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-rw-r--r--fs/xfs/xfs_buf_item_recover.c1071
1 files changed, 1071 insertions, 0 deletions
diff --git a/fs/xfs/xfs_buf_item_recover.c b/fs/xfs/xfs_buf_item_recover.c
new file mode 100644
index 000000000..43167f543
--- /dev/null
+++ b/fs/xfs/xfs_buf_item_recover.c
@@ -0,0 +1,1071 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2000-2006 Silicon Graphics, Inc.
+ * All Rights Reserved.
+ */
+#include "xfs.h"
+#include "xfs_fs.h"
+#include "xfs_shared.h"
+#include "xfs_format.h"
+#include "xfs_log_format.h"
+#include "xfs_trans_resv.h"
+#include "xfs_bit.h"
+#include "xfs_mount.h"
+#include "xfs_trans.h"
+#include "xfs_buf_item.h"
+#include "xfs_trans_priv.h"
+#include "xfs_trace.h"
+#include "xfs_log.h"
+#include "xfs_log_priv.h"
+#include "xfs_log_recover.h"
+#include "xfs_error.h"
+#include "xfs_inode.h"
+#include "xfs_dir2.h"
+#include "xfs_quota.h"
+
+/*
+ * This is the number of entries in the l_buf_cancel_table used during
+ * recovery.
+ */
+#define XLOG_BC_TABLE_SIZE 64
+
+#define XLOG_BUF_CANCEL_BUCKET(log, blkno) \
+ ((log)->l_buf_cancel_table + ((uint64_t)blkno % XLOG_BC_TABLE_SIZE))
+
+/*
+ * This structure is used during recovery to record the buf log items which
+ * have been canceled and should not be replayed.
+ */
+struct xfs_buf_cancel {
+ xfs_daddr_t bc_blkno;
+ uint bc_len;
+ int bc_refcount;
+ struct list_head bc_list;
+};
+
+static struct xfs_buf_cancel *
+xlog_find_buffer_cancelled(
+ struct xlog *log,
+ xfs_daddr_t blkno,
+ uint len)
+{
+ struct list_head *bucket;
+ struct xfs_buf_cancel *bcp;
+
+ if (!log->l_buf_cancel_table)
+ return NULL;
+
+ bucket = XLOG_BUF_CANCEL_BUCKET(log, blkno);
+ list_for_each_entry(bcp, bucket, bc_list) {
+ if (bcp->bc_blkno == blkno && bcp->bc_len == len)
+ return bcp;
+ }
+
+ return NULL;
+}
+
+static bool
+xlog_add_buffer_cancelled(
+ struct xlog *log,
+ xfs_daddr_t blkno,
+ uint len)
+{
+ struct xfs_buf_cancel *bcp;
+
+ /*
+ * If we find an existing cancel record, this indicates that the buffer
+ * was cancelled multiple times. To ensure that during pass 2 we keep
+ * the record in the table until we reach its last occurrence in the
+ * log, a reference count is kept to tell how many times we expect to
+ * see this record during the second pass.
+ */
+ bcp = xlog_find_buffer_cancelled(log, blkno, len);
+ if (bcp) {
+ bcp->bc_refcount++;
+ return false;
+ }
+
+ bcp = kmem_alloc(sizeof(struct xfs_buf_cancel), 0);
+ bcp->bc_blkno = blkno;
+ bcp->bc_len = len;
+ bcp->bc_refcount = 1;
+ list_add_tail(&bcp->bc_list, XLOG_BUF_CANCEL_BUCKET(log, blkno));
+ return true;
+}
+
+/*
+ * Check if there is and entry for blkno, len in the buffer cancel record table.
+ */
+bool
+xlog_is_buffer_cancelled(
+ struct xlog *log,
+ xfs_daddr_t blkno,
+ uint len)
+{
+ return xlog_find_buffer_cancelled(log, blkno, len) != NULL;
+}
+
+/*
+ * Check if there is and entry for blkno, len in the buffer cancel record table,
+ * and decremented the reference count on it if there is one.
+ *
+ * Remove the cancel record once the refcount hits zero, so that if the same
+ * buffer is re-used again after its last cancellation we actually replay the
+ * changes made at that point.
+ */
+static bool
+xlog_put_buffer_cancelled(
+ struct xlog *log,
+ xfs_daddr_t blkno,
+ uint len)
+{
+ struct xfs_buf_cancel *bcp;
+
+ bcp = xlog_find_buffer_cancelled(log, blkno, len);
+ if (!bcp) {
+ ASSERT(0);
+ return false;
+ }
+
+ if (--bcp->bc_refcount == 0) {
+ list_del(&bcp->bc_list);
+ kmem_free(bcp);
+ }
+ return true;
+}
+
+/* log buffer item recovery */
+
+/*
+ * Sort buffer items for log recovery. Most buffer items should end up on the
+ * buffer list and are recovered first, with the following exceptions:
+ *
+ * 1. XFS_BLF_CANCEL buffers must be processed last because some log items
+ * might depend on the incor ecancellation record, and replaying a cancelled
+ * buffer item can remove the incore record.
+ *
+ * 2. XFS_BLF_INODE_BUF buffers are handled after most regular items so that
+ * we replay di_next_unlinked only after flushing the inode 'free' state
+ * to the inode buffer.
+ *
+ * See xlog_recover_reorder_trans for more details.
