LCOV - code coverage report
Current view: top level - fs/xfs/scrub - bitmap.c (source / functions) Hit Total Coverage
Test: fstests of 6.5.0-rc3-djwa @ Mon Jul 31 20:08:17 PDT 2023 Lines: 134 149 89.9 %
Date: 2023-07-31 20:08:17 Functions: 22 24 91.7 %

          Line data    Source code
       1             : // SPDX-License-Identifier: GPL-2.0-or-later
       2             : /*
       3             :  * Copyright (C) 2018-2023 Oracle.  All Rights Reserved.
       4             :  * Author: Darrick J. Wong <djwong@kernel.org>
       5             :  */
       6             : #include "xfs.h"
       7             : #include "xfs_fs.h"
       8             : #include "xfs_shared.h"
       9             : #include "xfs_bit.h"
      10             : #include "xfs_format.h"
      11             : #include "xfs_trans_resv.h"
      12             : #include "xfs_mount.h"
      13             : #include "xfs_btree.h"
      14             : #include "scrub/scrub.h"
      15             : #include "scrub/bitmap.h"
      16             : 
      17             : #include <linux/interval_tree_generic.h>
      18             : 
      19             : struct xbitmap_node {
      20             :         struct rb_node  bn_rbnode;
      21             : 
      22             :         /* First set bit of this interval and subtree. */
      23             :         uint64_t        bn_start;
      24             : 
      25             :         /* Last set bit of this interval. */
      26             :         uint64_t        bn_last;
      27             : 
      28             :         /* Last set bit of this subtree.  Do not touch this. */
      29             :         uint64_t        __bn_subtree_last;
      30             : };
      31             : 
      32             : /* Define our own interval tree type with uint64_t parameters. */
      33             : 
      34             : #define START(node) ((node)->bn_start)
      35             : #define LAST(node)  ((node)->bn_last)
      36             : 
      37             : /*
      38             :  * These functions are defined by the INTERVAL_TREE_DEFINE macro, but we'll
      39             :  * forward-declare them anyway for clarity.
      40             :  */
      41             : static inline void
      42             : xbitmap_tree_insert(struct xbitmap_node *node, struct rb_root_cached *root);
      43             : 
      44             : static inline void
      45             : xbitmap_tree_remove(struct xbitmap_node *node, struct rb_root_cached *root);
      46             : 
      47             : static inline struct xbitmap_node *
      48             : xbitmap_tree_iter_first(struct rb_root_cached *root, uint64_t start,
      49             :                         uint64_t last);
      50             : 
      51             : static inline struct xbitmap_node *
      52             : xbitmap_tree_iter_next(struct xbitmap_node *node, uint64_t start,
      53             :                        uint64_t last);
      54             : 
      55  1755034126 : INTERVAL_TREE_DEFINE(struct xbitmap_node, bn_rbnode, uint64_t,
      56             :                 __bn_subtree_last, START, LAST, static inline, xbitmap_tree)
      57             : 
      58             : /* Iterate each interval of a bitmap.  Do not change the bitmap. */
      59             : #define for_each_xbitmap_extent(bn, bitmap) \
      60             :         for ((bn) = rb_entry_safe(rb_first(&(bitmap)->xb_root.rb_root), \
      61             :                                    struct xbitmap_node, bn_rbnode); \
      62             :              (bn) != NULL; \
      63             :              (bn) = rb_entry_safe(rb_next(&(bn)->bn_rbnode), \
      64             :                                    struct xbitmap_node, bn_rbnode))
      65             : 
      66             : /* Clear a range of this bitmap. */
      67             : int
      68    70027949 : xbitmap_clear(
      69             :         struct xbitmap          *bitmap,
      70             :         uint64_t                start,
      71             :         uint64_t                len)
      72             : {
      73    70027949 :         struct xbitmap_node     *bn;
      74    70027949 :         struct xbitmap_node     *new_bn;
      75    70027949 :         uint64_t                last = start + len - 1;
      76             : 
      77    94628780 :         while ((bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last))) {
      78    24609673 :                 if (bn->bn_start < start && bn->bn_last > last) {
      79           2 :                         uint64_t        old_last = bn->bn_last;
      80             : 
      81             :                         /* overlaps with the entire clearing range */
      82           2 :                         xbitmap_tree_remove(bn, &bitmap->xb_root);
      83           2 :                         bn->bn_last = start - 1;
      84           2 :                         xbitmap_tree_insert(bn, &bitmap->xb_root);
