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|
- // 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_sb.h"
- #include "xfs_mount.h"
- #include "xfs_defer.h"
- #include "xfs_inode.h"
- #include "xfs_trans.h"
- #include "xfs_log.h"
- #include "xfs_log_priv.h"
- #include "xfs_log_recover.h"
- #include "xfs_trans_priv.h"
- #include "xfs_alloc.h"
- #include "xfs_ialloc.h"
- #include "xfs_trace.h"
- #include "xfs_icache.h"
- #include "xfs_error.h"
- #include "xfs_buf_item.h"
- #include "xfs_ag.h"
- #include "xfs_quota.h"
- #include "xfs_reflink.h"
- #define BLK_AVG(blk1, blk2) ((blk1+blk2) >> 1)
- STATIC int
- xlog_find_zeroed(
- struct xlog *,
- xfs_daddr_t *);
- STATIC int
- xlog_clear_stale_blocks(
- struct xlog *,
- xfs_lsn_t);
- STATIC int
- xlog_do_recovery_pass(
- struct xlog *, xfs_daddr_t, xfs_daddr_t, int, xfs_daddr_t *);
- /*
- * Sector aligned buffer routines for buffer create/read/write/access
- */
- /*
- * Verify the log-relative block number and length in basic blocks are valid for
- * an operation involving the given XFS log buffer. Returns true if the fields
- * are valid, false otherwise.
- */
- static inline bool
- xlog_verify_bno(
- struct xlog *log,
- xfs_daddr_t blk_no,
- int bbcount)
- {
- if (blk_no < 0 || blk_no >= log->l_logBBsize)
- return false;
- if (bbcount <= 0 || (blk_no + bbcount) > log->l_logBBsize)
- return false;
- return true;
- }
- /*
- * Allocate a buffer to hold log data. The buffer needs to be able to map to
- * a range of nbblks basic blocks at any valid offset within the log.
- */
- static char *
- xlog_alloc_buffer(
- struct xlog *log,
- int nbblks)
- {
- /*
- * Pass log block 0 since we don't have an addr yet, buffer will be
- * verified on read.
- */
- if (XFS_IS_CORRUPT(log->l_mp, !xlog_verify_bno(log, 0, nbblks))) {
- xfs_warn(log->l_mp, "Invalid block length (0x%x) for buffer",
- nbblks);
- return NULL;
- }
- /*
- * We do log I/O in units of log sectors (a power-of-2 multiple of the
- * basic block size), so we round up the requested size to accommodate
- * the basic blocks required for complete log sectors.
- *
- * In addition, the buffer may be used for a non-sector-aligned block
- * offset, in which case an I/O of the requested size could extend
- * beyond the end of the buffer. If the requested size is only 1 basic
- * block it will never straddle a sector boundary, so this won't be an
- * issue. Nor will this be a problem if the log I/O is done in basic
- * blocks (sector size 1). But otherwise we extend the buffer by one
- * extra log sector to ensure there's space to accommodate this
- * possibility.
- */
- if (nbblks > 1 && log->l_sectBBsize > 1)
- nbblks += log->l_sectBBsize;
- nbblks = round_up(nbblks, log->l_sectBBsize);
- return kvzalloc(BBTOB(nbblks), GFP_KERNEL | __GFP_RETRY_MAYFAIL);
- }
- /*
- * Return the address of the start of the given block number's data
- * in a log buffer. The buffer covers a log sector-aligned region.
- */
- static inline unsigned int
- xlog_align(
- struct xlog *log,
- xfs_daddr_t blk_no)
- {
- return BBTOB(blk_no & ((xfs_daddr_t)log->l_sectBBsize - 1));
- }
- static int
- xlog_do_io(
- struct xlog *log,
- xfs_daddr_t blk_no,
- unsigned int nbblks,
- char *data,
- enum req_op op)
- {
- int error;
- if (XFS_IS_CORRUPT(log->l_mp, !xlog_verify_bno(log, blk_no, nbblks))) {
- xfs_warn(log->l_mp,
- "Invalid log block/length (0x%llx, 0x%x) for buffer",
- blk_no, nbblks);
- return -EFSCORRUPTED;
- }
- blk_no = round_down(blk_no, log->l_sectBBsize);
- nbblks = round_up(nbblks, log->l_sectBBsize);
- ASSERT(nbblks > 0);
- error = xfs_rw_bdev(log->l_targ->bt_bdev, log->l_logBBstart + blk_no,
- BBTOB(nbblks), data, op);
- if (error && !xlog_is_shutdown(log)) {
- xfs_alert(log->l_mp,
- "log recovery %s I/O error at daddr 0x%llx len %d error %d",
- op == REQ_OP_WRITE ? "write" : "read",
- blk_no, nbblks, error);
- }
- return error;
- }
- STATIC int
- xlog_bread_noalign(
- struct xlog *log,
- xfs_daddr_t blk_no,
- int nbblks,
- char *data)
- {
- return xlog_do_io(log, blk_no, nbblks, data, REQ_OP_READ);
- }
- STATIC int
- xlog_bread(
- struct xlog *log,
- xfs_daddr_t blk_no,
- int nbblks,
- char *data,
- char **offset)
- {
- int error;
- error = xlog_do_io(log, blk_no, nbblks, data, REQ_OP_READ);
- if (!error)
- *offset = data + xlog_align(log, blk_no);
- return error;
- }
- STATIC int
- xlog_bwrite(
- struct xlog *log,
- xfs_daddr_t blk_no,
- int nbblks,
- char *data)
- {
- return xlog_do_io(log, blk_no, nbblks, data, REQ_OP_WRITE);
- }
- #ifdef DEBUG
- /*
- * dump debug superblock and log record information
- */
- STATIC void
- xlog_header_check_dump(
- xfs_mount_t *mp,
- xlog_rec_header_t *head)
- {
- xfs_debug(mp, "%s: SB : uuid = %pU, fmt = %d",
- __func__, &mp->m_sb.sb_uuid, XLOG_FMT);
- xfs_debug(mp, " log : uuid = %pU, fmt = %d",
- &head->h_fs_uuid, be32_to_cpu(head->h_fmt));
- }
- #else
- #define xlog_header_check_dump(mp, head)
- #endif
- /*
- * check log record header for recovery
- */
- STATIC int
- xlog_header_check_recover(
- xfs_mount_t *mp,
- xlog_rec_header_t *head)
- {
- ASSERT(head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM));
- /*
- * IRIX doesn't write the h_fmt field and leaves it zeroed
- * (XLOG_FMT_UNKNOWN). This stops us from trying to recover
- * a dirty log created in IRIX.
- */
- if (XFS_IS_CORRUPT(mp, head->h_fmt != cpu_to_be32(XLOG_FMT))) {
- xfs_warn(mp,
- "dirty log written in incompatible format - can't recover");
- xlog_header_check_dump(mp, head);
- return -EFSCORRUPTED;
- }
- if (XFS_IS_CORRUPT(mp, !uuid_equal(&mp->m_sb.sb_uuid,
- &head->h_fs_uuid))) {
- xfs_warn(mp,
- "dirty log entry has mismatched uuid - can't recover");
- xlog_header_check_dump(mp, head);
- return -EFSCORRUPTED;
- }
- return 0;
- }
- /*
- * read the head block of the log and check the header
- */
- STATIC int
- xlog_header_check_mount(
- xfs_mount_t *mp,
- xlog_rec_header_t *head)
- {
- ASSERT(head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM));
- if (uuid_is_null(&head->h_fs_uuid)) {
- /*
- * IRIX doesn't write the h_fs_uuid or h_fmt fields. If
- * h_fs_uuid is null, we assume this log was last mounted
- * by IRIX and continue.
- */
- xfs_warn(mp, "null uuid in log - IRIX style log");
- } else if (XFS_IS_CORRUPT(mp, !uuid_equal(&mp->m_sb.sb_uuid,
- &head->h_fs_uuid))) {
- xfs_warn(mp, "log has mismatched uuid - can't recover");
- xlog_header_check_dump(mp, head);
- return -EFSCORRUPTED;
- }
- return 0;
- }
- /*
- * This routine finds (to an approximation) the first block in the physical
- * log which contains the given cycle. It uses a binary search algorithm.
- * Note that the algorithm can not be perfect because the disk will not
- * necessarily be perfect.
- */
- STATIC int
- xlog_find_cycle_start(
- struct xlog *log,
- char *buffer,
- xfs_daddr_t first_blk,
- xfs_daddr_t *last_blk,
- uint cycle)
- {
- char *offset;
- xfs_daddr_t mid_blk;
- xfs_daddr_t end_blk;
- uint mid_cycle;
- int error;
- end_blk = *last_blk;
- mid_blk = BLK_AVG(first_blk, end_blk);
- while (mid_blk != first_blk && mid_blk != end_blk) {
- error = xlog_bread(log, mid_blk, 1, buffer, &offset);
- if (error)
- return error;
- mid_cycle = xlog_get_cycle(offset);
- if (mid_cycle == cycle)
- end_blk = mid_blk; /* last_half_cycle == mid_cycle */
- else
- first_blk = mid_blk; /* first_half_cycle == mid_cycle */
- mid_blk = BLK_AVG(first_blk, end_blk);
- }
- ASSERT((mid_blk == first_blk && mid_blk+1 == end_blk) ||
- (mid_blk == end_blk && mid_blk-1 == first_blk));
- *last_blk = end_blk;
- return 0;
- }
- /*
- * Check that a range of blocks does not contain stop_on_cycle_no.
- * Fill in *new_blk with the block offset where such a block is
- * found, or with -1 (an invalid block number) if there is no such
- * block in the range. The scan needs to occur from front to back
- * and the pointer into the region must be updated since a later
- * routine will need to perform another test.
- */
- STATIC int
- xlog_find_verify_cycle(
- struct xlog *log,
- xfs_daddr_t start_blk,
- int nbblks,
- uint stop_on_cycle_no,
- xfs_daddr_t *new_blk)
- {
- xfs_daddr_t i, j;
- uint cycle;
- char *buffer;
- xfs_daddr_t bufblks;
- char *buf = NULL;
- int error = 0;
- /*
- * Greedily allocate a buffer big enough to handle the full
- * range of basic blocks we'll be examining. If that fails,
- * try a smaller size. We need to be able to read at least
- * a log sector, or we're out of luck.
- */
- bufblks = 1 << ffs(nbblks);
- while (bufblks > log->l_logBBsize)
- bufblks >>= 1;
- while (!(buffer = xlog_alloc_buffer(log, bufblks))) {
- bufblks >>= 1;
- if (bufblks < log->l_sectBBsize)
- return -ENOMEM;
- }
- for (i = start_blk; i < start_blk + nbblks; i += bufblks) {
- int bcount;
- bcount = min(bufblks, (start_blk + nbblks - i));
- error = xlog_bread(log, i, bcount, buffer, &buf);
- if (error)
- goto out;
- for (j = 0; j < bcount; j++) {
- cycle = xlog_get_cycle(buf);
- if (cycle == stop_on_cycle_no) {
- *new_blk = i+j;
- goto out;
- }
- buf += BBSIZE;
- }
- }
- *new_blk = -1;
- out:
- kmem_free(buffer);
- return error;
- }
- static inline int
- xlog_logrec_hblks(struct xlog *log, struct xlog_rec_header *rh)
- {
- if (xfs_has_logv2(log->l_mp)) {
- int h_size = be32_to_cpu(rh->h_size);
- if ((be32_to_cpu(rh->h_version) & XLOG_VERSION_2) &&
- h_size > XLOG_HEADER_CYCLE_SIZE)
- return DIV_ROUND_UP(h_size, XLOG_HEADER_CYCLE_SIZE);
- }
- return 1;
- }
- /*
- * Potentially backup over partial log record write.
- *
- * In the typical case, last_blk is the number of the block directly after
- * a good log record. Therefore, we subtract one to get the block number
- * of the last block in the given buffer. extra_bblks contains the number
- * of blocks we would have read on a previous read. This happens when the
- * last log record is split over the end of the physical log.
- *
- * extra_bblks is the number of blocks potentially verified on a previous
- * call to this routine.
- */
- STATIC int
- xlog_find_verify_log_record(
- struct xlog *log,
- xfs_daddr_t start_blk,
- xfs_daddr_t *last_blk,
- int extra_bblks)
- {
- xfs_daddr_t i;
- char *buffer;
- char *offset = NULL;
- xlog_rec_header_t *head = NULL;
- int error = 0;
- int smallmem = 0;
- int num_blks = *last_blk - start_blk;
- int xhdrs;
- ASSERT(start_blk != 0 || *last_blk != start_blk);
- buffer = xlog_alloc_buffer(log, num_blks);
- if (!buffer) {
- buffer = xlog_alloc_buffer(log, 1);
- if (!buffer)
- return -ENOMEM;
- smallmem = 1;
- } else {
- error = xlog_bread(log, start_blk, num_blks, buffer, &offset);
- if (error)
- goto out;
- offset += ((num_blks - 1) << BBSHIFT);
- }
- for (i = (*last_blk) - 1; i >= 0; i--) {
- if (i < start_blk) {
- /* valid log record not found */
- xfs_warn(log->l_mp,
- "Log inconsistent (didn't find previous header)");
- ASSERT(0);
- error = -EFSCORRUPTED;
- goto out;
- }
- if (smallmem) {
- error = xlog_bread(log, i, 1, buffer, &offset);
- if (error)
- goto out;
- }
- head = (xlog_rec_header_t *)offset;
- if (head->h_magicno == cpu_to_be32(XLOG_HEADER_MAGIC_NUM))
- break;
- if (!smallmem)
- offset -= BBSIZE;
- }
- /*
- * We hit the beginning of the physical log & still no header. Return
- * to caller. If caller can handle a return of -1, then this routine
- * will be called again for the end of the physical log.
- */
- if (i == -1) {
- error = 1;
- goto out;
- }
- /*
- * We have the final block of the good log (the first block
- * of the log record _before_ the head. So we check the uuid.