+ */
+STATIC enum xlog_recover_reorder
+xlog_recover_buf_reorder(
+ struct xlog_recover_item *item)
+{
+ struct xfs_buf_log_format *buf_f = item->ri_buf[0].i_addr;
+
+ if (buf_f->blf_flags & XFS_BLF_CANCEL)
+ return XLOG_REORDER_CANCEL_LIST;
+ if (buf_f->blf_flags & XFS_BLF_INODE_BUF)
+ return XLOG_REORDER_INODE_BUFFER_LIST;
+ return XLOG_REORDER_BUFFER_LIST;
+}
+
+STATIC void
+xlog_recover_buf_ra_pass2(
+ struct xlog *log,
+ struct xlog_recover_item *item)
+{
+ struct xfs_buf_log_format *buf_f = item->ri_buf[0].i_addr;
+
+ xlog_buf_readahead(log, buf_f->blf_blkno, buf_f->blf_len, NULL);
+}
+
+/*
+ * Build up the table of buf cancel records so that we don't replay cancelled
+ * data in the second pass.
+ */
+static int
+xlog_recover_buf_commit_pass1(
+ struct xlog *log,
+ struct xlog_recover_item *item)
+{
+ struct xfs_buf_log_format *bf = item->ri_buf[0].i_addr;
+
+ if (!xfs_buf_log_check_iovec(&item->ri_buf[0])) {
+ xfs_err(log->l_mp, "bad buffer log item size (%d)",
+ item->ri_buf[0].i_len);
+ return -EFSCORRUPTED;
+ }
+
+ if (!(bf->blf_flags & XFS_BLF_CANCEL))
+ trace_xfs_log_recover_buf_not_cancel(log, bf);
+ else if (xlog_add_buffer_cancelled(log, bf->blf_blkno, bf->blf_len))
+ trace_xfs_log_recover_buf_cancel_add(log, bf);
+ else
+ trace_xfs_log_recover_buf_cancel_ref_inc(log, bf);
+ return 0;
+}
+
+/*
+ * Validate the recovered buffer is of the correct type and attach the
+ * appropriate buffer operations to them for writeback. Magic numbers are in a
+ * few places:
+ * the first 16 bits of the buffer (inode buffer, dquot buffer),
+ * the first 32 bits of the buffer (most blocks),
+ * inside a struct xfs_da_blkinfo at the start of the buffer.
+ */
+static void
+xlog_recover_validate_buf_type(
+ struct xfs_mount *mp,
+ struct xfs_buf *bp,
+ struct xfs_buf_log_format *buf_f,
+ xfs_lsn_t current_lsn)
+{
+ struct xfs_da_blkinfo *info = bp->b_addr;
+ uint32_t magic32;
+ uint16_t magic16;
+ uint16_t magicda;
+ char *warnmsg = NULL;
+
+ /*
+ * We can only do post recovery validation on items on CRC enabled
+ * fielsystems as we need to know when the buffer was written to be able
+ * to determine if we should have replayed the item. If we replay old
+ * metadata over a newer buffer, then it will enter a temporarily
+ * inconsistent state resulting in verification failures. Hence for now
+ * just avoid the verification stage for non-crc filesystems
+ */
+ if (!xfs_has_crc(mp))
+ return;
+
+ magic32 = be32_to_cpu(*(__be32 *)bp->b_addr);
+ magic16 = be16_to_cpu(*(__be16*)bp->b_addr);
+ magicda = be16_to_cpu(info->magic);
+ switch (xfs_blft_from_flags(buf_f)) {
+ case XFS_BLFT_BTREE_BUF:
+ switch (magic32) {
+ case XFS_ABTB_CRC_MAGIC:
+ case XFS_ABTB_MAGIC:
+ bp->b_ops = &xfs_bnobt_buf_ops;
+ break;
+ case XFS_ABTC_CRC_MAGIC:
+ case XFS_ABTC_MAGIC:
+ bp->b_ops = &xfs_cntbt_buf_ops;
+ break;
+ case XFS_IBT_CRC_MAGIC:
+ case XFS_IBT_MAGIC:
+ bp->b_ops = &xfs_inobt_buf_ops;
+ break;
+ case XFS_FIBT_CRC_MAGIC:
+ case XFS_FIBT_MAGIC:
+ bp->b_ops = &xfs_finobt_buf_ops;
+ break;
+ case XFS_BMAP_CRC_MAGIC:
+ case XFS_BMAP_MAGIC:
+ bp->b_ops = &xfs_bmbt_buf_ops;
+ break;
+ case XFS_RMAP_CRC_MAGIC:
+ bp->b_ops = &xfs_rmapbt_buf_ops;
+ break;
+ case XFS_REFC_CRC_MAGIC:
+ bp->b_ops = &xfs_refcountbt_buf_ops;
+ break;
+ default:
+ warnmsg = "Bad btree block magic!";
+ break;
+ }