      85             : 
      86             :                         /* add an extent */
      87           2 :                         new_bn = kmalloc(sizeof(struct xbitmap_node),
      88             :                                         XCHK_GFP_FLAGS);
      89           2 :                         if (!new_bn)
      90             :                                 return -ENOMEM;
      91           2 :                         new_bn->bn_start = last + 1;
      92           2 :                         new_bn->bn_last = old_last;
      93           2 :                         xbitmap_tree_insert(new_bn, &bitmap->xb_root);
      94    24609669 :                 } else if (bn->bn_start < start) {
      95             :                         /* overlaps with the left side of the clearing range */
      96      453087 :                         xbitmap_tree_remove(bn, &bitmap->xb_root);
      97      453087 :                         bn->bn_last = start - 1;
      98      453087 :                         xbitmap_tree_insert(bn, &bitmap->xb_root);
      99    24156582 :                 } else if (bn->bn_last > last) {
     100             :                         /* overlaps with the right side of the clearing range */
     101        8964 :                         xbitmap_tree_remove(bn, &bitmap->xb_root);
     102        8964 :                         bn->bn_start = last + 1;
     103        8964 :                         xbitmap_tree_insert(bn, &bitmap->xb_root);
     104        8964 :                         break;
     105             :                 } else {
     106             :                         /* in the middle of the clearing range */
     107    24147618 :                         xbitmap_tree_remove(bn, &bitmap->xb_root);
     108    24147685 :                         kfree(bn);
     109             :                 }
     110             :         }
     111             : 
     112             :         return 0;
     113             : }
     114             : 
     115             : /* Set a range of this bitmap. */
     116             : int
     117    46323495 : xbitmap_set(
     118             :         struct xbitmap          *bitmap,
     119             :         uint64_t                start,
     120             :         uint64_t                len)
     121             : {
     122    46323495 :         struct xbitmap_node     *left;
     123    46323495 :         struct xbitmap_node     *right;
     124    46323495 :         uint64_t                last = start + len - 1;
     125    46323495 :         int                     error;
     126             : 
     127             :         /* Is this whole range already set? */
     128    46323495 :         left = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
     129    46323611 :         if (left && left->bn_start <= start && left->bn_last >= last)
     130             :                 return 0;
     131             : 
     132             :         /* Clear out everything in the range we want to set. */
     133    46323611 :         error = xbitmap_clear(bitmap, start, len);
     134    46323870 :         if (error)
     135             :                 return error;
     136             : 
     137             :         /* Do we have a left-adjacent extent? */
     138    46323868 :         left = xbitmap_tree_iter_first(&bitmap->xb_root, start - 1, start - 1);
     139    46323631 :         ASSERT(!left || left->bn_last + 1 == start);
     140             : 
     141             :         /* Do we have a right-adjacent extent? */
     142    46323631 :         right = xbitmap_tree_iter_first(&bitmap->xb_root, last + 1, last + 1);
     143    46323975 :         ASSERT(!right || right->bn_start == last + 1);
     144             : 
     145    46323975 :         if (left && right) {
     146             :                 /* combine left and right adjacent extent */
     147      269843 :                 xbitmap_tree_remove(left, &bitmap->xb_root);
     148      269843 :                 xbitmap_tree_remove(right, &bitmap->xb_root);
     149      269843 :                 left->bn_last = right->bn_last;
     150      269843 :                 xbitmap_tree_insert(left, &bitmap->xb_root);
     151      269843 :                 kfree(right);
     152    46054132 :         } else if (left) {
     153             :                 /* combine with left extent */
     154     4585036 :                 xbitmap_tree_remove(left, &bitmap->xb_root);
     155     4585082 :                 left->bn_last = last;
     156     4585082 :                 xbitmap_tree_insert(left, &bitmap->xb_root);
     157    41469096 :         } else if (right) {
     158             :                 /* combine with right extent */
     159      736373 :                 xbitmap_tree_remove(right, &bitmap->xb_root);
     160      736373 :                 right->bn_start = start;
     161      736373 :                 xbitmap_tree_insert(right, &bitmap->xb_root);
