
+	gfs2_meta_ra(gl, dblock, extlen);
+	error = gfs2_meta_read(gl, dblock, DIO_START | DIO_WAIT, bh);
+
+	return error;
+}
+
+int gfs2_revoke_add(struct gfs2_sbd *sdp, uint64_t blkno, unsigned int where)
+{
+	struct list_head *head = &sdp->sd_revoke_list;
+	struct gfs2_revoke_replay *rr;
+	int found = 0;
+
+	list_for_each_entry(rr, head, rr_list) {
+		if (rr->rr_blkno == blkno) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (found) {
+		rr->rr_where = where;
+		return 0;
+	}
+
+	rr = kmalloc(sizeof(struct gfs2_revoke_replay), GFP_KERNEL);
+	if (!rr)
+		return -ENOMEM;
+
+	rr->rr_blkno = blkno;
+	rr->rr_where = where;
+	list_add(&rr->rr_list, head);
+
+	return 1;
+}
+
+int gfs2_revoke_check(struct gfs2_sbd *sdp, uint64_t blkno, unsigned int where)
+{
+	struct gfs2_revoke_replay *rr;
+	int wrap, a, b, revoke;
+	int found = 0;
+
+	list_for_each_entry(rr, &sdp->sd_revoke_list, rr_list) {
+		if (rr->rr_blkno == blkno) {
+			found = 1;
+			break;
+		}
+	}
+
+	if (!found)
+		return 0;
+
+	wrap = (rr->rr_where < sdp->sd_replay_tail);
+	a = (sdp->sd_replay_tail < where);
+	b = (where < rr->rr_where);
+	revoke = (wrap) ? (a || b) : (a && b);
+
+	return revoke;
+}
+
+void gfs2_revoke_clean(struct gfs2_sbd *sdp)
+{
+	struct list_head *head = &sdp->sd_revoke_list;
+	struct gfs2_revoke_replay *rr;
+
+	while (!list_empty(head)) {
+		rr = list_entry(head->next, struct gfs2_revoke_replay, rr_list);
+		list_del(&rr->rr_list);
+		kfree(rr);
+	}
+}
+
+/**
+ * get_log_header - read the log header for a given segment
+ * @jd: the journal
+ * @blk: the block to look at
+ * @lh: the log header to return
+ *
+ * Read the log header for a given segement in a given journal.  Do a few
+ * sanity checks on it.
+ *
+ * Returns: 0 on success,
+ *          1 if the header was invalid or incomplete,
+ *          errno on error
+ */
+
+static int get_log_header(struct gfs2_jdesc *jd, unsigned int blk,
+			  struct gfs2_log_header *head)
+{
+	struct buffer_head *bh;
+	struct gfs2_log_header lh;
+	uint32_t hash;
+	int error;
+
+	error = gfs2_replay_read_block(jd, blk, &bh);
+	if (error)
+		return error;
+
+	memcpy(&lh, bh->b_data, sizeof(struct gfs2_log_header));
+	lh.lh_hash = 0;
+	hash = gfs2_disk_hash((char *)&lh, sizeof(struct gfs2_log_header));
+	gfs2_log_header_in(&lh, bh->b_data);
+
+	brelse(bh);
+
+	if (lh.lh_header.mh_magic != GFS2_MAGIC ||
+	    lh.lh_header.mh_type != GFS2_METATYPE_LH ||
+	    lh.lh_blkno != blk ||
+	    lh.lh_hash != hash)
+		return 1;
+
+	*head = lh;
+
+	return 0;
+}
+
+/**
+ * find_good_lh - find a good log header
+ * @jd: the journal
+ * @blk: the segment to start searching from
+ * @lh: the log header to fill in
+ * @forward: if true search forward in the log, else search backward
+ *
+ * Call get_log_header() to get a log header for a segment, but if the
+ * segment is bad, either scan forward or backward until we find a good one.
