xfs: convert unwritten status of reverse mappings for shared files

Provide a function to convert an unwritten extent to a real one and
vice versa when shared extents are possible.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

diff --git a/fs/xfs/libxfs/xfs_rmap.c b/fs/xfs/libxfs/xfs_rmap.c
index bb5e2f8..3a8cc71 100644 (file)
--- a/fs/xfs/libxfs/xfs_rmap.c
+++ b/fs/xfs/libxfs/xfs_rmap.c
@@ -1278,6 +1278,384 @@ done:
        return error;
 }
 
+/*
+ * Convert an unwritten extent to a real extent or vice versa.  If there is no
+ * possibility of overlapping extents, delegate to the simpler convert
+ * function.
+ */
+STATIC int
+xfs_rmap_convert_shared(
+       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 and 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_range(cur, bno, owner, offset, flags,
+                       &PREV, &i);
+       XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+
+       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;
+
+       /* Is there a left record that abuts our range? */
+       error = xfs_rmap_find_left_neighbor(cur, bno, owner, offset, newext,
+                       &LEFT, &i);
+       if (error)
+               goto done;
+       if (i) {
+               state |= RMAP_LEFT_VALID;
+               XFS_WANT_CORRUPTED_GOTO(mp,
+                               LEFT.rm_startblock + LEFT.rm_blockcount <= bno,
+                               done);
+               if (xfs_rmap_is_mergeable(&LEFT, owner, newext))
+                       state |= RMAP_LEFT_CONTIG;
+       }
+
+       /* Is there a right record that abuts our range? */
+       error = xfs_rmap_lookup_eq(cur, bno + len, len, owner, offset + len,
+                       newext, &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 (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_);
+       /*
+        * 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_rmap_delete(cur, RIGHT.rm_startblock,
+                               RIGHT.rm_blockcount, RIGHT.rm_owner,
+                               RIGHT.rm_offset, RIGHT.rm_flags);
+               if (error)
+                       goto done;
+               error = xfs_rmap_delete(cur, PREV.rm_startblock,
+                               PREV.rm_blockcount, PREV.rm_owner,
+                               PREV.rm_offset, PREV.rm_flags);
+               if (error)
+                       goto done;
+               NEW = LEFT;
+               error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags, &i);
+               if (error)
+                       goto done;
+               XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+               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.
+                */
+               error = xfs_rmap_delete(cur, PREV.rm_startblock,
+                               PREV.rm_blockcount, PREV.rm_owner,
+                               PREV.rm_offset, PREV.rm_flags);
+               if (error)
+                       goto done;
+               NEW = LEFT;
+               error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags, &i);
+               if (error)
+                       goto done;
+               XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+               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_rmap_delete(cur, RIGHT.rm_startblock,
+                               RIGHT.rm_blockcount, RIGHT.rm_owner,
+                               RIGHT.rm_offset, RIGHT.rm_flags);
+               if (error)
+                       goto done;
+               NEW = PREV;
+               error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags, &i);
+               if (error)
+                       goto done;
+               XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+               NEW.rm_blockcount += RIGHT.rm_blockcount;
+               NEW.rm_flags = RIGHT.rm_flags;
+               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;
+               error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags, &i);
+               if (error)
+                       goto done;
+               XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+               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;
+               error = xfs_rmap_delete(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags);
+               if (error)
+                       goto done;
+               NEW.rm_offset += len;
+               NEW.rm_startblock += len;
+               NEW.rm_blockcount -= len;
+               error = xfs_rmap_insert(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags);
+               if (error)
+                       goto done;
+               NEW = LEFT;
+               error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags, &i);
+               if (error)
+                       goto done;