- */
- if ((error = xlog_header_check_mount(log->l_mp, head)))
- goto out;
- /*
- * We may have found a log record header before we expected one.
- * last_blk will be the 1st block # with a given cycle #. We may end
- * up reading an entire log record. In this case, we don't want to
- * reset last_blk. Only when last_blk points in the middle of a log
- * record do we update last_blk.
- */
- xhdrs = xlog_logrec_hblks(log, head);
- if (*last_blk - i + extra_bblks !=
- BTOBB(be32_to_cpu(head->h_len)) + xhdrs)
- *last_blk = i;
- out:
- kmem_free(buffer);
- return error;
- }
- /*
- * Head is defined to be the point of the log where the next log write
- * could go. This means that incomplete LR writes at the end are
- * eliminated when calculating the head. We aren't guaranteed that previous
- * LR have complete transactions. We only know that a cycle number of
- * current cycle number -1 won't be present in the log if we start writing
- * from our current block number.
- *
- * last_blk contains the block number of the first block with a given
- * cycle number.
- *
- * Return: zero if normal, non-zero if error.
- */
- STATIC int
- xlog_find_head(
- struct xlog *log,
- xfs_daddr_t *return_head_blk)
- {
- char *buffer;
- char *offset;
- xfs_daddr_t new_blk, first_blk, start_blk, last_blk, head_blk;
- int num_scan_bblks;
- uint first_half_cycle, last_half_cycle;
- uint stop_on_cycle;
- int error, log_bbnum = log->l_logBBsize;
- /* Is the end of the log device zeroed? */
- error = xlog_find_zeroed(log, &first_blk);
- if (error < 0) {
- xfs_warn(log->l_mp, "empty log check failed");
- return error;
- }
- if (error == 1) {
- *return_head_blk = first_blk;
- /* Is the whole lot zeroed? */
- if (!first_blk) {
- /* Linux XFS shouldn't generate totally zeroed logs -
- * mkfs etc write a dummy unmount record to a fresh
- * log so we can store the uuid in there
- */
- xfs_warn(log->l_mp, "totally zeroed log");
- }
- return 0;
- }
- first_blk = 0; /* get cycle # of 1st block */
- buffer = xlog_alloc_buffer(log, 1);
- if (!buffer)
- return -ENOMEM;
- error = xlog_bread(log, 0, 1, buffer, &offset);
- if (error)
- goto out_free_buffer;
- first_half_cycle = xlog_get_cycle(offset);
- last_blk = head_blk = log_bbnum - 1; /* get cycle # of last block */
- error = xlog_bread(log, last_blk, 1, buffer, &offset);
- if (error)
- goto out_free_buffer;
- last_half_cycle = xlog_get_cycle(offset);
- ASSERT(last_half_cycle != 0);
- /*
- * If the 1st half cycle number is equal to the last half cycle number,
- * then the entire log is stamped with the same cycle number. In this
- * case, head_blk can't be set to zero (which makes sense). The below
- * math doesn't work out properly with head_blk equal to zero. Instead,
- * we set it to log_bbnum which is an invalid block number, but this
- * value makes the math correct. If head_blk doesn't changed through
- * all the tests below, *head_blk is set to zero at the very end rather
- * than log_bbnum. In a sense, log_bbnum and zero are the same block
- * in a circular file.
- */
- if (first_half_cycle == last_half_cycle) {
- /*
- * In this case we believe that the entire log should have
- * cycle number last_half_cycle. We need to scan backwards
- * from the end verifying that there are no holes still
- * containing last_half_cycle - 1. If we find such a hole,
- * then the start of that hole will be the new head. The
- * simple case looks like
- * x | x ... | x - 1 | x
- * Another case that fits this picture would be
- * x | x + 1 | x ... | x
- * In this case the head really is somewhere at the end of the
- * log, as one of the latest writes at the beginning was
- * incomplete.
- * One more case is
- * x | x + 1 | x ... | x - 1 | x
- * This is really the combination of the above two cases, and
- * the head has to end up at the start of the x-1 hole at the
- * end of the log.
- *
- * In the 256k log case, we will read from the beginning to the
- * end of the log and search for cycle numbers equal to x-1.
- * We don't worry about the x+1 blocks that we encounter,
- * because we know that they cannot be the head since the log
- * started with x.
- */
- head_blk = log_bbnum;
- stop_on_cycle = last_half_cycle - 1;
- } else {
- /*
- * In this case we want to find the first block with cycle
- * number matching last_half_cycle. We expect the log to be
- * some variation on
- * x + 1 ... | x ... | x
- * The first block with cycle number x (last_half_cycle) will
- * be where the new head belongs. First we do a binary search
- * for the first occurrence of last_half_cycle. The binary
- * search may not be totally accurate, so then we scan back
- * from there looking for occurrences of last_half_cycle before
- * us. If that backwards scan wraps around the beginning of
- * the log, then we look for occurrences of last_half_cycle - 1
- * at the end of the log. The cases we're looking for look
- * like
- * v binary search stopped here
- * x + 1 ... | x | x + 1 | x ... | x
- * ^ but we want to locate this spot
- * or
- * <---------> less than scan distance
- * x + 1 ... | x ... | x - 1 | x
- * ^ we want to locate this spot
- */
- stop_on_cycle = last_half_cycle;
- error = xlog_find_cycle_start(log, buffer, first_blk, &head_blk,
- last_half_cycle);
- if (error)
- goto out_free_buffer;
- }
- /*
- * Now validate the answer. Scan back some number of maximum possible
- * blocks and make sure each one has the expected cycle number. The
- * maximum is determined by the total possible amount of buffering
- * in the in-core log. The following number can be made tighter if
- * we actually look at the block size of the filesystem.
- */
- num_scan_bblks = min_t(int, log_bbnum, XLOG_TOTAL_REC_SHIFT(log));
- if (head_blk >= num_scan_bblks) {
- /*
- * We are guaranteed that the entire check can be performed
- * in one buffer.
- */
- start_blk = head_blk - num_scan_bblks;
- if ((error = xlog_find_verify_cycle(log,
- start_blk, num_scan_bblks,
- stop_on_cycle, &new_blk)))
- goto out_free_buffer;
- if (new_blk != -1)
- head_blk = new_blk;
- } else { /* need to read 2 parts of log */
- /*
- * We are going to scan backwards in the log in two parts.
- * First we scan the physical end of the log. In this part
- * of the log, we are looking for blocks with cycle number
- * last_half_cycle - 1.
- * If we find one, then we know that the log starts there, as
- * we've found a hole that didn't get written in going around
- * the end of the physical log. The simple case for this is
- * x + 1 ... | x ... | x - 1 | x
- * <---------> less than scan distance
- * If all of the blocks at the end of the log have cycle number
- * last_half_cycle, then we check the blocks at the start of
- * the log looking for occurrences of last_half_cycle. If we
- * find one, then our current estimate for the location of the
- * first occurrence of last_half_cycle is wrong and we move
- * back to the hole we've found. This case looks like
- * x + 1 ... | x | x + 1 | x ...
- * ^ binary search stopped here
- * Another case we need to handle that only occurs in 256k
- * logs is
- * x + 1 ... | x ... | x+1 | x ...
- * ^ binary search stops here
- * In a 256k log, the scan at the end of the log will see the
- * x + 1 blocks. We need to skip past those since that is
- * certainly not the head of the log. By searching for
- * last_half_cycle-1 we accomplish that.
- */
- ASSERT(head_blk <= INT_MAX &&
- (xfs_daddr_t) num_scan_bblks >= head_blk);
- start_blk = log_bbnum - (num_scan_bblks - head_blk);
- if ((error = xlog_find_verify_cycle(log, start_blk,
- num_scan_bblks - (int)head_blk,
- (stop_on_cycle - 1), &new_blk)))
- goto out_free_buffer;
- if (new_blk != -1) {
- head_blk = new_blk;
- goto validate_head;
- }
- /*
- * Scan beginning of log now. The last part of the physical
- * log is good. This scan needs to verify that it doesn't find
- * the last_half_cycle.
- */
- start_blk = 0;
- ASSERT(head_blk <= INT_MAX);
- if ((error = xlog_find_verify_cycle(log,
- start_blk, (int)head_blk,
- stop_on_cycle, &new_blk)))
- goto out_free_buffer;
- if (new_blk != -1)
- head_blk = new_blk;
- }
- validate_head:
- /*
- * Now we need to make sure head_blk is not pointing to a block in
- * the middle of a log record.
- */
- num_scan_bblks = XLOG_REC_SHIFT(log);
- if (head_blk >= num_scan_bblks) {
- start_blk = head_blk - num_scan_bblks; /* don't read head_blk */
- /* start ptr at last block ptr before head_blk */
- error = xlog_find_verify_log_record(log, start_blk, &head_blk, 0);
- if (error == 1)
- error = -EIO;
- if (error)
- goto out_free_buffer;
- } else {
- start_blk = 0;
- ASSERT(head_blk <= INT_MAX);
- error = xlog_find_verify_log_record(log, start_blk, &head_blk, 0);
- if (error < 0)
- goto out_free_buffer;
- if (error == 1) {
- /* We hit the beginning of the log during our search */
- start_blk = log_bbnum - (num_scan_bblks - head_blk);
- new_blk = log_bbnum;
- ASSERT(start_blk <= INT_MAX &&
- (xfs_daddr_t) log_bbnum-start_blk >= 0);
- ASSERT(head_blk <= INT_MAX);
- error = xlog_find_verify_log_record(log, start_blk,
- &new_blk, (int)head_blk);
- if (error == 1)
- error = -EIO;
- if (error)
- goto out_free_buffer;
- if (new_blk != log_bbnum)
- head_blk = new_blk;
- } else if (error)
- goto out_free_buffer;
- }
- kmem_free(buffer);
- if (head_blk == log_bbnum)
- *return_head_blk = 0;
- else
- *return_head_blk = head_blk;
- /*
- * When returning here, we have a good block number. Bad block
- * means that during a previous crash, we didn't have a clean break
- * from cycle number N to cycle number N-1. In this case, we need
- * to find the first block with cycle number N-1.
- */
- return 0;
- out_free_buffer:
- kmem_free(buffer);
- if (error)
- xfs_warn(log->l_mp, "failed to find log head");
- return error;
- }
- /*
- * Seek backwards in the log for log record headers.
- *
- * Given a starting log block, walk backwards until we find the provided number
- * of records or hit the provided tail block. The return value is the number of
- * records encountered or a negative error code. The log block and buffer
- * pointer of the last record seen are returned in rblk and rhead respectively.
- */
- STATIC int
- xlog_rseek_logrec_hdr(
- struct xlog *log,
- xfs_daddr_t head_blk,
- xfs_daddr_t tail_blk,
- int count,
- char *buffer,
- xfs_daddr_t *rblk,
- struct xlog_rec_header **rhead,
- bool *wrapped)
- {
- int i;
- int error;
- int found = 0;
- char *offset = NULL;
- xfs_daddr_t end_blk;
- *wrapped = false;
- /*
- * Walk backwards from the head block until we hit the tail or the first
- * block in the log.
- */
- end_blk = head_blk > tail_blk ? tail_blk : 0;
- for (i = (int) head_blk - 1; i >= end_blk; i--) {
- error = xlog_bread(log, i, 1, buffer, &offset);
- if (error)
- goto out_error;
- if (*(__be32 *) offset == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {
- *rblk = i;
- *rhead = (struct xlog_rec_header *) offset;
- if (++found == count)
- break;
- }
- }
- /*
- * If we haven't hit the tail block or the log record header count,
- * start looking again from the end of the physical log. Note that
- * callers can pass head == tail if the tail is not yet known.
- */
- if (tail_blk >= head_blk && found != count) {
- for (i = log->l_logBBsize - 1; i >= (int) tail_blk; i--) {
- error = xlog_bread(log, i, 1, buffer, &offset);
- if (error)
- goto out_error;
- if (*(__be32 *)offset ==
- cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {
- *wrapped = true;
- *rblk = i;
- *rhead = (struct xlog_rec_header *) offset;
- if (++found == count)
- break;
- }
- }
- }
- return found;
- out_error:
- return error;
- }
- /*
- * Seek forward in the log for log record headers.
- *
- * Given head and tail blocks, walk forward from the tail block until we find
- * the provided number of records or hit the head block. The return value is the
- * number of records encountered or a negative error code. The log block and
- * buffer pointer of the last record seen are returned in rblk and rhead
- * respectively.
- */
- STATIC int
- xlog_seek_logrec_hdr(
- struct xlog *log,
- xfs_daddr_t head_blk,
- xfs_daddr_t tail_blk,
- int count,
- char *buffer,
- xfs_daddr_t *rblk,
- struct xlog_rec_header **rhead,
- bool *wrapped)
- {
- int i;
- int error;
- int found = 0;
- char *offset = NULL;
- xfs_daddr_t end_blk;
- *wrapped = false;
- /*
- * Walk forward from the tail block until we hit the head or the last
- * block in the log.
- */
- end_blk = head_blk > tail_blk ? head_blk : log->l_logBBsize - 1;
- for (i = (int) tail_blk; i <= end_blk; i++) {
- error = xlog_bread(log, i, 1, buffer, &offset);
- if (error)
- goto out_error;
- if (*(__be32 *) offset == cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {
- *rblk = i;
- *rhead = (struct xlog_rec_header *) offset;
- if (++found == count)
- break;
- }
- }
- /*
- * If we haven't hit the head block or the log record header count,
- * start looking again from the start of the physical log.
- */
- if (tail_blk > head_blk && found != count) {
- for (i = 0; i < (int) head_blk; i++) {
- error = xlog_bread(log, i, 1, buffer, &offset);
- if (error)
- goto out_error;
- if (*(__be32 *)offset ==
- cpu_to_be32(XLOG_HEADER_MAGIC_NUM)) {
- *wrapped = true;
- *rblk = i;
- *rhead = (struct xlog_rec_header *) offset;
- if (++found == count)
- break;
- }
- }
- }
- return found;
- out_error:
- return error;
- }
- /*
- * Calculate distance from head to tail (i.e., unused space in the log).