+ break;
+ case XFS_BLFT_AGF_BUF:
+ if (magic32 != XFS_AGF_MAGIC) {
+ warnmsg = "Bad AGF block magic!";
+ break;
+ }
+ bp->b_ops = &xfs_agf_buf_ops;
+ break;
+ case XFS_BLFT_AGFL_BUF:
+ if (magic32 != XFS_AGFL_MAGIC) {
+ warnmsg = "Bad AGFL block magic!";
+ break;
+ }
+ bp->b_ops = &xfs_agfl_buf_ops;
+ break;
+ case XFS_BLFT_AGI_BUF:
+ if (magic32 != XFS_AGI_MAGIC) {
+ warnmsg = "Bad AGI block magic!";
+ break;
+ }
+ bp->b_ops = &xfs_agi_buf_ops;
+ break;
+ case XFS_BLFT_UDQUOT_BUF:
+ case XFS_BLFT_PDQUOT_BUF:
+ case XFS_BLFT_GDQUOT_BUF:
+#ifdef CONFIG_XFS_QUOTA
+ if (magic16 != XFS_DQUOT_MAGIC) {
+ warnmsg = "Bad DQUOT block magic!";
+ break;
+ }
+ bp->b_ops = &xfs_dquot_buf_ops;
+#else
+ xfs_alert(mp,
+ "Trying to recover dquots without QUOTA support built in!");
+ ASSERT(0);
+#endif
+ break;
+ case XFS_BLFT_DINO_BUF:
+ if (magic16 != XFS_DINODE_MAGIC) {
+ warnmsg = "Bad INODE block magic!";
+ break;
+ }
+ bp->b_ops = &xfs_inode_buf_ops;
+ break;
+ case XFS_BLFT_SYMLINK_BUF:
+ if (magic32 != XFS_SYMLINK_MAGIC) {
+ warnmsg = "Bad symlink block magic!";
+ break;
+ }
+ bp->b_ops = &xfs_symlink_buf_ops;
+ break;
+ case XFS_BLFT_DIR_BLOCK_BUF:
+ if (magic32 != XFS_DIR2_BLOCK_MAGIC &&
+ magic32 != XFS_DIR3_BLOCK_MAGIC) {
+ warnmsg = "Bad dir block magic!";
+ break;
+ }
+ bp->b_ops = &xfs_dir3_block_buf_ops;
+ break;
+ case XFS_BLFT_DIR_DATA_BUF:
+ if (magic32 != XFS_DIR2_DATA_MAGIC &&
+ magic32 != XFS_DIR3_DATA_MAGIC) {
+ warnmsg = "Bad dir data magic!";
+ break;
+ }
+ bp->b_ops = &xfs_dir3_data_buf_ops;
+ break;
+ case XFS_BLFT_DIR_FREE_BUF:
+ if (magic32 != XFS_DIR2_FREE_MAGIC &&
+ magic32 != XFS_DIR3_FREE_MAGIC) {
+ warnmsg = "Bad dir3 free magic!";
+ break;
+ }
+ bp->b_ops = &xfs_dir3_free_buf_ops;
+ break;
+ case XFS_BLFT_DIR_LEAF1_BUF:
+ if (magicda != XFS_DIR2_LEAF1_MAGIC &&
+ magicda != XFS_DIR3_LEAF1_MAGIC) {
+ warnmsg = "Bad dir leaf1 magic!";
+ break;
+ }
+ bp->b_ops = &xfs_dir3_leaf1_buf_ops;
+ break;
+ case XFS_BLFT_DIR_LEAFN_BUF:
+ if (magicda != XFS_DIR2_LEAFN_MAGIC &&
+ magicda != XFS_DIR3_LEAFN_MAGIC) {
+ warnmsg = "Bad dir leafn magic!";
+ break;
+ }
+ bp->b_ops = &xfs_dir3_leafn_buf_ops;
+ break;
+ case XFS_BLFT_DA_NODE_BUF:
+ if (magicda != XFS_DA_NODE_MAGIC &&
+ magicda != XFS_DA3_NODE_MAGIC) {
+ warnmsg = "Bad da node magic!";
+ break;
+ }
+ bp->b_ops = &xfs_da3_node_buf_ops;
+ break;
+ case XFS_BLFT_ATTR_LEAF_BUF:
+ if (magicda != XFS_ATTR_LEAF_MAGIC &&
+ magicda != XFS_ATTR3_LEAF_MAGIC) {
+ warnmsg = "Bad attr leaf magic!";
+ break;
+ }
+ bp->b_ops = &xfs_attr3_leaf_buf_ops;
+ break;
+ case XFS_BLFT_ATTR_RMT_BUF:
+ if (magic32 != XFS_ATTR3_RMT_MAGIC) {
+ warnmsg = "Bad attr remote magic!";
+ break;
+ }
+ bp->b_ops = &xfs_attr3_rmt_buf_ops;
+ break;
+ case XFS_BLFT_SB_BUF:
+ if (magic32 != XFS_SB_MAGIC) {
+ warnmsg = "Bad SB block magic!";
+ break;
+ }
+ bp->b_ops = &xfs_sb_buf_ops;
+ break;
+#ifdef CONFIG_XFS_RT
+ case XFS_BLFT_RTBITMAP_BUF:
+ case XFS_BLFT_RTSUMMARY_BUF:
+ /* no magic numbers for verification of RT buffers */
+ bp->b_ops = &xfs_rtbuf_ops;
+ break;
+#endif /* CONFIG_XFS_RT */
+ default:
+ xfs_warn(mp, "Unknown buffer type %d!",
+ xfs_blft_from_flags(buf_f));
+ break;
+ }
+
+ /*
+ * Nothing else to do in the case of a NULL current LSN as this means
+ * the buffer is more recent than the change in the log and will be
+ * skipped.
