| // 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 = roundup_pow_of_two(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: |
| kvfree(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: |
| kvfree(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; |
| } |
| |
| kvfree(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: |
| kvfree(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: |
| kvfree(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); |
| kvfree(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); |
| log->l_ailp->ail_head_lsn = |
| atomic64_read(&log->l_tail_lsn); |
| *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)); |
| log->l_ailp->ail_head_lsn = be64_to_cpu(rhead->h_lsn); |
| } |
| |
| /* |
| * 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: |
| kvfree(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; |
| int ret = 1; |
| |
| *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; |
| goto out_free_buffer; |
| } |
| |
| /* 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 */ |
| ret = 0; |
| goto out_free_buffer; |
| } |
| |
| /* 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: |
| kvfree(buffer); |
| if (error) |
| return error; |
| return ret; |
| } |
| |
| /* |
| * 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 = roundup_pow_of_two(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: |
| kvfree(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_defer_pending *dfp, *n; |
| |
| list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) { |
| struct xfs_log_item *lip = dfp->dfp_intent; |
| |
| if (lip->li_type != intent_type) |
| continue; |
| if (!lip->li_ops->iop_match(lip, intent_id)) |
| continue; |
| |
| ASSERT(xlog_item_is_intent(lip)); |
| |
| xfs_defer_cancel_recovery(log->l_mp, dfp); |
| } |
| } |
| |
| 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; |
| } |
| |
| /* |
| * Get an inode so that we can recover a log operation. |
| * |
| * Log intent items that target inodes effectively contain a file handle. |
| * Check that the generation number matches the intent item like we do for |
| * other file handles. Log intent items defined after this validation weakness |
| * was identified must use this function. |
| */ |
| int |
| xlog_recover_iget_handle( |
| struct xfs_mount *mp, |
| xfs_ino_t ino, |
| uint32_t gen, |
| struct xfs_inode **ipp) |
| { |
| struct xfs_inode *ip; |
| int error; |
| |
| error = xlog_recover_iget(mp, ino, &ip); |
| if (error) |
| return error; |
| |
| if (VFS_I(ip)->i_generation != gen) { |
| xfs_irele(ip); |
| return -EFSCORRUPTED; |
| } |
| |
| *ipp = ip; |
| 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, |
| &xlog_xmi_item_ops, |
| &xlog_xmd_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); |
| } |
| |
| /* |
| * Create a deferred work structure for resuming and tracking the progress of a |
| * log intent item that was found during recovery. |
| */ |
| void |
| xlog_recover_intent_item( |
| struct xlog *log, |
| struct xfs_log_item *lip, |
| xfs_lsn_t lsn, |
| const struct xfs_defer_op_type *ops) |
| { |
| ASSERT(xlog_item_is_intent(lip)); |
| |
| xfs_defer_start_recovery(lip, &log->r_dfops, ops); |
| |
| /* |
| * Insert the intent into the AIL directly and drop one reference so |
| * that finishing or canceling the work will drop the other. |
| */ |
| xfs_trans_ail_insert(log->l_ailp, lip, lsn); |
| lip->li_ops->iop_unpin(lip, 0); |
| } |
| |
| 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 = kzalloc(sizeof(struct xlog_recover_item), |
| GFP_KERNEL | __GFP_NOFAIL); |
| 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 = xlog_kvmalloc(len); |
| 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); |
| kvfree(ptr); |
| return -EFSCORRUPTED; |
| } |
| |
| item->ri_total = in_f->ilf_size; |
| item->ri_buf = kzalloc(item->ri_total * sizeof(xfs_log_iovec_t), |
| GFP_KERNEL | __GFP_NOFAIL); |
| } |
| |
| 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); |
| kvfree(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++) |
| kvfree(item->ri_buf[i].i_addr); |
| /* Free the item itself */ |
| kfree(item->ri_buf); |
| kfree(item); |
| } |
| /* Free the transaction recover structure */ |
| kfree(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 = kzalloc(sizeof(struct xlog_recover), GFP_KERNEL | __GFP_NOFAIL); |
