Delalloc conversion has traditionally been part of our function to
allocate blocks on disk (first xfs_bmapi, then xfs_bmapi_write), but
delalloc conversion is a little special as we really do not want
to allocate blocks over holes, for which we don't have reservations.
Split the delalloc conversions into a separate helper to keep the
code simple and structured.
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
---
fs/xfs/libxfs/xfs_bmap.c | 104 +++++++++++++++++++++------------------
fs/xfs/libxfs/xfs_bmap.h | 4 --
2 files changed, 57 insertions(+), 51 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index d75f45d9b7d1..818cd018d510 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4327,22 +4327,6 @@ xfs_bmapi_write(
bma.datatype = 0;
bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
- /*
- * The delalloc flag means the caller wants to allocate the entire
- * delalloc extent backing bno where bno may not necessarily match the
- * startoff. Now that we've looked up the extent, reset the range to
- * map based on the extent in the file. If we're in a hole, this may be
- * an error so don't adjust anything.
- */
- if ((flags & XFS_BMAPI_DELALLOC) &&
- !eof && bno >= bma.got.br_startoff) {
- bno = bma.got.br_startoff;
- len = bma.got.br_blockcount;
-#ifdef DEBUG
- orig_bno = bno;
- orig_len = len;
-#endif
- }
n = 0;
end = bno + len;
obno = bno;
@@ -4359,26 +4343,7 @@ xfs_bmapi_write(
ASSERT(!((flags & XFS_BMAPI_CONVERT) &&
(flags & XFS_BMAPI_COWFORK)));
- if (flags & XFS_BMAPI_DELALLOC) {
- /*
- * For the COW fork we can reasonably get a
- * request for converting an extent that races
- * with other threads already having converted
- * part of it, as there converting COW to
- * regular blocks is not protected using the
- * IOLOCK.
- */
- ASSERT(flags & XFS_BMAPI_COWFORK);
- if (!(flags & XFS_BMAPI_COWFORK)) {
- error = -EIO;
- goto error0;
- }
-
- if (eof || bno >= end)
- break;
- } else {
- need_alloc = true;
- }
+ need_alloc = true;
} else if (isnullstartblock(bma.got.br_startblock)) {
wasdelay = true;
}
@@ -4487,21 +4452,66 @@ xfs_bmapi_convert_delalloc(
xfs_fileoff_t offset_fsb,
struct xfs_bmbt_irec *imap)
{
- int flags = XFS_BMAPI_DELALLOC, nimaps = 1, error;
+ struct xfs_ifork *ifp = XFS_IFORK_PTR(ip, whichfork);
+ struct xfs_bmalloca bma = { NULL };
+ int error;
- if (whichfork == XFS_COW_FORK)
- flags |= XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC;
+ if (!xfs_iext_lookup_extent(ip, ifp, offset_fsb, &bma.icur, &bma.got) ||
+ bma.got.br_startoff > offset_fsb) {
+ /*
+ * No extent found in the range we are trying to convert. This
+ * should only happen for the COW fork, where another thread
+ * might have moved the extent to the data fork in the meantime.
+ */
+ WARN_ON_ONCE(whichfork != XFS_COW_FORK);
+ return -EAGAIN;
+ }
/*
- * The DELALLOC flag always allocates the entire extent; pass a dummy
- * length of 1.
+ * If we find a real extent here we raced with another thread converting
+ * the extent. Just return the real extent at this offset.
*/
- flags |= XFS_BMAPI_DELALLOC;
- error = xfs_bmapi_write(tp, ip, offset_fsb, 1, flags,
- XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK),
- imap, &nimaps);
- if (!error && !nimaps)
- error = -EFSCORRUPTED;
+ if (!isnullstartblock(bma.got.br_startblock)) {
+ *imap = bma.got;
+ return 0;
+ }
+
+ bma.tp = tp;
+ bma.ip = ip;
+ bma.wasdel = true;
+ bma.offset = bma.got.br_startoff;
+ bma.length = bma.got.br_blockcount;
+ bma.total = XFS_EXTENTADD_SPACE_RES(ip->i_mount, XFS_DATA_FORK);
+ bma.minleft = xfs_bmapi_minleft(tp, ip, whichfork);
+ if (whichfork == XFS_COW_FORK)
+ bma.flags = XFS_BMAPI_COWFORK | XFS_BMAPI_PREALLOC;
+
+ if (!xfs_iext_peek_prev_extent(ifp, &bma.icur, &bma.prev))
+ bma.prev.br_startoff = NULLFILEOFF;
+
+ error = xfs_bmapi_allocate(&bma);
+ if (error)
+ goto out_finish;
+ if (WARN_ON_ONCE(bma.blkno == NULLFSBLOCK)) {
+ error = -ENOSPC;
+ goto out_finish;
+ }
+
+ ASSERT(!isnullstartblock(bma.got.br_startblock));
+ ASSERT(bma.got.br_startblock || XFS_IS_REALTIME_INODE(ip));
+ *imap = bma.got;
+
+ if (whichfork == XFS_COW_FORK) {
+ error = xfs_refcount_alloc_cow_extent(tp, bma.blkno,
+ bma.length);
+ if (error)
+ goto out_finish;
+ }
+
+ error = xfs_bmap_btree_to_extents(tp, ip, bma.cur, &bma.logflags,
+ whichfork);
+out_finish:
+ xfs_bmapi_finish(&bma, whichfork, error);
return error;
}
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index c385987251cd..5bdfa8001f07 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -95,9 +95,6 @@ struct xfs_extent_free_item
/* Map something in the CoW fork. */
#define XFS_BMAPI_COWFORK 0x200
-/* Only convert delalloc space, don't allocate entirely new extents */
-#define XFS_BMAPI_DELALLOC 0x400
-
/* Only convert unwritten extents, don't allocate new blocks */
#define XFS_BMAPI_CONVERT_ONLY 0x800
@@ -117,7 +114,6 @@ struct xfs_extent_free_item
{ XFS_BMAPI_ZERO, "ZERO" }, \
{ XFS_BMAPI_REMAP, "REMAP" }, \
{ XFS_BMAPI_COWFORK, "COWFORK" }, \
- { XFS_BMAPI_DELALLOC, "DELALLOC" }, \
{ XFS_BMAPI_CONVERT_ONLY, "CONVERT_ONLY" }, \
{ XFS_BMAPI_NODISCARD, "NODISCARD" }, \
{ XFS_BMAPI_NORMAP, "NORMAP" }
--
2.20.1
