Hi Dave, Thank you for the patch! Perhaps something to improve: [auto build test WARNING on xfs-linux/for-next] [also build test WARNING on v5.16-rc3 next-20211202] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch] url: https://github.com/0day-ci/linux/commits/Dave-Chinner/xfs-more-work-towards-shrinking/20211203-080331 base: https://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git for-next config: hexagon-randconfig-r036-20211203 (https://download.01.org/0day-ci/archive/20211203/202112031527.dpUjvB8h-lkp@xxxxxxxxx/config) compiler: clang version 14.0.0 (https://github.com/llvm/llvm-project 1e328b06c15273edf4a40a27ca24931b5efb3a87) reproduce (this is a W=1 build): wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross chmod +x ~/bin/make.cross # https://github.com/0day-ci/linux/commit/bf14ac7fff281f5586699613ea95b4671aa8a811 git remote add linux-review https://github.com/0day-ci/linux git fetch --no-tags linux-review Dave-Chinner/xfs-more-work-towards-shrinking/20211203-080331 git checkout bf14ac7fff281f5586699613ea95b4671aa8a811 # save the config file to linux build tree mkdir build_dir COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=hexagon SHELL=/bin/bash fs/xfs/ If you fix the issue, kindly add following tag as appropriate Reported-by: kernel test robot <lkp@xxxxxxxxx> All warnings (new ones prefixed by >>): >> fs/xfs/xfs_reflink.c:129:1: warning: no previous prototype for function 'xfs_reflink_find_shared' [-Wmissing-prototypes] xfs_reflink_find_shared( ^ fs/xfs/xfs_reflink.c:128:1: note: declare 'static' if the function is not intended to be used outside of this translation unit int ^ static fs/xfs/xfs_reflink.c:996:12: warning: variable 'qdelta' set but not used [-Wunused-but-set-variable] int64_t qdelta = 0; ^ 2 warnings generated. vim +/xfs_reflink_find_shared +129 fs/xfs/xfs_reflink.c 3993baeb3c52f4 Darrick J. Wong 2016-10-03 32 3993baeb3c52f4 Darrick J. Wong 2016-10-03 33 /* 3993baeb3c52f4 Darrick J. Wong 2016-10-03 34 * Copy on Write of Shared Blocks 3993baeb3c52f4 Darrick J. Wong 2016-10-03 35 * 3993baeb3c52f4 Darrick J. Wong 2016-10-03 36 * XFS must preserve "the usual" file semantics even when two files share 3993baeb3c52f4 Darrick J. Wong 2016-10-03 37 * the same physical blocks. This means that a write to one file must not 3993baeb3c52f4 Darrick J. Wong 2016-10-03 38 * alter the blocks in a different file; the way that we'll do that is 3993baeb3c52f4 Darrick J. Wong 2016-10-03 39 * through the use of a copy-on-write mechanism. At a high level, that 3993baeb3c52f4 Darrick J. Wong 2016-10-03 40 * means that when we want to write to a shared block, we allocate a new 3993baeb3c52f4 Darrick J. Wong 2016-10-03 41 * block, write the data to the new block, and if that succeeds we map the 3993baeb3c52f4 Darrick J. Wong 2016-10-03 42 * new block into the file. 3993baeb3c52f4 Darrick J. Wong 2016-10-03 43 * 3993baeb3c52f4 Darrick J. Wong 2016-10-03 44 * XFS provides a "delayed allocation" mechanism that defers the allocation 3993baeb3c52f4 Darrick J. Wong 2016-10-03 45 * of disk blocks to dirty-but-not-yet-mapped file blocks as long as 3993baeb3c52f4 Darrick J. Wong 2016-10-03 46 * possible. This reduces fragmentation by enabling the filesystem