- */
- static inline int
- xlog_tail_distance(
- struct xlog *log,
- xfs_daddr_t head_blk,
- xfs_daddr_t tail_blk)
- {
- if (head_blk < tail_blk)
- return tail_blk - head_blk;
- return tail_blk + (log->l_logBBsize - head_blk);
- }
- /*
- * Verify the log tail. This is particularly important when torn or incomplete
- * writes have been detected near the front of the log and the head has been
- * walked back accordingly.
- *
- * We also have to handle the case where the tail was pinned and the head
- * blocked behind the tail right before a crash. If the tail had been pushed
- * immediately prior to the crash and the subsequent checkpoint was only
- * partially written, it's possible it overwrote the last referenced tail in the
- * log with garbage. This is not a coherency problem because the tail must have
- * been pushed before it can be overwritten, but appears as log corruption to
- * recovery because we have no way to know the tail was updated if the
- * subsequent checkpoint didn't write successfully.
- *
- * Therefore, CRC check the log from tail to head. If a failure occurs and the
- * offending record is within max iclog bufs from the head, walk the tail
- * forward and retry until a valid tail is found or corruption is detected out
- * of the range of a possible overwrite.
- */
- STATIC int
- xlog_verify_tail(
- struct xlog *log,
- xfs_daddr_t head_blk,
- xfs_daddr_t *tail_blk,
- int hsize)
- {
- struct xlog_rec_header *thead;
- char *buffer;
- xfs_daddr_t first_bad;
- int error = 0;
- bool wrapped;
- xfs_daddr_t tmp_tail;
- xfs_daddr_t orig_tail = *tail_blk;
- buffer = xlog_alloc_buffer(log, 1);
- if (!buffer)
- return -ENOMEM;
- /*
- * Make sure the tail points to a record (returns positive count on
- * success).
- */
- error = xlog_seek_logrec_hdr(log, head_blk, *tail_blk, 1, buffer,
- &tmp_tail, &thead, &wrapped);
- if (error < 0)
- goto out;
- if (*tail_blk != tmp_tail)
- *tail_blk = tmp_tail;
- /*
- * Run a CRC check from the tail to the head. We can't just check
- * MAX_ICLOGS records past the tail because the tail may point to stale
- * blocks cleared during the search for the head/tail. These blocks are
- * overwritten with zero-length records and thus record count is not a
- * reliable indicator of the iclog state before a crash.
- */
- first_bad = 0;
- error = xlog_do_recovery_pass(log, head_blk, *tail_blk,
- XLOG_RECOVER_CRCPASS, &first_bad);
- while ((error == -EFSBADCRC || error == -EFSCORRUPTED) && first_bad) {
- int tail_distance;
- /*
- * Is corruption within range of the head? If so, retry from
- * the next record. Otherwise return an error.
- */
- tail_distance = xlog_tail_distance(log, head_blk, first_bad);
- if (tail_distance > BTOBB(XLOG_MAX_ICLOGS * hsize))
- break;
- /* skip to the next record; returns positive count on success */
- error = xlog_seek_logrec_hdr(log, head_blk, first_bad, 2,
- buffer, &tmp_tail, &thead, &wrapped);
- if (error < 0)
- goto out;
- *tail_blk = tmp_tail;
- first_bad = 0;
- error = xlog_do_recovery_pass(log, head_blk, *tail_blk,
- XLOG_RECOVER_CRCPASS, &first_bad);
- }
- if (!error && *tail_blk != orig_tail)
- xfs_warn(log->l_mp,
- "Tail block (0x%llx) overwrite detected. Updated to 0x%llx",
- orig_tail, *tail_blk);
- out:
- kmem_free(buffer);
- return error;
- }
- /*
- * Detect and trim torn writes from the head of the log.
- *
- * Storage without sector atomicity guarantees can result in torn writes in the
- * log in the event of a crash. Our only means to detect this scenario is via
- * CRC verification. While we can't always be certain that CRC verification
- * failure is due to a torn write vs. an unrelated corruption, we do know that
- * only a certain number (XLOG_MAX_ICLOGS) of log records can be written out at
- * one time. Therefore, CRC verify up to XLOG_MAX_ICLOGS records at the head of
- * the log and treat failures in this range as torn writes as a matter of
- * policy. In the event of CRC failure, the head is walked back to the last good
- * record in the log and the tail is updated from that record and verified.
- */
- STATIC int
- xlog_verify_head(
- struct xlog *log,
- xfs_daddr_t *head_blk, /* in/out: unverified head */
- xfs_daddr_t *tail_blk, /* out: tail block */
- char *buffer,
- xfs_daddr_t *rhead_blk, /* start blk of last record */
- struct xlog_rec_header **rhead, /* ptr to last record */
- bool *wrapped) /* last rec. wraps phys. log */
- {
- struct xlog_rec_header *tmp_rhead;
- char *tmp_buffer;
- xfs_daddr_t first_bad;
- xfs_daddr_t tmp_rhead_blk;
- int found;
- int error;
- bool tmp_wrapped;
- /*
- * Check the head of the log for torn writes. Search backwards from the
- * head until we hit the tail or the maximum number of log record I/Os
- * that could have been in flight at one time. Use a temporary buffer so
- * we don't trash the rhead/buffer pointers from the caller.
- */
- tmp_buffer = xlog_alloc_buffer(log, 1);
- if (!tmp_buffer)
- return -ENOMEM;
- error = xlog_rseek_logrec_hdr(log, *head_blk, *tail_blk,
- XLOG_MAX_ICLOGS, tmp_buffer,
- &tmp_rhead_blk, &tmp_rhead, &tmp_wrapped);
- kmem_free(tmp_buffer);
- if (error < 0)
- return error;
- /*
- * Now run a CRC verification pass over the records starting at the
- * block found above to the current head. If a CRC failure occurs, the
- * log block of the first bad record is saved in first_bad.
- */
- error = xlog_do_recovery_pass(log, *head_blk, tmp_rhead_blk,
- XLOG_RECOVER_CRCPASS, &first_bad);
- if ((error == -EFSBADCRC || error == -EFSCORRUPTED) && first_bad) {
- /*
- * We've hit a potential torn write. Reset the error and warn
- * about it.
- */
- error = 0;
- xfs_warn(log->l_mp,
- "Torn write (CRC failure) detected at log block 0x%llx. Truncating head block from 0x%llx.",
- first_bad, *head_blk);
- /*
- * Get the header block and buffer pointer for the last good
- * record before the bad record.
- *
- * Note that xlog_find_tail() clears the blocks at the new head
- * (i.e., the records with invalid CRC) if the cycle number
- * matches the current cycle.
- */
- found = xlog_rseek_logrec_hdr(log, first_bad, *tail_blk, 1,
- buffer, rhead_blk, rhead, wrapped);
- if (found < 0)
- return found;
- if (found == 0) /* XXX: right thing to do here? */
- return -EIO;
- /*
- * Reset the head block to the starting block of the first bad
- * log record and set the tail block based on the last good
- * record.
- *
- * Bail out if the updated head/tail match as this indicates
- * possible corruption outside of the acceptable
- * (XLOG_MAX_ICLOGS) range. This is a job for xfs_repair...
- */
- *head_blk = first_bad;
- *tail_blk = BLOCK_LSN(be64_to_cpu((*rhead)->h_tail_lsn));
- if (*head_blk == *tail_blk) {
- ASSERT(0);
- return 0;
- }
- }
- if (error)
- return error;
- return xlog_verify_tail(log, *head_blk, tail_blk,
- be32_to_cpu((*rhead)->h_size));
- }
- /*
- * We need to make sure we handle log wrapping properly, so we can't use the
- * calculated logbno directly. Make sure it wraps to the correct bno inside the
- * log.
- *
- * The log is limited to 32 bit sizes, so we use the appropriate modulus
- * operation here and cast it back to a 64 bit daddr on return.
- */
- static inline xfs_daddr_t
- xlog_wrap_logbno(
- struct xlog *log,
- xfs_daddr_t bno)
- {
- int mod;
- div_s64_rem(bno, log->l_logBBsize, &mod);
- return mod;
- }
- /*
- * Check whether the head of the log points to an unmount record. In other
- * words, determine whether the log is clean. If so, update the in-core state
- * appropriately.
- */
- static int
- xlog_check_unmount_rec(
- struct xlog *log,
- xfs_daddr_t *head_blk,
- xfs_daddr_t *tail_blk,
- struct xlog_rec_header *rhead,
- xfs_daddr_t rhead_blk,
- char *buffer,
- bool *clean)
- {
- struct xlog_op_header *op_head;
- xfs_daddr_t umount_data_blk;
- xfs_daddr_t after_umount_blk;
- int hblks;
- int error;
- char *offset;
- *clean = false;
- /*
- * Look for unmount record. If we find it, then we know there was a
- * clean unmount. Since 'i' could be the last block in the physical
- * log, we convert to a log block before comparing to the head_blk.
- *
- * Save the current tail lsn to use to pass to xlog_clear_stale_blocks()
- * below. We won't want to clear the unmount record if there is one, so
- * we pass the lsn of the unmount record rather than the block after it.
- */
- hblks = xlog_logrec_hblks(log, rhead);
- after_umount_blk = xlog_wrap_logbno(log,
- rhead_blk + hblks + BTOBB(be32_to_cpu(rhead->h_len)));
- if (*head_blk == after_umount_blk &&
- be32_to_cpu(rhead->h_num_logops) == 1) {
- umount_data_blk = xlog_wrap_logbno(log, rhead_blk + hblks);
- error = xlog_bread(log, umount_data_blk, 1, buffer, &offset);
- if (error)
- return error;
- op_head = (struct xlog_op_header *)offset;
- if (op_head->oh_flags & XLOG_UNMOUNT_TRANS) {
- /*
- * Set tail and last sync so that newly written log
- * records will point recovery to after the current
- * unmount record.
- */
- xlog_assign_atomic_lsn(&log->l_tail_lsn,
- log->l_curr_cycle, after_umount_blk);
- xlog_assign_atomic_lsn(&log->l_last_sync_lsn,
- log->l_curr_cycle, after_umount_blk);
- *tail_blk = after_umount_blk;
- *clean = true;
- }
- }
- return 0;
- }
- static void
- xlog_set_state(
- struct xlog *log,
- xfs_daddr_t head_blk,
- struct xlog_rec_header *rhead,
- xfs_daddr_t rhead_blk,
- bool bump_cycle)
- {
- /*
- * Reset log values according to the state of the log when we
- * crashed. In the case where head_blk == 0, we bump curr_cycle
- * one because the next write starts a new cycle rather than
- * continuing the cycle of the last good log record. At this
- * point we have guaranteed that all partial log records have been
- * accounted for. Therefore, we know that the last good log record
- * written was complete and ended exactly on the end boundary
- * of the physical log.
- */
- log->l_prev_block = rhead_blk;
- log->l_curr_block = (int)head_blk;
- log->l_curr_cycle = be32_to_cpu(rhead->h_cycle);
- if (bump_cycle)
- log->l_curr_cycle++;
- atomic64_set(&log->l_tail_lsn, be64_to_cpu(rhead->h_tail_lsn));
- atomic64_set(&log->l_last_sync_lsn, be64_to_cpu(rhead->h_lsn));
- xlog_assign_grant_head(&log->l_reserve_head.grant, log->l_curr_cycle,
- BBTOB(log->l_curr_block));
- xlog_assign_grant_head(&log->l_write_head.grant, log->l_curr_cycle,
- BBTOB(log->l_curr_block));
- }
- /*
- * Find the sync block number or the tail of the log.
- *
- * This will be the block number of the last record to have its
- * associated buffers synced to disk. Every log record header has
- * a sync lsn embedded in it. LSNs hold block numbers, so it is easy
- * to get a sync block number. The only concern is to figure out which
- * log record header to believe.
- *
- * The following algorithm uses the log record header with the largest
- * lsn. The entire log record does not need to be valid. We only care
- * that the header is valid.
- *
- * We could speed up search by using current head_blk buffer, but it is not
- * available.
- */
- STATIC int
- xlog_find_tail(
- struct xlog *log,
- xfs_daddr_t *head_blk,
- xfs_daddr_t *tail_blk)
- {
- xlog_rec_header_t *rhead;
- char *offset = NULL;
- char *buffer;
- int error;
- xfs_daddr_t rhead_blk;
- xfs_lsn_t tail_lsn;
- bool wrapped = false;
- bool clean = false;
- /*
- * Find previous log record
- */
- if ((error = xlog_find_head(log, head_blk)))
- return error;
- ASSERT(*head_blk < INT_MAX);
- buffer = xlog_alloc_buffer(log, 1);
- if (!buffer)
- return -ENOMEM;
- if (*head_blk == 0) { /* special case */
- error = xlog_bread(log, 0, 1, buffer, &offset);
- if (error)
- goto done;
- if (xlog_get_cycle(offset) == 0) {
- *tail_blk = 0;
- /* leave all other log inited values alone */
- goto done;
- }
- }
- /*
- * Search backwards through the log looking for the log record header
- * block. This wraps all the way back around to the head so something is
- * seriously wrong if we can't find it.
- */
- error = xlog_rseek_logrec_hdr(log, *head_blk, *head_blk, 1, buffer,
- &rhead_blk, &rhead, &wrapped);
- if (error < 0)
- goto done;
- if (!error) {
- xfs_warn(log->l_mp, "%s: couldn't find sync record", __func__);
- error = -EFSCORRUPTED;
- goto done;
- }
- *tail_blk = BLOCK_LSN(be64_to_cpu(rhead->h_tail_lsn));
- /*
- * Set the log state based on the current head record.
- */
- xlog_set_state(log, *head_blk, rhead, rhead_blk, wrapped);
- tail_lsn = atomic64_read(&log->l_tail_lsn);
- /*
- * Look for an unmount record at the head of the log. This sets the log
- * state to determine whether recovery is necessary.