+ */
+ if (current_lsn == NULLCOMMITLSN)
+ return;
+
+ if (warnmsg) {
+ xfs_warn(mp, warnmsg);
+ ASSERT(0);
+ }
+
+ /*
+ * We must update the metadata LSN of the buffer as it is written out to
+ * ensure that older transactions never replay over this one and corrupt
+ * the buffer. This can occur if log recovery is interrupted at some
+ * point after the current transaction completes, at which point a
+ * subsequent mount starts recovery from the beginning.
+ *
+ * Write verifiers update the metadata LSN from log items attached to
+ * the buffer. Therefore, initialize a bli purely to carry the LSN to
+ * the verifier.
+ */
+ if (bp->b_ops) {
+ struct xfs_buf_log_item *bip;
+
+ bp->b_flags |= _XBF_LOGRECOVERY;
+ xfs_buf_item_init(bp, mp);
+ bip = bp->b_log_item;
+ bip->bli_item.li_lsn = current_lsn;
+ }
+}
+
+/*
+ * Perform a 'normal' buffer recovery. Each logged region of the
+ * buffer should be copied over the corresponding region in the
+ * given buffer. The bitmap in the buf log format structure indicates
+ * where to place the logged data.
+ */
+STATIC void
+xlog_recover_do_reg_buffer(
+ struct xfs_mount *mp,
+ struct xlog_recover_item *item,
+ struct xfs_buf *bp,
+ struct xfs_buf_log_format *buf_f,
+ xfs_lsn_t current_lsn)
+{
+ int i;
+ int bit;
+ int nbits;
+ xfs_failaddr_t fa;
+ const size_t size_disk_dquot = sizeof(struct xfs_disk_dquot);
+
+ trace_xfs_log_recover_buf_reg_buf(mp->m_log, buf_f);
+
+ bit = 0;
+ i = 1; /* 0 is the buf format structure */
+ while (1) {
+ bit = xfs_next_bit(buf_f->blf_data_map,
+ buf_f->blf_map_size, bit);
+ if (bit == -1)
+ break;
+ nbits = xfs_contig_bits(buf_f->blf_data_map,
+ buf_f->blf_map_size, bit);
+ ASSERT(nbits > 0);
+ ASSERT(item->ri_buf[i].i_addr != NULL);
+ ASSERT(item->ri_buf[i].i_len % XFS_BLF_CHUNK == 0);
+ ASSERT(BBTOB(bp->b_length) >=
+ ((uint)bit << XFS_BLF_SHIFT) + (nbits << XFS_BLF_SHIFT));
+
+ /*
+ * The dirty regions logged in the buffer, even though
+ * contiguous, may span multiple chunks. This is because the
+ * dirty region may span a physical page boundary in a buffer
+ * and hence be split into two separate vectors for writing into
+ * the log. Hence we need to trim nbits back to the length of
+ * the current region being copied out of the log.
+ */
+ if (item->ri_buf[i].i_len < (nbits << XFS_BLF_SHIFT))
+ nbits = item->ri_buf[i].i_len >> XFS_BLF_SHIFT;
+
+ /*
+ * Do a sanity check if this is a dquot buffer. Just checking
+ * the first dquot in the buffer should do. XXXThis is
+ * probably a good thing to do for other buf types also.
+ */
+ fa = NULL;
+ if (buf_f->blf_flags &
+ (XFS_BLF_UDQUOT_BUF|XFS_BLF_PDQUOT_BUF|XFS_BLF_GDQUOT_BUF)) {
+ if (item->ri_buf[i].i_addr == NULL) {
+ xfs_alert(mp,
+ "XFS: NULL dquot in %s.", __func__);
+ goto next;
+ }
+ if (item->ri_buf[i].i_len < size_disk_dquot) {
+ xfs_alert(mp,
+ "XFS: dquot too small (%d) in %s.",
+ item->ri_buf[i].i_len, __func__);
+ goto next;
+ }
+ fa = xfs_dquot_verify(mp, item->ri_buf[i].i_addr, -1);
+ if (fa) {
+ xfs_alert(mp,
+ "dquot corrupt at %pS trying to replay into block 0x%llx",
+ fa, xfs_buf_daddr(bp));
+ goto next;
+ }
+ }
+
+ memcpy(xfs_buf_offset(bp,
+ (uint)bit << XFS_BLF_SHIFT), /* dest */
+ item->ri_buf[i].i_addr, /* source */
+ nbits<<XFS_BLF_SHIFT); /* length */
+ next:
+ i++;
+ bit += nbits;
+ }
+
+ /* Shouldn't be any more regions */
+ ASSERT(i == item->ri_total);
+
+ xlog_recover_validate_buf_type(mp, bp, buf_f, current_lsn);
+}
+
+/*
+ * Perform a dquot buffer recovery.
+ * Simple algorithm: if we have found a QUOTAOFF log item of the same type
+ * (ie. USR or GRP), then just toss this buffer away; don't recover it.
+ * Else, treat it as a regular buffer and do recovery.
+ *
+ * Return false if the buffer was tossed and true if we recovered the buffer to
+ * indicate to the caller if the buffer needs writing.
+ */
+STATIC bool
+xlog_recover_do_dquot_buffer(
+ struct xfs_mount *mp,
+ struct xlog *log,
+ struct xlog_recover_item *item,
+ struct xfs_buf *bp,
+ struct xfs_buf_log_format *buf_f)
+{
+ uint type;
+
+ trace_xfs_log_recover_buf_dquot_buf(log, buf_f);
+
+ /*
+ * Filesystems are required to send in quota flags at mount time.