+ *
+ * Returns: errno
+ */
+
+static int find_good_lh(struct gfs2_jdesc *jd, unsigned int *blk,
+			struct gfs2_log_header *head)
+{
+	unsigned int orig_blk = *blk;
+	int error;
+
+	for (;;) {
+		error = get_log_header(jd, *blk, head);
+		if (error <= 0)
+			return error;
+
+		if (++*blk == jd->jd_blocks)
+			*blk = 0;
+
+		if (*blk == orig_blk) {
+			gfs2_consist_inode(jd->jd_inode);
+			return -EIO;
+		}
+	}
+}
+
+/**
+ * jhead_scan - make sure we've found the head of the log
+ * @jd: the journal
+ * @head: this is filled in with the log descriptor of the head
+ *
+ * At this point, seg and lh should be either the head of the log or just
+ * before.  Scan forward until we find the head.
+ *
+ * Returns: errno
+ */
+
+static int jhead_scan(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
+{
+	unsigned int blk = head->lh_blkno;
+	struct gfs2_log_header lh;
+	int error;
+
+	for (;;) {
+		if (++blk == jd->jd_blocks)
+			blk = 0;
+
+		error = get_log_header(jd, blk, &lh);
+		if (error < 0)
+			return error;
+		if (error == 1)
+			continue;
+
+		if (lh.lh_sequence == head->lh_sequence) {
+			gfs2_consist_inode(jd->jd_inode);
+			return -EIO;
+		}
+		if (lh.lh_sequence < head->lh_sequence)
+			break;
+
+		*head = lh;
+	}
+
+	return 0;
+}
+
+/**
+ * gfs2_find_jhead - find the head of a log
+ * @jd: the journal
+ * @head: the log descriptor for the head of the log is returned here
+ *
+ * Do a binary search of a journal and find the valid log entry with the
+ * highest sequence number.  (i.e. the log head)
+ *
+ * Returns: errno
+ */
+
+int gfs2_find_jhead(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
+{
+	struct gfs2_log_header lh_1, lh_m;
+	uint32_t blk_1, blk_2, blk_m;
+	int error;
+
+	blk_1 = 0;
+	blk_2 = jd->jd_blocks - 1;
+
+	for (;;) {
+		blk_m = (blk_1 + blk_2) / 2;
+
+		error = find_good_lh(jd, &blk_1, &lh_1);
+		if (error)
+			return error;
+
+		error = find_good_lh(jd, &blk_m, &lh_m);
+		if (error)
+			return error;
+
+		if (blk_1 == blk_m || blk_m == blk_2)
+			break;
+
+		if (lh_1.lh_sequence <= lh_m.lh_sequence)
+			blk_1 = blk_m;
+		else
+			blk_2 = blk_m;
+	}
+
+	error = jhead_scan(jd, &lh_1);
+	if (error)
+		return error;
+
+	*head = lh_1;
+
+	return error;
+}
+
+/**
+ * foreach_descriptor - go through the active part of the log
+ * @jd: the journal
+ * @start: the first log header in the active region
+ * @end: the last log header (don't process the contents of this entry))
+ *
+ * Call a given function once for every log descriptor in the active
+ * portion of the log.