- */
- error = xlog_check_unmount_rec(log, head_blk, tail_blk, rhead,
- rhead_blk, buffer, &clean);
- if (error)
- goto done;
- /*
- * Verify the log head if the log is not clean (e.g., we have anything
- * but an unmount record at the head). This uses CRC verification to
- * detect and trim torn writes. If discovered, CRC failures are
- * considered torn writes and the log head is trimmed accordingly.
- *
- * Note that we can only run CRC verification when the log is dirty
- * because there's no guarantee that the log data behind an unmount
- * record is compatible with the current architecture.
- */
- if (!clean) {
- xfs_daddr_t orig_head = *head_blk;
- error = xlog_verify_head(log, head_blk, tail_blk, buffer,
- &rhead_blk, &rhead, &wrapped);
- if (error)
- goto done;
- /* update in-core state again if the head changed */
- if (*head_blk != orig_head) {
- xlog_set_state(log, *head_blk, rhead, rhead_blk,
- wrapped);
- tail_lsn = atomic64_read(&log->l_tail_lsn);
- error = xlog_check_unmount_rec(log, head_blk, tail_blk,
- rhead, rhead_blk, buffer,
- &clean);
- if (error)
- goto done;
- }
- }
- /*
- * Note that the unmount was clean. If the unmount was not clean, we
- * need to know this to rebuild the superblock counters from the perag
- * headers if we have a filesystem using non-persistent counters.
- */
- if (clean)
- set_bit(XFS_OPSTATE_CLEAN, &log->l_mp->m_opstate);
- /*
- * Make sure that there are no blocks in front of the head
- * with the same cycle number as the head. This can happen
- * because we allow multiple outstanding log writes concurrently,
- * and the later writes might make it out before earlier ones.
- *
- * We use the lsn from before modifying it so that we'll never
- * overwrite the unmount record after a clean unmount.
- *
- * Do this only if we are going to recover the filesystem
- *
- * NOTE: This used to say "if (!readonly)"
- * However on Linux, we can & do recover a read-only filesystem.
- * We only skip recovery if NORECOVERY is specified on mount,
- * in which case we would not be here.
- *
- * But... if the -device- itself is readonly, just skip this.
- * We can't recover this device anyway, so it won't matter.
- */
- if (!xfs_readonly_buftarg(log->l_targ))
- error = xlog_clear_stale_blocks(log, tail_lsn);
- done:
- kmem_free(buffer);
- if (error)
- xfs_warn(log->l_mp, "failed to locate log tail");
- return error;
- }
- /*
- * Is the log zeroed at all?
- *
- * The last binary search should be changed to perform an X block read
- * once X becomes small enough. You can then search linearly through
- * the X blocks. This will cut down on the number of reads we need to do.
- *
- * If the log is partially zeroed, this routine will pass back the blkno
- * of the first block with cycle number 0. It won't have a complete LR
- * preceding it.
- *
- * Return:
- * 0 => the log is completely written to
- * 1 => use *blk_no as the first block of the log
- * <0 => error has occurred
- */
- STATIC int
- xlog_find_zeroed(
- struct xlog *log,
- xfs_daddr_t *blk_no)
- {
- char *buffer;
- char *offset;
- uint first_cycle, last_cycle;
- xfs_daddr_t new_blk, last_blk, start_blk;
- xfs_daddr_t num_scan_bblks;
- int error, log_bbnum = log->l_logBBsize;
- *blk_no = 0;
- /* check totally zeroed log */
- buffer = xlog_alloc_buffer(log, 1);
- if (!buffer)
- return -ENOMEM;
- error = xlog_bread(log, 0, 1, buffer, &offset);
- if (error)
- goto out_free_buffer;
- first_cycle = xlog_get_cycle(offset);
- if (first_cycle == 0) { /* completely zeroed log */
- *blk_no = 0;
- kmem_free(buffer);
- return 1;
- }
- /* check partially zeroed log */
- error = xlog_bread(log, log_bbnum-1, 1, buffer, &offset);
- if (error)
- goto out_free_buffer;
- last_cycle = xlog_get_cycle(offset);
- if (last_cycle != 0) { /* log completely written to */
- kmem_free(buffer);
- return 0;
- }
- /* we have a partially zeroed log */
- last_blk = log_bbnum-1;
- error = xlog_find_cycle_start(log, buffer, 0, &last_blk, 0);
- if (error)
- goto out_free_buffer;
- /*
- * Validate the answer. Because there is no way to guarantee that
- * the entire log is made up of log records which are the same size,
- * we scan over the defined maximum blocks. At this point, the maximum
- * is not chosen to mean anything special. XXXmiken
- */
- num_scan_bblks = XLOG_TOTAL_REC_SHIFT(log);
- ASSERT(num_scan_bblks <= INT_MAX);
- if (last_blk < num_scan_bblks)
- num_scan_bblks = last_blk;
- start_blk = last_blk - num_scan_bblks;
- /*
- * We search for any instances of cycle number 0 that occur before
- * our current estimate of the head. What we're trying to detect is
- * 1 ... | 0 | 1 | 0...
- * ^ binary search ends here
- */
- if ((error = xlog_find_verify_cycle(log, start_blk,
- (int)num_scan_bblks, 0, &new_blk)))
- goto out_free_buffer;
- if (new_blk != -1)
- last_blk = new_blk;
- /*
- * Potentially backup over partial log record write. We don't need
- * to search the end of the log because we know it is zero.
- */
- error = xlog_find_verify_log_record(log, start_blk, &last_blk, 0);
- if (error == 1)
- error = -EIO;
- if (error)
- goto out_free_buffer;
- *blk_no = last_blk;
- out_free_buffer:
- kmem_free(buffer);
- if (error)
- return error;
- return 1;
- }
- /*
- * These are simple subroutines used by xlog_clear_stale_blocks() below
- * to initialize a buffer full of empty log record headers and write
- * them into the log.
- */
- STATIC void
- xlog_add_record(
- struct xlog *log,
- char *buf,
- int cycle,
- int block,
- int tail_cycle,
- int tail_block)
- {
- xlog_rec_header_t *recp = (xlog_rec_header_t *)buf;
- memset(buf, 0, BBSIZE);
- recp->h_magicno = cpu_to_be32(XLOG_HEADER_MAGIC_NUM);
- recp->h_cycle = cpu_to_be32(cycle);
- recp->h_version = cpu_to_be32(
- xfs_has_logv2(log->l_mp) ? 2 : 1);
- recp->h_lsn = cpu_to_be64(xlog_assign_lsn(cycle, block));
- recp->h_tail_lsn = cpu_to_be64(xlog_assign_lsn(tail_cycle, tail_block));
- recp->h_fmt = cpu_to_be32(XLOG_FMT);
- memcpy(&recp->h_fs_uuid, &log->l_mp->m_sb.sb_uuid, sizeof(uuid_t));
- }
- STATIC int
- xlog_write_log_records(
- struct xlog *log,
- int cycle,
- int start_block,
- int blocks,
- int tail_cycle,
- int tail_block)
- {
- char *offset;
- char *buffer;
- int balign, ealign;
- int sectbb = log->l_sectBBsize;
- int end_block = start_block + blocks;
- int bufblks;
- int error = 0;
- int i, j = 0;
- /*
- * Greedily allocate a buffer big enough to handle the full
- * range of basic blocks to be written. If that fails, try
- * a smaller size. We need to be able to write at least a
- * log sector, or we're out of luck.
- */
- bufblks = 1 << ffs(blocks);
- while (bufblks > log->l_logBBsize)
- bufblks >>= 1;
- while (!(buffer = xlog_alloc_buffer(log, bufblks))) {
- bufblks >>= 1;
- if (bufblks < sectbb)
- return -ENOMEM;
- }
- /* We may need to do a read at the start to fill in part of
- * the buffer in the starting sector not covered by the first
- * write below.
- */
- balign = round_down(start_block, sectbb);
- if (balign != start_block) {
- error = xlog_bread_noalign(log, start_block, 1, buffer);
- if (error)
- goto out_free_buffer;
- j = start_block - balign;
- }
- for (i = start_block; i < end_block; i += bufblks) {
- int bcount, endcount;
- bcount = min(bufblks, end_block - start_block);
- endcount = bcount - j;
- /* We may need to do a read at the end to fill in part of
- * the buffer in the final sector not covered by the write.
- * If this is the same sector as the above read, skip it.
- */
- ealign = round_down(end_block, sectbb);
- if (j == 0 && (start_block + endcount > ealign)) {
- error = xlog_bread_noalign(log, ealign, sectbb,
- buffer + BBTOB(ealign - start_block));
- if (error)
- break;
- }
- offset = buffer + xlog_align(log, start_block);
- for (; j < endcount; j++) {
- xlog_add_record(log, offset, cycle, i+j,
- tail_cycle, tail_block);
- offset += BBSIZE;
- }
- error = xlog_bwrite(log, start_block, endcount, buffer);
- if (error)
- break;
- start_block += endcount;
- j = 0;
- }
- out_free_buffer:
- kmem_free(buffer);
- return error;
- }
- /*
- * This routine is called to blow away any incomplete log writes out
- * in front of the log head. We do this so that we won't become confused
- * if we come up, write only a little bit more, and then crash again.
- * If we leave the partial log records out there, this situation could
- * cause us to think those partial writes are valid blocks since they
- * have the current cycle number. We get rid of them by overwriting them
- * with empty log records with the old cycle number rather than the
- * current one.
- *
- * The tail lsn is passed in rather than taken from
- * the log so that we will not write over the unmount record after a
- * clean unmount in a 512 block log. Doing so would leave the log without
- * any valid log records in it until a new one was written. If we crashed
- * during that time we would not be able to recover.
- */
- STATIC int
- xlog_clear_stale_blocks(
- struct xlog *log,
- xfs_lsn_t tail_lsn)
- {
- int tail_cycle, head_cycle;
- int tail_block, head_block;
- int tail_distance, max_distance;
- int distance;
- int error;
- tail_cycle = CYCLE_LSN(tail_lsn);
- tail_block = BLOCK_LSN(tail_lsn);
- head_cycle = log->l_curr_cycle;
- head_block = log->l_curr_block;
- /*
- * Figure out the distance between the new head of the log
- * and the tail. We want to write over any blocks beyond the
- * head that we may have written just before the crash, but
- * we don't want to overwrite the tail of the log.
- */
- if (head_cycle == tail_cycle) {
- /*
- * The tail is behind the head in the physical log,
- * so the distance from the head to the tail is the
- * distance from the head to the end of the log plus
- * the distance from the beginning of the log to the
- * tail.
- */
- if (XFS_IS_CORRUPT(log->l_mp,
- head_block < tail_block ||
- head_block >= log->l_logBBsize))
- return -EFSCORRUPTED;
- tail_distance = tail_block + (log->l_logBBsize - head_block);
- } else {
- /*
- * The head is behind the tail in the physical log,
- * so the distance from the head to the tail is just
- * the tail block minus the head block.
- */
- if (XFS_IS_CORRUPT(log->l_mp,
- head_block >= tail_block ||
- head_cycle != tail_cycle + 1))
- return -EFSCORRUPTED;
- tail_distance = tail_block - head_block;
- }
- /*
- * If the head is right up against the tail, we can't clear
- * anything.
- */
- if (tail_distance <= 0) {
- ASSERT(tail_distance == 0);
- return 0;
- }
- max_distance = XLOG_TOTAL_REC_SHIFT(log);
- /*
- * Take the smaller of the maximum amount of outstanding I/O
- * we could have and the distance to the tail to clear out.
- * We take the smaller so that we don't overwrite the tail and
- * we don't waste all day writing from the head to the tail
- * for no reason.
- */
- max_distance = min(max_distance, tail_distance);
- if ((head_block + max_distance) <= log->l_logBBsize) {
- /*
- * We can stomp all the blocks we need to without
- * wrapping around the end of the log. Just do it
- * in a single write. Use the cycle number of the
- * current cycle minus one so that the log will look like:
- * n ... | n - 1 ...
- */
- error = xlog_write_log_records(log, (head_cycle - 1),
- head_block, max_distance, tail_cycle,
- tail_block);
- if (error)
- return error;
- } else {
- /*
- * We need to wrap around the end of the physical log in
- * order to clear all the blocks. Do it in two separate
- * I/Os. The first write should be from the head to the
- * end of the physical log, and it should use the current
- * cycle number minus one just like above.
- */
- distance = log->l_logBBsize - head_block;
- error = xlog_write_log_records(log, (head_cycle - 1),
- head_block, distance, tail_cycle,
- tail_block);
- if (error)
- return error;
- /*
- * Now write the blocks at the start of the physical log.
- * This writes the remainder of the blocks we want to clear.
- * It uses the current cycle number since we're now on the
- * same cycle as the head so that we get:
- * n ... n ... | n - 1 ...
- * ^^^^^ blocks we're writing
- */
- distance = max_distance - (log->l_logBBsize - head_block);
- error = xlog_write_log_records(log, head_cycle, 0, distance,
- tail_cycle, tail_block);
- if (error)
- return error;
- }
- return 0;
- }
- /*
- * Release the recovered intent item in the AIL that matches the given intent
- * type and intent id.