     162             :         } else {
     163             :                 /* add an extent */
     164    40732723 :                 left = kmalloc(sizeof(struct xbitmap_node), XCHK_GFP_FLAGS);
     165    40732909 :                 if (!left)
     166             :                         return -ENOMEM;
     167    40732909 :                 left->bn_start = start;
     168    40732909 :                 left->bn_last = last;
     169    40732909 :                 xbitmap_tree_insert(left, &bitmap->xb_root);
     170             :         }
     171             : 
     172             :         return 0;
     173             : }
     174             : 
     175             : /* Free everything related to this bitmap. */
     176             : void
     177     3175487 : xbitmap_destroy(
     178             :         struct xbitmap          *bitmap)
     179             : {
     180     3175487 :         struct xbitmap_node     *bn;
     181             : 
     182    19490820 :         while ((bn = xbitmap_tree_iter_first(&bitmap->xb_root, 0, -1ULL))) {
     183    16315301 :                 xbitmap_tree_remove(bn, &bitmap->xb_root);
     184    16315321 :                 kfree(bn);
     185             :         }
     186     3175462 : }
     187             : 
     188             : /* Set up a per-AG block bitmap. */
     189             : void
     190     3175510 : xbitmap_init(
     191             :         struct xbitmap          *bitmap)
     192             : {
     193     3175510 :         bitmap->xb_root = RB_ROOT_CACHED;
     194     3175510 : }
     195             : 
     196             : /*
     197             :  * Remove all the blocks mentioned in @sub from the extents in @bitmap.
     198             :  *
     199             :  * The intent is that callers will iterate the rmapbt for all of its records
     200             :  * for a given owner to generate @bitmap; and iterate all the blocks of the
     201             :  * metadata structures that are not being rebuilt and have the same rmapbt
     202             :  * owner to generate @sub.  This routine subtracts all the extents
     203             :  * mentioned in sub from all the extents linked in @bitmap, which leaves
     204             :  * @bitmap as the list of blocks that are not accounted for, which we assume
     205             :  * are the dead blocks of the old metadata structure.  The blocks mentioned in
     206             :  * @bitmap can be reaped.
     207             :  *
     208             :  * This is the logical equivalent of bitmap &= ~sub.
     209             :  */
     210             : int
     211      554660 : xbitmap_disunion(
     212             :         struct xbitmap          *bitmap,
     213             :         struct xbitmap          *sub)
     214             : {
     215      554660 :         struct xbitmap_node     *bn;
     216      554660 :         int                     error;
     217             : 
     218     1109320 :         if (xbitmap_empty(bitmap) || xbitmap_empty(sub))
     219             :                 return 0;
     220             : 
     221    17054832 :         for_each_xbitmap_extent(bn, sub) {
     222    16315313 :                 error = xbitmap_clear(bitmap, bn->bn_start,
     223    16315313 :                                 bn->bn_last - bn->bn_start + 1);
     224    16315306 :                 if (error)
     225           0 :                         return error;
     226             :         }
     227             : 
     228             :         return 0;
     229             : }
     230             : 
     231             : /*
     232             :  * Record all btree blocks seen while iterating all records of a btree.
     233             :  *
     234             :  * We know that the btree query_all function starts at the left edge and walks
     235             :  * towards the right edge of the tree.  Therefore, we know that we can walk up
     236             :  * the btree cursor towards the root; if the pointer for a given level points
     237             :  * to the first record/key in that block, we haven't seen this block before;
     238             :  * and therefore we need to remember that we saw this block in the btree.
     239             :  *
     240             :  * So if our btree is:
     241             :  *
     242             :  *    4
     243             :  *  / | \
     244             :  * 1  2  3
     245             :  *
     246             :  * Pretend for this example that each leaf block has 100 btree records.  For
     247             :  * the first btree record, we'll observe that bc_levels[0].ptr == 1, so we
     248             :  * record that we saw block 1.  Then we observe that bc_levels[1].ptr == 1, so
     249             :  * we record block 4.  The list is [1, 4].
     250             :  *
     251             :  * For the second btree record, we see that bc_levels[0].ptr == 2, so we exit
     252             :  * the loop.  The list remains [1, 4].