+ *
+ * Returns: errno
+ */
+
+static int foreach_descriptor(struct gfs2_jdesc *jd, unsigned int start,
+			      unsigned int end, int pass)
+{
+	struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;
+	struct buffer_head *bh;
+	struct gfs2_log_descriptor *ld;
+	int error = 0;
+	u32 length;
+	__be64 *ptr;
+	unsigned int offset = sizeof(struct gfs2_log_descriptor);
+	offset += (sizeof(__be64)-1);
+	offset &= ~(sizeof(__be64)-1);
+
+	while (start != end) {
+		error = gfs2_replay_read_block(jd, start, &bh);
+		if (error)
+			return error;
+		if (gfs2_meta_check(sdp, bh)) {
+			brelse(bh);
+			return -EIO;
+		}
+		ld = (struct gfs2_log_descriptor *)bh->b_data;
+		length = be32_to_cpu(ld->ld_length);
+
+		if (be16_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
+			struct gfs2_log_header lh;
+			error = get_log_header(jd, start, &lh);
+			if (!error) {
+				gfs2_replay_incr_blk(sdp, &start);
+				continue;
+			}
+			if (error == 1) {
+				gfs2_consist_inode(jd->jd_inode);
+				error = -EIO;
+			}
+			brelse(bh);
+			return error;
+		} else if (gfs2_metatype_check(sdp, bh, GFS2_METATYPE_LD)) {
+			brelse(bh);
+			return -EIO;
+		}
+		ptr = (__be64 *)(bh->b_data + offset);
+		error = lops_scan_elements(jd, start, ld, ptr, pass);
+		if (error) {
+			brelse(bh);
+			return error;
+		}
+
+		while (length--)
+			gfs2_replay_incr_blk(sdp, &start);
+
+		brelse(bh);
+	}
+
+	return 0;
+}
+
+/**
+ * clean_journal - mark a dirty journal as being clean
+ * @sdp: the filesystem
+ * @jd: the journal
+ * @gl: the journal's glock
+ * @head: the head journal to start from
+ *
+ * Returns: errno
+ */
+
+static int clean_journal(struct gfs2_jdesc *jd, struct gfs2_log_header *head)
+{
+	struct gfs2_inode *ip = jd->jd_inode;
+	struct gfs2_sbd *sdp = ip->i_sbd;
+	unsigned int lblock;
+	int new = 0;
+	uint64_t dblock;
+	struct gfs2_log_header *lh;
+	uint32_t hash;
+	struct buffer_head *bh;
+	int error;
+	
+	lblock = head->lh_blkno;
+	gfs2_replay_incr_blk(sdp, &lblock);
+	error = gfs2_block_map(ip, lblock, &new, &dblock, NULL);
+	if (error)
+		return error;
+	if (!dblock) {
+		gfs2_consist_inode(ip);
+		return -EIO;
+	}
+
+	bh = sb_getblk(sdp->sd_vfs, dblock);
+	lock_buffer(bh);
+	memset(bh->b_data, 0, bh->b_size);
+	set_buffer_uptodate(bh);
+	clear_buffer_dirty(bh);
+	unlock_buffer(bh);
+
+	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 = cpu_to_be64(head->lh_sequence + 1);
+	lh->lh_flags = cpu_to_be32(GFS2_LOG_HEAD_UNMOUNT);
+	lh->lh_blkno = cpu_to_be32(lblock);
+	hash = gfs2_disk_hash((const char *)lh, 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);
+
+	return error;
+}
+
+/**
+ * gfs2_recover_journal - recovery a given journal
+ * @jd: the struct gfs2_jdesc describing the journal
+ * @wait: Don't return until the journal is clean (or an error is encountered)
+ *
+ * Acquire the journal's lock, check to see if the journal is clean, and
+ * do recovery if necessary.