- */
- void
- xlog_recover_release_intent(
- struct xlog *log,
- unsigned short intent_type,
- uint64_t intent_id)
- {
- struct xfs_ail_cursor cur;
- struct xfs_log_item *lip;
- struct xfs_ail *ailp = log->l_ailp;
- spin_lock(&ailp->ail_lock);
- for (lip = xfs_trans_ail_cursor_first(ailp, &cur, 0); lip != NULL;
- lip = xfs_trans_ail_cursor_next(ailp, &cur)) {
- if (lip->li_type != intent_type)
- continue;
- if (!lip->li_ops->iop_match(lip, intent_id))
- continue;
- spin_unlock(&ailp->ail_lock);
- lip->li_ops->iop_release(lip);
- spin_lock(&ailp->ail_lock);
- break;
- }
- xfs_trans_ail_cursor_done(&cur);
- spin_unlock(&ailp->ail_lock);
- }
- int
- xlog_recover_iget(
- struct xfs_mount *mp,
- xfs_ino_t ino,
- struct xfs_inode **ipp)
- {
- int error;
- error = xfs_iget(mp, NULL, ino, 0, 0, ipp);
- if (error)
- return error;
- error = xfs_qm_dqattach(*ipp);
- if (error) {
- xfs_irele(*ipp);
- return error;
- }
- if (VFS_I(*ipp)->i_nlink == 0)
- xfs_iflags_set(*ipp, XFS_IRECOVERY);
- return 0;
- }
- /******************************************************************************
- *
- * Log recover routines
- *
- ******************************************************************************
- */
- static const struct xlog_recover_item_ops *xlog_recover_item_ops[] = {
- &xlog_buf_item_ops,
- &xlog_inode_item_ops,
- &xlog_dquot_item_ops,
- &xlog_quotaoff_item_ops,
- &xlog_icreate_item_ops,
- &xlog_efi_item_ops,
- &xlog_efd_item_ops,
- &xlog_rui_item_ops,
- &xlog_rud_item_ops,
- &xlog_cui_item_ops,
- &xlog_cud_item_ops,
- &xlog_bui_item_ops,
- &xlog_bud_item_ops,
- &xlog_attri_item_ops,
- &xlog_attrd_item_ops,
- };
- static const struct xlog_recover_item_ops *
- xlog_find_item_ops(
- struct xlog_recover_item *item)
- {
- unsigned int i;
- for (i = 0; i < ARRAY_SIZE(xlog_recover_item_ops); i++)
- if (ITEM_TYPE(item) == xlog_recover_item_ops[i]->item_type)
- return xlog_recover_item_ops[i];
- return NULL;
- }
- /*
- * Sort the log items in the transaction.
- *
- * The ordering constraints are defined by the inode allocation and unlink
- * behaviour. The rules are:
- *
- * 1. Every item is only logged once in a given transaction. Hence it
- * represents the last logged state of the item. Hence ordering is
- * dependent on the order in which operations need to be performed so
- * required initial conditions are always met.
- *
- * 2. Cancelled buffers are recorded in pass 1 in a separate table and
- * there's nothing to replay from them so we can simply cull them
- * from the transaction. However, we can't do that until after we've
- * replayed all the other items because they may be dependent on the
- * cancelled buffer and replaying the cancelled buffer can remove it
- * form the cancelled buffer table. Hence they have tobe done last.
- *
- * 3. Inode allocation buffers must be replayed before inode items that
- * read the buffer and replay changes into it. For filesystems using the
- * ICREATE transactions, this means XFS_LI_ICREATE objects need to get
- * treated the same as inode allocation buffers as they create and
- * initialise the buffers directly.
- *
- * 4. Inode unlink buffers must be replayed after inode items are replayed.
- * This ensures that inodes are completely flushed to the inode buffer
- * in a "free" state before we remove the unlinked inode list pointer.
- *
- * Hence the ordering needs to be inode allocation buffers first, inode items
- * second, inode unlink buffers third and cancelled buffers last.
- *
- * But there's a problem with that - we can't tell an inode allocation buffer
- * apart from a regular buffer, so we can't separate them. We can, however,
- * tell an inode unlink buffer from the others, and so we can separate them out
- * from all the other buffers and move them to last.
- *
- * Hence, 4 lists, in order from head to tail:
- * - buffer_list for all buffers except cancelled/inode unlink buffers
- * - item_list for all non-buffer items
- * - inode_buffer_list for inode unlink buffers
- * - cancel_list for the cancelled buffers
- *
- * Note that we add objects to the tail of the lists so that first-to-last
- * ordering is preserved within the lists. Adding objects to the head of the
- * list means when we traverse from the head we walk them in last-to-first
- * order. For cancelled buffers and inode unlink buffers this doesn't matter,
- * but for all other items there may be specific ordering that we need to
- * preserve.
- */
- STATIC int
- xlog_recover_reorder_trans(
- struct xlog *log,
- struct xlog_recover *trans,
- int pass)
- {
- struct xlog_recover_item *item, *n;
- int error = 0;
- LIST_HEAD(sort_list);
- LIST_HEAD(cancel_list);
- LIST_HEAD(buffer_list);
- LIST_HEAD(inode_buffer_list);
- LIST_HEAD(item_list);
- list_splice_init(&trans->r_itemq, &sort_list);
- list_for_each_entry_safe(item, n, &sort_list, ri_list) {
- enum xlog_recover_reorder fate = XLOG_REORDER_ITEM_LIST;
- item->ri_ops = xlog_find_item_ops(item);
- if (!item->ri_ops) {
- xfs_warn(log->l_mp,
- "%s: unrecognized type of log operation (%d)",
- __func__, ITEM_TYPE(item));
- ASSERT(0);
- /*
- * return the remaining items back to the transaction
- * item list so they can be freed in caller.
- */
- if (!list_empty(&sort_list))
- list_splice_init(&sort_list, &trans->r_itemq);
- error = -EFSCORRUPTED;
- break;
- }
- if (item->ri_ops->reorder)
- fate = item->ri_ops->reorder(item);
- switch (fate) {
- case XLOG_REORDER_BUFFER_LIST:
- list_move_tail(&item->ri_list, &buffer_list);
- break;
- case XLOG_REORDER_CANCEL_LIST:
- trace_xfs_log_recover_item_reorder_head(log,
- trans, item, pass);
- list_move(&item->ri_list, &cancel_list);
- break;
- case XLOG_REORDER_INODE_BUFFER_LIST:
- list_move(&item->ri_list, &inode_buffer_list);
- break;
- case XLOG_REORDER_ITEM_LIST:
- trace_xfs_log_recover_item_reorder_tail(log,
- trans, item, pass);
- list_move_tail(&item->ri_list, &item_list);
- break;
- }
- }
- ASSERT(list_empty(&sort_list));
- if (!list_empty(&buffer_list))
- list_splice(&buffer_list, &trans->r_itemq);
- if (!list_empty(&item_list))
- list_splice_tail(&item_list, &trans->r_itemq);
- if (!list_empty(&inode_buffer_list))
- list_splice_tail(&inode_buffer_list, &trans->r_itemq);
- if (!list_empty(&cancel_list))
- list_splice_tail(&cancel_list, &trans->r_itemq);
- return error;
- }
- void
- xlog_buf_readahead(
- struct xlog *log,
- xfs_daddr_t blkno,
- uint len,
- const struct xfs_buf_ops *ops)
- {
- if (!xlog_is_buffer_cancelled(log, blkno, len))
- xfs_buf_readahead(log->l_mp->m_ddev_targp, blkno, len, ops);
- }
- STATIC int
- xlog_recover_items_pass2(
- struct xlog *log,
- struct xlog_recover *trans,
- struct list_head *buffer_list,
- struct list_head *item_list)
- {
- struct xlog_recover_item *item;
- int error = 0;
- list_for_each_entry(item, item_list, ri_list) {
- trace_xfs_log_recover_item_recover(log, trans, item,
- XLOG_RECOVER_PASS2);
- if (item->ri_ops->commit_pass2)
- error = item->ri_ops->commit_pass2(log, buffer_list,
- item, trans->r_lsn);
- if (error)
- return error;
- }
- return error;
- }
- /*
- * Perform the transaction.
- *
- * If the transaction modifies a buffer or inode, do it now. Otherwise,
- * EFIs and EFDs get queued up by adding entries into the AIL for them.
- */
- STATIC int
- xlog_recover_commit_trans(
- struct xlog *log,
- struct xlog_recover *trans,
- int pass,
- struct list_head *buffer_list)
- {
- int error = 0;
- int items_queued = 0;
- struct xlog_recover_item *item;
- struct xlog_recover_item *next;
- LIST_HEAD (ra_list);
- LIST_HEAD (done_list);
- #define XLOG_RECOVER_COMMIT_QUEUE_MAX 100
- hlist_del_init(&trans->r_list);
- error = xlog_recover_reorder_trans(log, trans, pass);
- if (error)
- return error;
- list_for_each_entry_safe(item, next, &trans->r_itemq, ri_list) {
- trace_xfs_log_recover_item_recover(log, trans, item, pass);
- switch (pass) {
- case XLOG_RECOVER_PASS1:
- if (item->ri_ops->commit_pass1)
- error = item->ri_ops->commit_pass1(log, item);
- break;
- case XLOG_RECOVER_PASS2:
- if (item->ri_ops->ra_pass2)
- item->ri_ops->ra_pass2(log, item);
- list_move_tail(&item->ri_list, &ra_list);
- items_queued++;
- if (items_queued >= XLOG_RECOVER_COMMIT_QUEUE_MAX) {
- error = xlog_recover_items_pass2(log, trans,
- buffer_list, &ra_list);
- list_splice_tail_init(&ra_list, &done_list);
- items_queued = 0;
- }
- break;
- default:
- ASSERT(0);
- }
- if (error)
- goto out;
- }
- out:
- if (!list_empty(&ra_list)) {
- if (!error)
- error = xlog_recover_items_pass2(log, trans,
- buffer_list, &ra_list);
- list_splice_tail_init(&ra_list, &done_list);
- }
- if (!list_empty(&done_list))
- list_splice_init(&done_list, &trans->r_itemq);
- return error;
- }
- STATIC void
- xlog_recover_add_item(
- struct list_head *head)
- {
- struct xlog_recover_item *item;
- item = kmem_zalloc(sizeof(struct xlog_recover_item), 0);
- INIT_LIST_HEAD(&item->ri_list);
- list_add_tail(&item->ri_list, head);
- }
- STATIC int
- xlog_recover_add_to_cont_trans(
- struct xlog *log,
- struct xlog_recover *trans,
- char *dp,
- int len)
- {
- struct xlog_recover_item *item;
- char *ptr, *old_ptr;
- int old_len;
- /*
- * If the transaction is empty, the header was split across this and the
- * previous record. Copy the rest of the header.
- */
- if (list_empty(&trans->r_itemq)) {
- ASSERT(len <= sizeof(struct xfs_trans_header));
- if (len > sizeof(struct xfs_trans_header)) {
- xfs_warn(log->l_mp, "%s: bad header length", __func__);
- return -EFSCORRUPTED;
- }
- xlog_recover_add_item(&trans->r_itemq);
- ptr = (char *)&trans->r_theader +
- sizeof(struct xfs_trans_header) - len;
- memcpy(ptr, dp, len);
- return 0;
- }
- /* take the tail entry */
- item = list_entry(trans->r_itemq.prev, struct xlog_recover_item,
- ri_list);
- old_ptr = item->ri_buf[item->ri_cnt-1].i_addr;
- old_len = item->ri_buf[item->ri_cnt-1].i_len;
- ptr = kvrealloc(old_ptr, old_len, len + old_len, GFP_KERNEL);
- if (!ptr)
- return -ENOMEM;
- memcpy(&ptr[old_len], dp, len);
- item->ri_buf[item->ri_cnt-1].i_len += len;
- item->ri_buf[item->ri_cnt-1].i_addr = ptr;
- trace_xfs_log_recover_item_add_cont(log, trans, item, 0);
- return 0;
- }
- /*
- * The next region to add is the start of a new region. It could be
- * a whole region or it could be the first part of a new region. Because
- * of this, the assumption here is that the type and size fields of all
- * format structures fit into the first 32 bits of the structure.
- *
- * This works because all regions must be 32 bit aligned. Therefore, we
- * either have both fields or we have neither field. In the case we have
- * neither field, the data part of the region is zero length. We only have
- * a log_op_header and can throw away the header since a new one will appear
- * later. If we have at least 4 bytes, then we can determine how many regions
- * will appear in the current log item.
- */
- STATIC int
- xlog_recover_add_to_trans(
- struct xlog *log,
- struct xlog_recover *trans,
- char *dp,
- int len)
- {
- struct xfs_inode_log_format *in_f; /* any will do */
- struct xlog_recover_item *item;
- char *ptr;
- if (!len)
- return 0;
- if (list_empty(&trans->r_itemq)) {
- /* we need to catch log corruptions here */
- if (*(uint *)dp != XFS_TRANS_HEADER_MAGIC) {
- xfs_warn(log->l_mp, "%s: bad header magic number",
- __func__);
- ASSERT(0);
- return -EFSCORRUPTED;
- }
- if (len > sizeof(struct xfs_trans_header)) {
- xfs_warn(log->l_mp, "%s: bad header length", __func__);
- ASSERT(0);
- return -EFSCORRUPTED;
- }
- /*
- * The transaction header can be arbitrarily split across op
- * records. If we don't have the whole thing here, copy what we
- * do have and handle the rest in the next record.
- */
- if (len == sizeof(struct xfs_trans_header))
- xlog_recover_add_item(&trans->r_itemq);
- memcpy(&trans->r_theader, dp, len);
- return 0;
- }
- ptr = kmem_alloc(len, 0);
- memcpy(ptr, dp, len);
- in_f = (struct xfs_inode_log_format *)ptr;
- /* take the tail entry */
- item = list_entry(trans->r_itemq.prev, struct xlog_recover_item,
- ri_list);
- if (item->ri_total != 0 &&
- item->ri_total == item->ri_cnt) {
- /* tail item is in use, get a new one */
- xlog_recover_add_item(&trans->r_itemq);
- item = list_entry(trans->r_itemq.prev,
- struct xlog_recover_item, ri_list);
- }
- if (item->ri_total == 0) { /* first region to be added */
- if (in_f->ilf_size == 0 ||
- in_f->ilf_size > XLOG_MAX_REGIONS_IN_ITEM) {
- xfs_warn(log->l_mp,
- "bad number of regions (%d) in inode log format",
- in_f->ilf_size);
- ASSERT(0);
- kmem_free(ptr);
- return -EFSCORRUPTED;
- }
- item->ri_total = in_f->ilf_size;
- item->ri_buf =
- kmem_zalloc(item->ri_total * sizeof(xfs_log_iovec_t),
- 0);
- }
- if (item->ri_total <= item->ri_cnt) {
- xfs_warn(log->l_mp,
- "log item region count (%d) overflowed size (%d)",
- item->ri_cnt, item->ri_total);
- ASSERT(0);
- kmem_free(ptr);
- return -EFSCORRUPTED;
- }
- /* Description region is ri_buf[0] */
- item->ri_buf[item->ri_cnt].i_addr = ptr;
- item->ri_buf[item->ri_cnt].i_len = len;
- item->ri_cnt++;
- trace_xfs_log_recover_item_add(log, trans, item, 0);
- return 0;
- }
- /*
- * Free up any resources allocated by the transaction
- *
- * Remember that EFIs, EFDs, and IUNLINKs are handled later.