+ */
+ if (!mp->m_qflags)
+ return false;
+
+ type = 0;
+ if (buf_f->blf_flags & XFS_BLF_UDQUOT_BUF)
+ type |= XFS_DQTYPE_USER;
+ if (buf_f->blf_flags & XFS_BLF_PDQUOT_BUF)
+ type |= XFS_DQTYPE_PROJ;
+ if (buf_f->blf_flags & XFS_BLF_GDQUOT_BUF)
+ type |= XFS_DQTYPE_GROUP;
+ /*
+ * This type of quotas was turned off, so ignore this buffer
+ */
+ if (log->l_quotaoffs_flag & type)
+ return false;
+
+ xlog_recover_do_reg_buffer(mp, item, bp, buf_f, NULLCOMMITLSN);
+ return true;
+}
+
+/*
+ * Perform recovery for a buffer full of inodes. In these buffers, the only
+ * data which should be recovered is that which corresponds to the
+ * di_next_unlinked pointers in the on disk inode structures. The rest of the
+ * data for the inodes is always logged through the inodes themselves rather
+ * than the inode buffer and is recovered in xlog_recover_inode_pass2().
+ *
+ * The only time when buffers full of inodes are fully recovered is when the
+ * buffer is full of newly allocated inodes. In this case the buffer will
+ * not be marked as an inode buffer and so will be sent to
+ * xlog_recover_do_reg_buffer() below during recovery.
+ */
+STATIC int
+xlog_recover_do_inode_buffer(
+ struct xfs_mount *mp,
+ struct xlog_recover_item *item,
+ struct xfs_buf *bp,
+ struct xfs_buf_log_format *buf_f)
+{
+ int i;
+ int item_index = 0;
+ int bit = 0;
+ int nbits = 0;
+ int reg_buf_offset = 0;
+ int reg_buf_bytes = 0;
+ int next_unlinked_offset;
+ int inodes_per_buf;
+ xfs_agino_t *logged_nextp;
+ xfs_agino_t *buffer_nextp;
+
+ trace_xfs_log_recover_buf_inode_buf(mp->m_log, buf_f);
+
+ /*
+ * Post recovery validation only works properly on CRC enabled
+ * filesystems.
+ */
+ if (xfs_has_crc(mp))
+ bp->b_ops = &xfs_inode_buf_ops;
+
+ inodes_per_buf = BBTOB(bp->b_length) >> mp->m_sb.sb_inodelog;
+ for (i = 0; i < inodes_per_buf; i++) {
+ next_unlinked_offset = (i * mp->m_sb.sb_inodesize) +
+ offsetof(struct xfs_dinode, di_next_unlinked);
+
+ while (next_unlinked_offset >=
+ (reg_buf_offset + reg_buf_bytes)) {
+ /*
+ * The next di_next_unlinked field is beyond
+ * the current logged region. Find the next
+ * logged region that contains or is beyond
+ * the current di_next_unlinked field.
+ */
+ bit += nbits;
+ bit = xfs_next_bit(buf_f->blf_data_map,
+ buf_f->blf_map_size, bit);
+
+ /*
+ * If there are no more logged regions in the
+ * buffer, then we're done.
+ */
+ if (bit == -1)
+ return 0;
+
+ nbits = xfs_contig_bits(buf_f->blf_data_map,
+ buf_f->blf_map_size, bit);
+ ASSERT(nbits > 0);
+ reg_buf_offset = bit << XFS_BLF_SHIFT;
+ reg_buf_bytes = nbits << XFS_BLF_SHIFT;
+ item_index++;
+ }
+
+ /*
+ * If the current logged region starts after the current
+ * di_next_unlinked field, then move on to the next
+ * di_next_unlinked field.
+ */
+ if (next_unlinked_offset < reg_buf_offset)
+ continue;
+
+ ASSERT(item->ri_buf[item_index].i_addr != NULL);
+ ASSERT((item->ri_buf[item_index].i_len % XFS_BLF_CHUNK) == 0);
+ ASSERT((reg_buf_offset + reg_buf_bytes) <= BBTOB(bp->b_length));
+
+ /*
+ * The current logged region contains a copy of the
+ * current di_next_unlinked field. Extract its value
+ * and copy it to the buffer copy.
+ */
+ logged_nextp = item->ri_buf[item_index].i_addr +
+ next_unlinked_offset - reg_buf_offset;
+ if (XFS_IS_CORRUPT(mp, *logged_nextp == 0)) {
+ xfs_alert(mp,
+ "Bad inode buffer log record (ptr = "PTR_FMT", bp = "PTR_FMT"). "
+ "Trying to replay bad (0) inode di_next_unlinked field.",
+ item, bp);
+ return -EFSCORRUPTED;
+ }
+
+ buffer_nextp = xfs_buf_offset(bp, next_unlinked_offset);
+ *buffer_nextp = *logged_nextp;
+
+ /*
+ * If necessary, recalculate the CRC in the on-disk inode. We
+ * have to leave the inode in a consistent state for whoever
+ * reads it next....