to ask 3993baeb3c52f4 Darrick J. Wong 2016-10-03 47 * for bigger chunks less often, which is exactly what we want for CoW. 3993baeb3c52f4 Darrick J. Wong 2016-10-03 48 * 3993baeb3c52f4 Darrick J. Wong 2016-10-03 49 * The delalloc mechanism begins when the kernel wants to make a block 3993baeb3c52f4 Darrick J. Wong 2016-10-03 50 * writable (write_begin or page_mkwrite). If the offset is not mapped, we 3993baeb3c52f4 Darrick J. Wong 2016-10-03 51 * create a delalloc mapping, which is a regular in-core extent, but without 3993baeb3c52f4 Darrick J. Wong 2016-10-03 52 * a real startblock. (For delalloc mappings, the startblock encodes both 3993baeb3c52f4 Darrick J. Wong 2016-10-03 53 * a flag that this is a delalloc mapping, and a worst-case estimate of how 3993baeb3c52f4 Darrick J. Wong 2016-10-03 54 * many blocks might be required to put the mapping into the BMBT.) delalloc 3993baeb3c52f4 Darrick J. Wong 2016-10-03 55 * mappings are a reservation against the free space in the filesystem; 3993baeb3c52f4 Darrick J. Wong 2016-10-03 56 * adjacent mappings can also be combined into fewer larger mappings. 3993baeb3c52f4 Darrick J. Wong 2016-10-03 57 * 5eda43000064a6 Darrick J. Wong 2017-02-02 58 * As an optimization, the CoW extent size hint (cowextsz) creates 5eda43000064a6 Darrick J. Wong 2017-02-02 59 * outsized aligned delalloc reservations in the hope of landing out of 5eda43000064a6 Darrick J. Wong 2017-02-02 60 * order nearby CoW writes in a single extent on disk, thereby reducing 5eda43000064a6 Darrick J. Wong 2017-02-02 61 * fragmentation and improving future performance. 5eda43000064a6 Darrick J. Wong 2017-02-02 62 * 5eda43000064a6 Darrick J. Wong 2017-02-02 63 * D: --RRRRRRSSSRRRRRRRR--- (data fork) 5eda43000064a6 Darrick J. Wong 2017-02-02 64 * C: ------DDDDDDD--------- (CoW fork) 5eda43000064a6 Darrick J. Wong 2017-02-02 65 * 3993baeb3c52f4 Darrick J. Wong 2016-10-03 66 * When dirty pages are being written out (typically in writepage), the 5eda43000064a6 Darrick J. Wong 2017-02-02 67 * delalloc reservations are converted into unwritten mappings by 5eda43000064a6 Darrick J. Wong 2017-02-02 68 * allocating blocks and replacing the delalloc mapping with real ones. 5eda43000064a6 Darrick J. Wong 2017-02-02 69 * A delalloc mapping can be replaced by several unwritten ones if the 5eda43000064a6 Darrick J. Wong 2017-02-02 70 * free space is fragmented. 5eda43000064a6 Darrick J. Wong 2017-02-02 71 * 5eda43000064a6 Darrick J. Wong 2017-02-02 72 * D: --RRRRRRSSSRRRRRRRR--- 5eda43000064a6 Darrick J. Wong 2017-02-02 73 * C: ------UUUUUUU--------- 3993baeb3c52f4 Darrick J. Wong 2016-10-03 74 * 3993baeb3c52f4 Darrick J. Wong 2016-10-03 75 * We want to adapt the delalloc mechanism for copy-on-write, since the 3993baeb3c52f4 Darrick J. Wong 2016-10-03 76 * write paths are similar. The first two steps (creating the reservation 3993baeb3c52f4 Darrick J. Wong 2016-10-03 77 * and allocating the blocks) are exactly the same as delalloc except that 3993baeb3c52f4 Darrick J. Wong 2016-10-03 78 * the mappings must be stored in a separate CoW fork because we do not want 3993baeb3c52f4 Darrick J. Wong 2016-10-03 79 * to disturb the mapping in the data fork until we're sure that the write 3993baeb3c52f4 Darrick J. Wong 2016-10-03 80 * succeeded. IO completion in this case is the process of removing the old 3993baeb3c52f4 Darrick J. Wong 2016-10-03 81 * mapping from the data fork and moving the new mapping from the CoW fork to 3993baeb3c52f4 Darrick J. Wong 2016-10-03 82 * the data fork. This will be discussed shortly. 