From fb7d9267692a5cdc01648bf4c8fdca51054bc0f2 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Wed, 3 Aug 2016 12:03:19 +1000 Subject: [PATCH] xfs: convert unwritten status of reverse mappings Provide a function to convert an unwritten rmap extent to a real one and vice versa. [ dchinner: Note that this algorithm and code was derived from the existing bmapbt unwritten extent conversion code in xfs_bmap_add_extent_unwritten_real(). ] Signed-off-by: Darrick J. Wong Reviewed-by: Dave Chinner Signed-off-by: Dave Chinner --- fs/xfs/libxfs/xfs_rmap.c | 441 +++++++++++++++++++++++++++++++++++++++++++++++ fs/xfs/xfs_trace.h | 5 + 2 files changed, 446 insertions(+) diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c index 1e48a0b..7439272 100644 --- a/fs/xfs/libxfs/xfs_rmap.c +++ b/fs/xfs/libxfs/xfs_rmap.c @@ -610,6 +610,447 @@ out_error: return error; } +#define RMAP_LEFT_CONTIG (1 << 0) +#define RMAP_RIGHT_CONTIG (1 << 1) +#define RMAP_LEFT_FILLING (1 << 2) +#define RMAP_RIGHT_FILLING (1 << 3) +#define RMAP_LEFT_VALID (1 << 6) +#define RMAP_RIGHT_VALID (1 << 7) + +#define LEFT r[0] +#define RIGHT r[1] +#define PREV r[2] +#define NEW r[3] + +/* + * Convert an unwritten extent to a real extent or vice versa. + * Does not handle overlapping extents. + */ +STATIC int +xfs_rmap_convert( + struct xfs_btree_cur *cur, + xfs_agblock_t bno, + xfs_extlen_t len, + bool unwritten, + struct xfs_owner_info *oinfo) +{ + struct xfs_mount *mp = cur->bc_mp; + struct xfs_rmap_irec r[4]; /* neighbor extent entries */ + /* left is 0, right is 1, prev is 2 */ + /* new is 3 */ + uint64_t owner; + uint64_t offset; + uint64_t new_endoff; + unsigned int oldext; + unsigned int newext; + unsigned int flags = 0; + int i; + int state = 0; + int error; + + xfs_owner_info_unpack(oinfo, &owner, &offset, &flags); + ASSERT(!(XFS_RMAP_NON_INODE_OWNER(owner) || + (flags & (XFS_RMAP_ATTR_FORK | XFS_RMAP_BMBT_BLOCK)))); + oldext = unwritten ? XFS_RMAP_UNWRITTEN : 0; + new_endoff = offset + len; + trace_xfs_rmap_convert(mp, cur->bc_private.a.agno, bno, len, + unwritten, oinfo); + + /* + * For the initial lookup, look for an exact match or the left-adjacent + * record for our insertion point. This will also give us the record for + * start block contiguity tests. + */ + error = xfs_rmap_lookup_le(cur, bno, len, owner, offset, oldext, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + + error = xfs_rmap_get_rec(cur, &PREV, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + trace_xfs_rmap_lookup_le_range_result(cur->bc_mp, + cur->bc_private.a.agno, PREV.rm_startblock, + PREV.rm_blockcount, PREV.rm_owner, + PREV.rm_offset, PREV.rm_flags); + + ASSERT(PREV.rm_offset <= offset); + ASSERT(PREV.rm_offset + PREV.rm_blockcount >= new_endoff); + ASSERT((PREV.rm_flags & XFS_RMAP_UNWRITTEN) == oldext); + newext = ~oldext & XFS_RMAP_UNWRITTEN; + + /* + * Set flags determining what part of the previous oldext allocation + * extent is being replaced by a newext allocation. + */ + if (PREV.rm_offset == offset) + state |= RMAP_LEFT_FILLING; + if (PREV.rm_offset + PREV.rm_blockcount == new_endoff) + state |= RMAP_RIGHT_FILLING; + + /* + * Decrement the cursor to see if we have a left-adjacent record to our + * insertion point. This will give us the record for end block + * contiguity tests. + */ + error = xfs_btree_decrement(cur, 0, &i); + if (error) + goto done; + if (i) { + state |= RMAP_LEFT_VALID; + error = xfs_rmap_get_rec(cur, &LEFT, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + XFS_WANT_CORRUPTED_GOTO(mp, + LEFT.rm_startblock + LEFT.rm_blockcount <= bno, + done); + trace_xfs_rmap_find_left_neighbor_result(cur->bc_mp, + cur->bc_private.a.agno, LEFT.rm_startblock, + LEFT.rm_blockcount, LEFT.rm_owner, + LEFT.rm_offset, LEFT.rm_flags); + if (LEFT.rm_startblock + LEFT.rm_blockcount == bno && + LEFT.rm_offset + LEFT.rm_blockcount == offset && + xfs_rmap_is_mergeable(&LEFT, owner, newext)) + state |= RMAP_LEFT_CONTIG; + } + + /* + * Increment the cursor to see if we have a right-adjacent record to our + * insertion point. This will give us the record for end block + * contiguity tests. + */ + error = xfs_btree_increment(cur, 0, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + error = xfs_btree_increment(cur, 0, &i); + if (error) + goto done; + if (i) { + state |= RMAP_RIGHT_VALID; + error = xfs_rmap_get_rec(cur, &RIGHT, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + XFS_WANT_CORRUPTED_GOTO(mp, bno + len <= RIGHT.rm_startblock, + done); + trace_xfs_rmap_find_right_neighbor_result(cur->bc_mp, + cur->bc_private.a.agno, RIGHT.rm_startblock, + RIGHT.rm_blockcount, RIGHT.rm_owner, + RIGHT.rm_offset, RIGHT.rm_flags); + if (bno + len == RIGHT.rm_startblock && + offset + len == RIGHT.rm_offset && + xfs_rmap_is_mergeable(&RIGHT, owner, newext)) + state |= RMAP_RIGHT_CONTIG; + } + + /* check that left + prev + right is not too long */ + if ((state & (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG | + RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG)) == + (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG | + RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG) && + (unsigned long)LEFT.rm_blockcount + len + + RIGHT.rm_blockcount > XFS_RMAP_LEN_MAX) + state &= ~RMAP_RIGHT_CONTIG; + + trace_xfs_rmap_convert_state(mp, cur->bc_private.a.agno, state, + _RET_IP_); + + /* reset the cursor back to PREV */ + error = xfs_rmap_lookup_le(cur, bno, len, owner, offset, oldext, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + + /* + * Switch out based on the FILLING and CONTIG state bits. + */ + switch (state & (RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG | + RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG)) { + case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG | + RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG: + /* + * Setting all of a previous oldext extent to newext. + * The left and right neighbors are both contiguous with new. + */ + error = xfs_btree_increment(cur, 0, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + trace_xfs_rmap_delete(mp, cur->bc_private.a.agno, + RIGHT.rm_startblock, RIGHT.rm_blockcount, + RIGHT.rm_owner, RIGHT.rm_offset, + RIGHT.rm_flags); + error = xfs_btree_delete(cur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + error = xfs_btree_decrement(cur, 0, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + trace_xfs_rmap_delete(mp, cur->bc_private.a.agno, + PREV.rm_startblock, PREV.rm_blockcount, + PREV.rm_owner, PREV.rm_offset, + PREV.rm_flags); + error = xfs_btree_delete(cur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + error = xfs_btree_decrement(cur, 0, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + NEW = LEFT; + NEW.rm_blockcount += PREV.rm_blockcount + RIGHT.rm_blockcount; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + break; + + case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG: + /* + * Setting all of a previous oldext extent to newext. + * The left neighbor is contiguous, the right is not. + */ + trace_xfs_rmap_delete(mp, cur->bc_private.a.agno, + PREV.rm_startblock, PREV.rm_blockcount, + PREV.rm_owner, PREV.rm_offset, + PREV.rm_flags); + error = xfs_btree_delete(cur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + error = xfs_btree_decrement(cur, 0, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + NEW = LEFT; + NEW.rm_blockcount += PREV.rm_blockcount; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + break; + + case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG: + /* + * Setting all of a previous oldext extent to newext. + * The right neighbor is contiguous, the left is not. + */ + error = xfs_btree_increment(cur, 0, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + trace_xfs_rmap_delete(mp, cur->bc_private.a.agno, + RIGHT.rm_startblock, RIGHT.rm_blockcount, + RIGHT.rm_owner, RIGHT.rm_offset, + RIGHT.rm_flags); + error = xfs_btree_delete(cur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + error = xfs_btree_decrement(cur, 0, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + NEW = PREV; + NEW.rm_blockcount = len + RIGHT.rm_blockcount; + NEW.rm_flags = newext; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + break; + + case RMAP_LEFT_FILLING | RMAP_RIGHT_FILLING: + /* + * Setting all of a previous oldext extent to newext. + * Neither the left nor right neighbors are contiguous with + * the new one. + */ + NEW = PREV; + NEW.rm_flags = newext; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + break; + + case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG: + /* + * Setting the first part of a previous oldext extent to newext. + * The left neighbor is contiguous. + */ + NEW = PREV; + NEW.rm_offset += len; + NEW.rm_startblock += len; + NEW.rm_blockcount -= len; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + error = xfs_btree_decrement(cur, 0, &i); + if (error) + goto done; + NEW = LEFT; + NEW.rm_blockcount += len; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + break; + + case RMAP_LEFT_FILLING: + /* + * Setting the first part of a previous oldext extent to newext. + * The left neighbor is not contiguous. + */ + NEW = PREV; + NEW.rm_startblock += len; + NEW.rm_offset += len; + NEW.rm_blockcount -= len; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + NEW.rm_startblock = bno; + NEW.rm_owner = owner; + NEW.rm_offset = offset; + NEW.rm_blockcount = len; + NEW.rm_flags = newext; + cur->bc_rec.r = NEW; + trace_xfs_rmap_insert(mp, cur->bc_private.a.agno, bno, + len, owner, offset, newext); + error = xfs_btree_insert(cur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + break; + + case RMAP_RIGHT_FILLING | RMAP_RIGHT_CONTIG: + /* + * Setting the last part of a previous oldext extent to newext. + * The right neighbor is contiguous with the new allocation. + */ + NEW = PREV; + NEW.rm_blockcount -= len; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + error = xfs_btree_increment(cur, 0, &i); + if (error) + goto done; + NEW = RIGHT; + NEW.rm_offset = offset; + NEW.rm_startblock = bno; + NEW.rm_blockcount += len; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + break; + + case RMAP_RIGHT_FILLING: + /* + * Setting the last part of a previous oldext extent to newext. + * The right neighbor is not contiguous. + */ + NEW = PREV; + NEW.rm_blockcount -= len; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + error = xfs_rmap_lookup_eq(cur, bno, len, owner, offset, + oldext, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done); + NEW.rm_startblock = bno; + NEW.rm_owner = owner; + NEW.rm_offset = offset; + NEW.rm_blockcount = len; + NEW.rm_flags = newext; + cur->bc_rec.r = NEW; + trace_xfs_rmap_insert(mp, cur->bc_private.a.agno, bno, + len, owner, offset, newext); + error = xfs_btree_insert(cur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + break; + + case 0: + /* + * Setting the middle part of a previous oldext extent to + * newext. Contiguity is impossible here. + * One extent becomes three extents. + */ + /* new right extent - oldext */ + NEW.rm_startblock = bno + len; + NEW.rm_owner = owner; + NEW.rm_offset = new_endoff; + NEW.rm_blockcount = PREV.rm_offset + PREV.rm_blockcount - + new_endoff; + NEW.rm_flags = PREV.rm_flags; + error = xfs_rmap_update(cur, &NEW); + if (error) + goto done; + /* new left extent - oldext */ + NEW = PREV; + NEW.rm_blockcount = offset - PREV.rm_offset; + cur->bc_rec.r = NEW; + trace_xfs_rmap_insert(mp, cur->bc_private.a.agno, + NEW.rm_startblock, NEW.rm_blockcount, + NEW.rm_owner, NEW.rm_offset, + NEW.rm_flags); + error = xfs_btree_insert(cur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + /* + * Reset the cursor to the position of the new extent + * we are about to insert as we can't trust it after + * the previous insert. + */ + error = xfs_rmap_lookup_eq(cur, bno, len, owner, offset, + oldext, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 0, done); + /* new middle extent - newext */ + cur->bc_rec.r.rm_flags &= ~XFS_RMAP_UNWRITTEN; + cur->bc_rec.r.rm_flags |= newext; + trace_xfs_rmap_insert(mp, cur->bc_private.a.agno, bno, len, + owner, offset, newext); + error = xfs_btree_insert(cur, &i); + if (error) + goto done; + XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done); + break; + + case RMAP_LEFT_FILLING | RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG: + case RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG: + case RMAP_LEFT_FILLING | RMAP_RIGHT_CONTIG: + case RMAP_RIGHT_FILLING | RMAP_LEFT_CONTIG: + case RMAP_LEFT_CONTIG | RMAP_RIGHT_CONTIG: + case RMAP_LEFT_CONTIG: + case RMAP_RIGHT_CONTIG: + /* + * These cases are all impossible. + */ + ASSERT(0); + } + + trace_xfs_rmap_convert_done(mp, cur->bc_private.a.agno, bno, len, + unwritten, oinfo); +done: + if (error) + trace_xfs_rmap_convert_error(cur->bc_mp, + cur->bc_private.a.agno, error, _RET_IP_); + return error; +} + +#undef NEW +#undef LEFT +#undef RIGHT +#undef PREV + struct xfs_rmap_query_range_info { xfs_rmap_query_range_fn fn; void *priv; diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index e099eda..551b7e2 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -2499,6 +2499,10 @@ DEFINE_AG_ERROR_EVENT(xfs_rmap_unmap_error); DEFINE_RMAP_EVENT(xfs_rmap_map); DEFINE_RMAP_EVENT(xfs_rmap_map_done); DEFINE_AG_ERROR_EVENT(xfs_rmap_map_error); +DEFINE_RMAP_EVENT(xfs_rmap_convert); +DEFINE_RMAP_EVENT(xfs_rmap_convert_done); +DEFINE_AG_ERROR_EVENT(xfs_rmap_convert_error); +DEFINE_AG_ERROR_EVENT(xfs_rmap_convert_state); DECLARE_EVENT_CLASS(xfs_rmapbt_class, TP_PROTO(struct xfs_mount *mp, xfs_agnumber_t agno, @@ -2553,6 +2557,7 @@ DEFINE_AG_ERROR_EVENT(xfs_rmap_delete_error); DEFINE_AG_ERROR_EVENT(xfs_rmap_update_error); DEFINE_RMAPBT_EVENT(xfs_rmap_lookup_le_range_result); DEFINE_RMAPBT_EVENT(xfs_rmap_find_right_neighbor_result); +DEFINE_RMAPBT_EVENT(xfs_rmap_find_left_neighbor_result); #endif /* _TRACE_XFS_H */ -- 2.7.4