+ */
+ xfs_dinode_calc_crc(mp,
+ xfs_buf_offset(bp, i * mp->m_sb.sb_inodesize));
+
+ }
+
+ return 0;
+}
+
+/*
+ * V5 filesystems know the age of the buffer on disk being recovered. We can
+ * have newer objects on disk than we are replaying, and so for these cases we
+ * don't want to replay the current change as that will make the buffer contents
+ * temporarily invalid on disk.
+ *
+ * The magic number might not match the buffer type we are going to recover
+ * (e.g. reallocated blocks), so we ignore the xfs_buf_log_format flags. Hence
+ * extract the LSN of the existing object in the buffer based on it's current
+ * magic number. If we don't recognise the magic number in the buffer, then
+ * return a LSN of -1 so that the caller knows it was an unrecognised block and
+ * so can recover the buffer.
+ *
+ * Note: we cannot rely solely on magic number matches to determine that the
+ * buffer has a valid LSN - we also need to verify that it belongs to this
+ * filesystem, so we need to extract the object's LSN and compare it to that
+ * which we read from the superblock. If the UUIDs don't match, then we've got a
+ * stale metadata block from an old filesystem instance that we need to recover
+ * over the top of.
+ */
+static xfs_lsn_t
+xlog_recover_get_buf_lsn(
+ struct xfs_mount *mp,
+ struct xfs_buf *bp,
+ struct xfs_buf_log_format *buf_f)
+{
+ uint32_t magic32;
+ uint16_t magic16;
+ uint16_t magicda;
+ void *blk = bp->b_addr;
+ uuid_t *uuid;
+ xfs_lsn_t lsn = -1;
+ uint16_t blft;
+
+ /* v4 filesystems always recover immediately */
+ if (!xfs_has_crc(mp))
+ goto recover_immediately;
+
+ /*
+ * realtime bitmap and summary file blocks do not have magic numbers or
+ * UUIDs, so we must recover them immediately.
+ */
+ blft = xfs_blft_from_flags(buf_f);
+ if (blft == XFS_BLFT_RTBITMAP_BUF || blft == XFS_BLFT_RTSUMMARY_BUF)
+ goto recover_immediately;
+
+ magic32 = be32_to_cpu(*(__be32 *)blk);
+ switch (magic32) {
+ case XFS_ABTB_CRC_MAGIC:
+ case XFS_ABTC_CRC_MAGIC:
+ case XFS_ABTB_MAGIC:
+ case XFS_ABTC_MAGIC:
+ case XFS_RMAP_CRC_MAGIC:
+ case XFS_REFC_CRC_MAGIC:
+ case XFS_FIBT_CRC_MAGIC:
+ case XFS_FIBT_MAGIC:
+ case XFS_IBT_CRC_MAGIC:
+ case XFS_IBT_MAGIC: {
+ struct xfs_btree_block *btb = blk;
+
+ lsn = be64_to_cpu(btb->bb_u.s.bb_lsn);
+ uuid = &btb->bb_u.s.bb_uuid;
+ break;
+ }
+ case XFS_BMAP_CRC_MAGIC:
+ case XFS_BMAP_MAGIC: {
+ struct xfs_btree_block *btb = blk;
+
+ lsn = be64_to_cpu(btb->bb_u.l.bb_lsn);
+ uuid = &btb->bb_u.l.bb_uuid;
+ break;
+ }
+ case XFS_AGF_MAGIC:
+ lsn = be64_to_cpu(((struct xfs_agf *)blk)->agf_lsn);
+ uuid = &((struct xfs_agf *)blk)->agf_uuid;
+ break;
+ case XFS_AGFL_MAGIC:
+ lsn = be64_to_cpu(((struct xfs_agfl *)blk)->agfl_lsn);
+ uuid = &((struct xfs_agfl *)blk)->agfl_uuid;
+ break;
+ case XFS_AGI_MAGIC:
+ lsn = be64_to_cpu(((struct xfs_agi *)blk)->agi_lsn);
+ uuid = &((struct xfs_agi *)blk)->agi_uuid;
+ break;
+ case XFS_SYMLINK_MAGIC:
+ lsn = be64_to_cpu(((struct xfs_dsymlink_hdr *)blk)->sl_lsn);
+ uuid = &((struct xfs_dsymlink_hdr *)blk)->sl_uuid;
+ break;
+ case XFS_DIR3_BLOCK_MAGIC:
+ case XFS_DIR3_DATA_MAGIC:
+ case XFS_DIR3_FREE_MAGIC:
+ lsn = be64_to_cpu(((struct xfs_dir3_blk_hdr *)blk)->lsn);
+ uuid = &((struct xfs_dir3_blk_hdr *)blk)->uuid;
+ break;
+ case XFS_ATTR3_RMT_MAGIC:
+ /*
+ * Remote attr blocks are written synchronously, rather than
+ * being logged. That means they do not contain a valid LSN
+ * (i.e. transactionally ordered) in them, and hence any time we
+ * see a buffer to replay over the top of a remote attribute
+ * block we should simply do so.
+ */
+ goto recover_immediately;
+ case XFS_SB_MAGIC:
+ /*
+ * superblock uuids are magic. We may or may not have a
+ * sb_meta_uuid on disk, but it will be set in the in-core
+ * superblock. We set the uuid pointer for verification
+ * according to the superblock feature mask to ensure we check
+ * the relevant UUID in the superblock.