- */
- STATIC void
- xlog_recover_free_trans(
- struct xlog_recover *trans)
- {
- struct xlog_recover_item *item, *n;
- int i;
- hlist_del_init(&trans->r_list);
- list_for_each_entry_safe(item, n, &trans->r_itemq, ri_list) {
- /* Free the regions in the item. */
- list_del(&item->ri_list);
- for (i = 0; i < item->ri_cnt; i++)
- kmem_free(item->ri_buf[i].i_addr);
- /* Free the item itself */
- kmem_free(item->ri_buf);
- kmem_free(item);
- }
- /* Free the transaction recover structure */
- kmem_free(trans);
- }
- /*
- * On error or completion, trans is freed.
- */
- STATIC int
- xlog_recovery_process_trans(
- struct xlog *log,
- struct xlog_recover *trans,
- char *dp,
- unsigned int len,
- unsigned int flags,
- int pass,
- struct list_head *buffer_list)
- {
- int error = 0;
- bool freeit = false;
- /* mask off ophdr transaction container flags */
- flags &= ~XLOG_END_TRANS;
- if (flags & XLOG_WAS_CONT_TRANS)
- flags &= ~XLOG_CONTINUE_TRANS;
- /*
- * Callees must not free the trans structure. We'll decide if we need to
- * free it or not based on the operation being done and it's result.
- */
- switch (flags) {
- /* expected flag values */
- case 0:
- case XLOG_CONTINUE_TRANS:
- error = xlog_recover_add_to_trans(log, trans, dp, len);
- break;
- case XLOG_WAS_CONT_TRANS:
- error = xlog_recover_add_to_cont_trans(log, trans, dp, len);
- break;
- case XLOG_COMMIT_TRANS:
- error = xlog_recover_commit_trans(log, trans, pass,
- buffer_list);
- /* success or fail, we are now done with this transaction. */
- freeit = true;
- break;
- /* unexpected flag values */
- case XLOG_UNMOUNT_TRANS:
- /* just skip trans */
- xfs_warn(log->l_mp, "%s: Unmount LR", __func__);
- freeit = true;
- break;
- case XLOG_START_TRANS:
- default:
- xfs_warn(log->l_mp, "%s: bad flag 0x%x", __func__, flags);
- ASSERT(0);
- error = -EFSCORRUPTED;
- break;
- }
- if (error || freeit)
- xlog_recover_free_trans(trans);
- return error;
- }
- /*
- * Lookup the transaction recovery structure associated with the ID in the
- * current ophdr. If the transaction doesn't exist and the start flag is set in
- * the ophdr, then allocate a new transaction for future ID matches to find.
- * Either way, return what we found during the lookup - an existing transaction
- * or nothing.
- */
- STATIC struct xlog_recover *
- xlog_recover_ophdr_to_trans(
- struct hlist_head rhash[],
- struct xlog_rec_header *rhead,
- struct xlog_op_header *ohead)
- {
- struct xlog_recover *trans;
- xlog_tid_t tid;
- struct hlist_head *rhp;
- tid = be32_to_cpu(ohead->oh_tid);
- rhp = &rhash[XLOG_RHASH(tid)];
- hlist_for_each_entry(trans, rhp, r_list) {
- if (trans->r_log_tid == tid)
- return trans;
- }
- /*
- * skip over non-start transaction headers - we could be
- * processing slack space before the next transaction starts
- */
- if (!(ohead->oh_flags & XLOG_START_TRANS))
- return NULL;
- ASSERT(be32_to_cpu(ohead->oh_len) == 0);
- /*
- * This is a new transaction so allocate a new recovery container to
- * hold the recovery ops that will follow.
- */
- trans = kmem_zalloc(sizeof(struct xlog_recover), 0);
- trans->r_log_tid = tid;
- trans->r_lsn = be64_to_cpu(rhead->h_lsn);
- INIT_LIST_HEAD(&trans->r_itemq);
- INIT_HLIST_NODE(&trans->r_list);
- hlist_add_head(&trans->r_list, rhp);
- /*
- * Nothing more to do for this ophdr. Items to be added to this new
- * transaction will be in subsequent ophdr containers.
- */
- return NULL;
- }
- STATIC int
- xlog_recover_process_ophdr(
- struct xlog *log,
- struct hlist_head rhash[],
- struct xlog_rec_header *rhead,
- struct xlog_op_header *ohead,
- char *dp,
- char *end,
- int pass,
- struct list_head *buffer_list)
- {
- struct xlog_recover *trans;
- unsigned int len;
- int error;
- /* Do we understand who wrote this op? */
- if (ohead->oh_clientid != XFS_TRANSACTION &&
- ohead->oh_clientid != XFS_LOG) {
- xfs_warn(log->l_mp, "%s: bad clientid 0x%x",
- __func__, ohead->oh_clientid);
- ASSERT(0);
- return -EFSCORRUPTED;
- }
- /*
- * Check the ophdr contains all the data it is supposed to contain.
- */
- len = be32_to_cpu(ohead->oh_len);
- if (dp + len > end) {
- xfs_warn(log->l_mp, "%s: bad length 0x%x", __func__, len);
- WARN_ON(1);
- return -EFSCORRUPTED;
- }
- trans = xlog_recover_ophdr_to_trans(rhash, rhead, ohead);
- if (!trans) {
- /* nothing to do, so skip over this ophdr */
- return 0;
- }
- /*
- * The recovered buffer queue is drained only once we know that all
- * recovery items for the current LSN have been processed. This is
- * required because:
- *
- * - Buffer write submission updates the metadata LSN of the buffer.
- * - Log recovery skips items with a metadata LSN >= the current LSN of
- * the recovery item.
- * - Separate recovery items against the same metadata buffer can share
- * a current LSN. I.e., consider that the LSN of a recovery item is
- * defined as the starting LSN of the first record in which its
- * transaction appears, that a record can hold multiple transactions,
- * and/or that a transaction can span multiple records.
- *
- * In other words, we are allowed to submit a buffer from log recovery
- * once per current LSN. Otherwise, we may incorrectly skip recovery
- * items and cause corruption.
- *
- * We don't know up front whether buffers are updated multiple times per
- * LSN. Therefore, track the current LSN of each commit log record as it
- * is processed and drain the queue when it changes. Use commit records
- * because they are ordered correctly by the logging code.
- */
- if (log->l_recovery_lsn != trans->r_lsn &&
- ohead->oh_flags & XLOG_COMMIT_TRANS) {
- error = xfs_buf_delwri_submit(buffer_list);
- if (error)
- return error;
- log->l_recovery_lsn = trans->r_lsn;
- }
- return xlog_recovery_process_trans(log, trans, dp, len,
- ohead->oh_flags, pass, buffer_list);
- }
- /*
- * There are two valid states of the r_state field. 0 indicates that the
- * transaction structure is in a normal state. We have either seen the
- * start of the transaction or the last operation we added was not a partial
- * operation. If the last operation we added to the transaction was a
- * partial operation, we need to mark r_state with XLOG_WAS_CONT_TRANS.
- *
- * NOTE: skip LRs with 0 data length.
- */
- STATIC int
- xlog_recover_process_data(
- struct xlog *log,
- struct hlist_head rhash[],
- struct xlog_rec_header *rhead,
- char *dp,
- int pass,
- struct list_head *buffer_list)
- {
- struct xlog_op_header *ohead;
- char *end;
- int num_logops;
- int error;
- end = dp + be32_to_cpu(rhead->h_len);
- num_logops = be32_to_cpu(rhead->h_num_logops);
- /* check the log format matches our own - else we can't recover */
- if (xlog_header_check_recover(log->l_mp, rhead))
- return -EIO;
- trace_xfs_log_recover_record(log, rhead, pass);
- while ((dp < end) && num_logops) {
- ohead = (struct xlog_op_header *)dp;
- dp += sizeof(*ohead);
- ASSERT(dp <= end);
- /* errors will abort recovery */
- error = xlog_recover_process_ophdr(log, rhash, rhead, ohead,
- dp, end, pass, buffer_list);
- if (error)
- return error;
- dp += be32_to_cpu(ohead->oh_len);
- num_logops--;
- }
- return 0;
- }
- /* Take all the collected deferred ops and finish them in order. */
- static int
- xlog_finish_defer_ops(
- struct xfs_mount *mp,
- struct list_head *capture_list)
- {
- struct xfs_defer_capture *dfc, *next;
- struct xfs_trans *tp;
- int error = 0;
- list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {
- struct xfs_trans_res resv;
- struct xfs_defer_resources dres;
- /*
- * Create a new transaction reservation from the captured
- * information. Set logcount to 1 to force the new transaction
- * to regrant every roll so that we can make forward progress
- * in recovery no matter how full the log might be.
- */
- resv.tr_logres = dfc->dfc_logres;
- resv.tr_logcount = 1;
- resv.tr_logflags = XFS_TRANS_PERM_LOG_RES;
- error = xfs_trans_alloc(mp, &resv, dfc->dfc_blkres,
- dfc->dfc_rtxres, XFS_TRANS_RESERVE, &tp);
- if (error) {
- xlog_force_shutdown(mp->m_log, SHUTDOWN_LOG_IO_ERROR);
- return error;
- }
- /*
- * Transfer to this new transaction all the dfops we captured
- * from recovering a single intent item.
- */
- list_del_init(&dfc->dfc_list);
- xfs_defer_ops_continue(dfc, tp, &dres);
- error = xfs_trans_commit(tp);
- xfs_defer_resources_rele(&dres);
- if (error)
- return error;
- }
- ASSERT(list_empty(capture_list));
- return 0;
- }
- /* Release all the captured defer ops and capture structures in this list. */
- static void
- xlog_abort_defer_ops(
- struct xfs_mount *mp,
- struct list_head *capture_list)
- {
- struct xfs_defer_capture *dfc;
- struct xfs_defer_capture *next;
- list_for_each_entry_safe(dfc, next, capture_list, dfc_list) {
- list_del_init(&dfc->dfc_list);
- xfs_defer_ops_capture_free(mp, dfc);
- }
- }
- /*
- * When this is called, all of the log intent items which did not have
- * corresponding log done items should be in the AIL. What we do now is update
- * the data structures associated with each one.
- *
- * Since we process the log intent items in normal transactions, they will be
- * removed at some point after the commit. This prevents us from just walking
- * down the list processing each one. We'll use a flag in the intent item to
- * skip those that we've already processed and use the AIL iteration mechanism's
- * generation count to try to speed this up at least a bit.
- *
- * When we start, we know that the intents are the only things in the AIL. As we
- * process them, however, other items are added to the AIL. Hence we know we
- * have started recovery on all the pending intents when we find an non-intent
- * item in the AIL.
- */
- STATIC int
- xlog_recover_process_intents(
- struct xlog *log)
- {
- LIST_HEAD(capture_list);
- struct xfs_ail_cursor cur;
- struct xfs_log_item *lip;
- struct xfs_ail *ailp;
- int error = 0;
- #if defined(DEBUG) || defined(XFS_WARN)
- xfs_lsn_t last_lsn;
- #endif
- ailp = log->l_ailp;
- spin_lock(&ailp->ail_lock);
- #if defined(DEBUG) || defined(XFS_WARN)
- last_lsn = xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block);
- #endif
- for (lip = xfs_trans_ail_cursor_first(ailp, &cur, 0);
- lip != NULL;
- lip = xfs_trans_ail_cursor_next(ailp, &cur)) {
- const struct xfs_item_ops *ops;
- if (!xlog_item_is_intent(lip))
- break;
- /*
- * We should never see a redo item with a LSN higher than
- * the last transaction we found in the log at the start
- * of recovery.
- */
- ASSERT(XFS_LSN_CMP(last_lsn, lip->li_lsn) >= 0);
- /*
- * NOTE: If your intent processing routine can create more
- * deferred ops, you /must/ attach them to the capture list in
- * the recover routine or else those subsequent intents will be
- * replayed in the wrong order!
- *
- * The recovery function can free the log item, so we must not
- * access lip after it returns.
- */
- spin_unlock(&ailp->ail_lock);
- ops = lip->li_ops;
- error = ops->iop_recover(lip, &capture_list);
- spin_lock(&ailp->ail_lock);
- if (error) {
- trace_xlog_intent_recovery_failed(log->l_mp, error,
- ops->iop_recover);
- break;
- }
- }
- xfs_trans_ail_cursor_done(&cur);
- spin_unlock(&ailp->ail_lock);
- if (error)
- goto err;
- error = xlog_finish_defer_ops(log->l_mp, &capture_list);
- if (error)
- goto err;
- return 0;
- err:
- xlog_abort_defer_ops(log->l_mp, &capture_list);
- return error;
- }
- /*
- * A cancel occurs when the mount has failed and we're bailing out. Release all
- * pending log intent items that we haven't started recovery on so they don't
- * pin the AIL.
- */
- STATIC void
- xlog_recover_cancel_intents(
- struct xlog *log)
- {
- struct xfs_log_item *lip;
- struct xfs_ail_cursor cur;
- struct xfs_ail *ailp;
- ailp = log->l_ailp;
- spin_lock(&ailp->ail_lock);
- lip = xfs_trans_ail_cursor_first(ailp, &cur, 0);
- while (lip != NULL) {
- if (!xlog_item_is_intent(lip))
- break;
- spin_unlock(&ailp->ail_lock);
- lip->li_ops->iop_release(lip);
- spin_lock(&ailp->ail_lock);
- lip = xfs_trans_ail_cursor_next(ailp, &cur);
- }
- xfs_trans_ail_cursor_done(&cur);
- spin_unlock(&ailp->ail_lock);
- }
- /*
- * This routine performs a transaction to null out a bad inode pointer
- * in an agi unlinked inode hash bucket.