     253             :  *
     254             :  * For the 101st btree record, we've moved onto leaf block 2.  Now
     255             :  * bc_levels[0].ptr == 1 again, so we record that we saw block 2.  We see that
     256             :  * bc_levels[1].ptr == 2, so we exit the loop.  The list is now [1, 4, 2].
     257             :  *
     258             :  * For the 102nd record, bc_levels[0].ptr == 2, so we continue.
     259             :  *
     260             :  * For the 201st record, we've moved on to leaf block 3.
     261             :  * bc_levels[0].ptr == 1, so we add 3 to the list.  Now it is [1, 4, 2, 3].
     262             :  *
     263             :  * For the 300th record we just exit, with the list being [1, 4, 2, 3].
     264             :  */
     265             : 
     266             : /* Mark a btree block to the agblock bitmap. */
     267             : STATIC int
     268     7576876 : xagb_bitmap_visit_btblock(
     269             :         struct xfs_btree_cur    *cur,
     270             :         int                     level,
     271             :         void                    *priv)
     272             : {
     273     7576876 :         struct xagb_bitmap      *bitmap = priv;
     274     7576876 :         struct xfs_buf          *bp;
     275     7576876 :         xfs_fsblock_t           fsbno;
     276     7576876 :         xfs_agblock_t           agbno;
     277             : 
     278     7576876 :         xfs_btree_get_block(cur, level, &bp);
     279     7576872 :         if (!bp)
     280             :                 return 0;
     281             : 
     282     7576872 :         fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
     283     7576898 :         agbno = XFS_FSB_TO_AGBNO(cur->bc_mp, fsbno);
     284             : 
     285     7576893 :         return xagb_bitmap_set(bitmap, agbno, 1);
     286             : }
     287             : 
     288             : /* Mark all (per-AG) btree blocks in the agblock bitmap. */
     289             : int
     290     2923094 : xagb_bitmap_set_btblocks(
     291             :         struct xagb_bitmap      *bitmap,
     292             :         struct xfs_btree_cur    *cur)
     293             : {
     294     2923094 :         return xfs_btree_visit_blocks(cur, xagb_bitmap_visit_btblock,
     295             :                         XFS_BTREE_VISIT_ALL, bitmap);
     296             : }
     297             : 
     298             : /*
     299             :  * Record all the buffers pointed to by the btree cursor.  Callers already
     300             :  * engaged in a btree walk should call this function to capture the list of
     301             :  * blocks going from the leaf towards the root.
     302             :  */
     303             : int
     304  2189030424 : xbitmap_set_btcur_path(
     305             :         struct xbitmap          *bitmap,
     306             :         struct xfs_btree_cur    *cur)
     307             : {
     308  2189030424 :         struct xfs_buf          *bp;
     309  2189030424 :         xfs_fsblock_t           fsb;
     310  2189030424 :         int                     i;
     311  2189030424 :         int                     error;
     312             : 
     313  2205304536 :         for (i = 0; i < cur->bc_nlevels && cur->bc_levels[i].ptr == 1; i++) {
     314    16266759 :                 xfs_btree_get_block(cur, i, &bp);
     315    16274119 :                 if (!bp)
     316           0 :                         continue;
     317    16274119 :                 fsb = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
     318    16274115 :                 error = xbitmap_set(bitmap, fsb, 1);
     319    16274112 :                 if (error)
     320           0 :                         return error;
     321             :         }
     322             : 
     323             :         return 0;
     324             : }
     325             : 
     326             : /* Collect a btree's block in the bitmap. */
     327             : STATIC int
     328     1494475 : xbitmap_collect_btblock(
     329             :         struct xfs_btree_cur    *cur,
     330             :         int                     level,
     331             :         void                    *priv)
     332             : {
     333     1494475 :         struct xbitmap          *bitmap = priv;
     334     1494475 :         struct xfs_buf          *bp;
     335     1494475 :         xfs_fsblock_t           fsbno;
     336             : 
     337     1494475 :         xfs_btree_get_block(cur, level, &bp);
     338     1494476 :         if (!bp)
     339             :                 return 0;
     340             : 
     341     1494476 :         fsbno = XFS_DADDR_TO_FSB(cur->bc_mp, xfs_buf_daddr(bp));
     342     1494475 :         return xbitmap_set(bitmap, fsbno, 1);
     343             : }
     344             : 
     345             : /* Walk the btree and mark the bitmap wherever a btree block is found. */
     346             : int
     347      369800 : xbitmap_set_btblocks(
     348             :         struct xbitmap          *bitmap,
     349             :         struct xfs_btree_cur    *cur)