+ */
+ lsn = be64_to_cpu(((struct xfs_dsb *)blk)->sb_lsn);
+ if (xfs_has_metauuid(mp))
+ uuid = &((struct xfs_dsb *)blk)->sb_meta_uuid;
+ else
+ uuid = &((struct xfs_dsb *)blk)->sb_uuid;
+ break;
+ default:
+ break;
+ }
+
+ if (lsn != (xfs_lsn_t)-1) {
+ if (!uuid_equal(&mp->m_sb.sb_meta_uuid, uuid))
+ goto recover_immediately;
+ return lsn;
+ }
+
+ magicda = be16_to_cpu(((struct xfs_da_blkinfo *)blk)->magic);
+ switch (magicda) {
+ case XFS_DIR3_LEAF1_MAGIC:
+ case XFS_DIR3_LEAFN_MAGIC:
+ case XFS_ATTR3_LEAF_MAGIC:
+ case XFS_DA3_NODE_MAGIC:
+ lsn = be64_to_cpu(((struct xfs_da3_blkinfo *)blk)->lsn);
+ uuid = &((struct xfs_da3_blkinfo *)blk)->uuid;
+ break;
+ default:
+ break;
+ }
+
+ if (lsn != (xfs_lsn_t)-1) {
+ if (!uuid_equal(&mp->m_sb.sb_meta_uuid, uuid))
+ goto recover_immediately;
+ return lsn;
+ }
+
+ /*
+ * We do individual object checks on dquot and inode buffers as they
+ * have their own individual LSN records. Also, we could have a stale
+ * buffer here, so we have to at least recognise these buffer types.
+ *
+ * A notd complexity here is inode unlinked list processing - it logs
+ * the inode directly in the buffer, but we don't know which inodes have
+ * been modified, and there is no global buffer LSN. Hence we need to
+ * recover all inode buffer types immediately. This problem will be
+ * fixed by logical logging of the unlinked list modifications.
+ */
+ magic16 = be16_to_cpu(*(__be16 *)blk);
+ switch (magic16) {
+ case XFS_DQUOT_MAGIC:
+ case XFS_DINODE_MAGIC:
+ goto recover_immediately;
+ default:
+ break;
+ }
+
+ /* unknown buffer contents, recover immediately */
+
+recover_immediately:
+ return (xfs_lsn_t)-1;
+
+}
+
+/*
+ * This routine replays a modification made to a buffer at runtime.
+ * There are actually two types of buffer, regular and inode, which
+ * are handled differently. Inode buffers are handled differently
+ * in that we only recover a specific set of data from them, namely
+ * the inode di_next_unlinked fields. This is because all other inode
+ * data is actually logged via inode records and any data we replay
+ * here which overlaps that may be stale.
+ *
+ * When meta-data buffers are freed at run time we log a buffer item
+ * with the XFS_BLF_CANCEL bit set to indicate that previous copies
+ * of the buffer in the log should not be replayed at recovery time.
+ * This is so that if the blocks covered by the buffer are reused for
+ * file data before we crash we don't end up replaying old, freed
+ * meta-data into a user's file.
+ *
+ * To handle the cancellation of buffer log items, we make two passes
+ * over the log during recovery. During the first we build a table of
+ * those buffers which have been cancelled, and during the second we
+ * only replay those buffers which do not have corresponding cancel
+ * records in the table. See xlog_recover_buf_pass[1,2] above
+ * for more details on the implementation of the table of cancel records.
+ */
+STATIC int
+xlog_recover_buf_commit_pass2(
+ struct xlog *log,
+ struct list_head *buffer_list,
+ struct xlog_recover_item *item,
+ xfs_lsn_t current_lsn)
+{
+ struct xfs_buf_log_format *buf_f = item->ri_buf[0].i_addr;
+ struct xfs_mount *mp = log->l_mp;
+ struct xfs_buf *bp;
+ int error;
+ uint buf_flags;
+ xfs_lsn_t lsn;
+
+ /*
+ * In this pass we only want to recover all the buffers which have
+ * not been cancelled and are not cancellation buffers themselves.
+ */
+ if (buf_f->blf_flags & XFS_BLF_CANCEL) {
+ if (xlog_put_buffer_cancelled(log, buf_f->blf_blkno,
+ buf_f->blf_len))
+ goto cancelled;
+ } else {
+
+ if (xlog_is_buffer_cancelled(log, buf_f->blf_blkno,
+ buf_f->blf_len))
+ goto cancelled;
+ }
+
+ trace_xfs_log_recover_buf_recover(log, buf_f);
+
+ buf_flags = 0;
+ if (buf_f->blf_flags & XFS_BLF_INODE_BUF)
+ buf_flags |= XBF_UNMAPPED;
+
+ error = xfs_buf_read(mp->m_ddev_targp, buf_f->blf_blkno, buf_f->blf_len,
+ buf_flags, &bp, NULL);
+ if (error)
+ return error;
+
+ /*
+ * Recover the buffer only if we get an LSN from it and it's less than
+ * the lsn of the transaction we are replaying.
+ *
+ * Note that we have to be extremely careful of readahead here.
+ * Readahead does not attach verfiers to the buffers so if we don't
+ * actually do any replay after readahead because of the LSN we found
+ * in the buffer if more recent than that current transaction then we
+ * need to attach the verifier directly. Failure to do so can lead to
+ * future recovery actions (e.g. EFI and unlinked list recovery) can
+ * operate on the buffers and they won't get the verifier attached. This
+ * can lead to blocks on disk having the correct content but a stale
+ * CRC.