- */
- STATIC void
- xlog_recover_clear_agi_bucket(
- struct xfs_perag *pag,
- int bucket)
- {
- struct xfs_mount *mp = pag->pag_mount;
- struct xfs_trans *tp;
- struct xfs_agi *agi;
- struct xfs_buf *agibp;
- int offset;
- int error;
- error = xfs_trans_alloc(mp, &M_RES(mp)->tr_clearagi, 0, 0, 0, &tp);
- if (error)
- goto out_error;
- error = xfs_read_agi(pag, tp, &agibp);
- if (error)
- goto out_abort;
- agi = agibp->b_addr;
- agi->agi_unlinked[bucket] = cpu_to_be32(NULLAGINO);
- offset = offsetof(xfs_agi_t, agi_unlinked) +
- (sizeof(xfs_agino_t) * bucket);
- xfs_trans_log_buf(tp, agibp, offset,
- (offset + sizeof(xfs_agino_t) - 1));
- error = xfs_trans_commit(tp);
- if (error)
- goto out_error;
- return;
- out_abort:
- xfs_trans_cancel(tp);
- out_error:
- xfs_warn(mp, "%s: failed to clear agi %d. Continuing.", __func__,
- pag->pag_agno);
- return;
- }
- static int
- xlog_recover_iunlink_bucket(
- struct xfs_perag *pag,
- struct xfs_agi *agi,
- int bucket)
- {
- struct xfs_mount *mp = pag->pag_mount;
- struct xfs_inode *prev_ip = NULL;
- struct xfs_inode *ip;
- xfs_agino_t prev_agino, agino;
- int error = 0;
- agino = be32_to_cpu(agi->agi_unlinked[bucket]);
- while (agino != NULLAGINO) {
- error = xfs_iget(mp, NULL,
- XFS_AGINO_TO_INO(mp, pag->pag_agno, agino),
- 0, 0, &ip);
- if (error)
- break;
- ASSERT(VFS_I(ip)->i_nlink == 0);
- ASSERT(VFS_I(ip)->i_mode != 0);
- xfs_iflags_clear(ip, XFS_IRECOVERY);
- agino = ip->i_next_unlinked;
- if (prev_ip) {
- ip->i_prev_unlinked = prev_agino;
- xfs_irele(prev_ip);
- /*
- * Ensure the inode is removed from the unlinked list
- * before we continue so that it won't race with
- * building the in-memory list here. This could be
- * serialised with the agibp lock, but that just
- * serialises via lockstepping and it's much simpler
- * just to flush the inodegc queue and wait for it to
- * complete.
- */
- xfs_inodegc_flush(mp);
- }
- prev_agino = agino;
- prev_ip = ip;
- }
- if (prev_ip) {
- ip->i_prev_unlinked = prev_agino;
- xfs_irele(prev_ip);
- }
- xfs_inodegc_flush(mp);
- return error;
- }
- /*
- * Recover AGI unlinked lists
- *
- * This is called during recovery to process any inodes which we unlinked but
- * not freed when the system crashed. These inodes will be on the lists in the
- * AGI blocks. What we do here is scan all the AGIs and fully truncate and free
- * any inodes found on the lists. Each inode is removed from the lists when it
- * has been fully truncated and is freed. The freeing of the inode and its
- * removal from the list must be atomic.
- *
- * If everything we touch in the agi processing loop is already in memory, this
- * loop can hold the cpu for a long time. It runs without lock contention,
- * memory allocation contention, the need wait for IO, etc, and so will run
- * until we either run out of inodes to process, run low on memory or we run out
- * of log space.
- *
- * This behaviour is bad for latency on single CPU and non-preemptible kernels,
- * and can prevent other filesystem work (such as CIL pushes) from running. This
- * can lead to deadlocks if the recovery process runs out of log reservation
- * space. Hence we need to yield the CPU when there is other kernel work
- * scheduled on this CPU to ensure other scheduled work can run without undue
- * latency.
- */
- static void
- xlog_recover_iunlink_ag(
- struct xfs_perag *pag)
- {
- struct xfs_agi *agi;
- struct xfs_buf *agibp;
- int bucket;
- int error;
- error = xfs_read_agi(pag, NULL, &agibp);
- if (error) {
- /*
- * AGI is b0rked. Don't process it.
- *
- * We should probably mark the filesystem as corrupt after we've
- * recovered all the ag's we can....
- */
- return;
- }
- /*
- * Unlock the buffer so that it can be acquired in the normal course of
- * the transaction to truncate and free each inode. Because we are not
- * racing with anyone else here for the AGI buffer, we don't even need
- * to hold it locked to read the initial unlinked bucket entries out of
- * the buffer. We keep buffer reference though, so that it stays pinned
- * in memory while we need the buffer.
- */
- agi = agibp->b_addr;
- xfs_buf_unlock(agibp);
- for (bucket = 0; bucket < XFS_AGI_UNLINKED_BUCKETS; bucket++) {
- error = xlog_recover_iunlink_bucket(pag, agi, bucket);
- if (error) {
- /*
- * Bucket is unrecoverable, so only a repair scan can
- * free the remaining unlinked inodes. Just empty the
- * bucket and remaining inodes on it unreferenced and
- * unfreeable.
- */
- xfs_inodegc_flush(pag->pag_mount);
- xlog_recover_clear_agi_bucket(pag, bucket);
- }
- }
- xfs_buf_rele(agibp);
- }
- static void
- xlog_recover_process_iunlinks(
- struct xlog *log)
- {
- struct xfs_perag *pag;
- xfs_agnumber_t agno;
- for_each_perag(log->l_mp, agno, pag)
- xlog_recover_iunlink_ag(pag);
- /*
- * Flush the pending unlinked inodes to ensure that the inactivations
- * are fully completed on disk and the incore inodes can be reclaimed
- * before we signal that recovery is complete.
- */
- xfs_inodegc_flush(log->l_mp);
- }
- STATIC void
- xlog_unpack_data(
- struct xlog_rec_header *rhead,
- char *dp,
- struct xlog *log)
- {
- int i, j, k;
- for (i = 0; i < BTOBB(be32_to_cpu(rhead->h_len)) &&
- i < (XLOG_HEADER_CYCLE_SIZE / BBSIZE); i++) {
- *(__be32 *)dp = *(__be32 *)&rhead->h_cycle_data[i];
- dp += BBSIZE;
- }
- if (xfs_has_logv2(log->l_mp)) {
- xlog_in_core_2_t *xhdr = (xlog_in_core_2_t *)rhead;
- for ( ; i < BTOBB(be32_to_cpu(rhead->h_len)); i++) {
- j = i / (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
- k = i % (XLOG_HEADER_CYCLE_SIZE / BBSIZE);
- *(__be32 *)dp = xhdr[j].hic_xheader.xh_cycle_data[k];
- dp += BBSIZE;
- }
- }
- }
- /*
- * CRC check, unpack and process a log record.
- */
- STATIC int
- xlog_recover_process(
- struct xlog *log,
- struct hlist_head rhash[],
- struct xlog_rec_header *rhead,
- char *dp,
- int pass,
- struct list_head *buffer_list)
- {
- __le32 old_crc = rhead->h_crc;
- __le32 crc;
- crc = xlog_cksum(log, rhead, dp, be32_to_cpu(rhead->h_len));
- /*
- * Nothing else to do if this is a CRC verification pass. Just return
- * if this a record with a non-zero crc. Unfortunately, mkfs always
- * sets old_crc to 0 so we must consider this valid even on v5 supers.
- * Otherwise, return EFSBADCRC on failure so the callers up the stack
- * know precisely what failed.
- */
- if (pass == XLOG_RECOVER_CRCPASS) {
- if (old_crc && crc != old_crc)
- return -EFSBADCRC;
- return 0;
- }
- /*
- * We're in the normal recovery path. Issue a warning if and only if the
- * CRC in the header is non-zero. This is an advisory warning and the
- * zero CRC check prevents warnings from being emitted when upgrading
- * the kernel from one that does not add CRCs by default.
- */
- if (crc != old_crc) {
- if (old_crc || xfs_has_crc(log->l_mp)) {
- xfs_alert(log->l_mp,
- "log record CRC mismatch: found 0x%x, expected 0x%x.",
- le32_to_cpu(old_crc),
- le32_to_cpu(crc));
- xfs_hex_dump(dp, 32);
- }
- /*
- * If the filesystem is CRC enabled, this mismatch becomes a
- * fatal log corruption failure.
- */
- if (xfs_has_crc(log->l_mp)) {
- XFS_ERROR_REPORT(__func__, XFS_ERRLEVEL_LOW, log->l_mp);
- return -EFSCORRUPTED;
- }
- }
- xlog_unpack_data(rhead, dp, log);
- return xlog_recover_process_data(log, rhash, rhead, dp, pass,
- buffer_list);
- }
- STATIC int
- xlog_valid_rec_header(
- struct xlog *log,
- struct xlog_rec_header *rhead,
- xfs_daddr_t blkno,
- int bufsize)
- {
- int hlen;
- if (XFS_IS_CORRUPT(log->l_mp,
- rhead->h_magicno != cpu_to_be32(XLOG_HEADER_MAGIC_NUM)))
- return -EFSCORRUPTED;
- if (XFS_IS_CORRUPT(log->l_mp,
- (!rhead->h_version ||
- (be32_to_cpu(rhead->h_version) &
- (~XLOG_VERSION_OKBITS))))) {
- xfs_warn(log->l_mp, "%s: unrecognised log version (%d).",
- __func__, be32_to_cpu(rhead->h_version));
- return -EFSCORRUPTED;
- }
- /*
- * LR body must have data (or it wouldn't have been written)
- * and h_len must not be greater than LR buffer size.
- */
- hlen = be32_to_cpu(rhead->h_len);
- if (XFS_IS_CORRUPT(log->l_mp, hlen <= 0 || hlen > bufsize))
- return -EFSCORRUPTED;
- if (XFS_IS_CORRUPT(log->l_mp,
- blkno > log->l_logBBsize || blkno > INT_MAX))
- return -EFSCORRUPTED;
- return 0;
- }
- /*
- * Read the log from tail to head and process the log records found.
- * Handle the two cases where the tail and head are in the same cycle
- * and where the active portion of the log wraps around the end of
- * the physical log separately. The pass parameter is passed through
- * to the routines called to process the data and is not looked at
- * here.
- */
- STATIC int
- xlog_do_recovery_pass(
- struct xlog *log,
- xfs_daddr_t head_blk,
- xfs_daddr_t tail_blk,
- int pass,
- xfs_daddr_t *first_bad) /* out: first bad log rec */
- {
- xlog_rec_header_t *rhead;
- xfs_daddr_t blk_no, rblk_no;
- xfs_daddr_t rhead_blk;
- char *offset;
- char *hbp, *dbp;
- int error = 0, h_size, h_len;
- int error2 = 0;
- int bblks, split_bblks;
- int hblks, split_hblks, wrapped_hblks;
- int i;
- struct hlist_head rhash[XLOG_RHASH_SIZE];
- LIST_HEAD (buffer_list);
- ASSERT(head_blk != tail_blk);
- blk_no = rhead_blk = tail_blk;
- for (i = 0; i < XLOG_RHASH_SIZE; i++)
- INIT_HLIST_HEAD(&rhash[i]);
- /*
- * Read the header of the tail block and get the iclog buffer size from
- * h_size. Use this to tell how many sectors make up the log header.
- */
- if (xfs_has_logv2(log->l_mp)) {
- /*
- * When using variable length iclogs, read first sector of
- * iclog header and extract the header size from it. Get a
- * new hbp that is the correct size.
- */
- hbp = xlog_alloc_buffer(log, 1);
- if (!hbp)
- return -ENOMEM;
- error = xlog_bread(log, tail_blk, 1, hbp, &offset);
- if (error)
- goto bread_err1;
- rhead = (xlog_rec_header_t *)offset;
- /*
- * xfsprogs has a bug where record length is based on lsunit but
- * h_size (iclog size) is hardcoded to 32k. Now that we
- * unconditionally CRC verify the unmount record, this means the
- * log buffer can be too small for the record and cause an
- * overrun.
- *
- * Detect this condition here. Use lsunit for the buffer size as
- * long as this looks like the mkfs case. Otherwise, return an
- * error to avoid a buffer overrun.
- */
- h_size = be32_to_cpu(rhead->h_size);
- h_len = be32_to_cpu(rhead->h_len);
- if (h_len > h_size && h_len <= log->l_mp->m_logbsize &&
- rhead->h_num_logops == cpu_to_be32(1)) {
- xfs_warn(log->l_mp,
- "invalid iclog size (%d bytes), using lsunit (%d bytes)",
- h_size, log->l_mp->m_logbsize);
- h_size = log->l_mp->m_logbsize;
- }
- error = xlog_valid_rec_header(log, rhead, tail_blk, h_size);
- if (error)
- goto bread_err1;
- hblks = xlog_logrec_hblks(log, rhead);
- if (hblks != 1) {
- kmem_free(hbp);
- hbp = xlog_alloc_buffer(log, hblks);
- }
- } else {
- ASSERT(log->l_sectBBsize == 1);
- hblks = 1;
- hbp = xlog_alloc_buffer(log, 1);
- h_size = XLOG_BIG_RECORD_BSIZE;
- }
- if (!hbp)
- return -ENOMEM;
- dbp = xlog_alloc_buffer(log, BTOBB(h_size));
- if (!dbp) {
- kmem_free(hbp);
- return -ENOMEM;
- }
- memset(rhash, 0, sizeof(rhash));
- if (tail_blk > head_blk) {
- /*
- * Perform recovery around the end of the physical log.
- * When the head is not on the same cycle number as the tail,
- * we can't do a sequential recovery.