3993baeb3c52f4 Darrick J. Wong 2016-10-03 83 * 3993baeb3c52f4 Darrick J. Wong 2016-10-03 84 * For now, unaligned directio writes will be bounced back to the page cache. 3993baeb3c52f4 Darrick J. Wong 2016-10-03 85 * Block-aligned directio writes will use the same mechanism as buffered 3993baeb3c52f4 Darrick J. Wong 2016-10-03 86 * writes. 3993baeb3c52f4 Darrick J. Wong 2016-10-03 87 * 5eda43000064a6 Darrick J. Wong 2017-02-02 88 * Just prior to submitting the actual disk write requests, we convert 5eda43000064a6 Darrick J. Wong 2017-02-02 89 * the extents representing the range of the file actually being written 5eda43000064a6 Darrick J. Wong 2017-02-02 90 * (as opposed to extra pieces created for the cowextsize hint) to real 5eda43000064a6 Darrick J. Wong 2017-02-02 91 * extents. This will become important in the next step: 5eda43000064a6 Darrick J. Wong 2017-02-02 92 * 5eda43000064a6 Darrick J. Wong 2017-02-02 93 * D: --RRRRRRSSSRRRRRRRR--- 5eda43000064a6 Darrick J. Wong 2017-02-02 94 * C: ------UUrrUUU--------- 5eda43000064a6 Darrick J. Wong 2017-02-02 95 * 3993baeb3c52f4 Darrick J. Wong 2016-10-03 96 * CoW remapping must be done after the data block write completes, 3993baeb3c52f4 Darrick J. Wong 2016-10-03 97 * because we don't want to destroy the old data fork map until we're sure 3993baeb3c52f4 Darrick J. Wong 2016-10-03 98 * the new block has been written. Since the new mappings are kept in a 3993baeb3c52f4 Darrick J. Wong 2016-10-03 99 * separate fork, we can simply iterate these mappings to find the ones 3993baeb3c52f4 Darrick J. Wong 2016-10-03 100 * that cover the file blocks that we just CoW'd. For each extent, simply 3993baeb3c52f4 Darrick J. Wong 2016-10-03 101 * unmap the corresponding range in the data fork, map the new range into 5eda43000064a6 Darrick J. Wong 2017-02-02 102 * the data fork, and remove the extent from the CoW fork. Because of 5eda43000064a6 Darrick J. Wong 2017-02-02 103 * the presence of the cowextsize hint, however, we must be careful 5eda43000064a6 Darrick J. Wong 2017-02-02 104 * only to remap the blocks that we've actually written out -- we must 5eda43000064a6 Darrick J. Wong 2017-02-02 105 * never remap delalloc reservations nor CoW staging blocks that have 5eda43000064a6 Darrick J. Wong 2017-02-02 106 * yet to be written. This corresponds exactly to the real extents in 5eda43000064a6 Darrick J. Wong 2017-02-02 107 * the CoW fork: 5eda43000064a6 Darrick J. Wong 2017-02-02 108 * 5eda43000064a6 Darrick J. Wong 2017-02-02 109 * D: --RRRRRRrrSRRRRRRRR--- 5eda43000064a6 Darrick J. Wong 2017-02-02 110 * C: ------UU--UUU--------- 3993baeb3c52f4 Darrick J. Wong 2016-10-03 111 * 3993baeb3c52f4 Darrick J. Wong 2016-10-03 112 * Since the remapping operation can be applied to an arbitrary file 3993baeb3c52f4 Darrick J. Wong 2016-10-03 113 * range, we record the need for the remap step as a flag in the ioend 3993baeb3c52f4 