+ *
+ * It is safe to assume these clean buffers are currently up to date.
+ * If the buffer is dirtied by a later transaction being replayed, then
+ * the verifier will be reset to match whatever recover turns that
+ * buffer into.
+ */
+ lsn = xlog_recover_get_buf_lsn(mp, bp, buf_f);
+ if (lsn && lsn != -1 && XFS_LSN_CMP(lsn, current_lsn) >= 0) {
+ trace_xfs_log_recover_buf_skip(log, buf_f);
+ xlog_recover_validate_buf_type(mp, bp, buf_f, NULLCOMMITLSN);
+
+ /*
+ * We're skipping replay of this buffer log item due to the log
+ * item LSN being behind the ondisk buffer. Verify the buffer
+ * contents since we aren't going to run the write verifier.
+ */
+ if (bp->b_ops) {
+ bp->b_ops->verify_read(bp);
+ error = bp->b_error;
+ }
+ goto out_release;
+ }
+
+ if (buf_f->blf_flags & XFS_BLF_INODE_BUF) {
+ error = xlog_recover_do_inode_buffer(mp, item, bp, buf_f);
+ if (error)
+ goto out_release;
+ } else if (buf_f->blf_flags &
+ (XFS_BLF_UDQUOT_BUF|XFS_BLF_PDQUOT_BUF|XFS_BLF_GDQUOT_BUF)) {
+ bool dirty;
+
+ dirty = xlog_recover_do_dquot_buffer(mp, log, item, bp, buf_f);
+ if (!dirty)
+ goto out_release;
+ } else {
+ xlog_recover_do_reg_buffer(mp, item, bp, buf_f, current_lsn);
+ }
+
+ /*
+ * Perform delayed write on the buffer. Asynchronous writes will be
+ * slower when taking into account all the buffers to be flushed.
+ *
+ * Also make sure that only inode buffers with good sizes stay in
+ * the buffer cache. The kernel moves inodes in buffers of 1 block
+ * or inode_cluster_size bytes, whichever is bigger. The inode
+ * buffers in the log can be a different size if the log was generated
+ * by an older kernel using unclustered inode buffers or a newer kernel
+ * running with a different inode cluster size. Regardless, if
+ * the inode buffer size isn't max(blocksize, inode_cluster_size)
+ * for *our* value of inode_cluster_size, then we need to keep
+ * the buffer out of the buffer cache so that the buffer won't
+ * overlap with future reads of those inodes.
+ */
+ if (XFS_DINODE_MAGIC ==
+ be16_to_cpu(*((__be16 *)xfs_buf_offset(bp, 0))) &&
+ (BBTOB(bp->b_length) != M_IGEO(log->l_mp)->inode_cluster_size)) {
+ xfs_buf_stale(bp);
+ error = xfs_bwrite(bp);
+ } else {
+ ASSERT(bp->b_mount == mp);
+ bp->b_flags |= _XBF_LOGRECOVERY;
+ xfs_buf_delwri_queue(bp, buffer_list);
+ }
+
+out_release:
+ xfs_buf_relse(bp);
+ return error;
+cancelled:
+ trace_xfs_log_recover_buf_cancel(log, buf_f);
+ return 0;
+}
+
+const struct xlog_recover_item_ops xlog_buf_item_ops = {
+ .item_type = XFS_LI_BUF,
+ .reorder = xlog_recover_buf_reorder,
+ .ra_pass2 = xlog_recover_buf_ra_pass2,
+ .commit_pass1 = xlog_recover_buf_commit_pass1,
+ .commit_pass2 = xlog_recover_buf_commit_pass2,
+};
+
+#ifdef DEBUG
+void
+xlog_check_buf_cancel_table(
+ struct xlog *log)
+{
+ int i;
+
+ for (i = 0; i < XLOG_BC_TABLE_SIZE; i++)
+ ASSERT(list_empty(&log->l_buf_cancel_table[i]));
+}
+#endif
+
+int
+xlog_alloc_buf_cancel_table(
+ struct xlog *log)
+{
+ void *p;
+ int i;
+
+ ASSERT(log->l_buf_cancel_table == NULL);
+
+ p = kmalloc_array(XLOG_BC_TABLE_SIZE, sizeof(struct list_head),
+ GFP_KERNEL);
+ if (!p)
+ return -ENOMEM;
+
+ log->l_buf_cancel_table = p;
+ for (i = 0; i < XLOG_BC_TABLE_SIZE; i++)
+ INIT_LIST_HEAD(&log->l_buf_cancel_table[i]);
+
+ return 0;
+}
+
+void
+xlog_free_buf_cancel_table(
+ struct xlog *log)
+{
+ int i;
+
+ if (!log->l_buf_cancel_table)
+ return;
+
+ for (i = 0; i < XLOG_BC_TABLE_SIZE; i++) {
+ struct xfs_buf_cancel *bc;
+
+ while ((bc = list_first_entry_or_null(
+ &log->l_buf_cancel_table[i],
+ struct xfs_buf_cancel, bc_list))) {
+ list_del(&bc->bc_list);
+ kmem_free(bc);
+ }
+ }
+
+ kmem_free(log->l_buf_cancel_table);
+ log->l_buf_cancel_table = NULL;
+}