     350             : {
     351      369800 :         return xfs_btree_visit_blocks(cur, xbitmap_collect_btblock,
     352             :                         XFS_BTREE_VISIT_ALL, bitmap);
     353             : }
     354             : 
     355             : /* How many bits are set in this bitmap? */
     356             : uint64_t
     357     2620906 : xbitmap_hweight(
     358             :         struct xbitmap          *bitmap)
     359             : {
     360     2620906 :         struct xbitmap_node     *bn;
     361     2620906 :         uint64_t                ret = 0;
     362             : 
     363     6524728 :         for_each_xbitmap_extent(bn, bitmap)
     364      641462 :                 ret += bn->bn_last - bn->bn_start + 1;
     365             : 
     366     2620922 :         return ret;
     367             : }
     368             : 
     369             : /* Call a function for every run of set bits in this bitmap. */
     370             : int
     371      554631 : xbitmap_walk(
     372             :         struct xbitmap          *bitmap,
     373             :         xbitmap_walk_fn         fn,
     374             :         void                    *priv)
     375             : {
     376      554631 :         struct xbitmap_node     *bn;
     377      554631 :         int                     error = 0;
     378             : 
     379     3305207 :         for_each_xbitmap_extent(bn, bitmap) {
     380     1282822 :                 error = fn(bn->bn_start, bn->bn_last - bn->bn_start + 1, priv);
     381     1282848 :                 if (error)
     382             :                         break;
     383             :         }
     384             : 
     385      554662 :         return error;
     386             : }
     387             : 
     388             : struct xbitmap_walk_bits {
     389             :         xbitmap_walk_bits_fn    fn;
     390             :         void                    *priv;
     391             : };
     392             : 
     393             : /* Walk all the bits in a run. */
     394             : static int
     395           0 : xbitmap_walk_bits_in_run(
     396             :         uint64_t                        start,
     397             :         uint64_t                        len,
     398             :         void                            *priv)
     399             : {
     400           0 :         struct xbitmap_walk_bits        *wb = priv;
     401           0 :         uint64_t                        i;
     402           0 :         int                             error = 0;
     403             : 
     404           0 :         for (i = start; i < start + len; i++) {
     405           0 :                 error = wb->fn(i, wb->priv);
     406           0 :                 if (error)
     407             :                         break;
     408             :         }
     409             : 
     410           0 :         return error;
     411             : }
     412             : 
     413             : /* Call a function for every set bit in this bitmap. */
     414             : int
     415      184871 : xbitmap_walk_bits(
     416             :         struct xbitmap                  *bitmap,
     417             :         xbitmap_walk_bits_fn            fn,
     418             :         void                            *priv)
     419             : {
     420      184871 :         struct xbitmap_walk_bits        wb = {.fn = fn, .priv = priv};
     421             : 
     422      184871 :         return xbitmap_walk(bitmap, xbitmap_walk_bits_in_run, &wb);
     423             : }
     424             : 
     425             : /* Does this bitmap have no bits set at all? */
     426             : bool
     427           0 : xbitmap_empty(
     428             :         struct xbitmap          *bitmap)
     429             : {
     430      554660 :         return bitmap->xb_root.rb_root.rb_node == NULL;
     431             : }
     432             : 
     433             : /* Is the start of the range set or clear?  And for how long? */
     434             : bool
     435     7390619 : xbitmap_test(
     436             :         struct xbitmap          *bitmap,
     437             :         uint64_t                start,
     438             :         uint64_t                *len)
     439             : {
     440     7390619 :         struct xbitmap_node     *bn;
     441     7390619 :         uint64_t                last = start + *len - 1;
     442             : 
     443     7390619 :         bn = xbitmap_tree_iter_first(&bitmap->xb_root, start, last);
     444     7390649 :         if (!bn)
     445             :                 return false;
     446     7390649 :         if (bn->bn_start <= start) {
     447     7390649 :                 if (bn->bn_last < last)
     448           0 :                         *len = bn->bn_last - start + 1;
     449     7390649 :                 return true;
     450             :         }
     451           0 :         *len = bn->bn_start - start;
     452           0 :         return false;
     453             : }

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