Darrick J. Wong 2016-10-03 114 * instead of declaring a new IO type. This is required for direct io 3993baeb3c52f4 Darrick J. Wong 2016-10-03 115 * because we only have ioend for the whole dio, and we have to be able to 3993baeb3c52f4 Darrick J. Wong 2016-10-03 116 * remember the presence of unwritten blocks and CoW blocks with a single 3993baeb3c52f4 Darrick J. Wong 2016-10-03 117 * ioend structure. Better yet, the more ground we can cover with one 3993baeb3c52f4 Darrick J. Wong 2016-10-03 118 * ioend, the better. 3993baeb3c52f4 Darrick J. Wong 2016-10-03 119 */ 2a06705cd59540 Darrick J. Wong 2016-10-03 120 2a06705cd59540 Darrick J. Wong 2016-10-03 121 /* 2a06705cd59540 Darrick J. Wong 2016-10-03 122 * Given an AG extent, find the lowest-numbered run of shared blocks 2a06705cd59540 Darrick J. Wong 2016-10-03 123 * within that range and return the range in fbno/flen. If 2a06705cd59540 Darrick J. Wong 2016-10-03 124 * find_end_of_shared is true, return the longest contiguous extent of 2a06705cd59540 Darrick J. Wong 2016-10-03 125 * shared blocks. If there are no shared extents, fbno and flen will 2a06705cd59540 Darrick J. Wong 2016-10-03 126 * be set to NULLAGBLOCK and 0, respectively. 2a06705cd59540 Darrick J. Wong 2016-10-03 127 */ 2a06705cd59540 Darrick J. Wong 2016-10-03 128 int 2a06705cd59540 Darrick J. Wong 2016-10-03 @129 xfs_reflink_find_shared( bf14ac7fff281f Dave Chinner 2021-12-03 130 struct xfs_perag *pag, 92ff7285f1df55 Darrick J. Wong 2017-06-16 131 struct xfs_trans *tp, 2a06705cd59540 Darrick J. Wong 2016-10-03 132 xfs_agblock_t agbno, 2a06705cd59540 Darrick J. Wong 2016-10-03 133 xfs_extlen_t aglen, 2a06705cd59540 Darrick J. Wong 2016-10-03 134 xfs_agblock_t *fbno, 2a06705cd59540 Darrick J. Wong 2016-10-03 135 xfs_extlen_t *flen, 2a06705cd59540 Darrick J. Wong 2016-10-03 136 bool find_end_of_shared) 2a06705cd59540 Darrick J. Wong 2016-10-03 137 { 2a06705cd59540 Darrick J. Wong 2016-10-03 138 struct xfs_buf *agbp; 2a06705cd59540 Darrick J. Wong 2016-10-03 139 struct xfs_btree_cur *cur; 2a06705cd59540 Darrick J. Wong 2016-10-03 140 int error; 2a06705cd59540 Darrick J. Wong 2016-10-03 141 bf14ac7fff281f Dave Chinner 2021-12-03 142 error = xfs_alloc_read_agf(pag, tp, 0, &agbp); 2a06705cd59540 Darrick J. Wong 2016-10-03 143 if (error) 2a06705cd59540 Darrick J. Wong 2016-10-03 144 return error; 2a06705cd59540 Darrick J. Wong 2016-10-03 145 bf14ac7fff281f Dave Chinner 2021-12-03 146 cur = xfs_refcountbt_init_cursor(pag->pag_mount, tp, agbp, pag); 2a06705cd59540 Darrick J. Wong 2016-10-03 147 2a06705cd59540 Darrick J. Wong 2016-10-03 148 error = xfs_refcount_find_shared(cur, agbno, aglen, fbno, flen, 2a06705cd59540 Darrick J. Wong 2016-10-03 149 find_end_of_shared); 2a06705cd59540 Darrick J. Wong 2016-10-03 150 0b04b6b875b32f Darrick J. Wong 2018-07-19 151 xfs_btree_del_cursor(cur, error); 2a06705cd59540 Darrick J. Wong 2016-10-03 152 92ff7285f1df55 Darrick J. Wong 2017-06-16 153 xfs_trans_brelse(tp, agbp); 2a06705cd59540 Darrick J. Wong 2016-10-03 154 return error; 2a06705cd59540 Darrick J. Wong 2016-10-03 155 } 2a06705cd59540 Darrick J. Wong 2016-10-03 156 --- 0-DAY CI Kernel Test Service, Intel Corporation https://lists.01.org/hyperkitty/list/kbuild-all@xxxxxxxxxxxx
