diff options
Diffstat (limited to 'fs/xfs/xfs_buf_item_recover.c')
| -rw-r--r-- | fs/xfs/xfs_buf_item_recover.c | 1071 |
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; +} |