From 45feef8f50b94d56d6a433ad5baf5cdf58e3db98 Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 20 Nov 2019 10:18:44 -0800 Subject: [PATCH] xfs: refactor xfs_dabuf_map Merge xfs_buf_map_from_irec and xfs_da_map_covers_blocks into a single loop in the caller. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/libxfs/xfs_da_btree.c | 166 +++++++++++++---------------------- 1 file changed, 59 insertions(+), 107 deletions(-) diff --git a/fs/xfs/libxfs/xfs_da_btree.c b/fs/xfs/libxfs/xfs_da_btree.c index f3087f061a48..e078817fc26c 100644 --- a/fs/xfs/libxfs/xfs_da_btree.c +++ b/fs/xfs/libxfs/xfs_da_btree.c @@ -2460,74 +2460,6 @@ xfs_da_shrink_inode( return error; } -/* - * See if the mapping(s) for this btree block are valid, i.e. - * don't contain holes, are logically contiguous, and cover the whole range. - */ -STATIC int -xfs_da_map_covers_blocks( - int nmap, - xfs_bmbt_irec_t *mapp, - xfs_dablk_t bno, - int count) -{ - int i; - xfs_fileoff_t off; - - for (i = 0, off = bno; i < nmap; i++) { - if (mapp[i].br_startblock == HOLESTARTBLOCK || - mapp[i].br_startblock == DELAYSTARTBLOCK) { - return 0; - } - if (off != mapp[i].br_startoff) { - return 0; - } - off += mapp[i].br_blockcount; - } - return off == bno + count; -} - -/* - * Convert a struct xfs_bmbt_irec to a struct xfs_buf_map. - * - * For the single map case, it is assumed that the caller has provided a pointer - * to a valid xfs_buf_map. For the multiple map case, this function will - * allocate the xfs_buf_map to hold all the maps and replace the caller's single - * map pointer with the allocated map. - */ -static int -xfs_buf_map_from_irec( - struct xfs_mount *mp, - struct xfs_buf_map **mapp, - int *nmaps, - struct xfs_bmbt_irec *irecs, - int nirecs) -{ - struct xfs_buf_map *map; - int i; - - ASSERT(*nmaps == 1); - ASSERT(nirecs >= 1); - - if (nirecs > 1) { - map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), - KM_NOFS); - if (!map) - return -ENOMEM; - *mapp = map; - } - - *nmaps = nirecs; - map = *mapp; - for (i = 0; i < *nmaps; i++) { - ASSERT(irecs[i].br_startblock != DELAYSTARTBLOCK && - irecs[i].br_startblock != HOLESTARTBLOCK); - map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock); - map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount); - } - return 0; -} - /* * Map the block we are given ready for reading. There are three possible return * values: @@ -2542,58 +2474,78 @@ xfs_dabuf_map( xfs_dablk_t bno, xfs_daddr_t mappedbno, int whichfork, - struct xfs_buf_map **map, + struct xfs_buf_map **mapp, int *nmaps) { struct xfs_mount *mp = dp->i_mount; int nfsb = xfs_dabuf_nfsb(mp, whichfork); - int error = 0; - struct xfs_bmbt_irec irec; - struct xfs_bmbt_irec *irecs = &irec; - int nirecs; + struct xfs_bmbt_irec irec, *irecs = &irec; + struct xfs_buf_map *map = *mapp; + xfs_fileoff_t off = bno; + int error = 0, nirecs, i; - ASSERT(map && *map); - ASSERT(*nmaps == 1); - - if (nfsb != 1) + if (nfsb > 1) irecs = kmem_zalloc(sizeof(irec) * nfsb, KM_NOFS); + nirecs = nfsb; - error = xfs_bmapi_read(dp, (xfs_fileoff_t)bno, nfsb, irecs, - &nirecs, xfs_bmapi_aflag(whichfork)); + error = xfs_bmapi_read(dp, bno, nfsb, irecs, &nirecs, + xfs_bmapi_aflag(whichfork)); if (error) - goto out; + goto out_free_irecs; - if (!xfs_da_map_covers_blocks(nirecs, irecs, bno, nfsb)) { - /* Caller ok with no mapping. */ - if (!XFS_IS_CORRUPT(mp, mappedbno != -2)) { - error = -1; - goto out; - } - - /* Caller expected a mapping, so abort. */ - if (xfs_error_level >= XFS_ERRLEVEL_LOW) { - int i; - - xfs_alert(mp, "%s: bno %lld dir: inode %lld", __func__, - (long long)bno, (long long)dp->i_ino); - for (i = 0; i < *nmaps; i++) { - xfs_alert(mp, -"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d", - i, - (long long)irecs[i].br_startoff, - (long long)irecs[i].br_startblock, - (long long)irecs[i].br_blockcount, - irecs[i].br_state); - } - } - error = -EFSCORRUPTED; - goto out; + /* + * Use the caller provided map for the single map case, else allocate a + * larger one that needs to be free by the caller. + */ + if (nirecs > 1) { + map = kmem_zalloc(nirecs * sizeof(struct xfs_buf_map), KM_NOFS); + if (!map) + goto out_free_irecs; + *mapp = map; } - error = xfs_buf_map_from_irec(mp, map, nmaps, irecs, nirecs); -out: + + for (i = 0; i < nirecs; i++) { + if (irecs[i].br_startblock == HOLESTARTBLOCK || + irecs[i].br_startblock == DELAYSTARTBLOCK) + goto invalid_mapping; + if (off != irecs[i].br_startoff) + goto invalid_mapping; + + map[i].bm_bn = XFS_FSB_TO_DADDR(mp, irecs[i].br_startblock); + map[i].bm_len = XFS_FSB_TO_BB(mp, irecs[i].br_blockcount); + off += irecs[i].br_blockcount; + } + + if (off != bno + nfsb) + goto invalid_mapping; + + *nmaps = nirecs; +out_free_irecs: if (irecs != &irec) kmem_free(irecs); return error; + +invalid_mapping: + /* Caller ok with no mapping. */ + if (XFS_IS_CORRUPT(mp, mappedbno != -2)) { + error = -EFSCORRUPTED; + if (xfs_error_level >= XFS_ERRLEVEL_LOW) { + xfs_alert(mp, "%s: bno %u inode %llu", + __func__, bno, dp->i_ino); + + for (i = 0; i < nirecs; i++) { + xfs_alert(mp, +"[%02d] br_startoff %lld br_startblock %lld br_blockcount %lld br_state %d", + i, irecs[i].br_startoff, + irecs[i].br_startblock, + irecs[i].br_blockcount, + irecs[i].br_state); + } + } + } else { + *nmaps = 0; + } + goto out_free_irecs; } /*