+ *
+ * Returns: errno
+ */
+
+int gfs2_recover_journal(struct gfs2_jdesc *jd, int wait)
+{
+	struct gfs2_sbd *sdp = jd->jd_inode->i_sbd;
+	struct gfs2_log_header head;
+	struct gfs2_holder j_gh, ji_gh, t_gh;
+	unsigned long t;
+	int ro = 0;
+	unsigned int pass;
+	int error;
+
+	fs_info(sdp, "jid=%u: Trying to acquire journal lock...\n", jd->jd_jid);
+
+	/* Aquire the journal lock so we can do recovery */
+
+	error = gfs2_glock_nq_num(sdp,
+				  jd->jd_jid, &gfs2_journal_glops,
+				  LM_ST_EXCLUSIVE,
+				  LM_FLAG_NOEXP |
+				  ((wait) ? 0 : LM_FLAG_TRY) |
+				  GL_NOCACHE, &j_gh);
+	switch (error) {
+	case 0:
+		break;
+
+	case GLR_TRYFAILED:
+		fs_info(sdp, "jid=%u: Busy\n", jd->jd_jid);
+		error = 0;
+
+	default:
+		goto fail;
+	};
+
+	error = gfs2_glock_nq_init(jd->jd_inode->i_gl, LM_ST_SHARED,
+				   LM_FLAG_NOEXP, &ji_gh);
+	if (error)
+		goto fail_gunlock_j;
+
+	fs_info(sdp, "jid=%u: Looking at journal...\n", jd->jd_jid);
+
+	error = gfs2_jdesc_check(jd);
+	if (error)
+		goto fail_gunlock_ji;
+
+	error = gfs2_find_jhead(jd, &head);
+	if (error)
+		goto fail_gunlock_ji;
+
+	if (!(head.lh_flags & GFS2_LOG_HEAD_UNMOUNT)) {
+		fs_info(sdp, "jid=%u: Acquiring the transaction lock...\n",
+			jd->jd_jid);
+
+		t = jiffies;
+
+		/* Acquire a shared hold on the transaction lock */
+
+		error = gfs2_glock_nq_init(sdp->sd_trans_gl,
+					   LM_ST_SHARED,
+					   LM_FLAG_NOEXP |
+					   LM_FLAG_PRIORITY |
+					   GL_NEVER_RECURSE |
+					   GL_NOCANCEL |
+					   GL_NOCACHE,
+					   &t_gh);
+		if (error)
+			goto fail_gunlock_ji;
+
+		if (test_bit(SDF_JOURNAL_CHECKED, &sdp->sd_flags)) {
+			if (!test_bit(SDF_JOURNAL_LIVE, &sdp->sd_flags))
+				ro = 1;
+		} else {
+			if (sdp->sd_vfs->s_flags & MS_RDONLY)
+				ro = 1;
+		}
+
+		if (ro) {
+			fs_warn(sdp, "jid=%u: Can't replay: read-only FS\n",
+				jd->jd_jid);
+			error = -EROFS;
+			goto fail_gunlock_tr;
+		}
+
+		fs_info(sdp, "jid=%u: Replaying journal...\n", jd->jd_jid);
+
+		for (pass = 0; pass < 2; pass++) {
+			lops_before_scan(jd, &head, pass);
+			error = foreach_descriptor(jd, head.lh_tail,
+						   head.lh_blkno, pass);
+			lops_after_scan(jd, error, pass);
+			if (error)
+				goto fail_gunlock_tr;
+		}
+
+		error = clean_journal(jd, &head);
+		if (error)
+			goto fail_gunlock_tr;
+
+		gfs2_glock_dq_uninit(&t_gh);
+
+		t = DIV_RU(jiffies - t, HZ);
+		
+		fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
+			jd->jd_jid, t);
+	}
+
+	gfs2_glock_dq_uninit(&ji_gh);
+
+	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
+
+	gfs2_glock_dq_uninit(&j_gh);
+
+	fs_info(sdp, "jid=%u: Done\n", jd->jd_jid);
+
+	return 0;
+
+ fail_gunlock_tr:
+	gfs2_glock_dq_uninit(&t_gh);
+
+ fail_gunlock_ji:
+	gfs2_glock_dq_uninit(&ji_gh);
+
+ fail_gunlock_j:
+	gfs2_glock_dq_uninit(&j_gh);
+
+	fs_info(sdp, "jid=%u: %s\n", jd->jd_jid, (error) ? "Failed" : "Done");
+
+ fail:
+	gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_GAVEUP);
+
+	return error;
+}
+
+/**
+ * gfs2_check_journals - Recover any dirty journals
+ * @sdp: the filesystem
+ *
+ */
+
+void gfs2_check_journals(struct gfs2_sbd *sdp)
+{
+	struct gfs2_jdesc *jd;
+
+	for (;;) {
+		jd = gfs2_jdesc_find_dirty(sdp);
+		if (!jd)
+			break;
+
+		if (jd != sdp->sd_jdesc)
+			gfs2_recover_journal(jd, NO_WAIT);
+	}
+}
+