| 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); |
| if (dp > end) { |
| xfs_warn(log->l_mp, "%s: op header overrun", __func__); |
| return -EFSCORRUPTED; |
| } |
| |
| /* 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_abort(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_defer_pending *dfp, *n; |
| int error = 0; |
| #if defined(DEBUG) || defined(XFS_WARN) |
| xfs_lsn_t last_lsn; |
| |
| last_lsn = xlog_assign_lsn(log->l_curr_cycle, log->l_curr_block); |
| #endif |
| |
| list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) { |
| ASSERT(xlog_item_is_intent(dfp->dfp_intent)); |
| |
| /* |
| * 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, dfp->dfp_intent->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 dfp->dfp_intent after it returns. It must dispose of |
| * @dfp if it returns 0. |
| */ |
| error = xfs_defer_finish_recovery(log->l_mp, dfp, |
| &capture_list); |
| if (error) |
| break; |
| } |
| 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_defer_pending *dfp, *n; |
| |
| list_for_each_entry_safe(dfp, n, &log->r_dfops, dfp_list) { |
| ASSERT(xlog_item_is_intent(dfp->dfp_intent)); |
| |
| xfs_defer_cancel_recovery(log->l_mp, dfp); |
| } |
| } |
| |
| /* |
| * Transfer ownership of the recovered pending work to the recovery transaction |
| * and try to finish the work. If there is more work to be done, the dfp will |
| * remain attached to the transaction. If not, the dfp is freed. |
| */ |
| int |
| xlog_recover_finish_intent( |
| struct xfs_trans *tp, |
| struct xfs_defer_pending *dfp) |
| { |
| int error; |
| |
| list_move(&dfp->dfp_list, &tp->t_dfops); |
| error = xfs_defer_finish_one(tp, dfp); |
| if (error == -EAGAIN) |
| return 0; |
| return error; |
| } |
| |
| /* |
| * 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, 0, &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. |
| */ |
| error = xfs_inodegc_flush(mp); |
| if (error) |
| break; |
| } |
| |
| prev_agino = agino; |
| prev_ip = ip; |
| } |
| |
| if (prev_ip) { |
| int error2; |
| |
| ip->i_prev_unlinked = prev_agino; |
| xfs_irele(prev_ip); |
| |
| error2 = xfs_inodegc_flush(mp); |
| if (error2 && !error) |
| return error2; |
| } |
| 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, 0, &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. |
| */ |
| 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); |
| } |
| |
| 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 = 1, 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]); |
| |
| hbp = xlog_alloc_buffer(log, hblks); |
| if (!hbp) |
| return -ENOMEM; |
| |
| /* |
| * 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. |
| */ |
| 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; |
| |
| /* |
| * This open codes xlog_logrec_hblks so that we can reuse the |
| * fixed up h_size value calculated above. Without that we'd |
| * still allocate the buffer based on the incorrect on-disk |
| * size. |
| */ |
| if (h_size > XLOG_HEADER_CYCLE_SIZE && |
| (rhead->h_version & cpu_to_be32(XLOG_VERSION_2))) { |
| hblks = DIV_ROUND_UP(h_size, XLOG_HEADER_CYCLE_SIZE); |
| if (hblks > 1) { |
| kvfree(hbp); |
| hbp = xlog_alloc_buffer(log, hblks); |
| if (!hbp) |
| return -ENOMEM; |
| } |
| } |
| } else { |
| ASSERT(log->l_sectBBsize == 1); |
| h_size = XLOG_BIG_RECORD_BSIZE; |
| } |
| |
| dbp = xlog_alloc_buffer(log, BTOBB(h_size)); |
| if (!dbp) { |
| kvfree(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: |
| kvfree(dbp); |
| bread_err1: |
| kvfree(hbp); |
| |
| /* |
| * Submit buffers that have been dirtied by the last record recovered. |
| */ |
| if (!list_empty(&buffer_list)) { |
| if (error) { |
| /* |
| * If there has been an item recovery error then we |
| * cannot allow partial checkpoint writeback to |
| * occur. We might have multiple checkpoints with the |
| * same start LSN in this buffer list, and partial |
| * writeback of a checkpoint in this situation can |
| * prevent future recovery of all the changes in the |
| * checkpoints at this start LSN. |
| * |
| * Note: Shutting down the filesystem will result in the |
| * delwri submission marking all the buffers stale, |
| * completing them and cleaning up _XBF_LOGRECOVERY |
| * state without doing any IO. |
| */ |
| xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); |
| } |
| 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_dad
|