+               XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+               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;
+               error = xfs_rmap_delete(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags);
+               if (error)
+                       goto done;
+               NEW.rm_offset += len;
+               NEW.rm_startblock += len;
+               NEW.rm_blockcount -= len;
+               error = xfs_rmap_insert(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags);
+               if (error)
+                       goto done;
+               error = xfs_rmap_insert(cur, bno, len, owner, offset, newext);
+               if (error)
+                       goto 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;
+               error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags, &i);
+               if (error)
+                       goto done;
+               XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+               NEW.rm_blockcount = offset - NEW.rm_offset;
+               error = xfs_rmap_update(cur, &NEW);
+               if (error)
+                       goto done;
+               NEW = RIGHT;
+               error = xfs_rmap_delete(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags);
+               if (error)
+                       goto done;
+               NEW.rm_offset = offset;
+               NEW.rm_startblock = bno;
+               NEW.rm_blockcount += len;
+               error = xfs_rmap_insert(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags);
+               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;
+               error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags, &i);
+               if (error)
+                       goto done;
+               XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+               NEW.rm_blockcount -= len;
+               error = xfs_rmap_update(cur, &NEW);
+               if (error)
+                       goto done;
+               error = xfs_rmap_insert(cur, bno, len, owner, offset, newext);
+               if (error)
+                       goto 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_insert(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner, NEW.rm_offset,
+                               NEW.rm_flags);
+               if (error)
+                       goto done;
+               /* new left extent - oldext */
+               NEW = PREV;
+               error = xfs_rmap_lookup_eq(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner,
+                               NEW.rm_offset, NEW.rm_flags, &i);
+               if (error)
+                       goto done;
+               XFS_WANT_CORRUPTED_GOTO(mp, i == 1, done);
+               NEW.rm_blockcount = offset - NEW.rm_offset;
+               error = xfs_rmap_update(cur, &NEW);
+               if (error)
+                       goto done;
+               /* new middle extent - newext */
+               NEW.rm_startblock = bno;
+               NEW.rm_blockcount = len;
+               NEW.rm_owner = owner;
+               NEW.rm_offset = offset;
+               NEW.rm_flags = newext;
+               error = xfs_rmap_insert(cur, NEW.rm_startblock,
+                               NEW.rm_blockcount, NEW.rm_owner, NEW.rm_offset,
+                               NEW.rm_flags);
+               if (error)
+                       goto 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
@@ -1754,6 +2132,10 @@ xfs_rmap_finish_one(
                error = xfs_rmap_convert(rcur, bno, blockcount, !unwritten,
                                &oinfo);
                break;
+       case XFS_RMAP_CONVERT_SHARED:
+               error = xfs_rmap_convert_shared(rcur, bno, blockcount,
+                               !unwritten, &oinfo);
+               break;
        default:
                ASSERT(0);
                error = -EFSCORRUPTED;
@@ -1857,7 +2239,8 @@ xfs_rmap_convert_extent(
        if (!xfs_rmap_update_is_needed(mp, whichfork))
                return 0;
 
-       return __xfs_rmap_add(mp, dfops, XFS_RMAP_CONVERT, ip->i_ino,
+       return __xfs_rmap_add(mp, dfops, xfs_is_reflink_inode(ip) ?
+                       XFS_RMAP_CONVERT_SHARED : XFS_RMAP_CONVERT, ip->i_ino,
                        whichfork, PREV);
 }
 

diff --git a/fs/xfs/xfs_rmap_item.c b/fs/xfs/xfs_rmap_item.c
index 3b8742e..73c8278 100644 (file)
--- a/fs/xfs/xfs_rmap_item.c
+++ b/fs/xfs/xfs_rmap_item.c
@@ -496,6 +496,9 @@ xfs_rui_recover(
                case XFS_RMAP_EXTENT_CONVERT:
                        type = XFS_RMAP_CONVERT;
                        break;
+               case XFS_RMAP_EXTENT_CONVERT_SHARED:
+                       type = XFS_RMAP_CONVERT_SHARED;
+                       break;
                case XFS_RMAP_EXTENT_ALLOC:
                        type = XFS_RMAP_ALLOC;
                        break;