- */
- while (blk_no < log->l_logBBsize) {
- /*
- * Check for header wrapping around physical end-of-log
- */
- offset = hbp;
- split_hblks = 0;
- wrapped_hblks = 0;
- if (blk_no + hblks <= log->l_logBBsize) {
- /* Read header in one read */
- error = xlog_bread(log, blk_no, hblks, hbp,
- &offset);
- if (error)
- goto bread_err2;
- } else {
- /* This LR is split across physical log end */
- if (blk_no != log->l_logBBsize) {
- /* some data before physical log end */
- ASSERT(blk_no <= INT_MAX);
- split_hblks = log->l_logBBsize - (int)blk_no;
- ASSERT(split_hblks > 0);
- error = xlog_bread(log, blk_no,
- split_hblks, hbp,
- &offset);
- if (error)
- goto bread_err2;
- }
- /*
- * Note: this black magic still works with
- * large sector sizes (non-512) only because:
- * - we increased the buffer size originally
- * by 1 sector giving us enough extra space
- * for the second read;
- * - the log start is guaranteed to be sector
- * aligned;
- * - we read the log end (LR header start)
- * _first_, then the log start (LR header end)
- * - order is important.
- */
- wrapped_hblks = hblks - split_hblks;
- error = xlog_bread_noalign(log, 0,
- wrapped_hblks,
- offset + BBTOB(split_hblks));
- if (error)
- goto bread_err2;
- }
- rhead = (xlog_rec_header_t *)offset;
- error = xlog_valid_rec_header(log, rhead,
- split_hblks ? blk_no : 0, h_size);
- if (error)
- goto bread_err2;
- bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
- blk_no += hblks;
- /*
- * Read the log record data in multiple reads if it
- * wraps around the end of the log. Note that if the
- * header already wrapped, blk_no could point past the
- * end of the log. The record data is contiguous in
- * that case.
- */
- if (blk_no + bblks <= log->l_logBBsize ||
- blk_no >= log->l_logBBsize) {
- rblk_no = xlog_wrap_logbno(log, blk_no);
- error = xlog_bread(log, rblk_no, bblks, dbp,
- &offset);
- if (error)
- goto bread_err2;
- } else {
- /* This log record is split across the
- * physical end of log */
- offset = dbp;
- split_bblks = 0;
- if (blk_no != log->l_logBBsize) {
- /* some data is before the physical
- * end of log */
- ASSERT(!wrapped_hblks);
- ASSERT(blk_no <= INT_MAX);
- split_bblks =
- log->l_logBBsize - (int)blk_no;
- ASSERT(split_bblks > 0);
- error = xlog_bread(log, blk_no,
- split_bblks, dbp,
- &offset);
- if (error)
- goto bread_err2;
- }
- /*
- * Note: this black magic still works with
- * large sector sizes (non-512) only because:
- * - we increased the buffer size originally
- * by 1 sector giving us enough extra space
- * for the second read;
- * - the log start is guaranteed to be sector
- * aligned;
- * - we read the log end (LR header start)
- * _first_, then the log start (LR header end)
- * - order is important.
- */
- error = xlog_bread_noalign(log, 0,
- bblks - split_bblks,
- offset + BBTOB(split_bblks));
- if (error)
- goto bread_err2;
- }
- error = xlog_recover_process(log, rhash, rhead, offset,
- pass, &buffer_list);
- if (error)
- goto bread_err2;
- blk_no += bblks;
- rhead_blk = blk_no;
- }
- ASSERT(blk_no >= log->l_logBBsize);
- blk_no -= log->l_logBBsize;
- rhead_blk = blk_no;
- }
- /* read first part of physical log */
- while (blk_no < head_blk) {
- error = xlog_bread(log, blk_no, hblks, hbp, &offset);
- if (error)
- goto bread_err2;
- rhead = (xlog_rec_header_t *)offset;
- error = xlog_valid_rec_header(log, rhead, blk_no, h_size);
- if (error)
- goto bread_err2;
- /* blocks in data section */
- bblks = (int)BTOBB(be32_to_cpu(rhead->h_len));
- error = xlog_bread(log, blk_no+hblks, bblks, dbp,
- &offset);
- if (error)
- goto bread_err2;
- error = xlog_recover_process(log, rhash, rhead, offset, pass,
- &buffer_list);
- if (error)
- goto bread_err2;
- blk_no += bblks + hblks;
- rhead_blk = blk_no;
- }
- bread_err2:
- kmem_free(dbp);
- bread_err1:
- kmem_free(hbp);
- /*
- * Submit buffers that have been added from the last record processed,
- * regardless of error status.
- */
- if (!list_empty(&buffer_list))
- error2 = xfs_buf_delwri_submit(&buffer_list);
- if (error && first_bad)
- *first_bad = rhead_blk;
- /*
- * Transactions are freed at commit time but transactions without commit
- * records on disk are never committed. Free any that may be left in the
- * hash table.
- */
- for (i = 0; i < XLOG_RHASH_SIZE; i++) {
- struct hlist_node *tmp;
- struct xlog_recover *trans;
- hlist_for_each_entry_safe(trans, tmp, &rhash[i], r_list)
- xlog_recover_free_trans(trans);
- }
- return error ? error : error2;
- }
- /*
- * Do the recovery of the log. We actually do this in two phases.
- * The two passes are necessary in order to implement the function
- * of cancelling a record written into the log. The first pass
- * determines those things which have been cancelled, and the
- * second pass replays log items normally except for those which
- * have been cancelled. The handling of the replay and cancellations
- * takes place in the log item type specific routines.
- *
- * The table of items which have cancel records in the log is allocated
- * and freed at this level, since only here do we know when all of
- * the log recovery has been completed.
- */
- STATIC int
- xlog_do_log_recovery(
- struct xlog *log,
- xfs_daddr_t head_blk,
- xfs_daddr_t tail_blk)
- {
- int error;
- ASSERT(head_blk != tail_blk);
- /*
- * First do a pass to find all of the cancelled buf log items.
- * Store them in the buf_cancel_table for use in the second pass.
- */
- error = xlog_alloc_buf_cancel_table(log);
- if (error)
- return error;
- error = xlog_do_recovery_pass(log, head_blk, tail_blk,
- XLOG_RECOVER_PASS1, NULL);
- if (error != 0)
- goto out_cancel;
- /*
- * Then do a second pass to actually recover the items in the log.
- * When it is complete free the table of buf cancel items.
- */
- error = xlog_do_recovery_pass(log, head_blk, tail_blk,
- XLOG_RECOVER_PASS2, NULL);
- if (!error)
- xlog_check_buf_cancel_table(log);
- out_cancel:
- xlog_free_buf_cancel_table(log);
- return error;
- }
- /*
- * Do the actual recovery
- */
- STATIC int
- xlog_do_recover(
- struct xlog *log,
- xfs_daddr_t head_blk,
- xfs_daddr_t tail_blk)
- {
- struct xfs_mount *mp = log->l_mp;
- struct xfs_buf *bp = mp->m_sb_bp;
- struct xfs_sb *sbp = &mp->m_sb;
- int error;
- trace_xfs_log_recover(log, head_blk, tail_blk);
- /*
- * First replay the images in the log.
- */
- error = xlog_do_log_recovery(log, head_blk, tail_blk);
- if (error)
- return error;
- if (xlog_is_shutdown(log))
- return -EIO;
- /*
- * We now update the tail_lsn since much of the recovery has completed
- * and there may be space available to use. If there were no extent
- * or iunlinks, we can free up the entire log and set the tail_lsn to
- * be the last_sync_lsn. This was set in xlog_find_tail to be the
- * lsn of the last known good LR on disk. If there are extent frees
- * or iunlinks they will have some entries in the AIL; so we look at
- * the AIL to determine how to set the tail_lsn.
- */
- xlog_assign_tail_lsn(mp);
- /*
- * Now that we've finished replaying all buffer and inode updates,
- * re-read the superblock and reverify it.
- */
- xfs_buf_lock(bp);
- xfs_buf_hold(bp);
- error = _xfs_buf_read(bp, XBF_READ);
- if (error) {
- if (!xlog_is_shutdown(log)) {
- xfs_buf_ioerror_alert(bp, __this_address);
- ASSERT(0);
- }
- xfs_buf_relse(bp);
- return error;
- }
- /* Convert superblock from on-disk format */
- xfs_sb_from_disk(sbp, bp->b_addr);
- xfs_buf_relse(bp);
- /* re-initialise in-core superblock and geometry structures */
- mp->m_features |= xfs_sb_version_to_features(sbp);
- xfs_reinit_percpu_counters(mp);
- error = xfs_initialize_perag(mp, sbp->sb_agcount, sbp->sb_dblocks,
- &mp->m_maxagi);
- if (error) {
- xfs_warn(mp, "Failed post-recovery per-ag init: %d", error);
- return error;
- }
- mp->m_alloc_set_aside = xfs_alloc_set_aside(mp);
- /* Normal transactions can now occur */
- clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate);
- return 0;
- }
- /*
- * Perform recovery and re-initialize some log variables in xlog_find_tail.
- *
- * Return error or zero.
- */
- int
- xlog_recover(
- struct xlog *log)
- {
- xfs_daddr_t head_blk, tail_blk;
- int error;
- /* find the tail of the log */
- error = xlog_find_tail(log, &head_blk, &tail_blk);
- if (error)
- return error;
- /*
- * The superblock was read before the log was available and thus the LSN
- * could not be verified. Check the superblock LSN against the current
- * LSN now that it's known.
- */
- if (xfs_has_crc(log->l_mp) &&
- !xfs_log_check_lsn(log->l_mp, log->l_mp->m_sb.sb_lsn))
- return -EINVAL;
- if (tail_blk != head_blk) {
- /* There used to be a comment here:
- *
- * disallow recovery on read-only mounts. note -- mount
- * checks for ENOSPC and turns it into an intelligent
- * error message.
- * ...but this is no longer true. Now, unless you specify
- * NORECOVERY (in which case this function would never be
- * called), we just go ahead and recover. We do this all
- * under the vfs layer, so we can get away with it unless
- * the device itself is read-only, in which case we fail.
- */
- if ((error = xfs_dev_is_read_only(log->l_mp, "recovery"))) {
- return error;
- }
- /*
- * Version 5 superblock log feature mask validation. We know the
- * log is dirty so check if there are any unknown log features
- * in what we need to recover. If there are unknown features
- * (e.g. unsupported transactions, then simply reject the
- * attempt at recovery before touching anything.
- */
- if (xfs_sb_is_v5(&log->l_mp->m_sb) &&
- xfs_sb_has_incompat_log_feature(&log->l_mp->m_sb,
- XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) {
- xfs_warn(log->l_mp,
- "Superblock has unknown incompatible log features (0x%x) enabled.",
- (log->l_mp->m_sb.sb_features_log_incompat &
- XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN));
- xfs_warn(log->l_mp,
- "The log can not be fully and/or safely recovered by this kernel.");
- xfs_warn(log->l_mp,
- "Please recover the log on a kernel that supports the unknown features.");
- return -EINVAL;
- }
- /*
- * Delay log recovery if the debug hook is set. This is debug
- * instrumentation to coordinate simulation of I/O failures with
- * log recovery.
- */
- if (xfs_globals.log_recovery_delay) {
- xfs_notice(log->l_mp,
- "Delaying log recovery for %d seconds.",
- xfs_globals.log_recovery_delay);
- msleep(xfs_globals.log_recovery_delay * 1000);
- }
- xfs_notice(log->l_mp, "Starting recovery (logdev: %s)",
- log->l_mp->m_logname ? log->l_mp->m_logname
- : "internal");
- error = xlog_do_recover(log, head_blk, tail_blk);
- set_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate);
- }
- return error;
- }
- /*
- * In the first part of recovery we replay inodes and buffers and build up the
- * list of intents which need to be processed. Here we process the intents and
- * clean up the on disk unlinked inode lists. This is separated from the first
- * part of recovery so that the root and real-time bitmap inodes can be read in
- * from disk in between the two stages. This is necessary so that we can free
- * space in the real-time portion of the file system.
- */
- int
- xlog_recover_finish(
- struct xlog *log)
- {
- int error;
- error = xlog_recover_process_intents(log);
- if (error) {
- /*
- * Cancel all the unprocessed intent items now so that we don't
- * leave them pinned in the AIL. This can cause the AIL to
- * livelock on the pinned item if anyone tries to push the AIL
- * (inode reclaim does this) before we get around to
- * xfs_log_mount_cancel.
- */
- xlog_recover_cancel_intents(log);
- xfs_alert(log->l_mp, "Failed to recover intents");
- xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
- return error;
- }
- /*
- * Sync the log to get all the intents out of the AIL. This isn't
- * absolutely necessary, but it helps in case the unlink transactions
- * would have problems pushing the intents out of the way.
- */
- xfs_log_force(log->l_mp, XFS_LOG_SYNC);
- /*
- * Now that we've recovered the log and all the intents, we can clear
- * the log incompat feature bits in the superblock because there's no
- * longer anything to protect. We rely on the AIL push to write out the
- * updated superblock after everything else.
- */
- if (xfs_clear_incompat_log_features(log->l_mp)) {
- error = xfs_sync_sb(log->l_mp, false);
- if (error < 0) {
- xfs_alert(log->l_mp,
- "Failed to clear log incompat features on recovery");
- return error;
- }
- }
- xlog_recover_process_iunlinks(log);
- /*
- * Recover any CoW staging blocks that are still referenced by the
- * ondisk refcount metadata. During mount there cannot be any live
- * staging extents as we have not permitted any user modifications.
- * Therefore, it is safe to free them all right now, even on a
- * read-only mount.
- */
- error = xfs_reflink_recover_cow(log->l_mp);
- if (error) {
- xfs_alert(log->l_mp,
- "Failed to recover leftover CoW staging extents, err %d.",
- error);
- /*
- * If we get an error here, make sure the log is shut down
- * but return zero so that any log items committed since the
- * end of intents processing can be pushed through the CIL
- * and AIL.
- */
- xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR);
- }
- return 0;
- }
- void
- xlog_recover_cancel(
- struct xlog *log)
- {
- if (xlog_recovery_needed(log))
- xlog_recover_cancel_intents(log);
- }
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