This commit was manufactured by cvs2svn to create branch 'vserver'.
[linux-2.6.git] / fs / gfs2 / recovery.c
diff --git a/fs/gfs2/recovery.c b/fs/gfs2/recovery.c
new file mode 100644 (file)
index 0000000..8bc182c
--- /dev/null
@@ -0,0 +1,571 @@
+/*
+ * 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/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 "gfs2.h"
+#include "incore.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"
+#include "util.h"
+#include "dir.h"
+
+int gfs2_replay_read_block(struct gfs2_jdesc *jd, unsigned int blk,
+                          struct buffer_head **bh)
+{
+       struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+       struct gfs2_glock *gl = ip->i_gl;
+       int new = 0;
+       u64 dblock;
+       u32 extlen;
+       int error;
+
+       error = gfs2_extent_map(&ip->i_inode, blk, &new, &dblock, &extlen);
+       if (error)
+               return error;
+       if (!dblock) {
+               gfs2_consist_inode(ip);
+               return -EIO;
+       }
+
+       *bh = gfs2_meta_ra(gl, dblock, extlen);
+
+       return error;
+}
+
+int gfs2_revoke_add(struct gfs2_sbd *sdp, u64 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, u64 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_host *head)
+{
+       struct buffer_head *bh;
+       struct gfs2_log_header_host lh;
+       const u32 nothing = 0;
+       u32 hash;
+       int error;
+
+       error = gfs2_replay_read_block(jd, blk, &bh);
+       if (error)
+               return error;
+
+       hash = crc32_le((u32)~0, bh->b_data, sizeof(struct gfs2_log_header) -
+                                            sizeof(u32));
+       hash = crc32_le(hash, (unsigned char const *)&nothing, sizeof(nothing));
+       hash ^= (u32)~0;
+       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_host *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(GFS2_I(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_host *head)
+{
+       unsigned int blk = head->lh_blkno;
+       struct gfs2_log_header_host 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(GFS2_I(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_host *head)
+{
+       struct gfs2_log_header_host lh_1, lh_m;
+       u32 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 = GFS2_SB(jd->jd_inode);
+       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 (be32_to_cpu(ld->ld_header.mh_type) == GFS2_METATYPE_LH) {
+                       struct gfs2_log_header_host lh;
+                       error = get_log_header(jd, start, &lh);
+                       if (!error) {
+                               gfs2_replay_incr_blk(sdp, &start);
+                               brelse(bh);
+                               continue;
+                       }
+                       if (error == 1) {
+                               gfs2_consist_inode(GFS2_I(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_host *head)
+{
+       struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+       unsigned int lblock;
+       struct gfs2_log_header *lh;
+       u32 hash;
+       struct buffer_head *bh;
+       int error;
+       struct buffer_head bh_map = { .b_state = 0, .b_blocknr = 0 };
+
+       lblock = head->lh_blkno;
+       gfs2_replay_incr_blk(sdp, &lblock);
+       bh_map.b_size = 1 << ip->i_inode.i_blkbits;
+       error = gfs2_block_map(&ip->i_inode, lblock, 0, &bh_map);
+       if (error)
+               return error;
+       if (!bh_map.b_blocknr) {
+               gfs2_consist_inode(ip);
+               return -EIO;
+       }
+
+       bh = sb_getblk(sdp->sd_vfs, bh_map.b_blocknr);
+       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_be32(GFS2_METATYPE_LH);
+       lh->lh_header.mh_format = cpu_to_be32(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
+ *
+ * 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)
+{
+       struct gfs2_inode *ip = GFS2_I(jd->jd_inode);
+       struct gfs2_sbd *sdp = GFS2_SB(jd->jd_inode);
+       struct gfs2_log_header_host head;
+       struct gfs2_holder j_gh, ji_gh, t_gh;
+       unsigned long t;
+       int ro = 0;
+       unsigned int pass;
+       int error;
+
+       if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
+               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 | 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(ip->i_gl, LM_ST_SHARED,
+                                          LM_FLAG_NOEXP, &ji_gh);
+               if (error)
+                       goto fail_gunlock_j;
+       } else {
+               fs_info(sdp, "jid=%u, already locked for use\n", jd->jd_jid);
+       }
+
+       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_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_ROUND_UP(jiffies - t, HZ);
+               fs_info(sdp, "jid=%u: Journal replayed in %lus\n",
+                       jd->jd_jid, t);
+       }
+
+       if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
+               gfs2_glock_dq_uninit(&ji_gh);
+
+       gfs2_lm_recovery_done(sdp, jd->jd_jid, LM_RD_SUCCESS);
+
+       if (jd->jd_jid != sdp->sd_lockstruct.ls_jid)
+               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:
+       if (jd->jd_jid != sdp->sd_lockstruct.ls_jid) {
+               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);
+       }
+}
+