| Author | Tokens | Token Proportion | Commits | Commit Proportion |
|---|---|---|---|---|
| Christoph Hellwig | 4708 | 40.79% | 46 | 16.67% |
| David Chinner | 2136 | 18.50% | 73 | 26.45% |
| Brian Foster | 2033 | 17.61% | 32 | 11.59% |
| Darrick J. Wong | 1143 | 9.90% | 56 | 20.29% |
| Nathan Scott | 767 | 6.64% | 17 | 6.16% |
| Zhi Yong Wu | 239 | 2.07% | 2 | 0.72% |
| Alex Elder | 130 | 1.13% | 9 | 3.26% |
| Hsiang Kao | 106 | 0.92% | 2 | 0.72% |
| Mark Tinguely | 101 | 0.87% | 2 | 0.72% |
| Russell Cattelan | 39 | 0.34% | 2 | 0.72% |
| Eric Sandeen | 27 | 0.23% | 7 | 2.54% |
| Lachlan McIlroy | 15 | 0.13% | 2 | 0.72% |
| Timothy Shimmin | 12 | 0.10% | 3 | 1.09% |
| Long Li | 11 | 0.10% | 2 | 0.72% |
| lei lu | 11 | 0.10% | 1 | 0.36% |
| Glen Overby | 10 | 0.09% | 1 | 0.36% |
| Joe Perches | 7 | 0.06% | 1 | 0.36% |
| Jan Kara | 6 | 0.05% | 1 | 0.36% |
| Stephen Lord | 6 | 0.05% | 1 | 0.36% |
| Allison Henderson | 6 | 0.05% | 1 | 0.36% |
| Jie Liu | 4 | 0.03% | 1 | 0.36% |
| Andy Poling | 4 | 0.03% | 1 | 0.36% |
| Amir Goldstein | 3 | 0.03% | 1 | 0.36% |
| Hariprasad Kelam | 2 | 0.02% | 1 | 0.36% |
| Bart Van Assche | 2 | 0.02% | 1 | 0.36% |
| Linus Torvalds (pre-git) | 2 | 0.02% | 1 | 0.36% |
| Wang Jianchao | 2 | 0.02% | 1 | 0.36% |
| Mimi Zohar | 2 | 0.02% | 1 | 0.36% |
| Harvey Harrison | 2 | 0.02% | 1 | 0.36% |
| Bhaskar Chowdhury | 2 | 0.02% | 1 | 0.36% |
| Chandra Seetharaman | 1 | 0.01% | 1 | 0.36% |
| Bill O'Donnell | 1 | 0.01% | 1 | 0.36% |
| Carlos Maiolino | 1 | 0.01% | 1 | 0.36% |
| Utako Kusaka | 1 | 0.01% | 1 | 0.36% |
| Randy Dunlap | 1 | 0.01% | 1 | 0.36% |
| Total | 11543 | 276 |
// 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_daddr_t tail_blk) { int error; ASSERT(head_blk != tail_blk); /* * First do a pass to find all of the cancelled buf log items. * Store them in the buf_cancel_table for use in the second pass. */ error = xlog_alloc_buf_cancel_table(log); if (error) return error; error = xlog_do_recovery_pass(log, head_blk, tail_blk, XLOG_RECOVER_PASS1, NULL); if (error != 0) goto out_cancel; /* * Then do a second pass to actually recover the items in the log. * When it is complete free the table of buf cancel items. */ error = xlog_do_recovery_pass(log, head_blk, tail_blk, XLOG_RECOVER_PASS2, NULL); if (!error) xlog_check_buf_cancel_table(log); out_cancel: xlog_free_buf_cancel_table(log); return error; } /* * Do the actual recovery */ STATIC int xlog_do_recover( struct xlog *log, xfs_daddr_t head_blk, xfs_daddr_t tail_blk) { struct xfs_mount *mp = log->l_mp; struct xfs_buf *bp = mp->m_sb_bp; struct xfs_sb *sbp = &mp->m_sb; int error; trace_xfs_log_recover(log, head_blk, tail_blk); /* * First replay the images in the log. */ error = xlog_do_log_recovery(log, head_blk, tail_blk); if (error) return error; if (xlog_is_shutdown(log)) return -EIO; /* * We now update the tail_lsn since much of the recovery has completed * and there may be space available to use. If there were no extent or * iunlinks, we can free up the entire log. This was set in * xlog_find_tail to be the lsn of the last known good LR on disk. If * there are extent frees or iunlinks they will have some entries in the * AIL; so we look at the AIL to determine how to set the tail_lsn. */ xfs_ail_assign_tail_lsn(log->l_ailp); /* * Now that we've finished replaying all buffer and inode updates, * re-read the superblock and reverify it. */ xfs_buf_lock(bp); xfs_buf_hold(bp); error = _xfs_buf_read(bp, XBF_READ); if (error) { if (!xlog_is_shutdown(log)) { xfs_buf_ioerror_alert(bp, __this_address); ASSERT(0); } xfs_buf_relse(bp); return error; } /* Convert superblock from on-disk format */ xfs_sb_from_disk(sbp, bp->b_addr); xfs_buf_relse(bp); /* re-initialise in-core superblock and geometry structures */ mp->m_features |= xfs_sb_version_to_features(sbp); xfs_reinit_percpu_counters(mp); error = xfs_initialize_perag(mp, sbp->sb_agcount, sbp->sb_dblocks, &mp->m_maxagi); if (error) { xfs_warn(mp, "Failed post-recovery per-ag init: %d", error); return error; } mp->m_alloc_set_aside = xfs_alloc_set_aside(mp); /* Normal transactions can now occur */ clear_bit(XLOG_ACTIVE_RECOVERY, &log->l_opstate); return 0; } /* * Perform recovery and re-initialize some log variables in xlog_find_tail. * * Return error or zero. */ int xlog_recover( struct xlog *log) { xfs_daddr_t head_blk, tail_blk; int error; /* find the tail of the log */ error = xlog_find_tail(log, &head_blk, &tail_blk); if (error) return error; /* * The superblock was read before the log was available and thus the LSN * could not be verified. Check the superblock LSN against the current * LSN now that it's known. */ if (xfs_has_crc(log->l_mp) && !xfs_log_check_lsn(log->l_mp, log->l_mp->m_sb.sb_lsn)) return -EINVAL; if (tail_blk != head_blk) { /* There used to be a comment here: * * disallow recovery on read-only mounts. note -- mount * checks for ENOSPC and turns it into an intelligent * error message. * ...but this is no longer true. Now, unless you specify * NORECOVERY (in which case this function would never be * called), we just go ahead and recover. We do this all * under the vfs layer, so we can get away with it unless * the device itself is read-only, in which case we fail. */ if ((error = xfs_dev_is_read_only(log->l_mp, "recovery"))) { return error; } /* * Version 5 superblock log feature mask validation. We know the * log is dirty so check if there are any unknown log features * in what we need to recover. If there are unknown features * (e.g. unsupported transactions, then simply reject the * attempt at recovery before touching anything. */ if (xfs_sb_is_v5(&log->l_mp->m_sb) && xfs_sb_has_incompat_log_feature(&log->l_mp->m_sb, XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)) { xfs_warn(log->l_mp, "Superblock has unknown incompatible log features (0x%x) enabled.", (log->l_mp->m_sb.sb_features_log_incompat & XFS_SB_FEAT_INCOMPAT_LOG_UNKNOWN)); xfs_warn(log->l_mp, "The log can not be fully and/or safely recovered by this kernel."); xfs_warn(log->l_mp, "Please recover the log on a kernel that supports the unknown features."); return -EINVAL; } /* * Delay log recovery if the debug hook is set. This is debug * instrumentation to coordinate simulation of I/O failures with * log recovery. */ if (xfs_globals.log_recovery_delay) { xfs_notice(log->l_mp, "Delaying log recovery for %d seconds.", xfs_globals.log_recovery_delay); msleep(xfs_globals.log_recovery_delay * 1000); } xfs_notice(log->l_mp, "Starting recovery (logdev: %s)", log->l_mp->m_logname ? log->l_mp->m_logname : "internal"); error = xlog_do_recover(log, head_blk, tail_blk); set_bit(XLOG_RECOVERY_NEEDED, &log->l_opstate); } return error; } /* * In the first part of recovery we replay inodes and buffers and build up the * list of intents which need to be processed. Here we process the intents and * clean up the on disk unlinked inode lists. This is separated from the first * part of recovery so that the root and real-time bitmap inodes can be read in * from disk in between the two stages. This is necessary so that we can free * space in the real-time portion of the file system. * * We run this whole process under GFP_NOFS allocation context. We do a * combination of non-transactional and transactional work, yet we really don't * want to recurse into the filesystem from direct reclaim during any of this * processing. This allows all the recovery code run here not to care about the * memory allocation context it is running in. */ int xlog_recover_finish( struct xlog *log) { unsigned int nofs_flags = memalloc_nofs_save(); int error; error = xlog_recover_process_intents(log); if (error) { /* * Cancel all the unprocessed intent items now so that we don't * leave them pinned in the AIL. This can cause the AIL to * livelock on the pinned item if anyone tries to push the AIL * (inode reclaim does this) before we get around to * xfs_log_mount_cancel. */ xlog_recover_cancel_intents(log); xfs_alert(log->l_mp, "Failed to recover intents"); xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); goto out_error; } /* * Sync the log to get all the intents out of the AIL. This isn't * absolutely necessary, but it helps in case the unlink transactions * would have problems pushing the intents out of the way. */ xfs_log_force(log->l_mp, XFS_LOG_SYNC); xlog_recover_process_iunlinks(log); /* * Recover any CoW staging blocks that are still referenced by the * ondisk refcount metadata. During mount there cannot be any live * staging extents as we have not permitted any user modifications. * Therefore, it is safe to free them all right now, even on a * read-only mount. */ error = xfs_reflink_recover_cow(log->l_mp); if (error) { xfs_alert(log->l_mp, "Failed to recover leftover CoW staging extents, err %d.", error); /* * If we get an error here, make sure the log is shut down * but return zero so that any log items committed since the * end of intents processing can be pushed through the CIL * and AIL. */ xlog_force_shutdown(log, SHUTDOWN_LOG_IO_ERROR); error = 0; goto out_error; } out_error: memalloc_nofs_restore(nofs_flags); return error; } void xlog_recover_cancel( struct xlog *log) { if (xlog_recovery_needed(log)) xlog_recover_cancel_intents(log); }
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