[PATCH 01/12] xfs: initialize iomap->flags in xfs_bmbt_to_iomap

Christoph Hellwig
2019-10-15T15:44:53Z

Currently we don't overwrite the flags field in the iomap in
xfs_bmbt_to_iomap. This works fine with 0-initialized iomaps on stack,
but is harmful once we want to be able to reuse an iomap in the
writeback code. Replace the shared paramter with a set of initial
flags an thus ensures the flags field is always reinitialized.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_iomap.c | 28 +++++++++++++++++-----------
fs/xfs/xfs_iomap.h | 2 +-
fs/xfs/xfs_pnfs.c | 2 +-
3 files changed, 19 insertions(+), 13 deletions(-)

diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index f780e223b118..54c9ec7ad337 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -54,7 +54,7 @@ xfs_bmbt_to_iomap(
struct xfs_inode *ip,
struct iomap *iomap,
struct xfs_bmbt_irec *imap,
- bool shared)
+ u16 flags)
{
struct xfs_mount *mp = ip->i_mount;

@@ -79,12 +79,11 @@ xfs_bmbt_to_iomap(
iomap->length = XFS_FSB_TO_B(mp, imap->br_blockcount);
iomap->bdev = xfs_find_bdev_for_inode(VFS_I(ip));
iomap->dax_dev = xfs_find_daxdev_for_inode(VFS_I(ip));
+ iomap->flags = flags;

if (xfs_ipincount(ip) &&
(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
iomap->flags |= IOMAP_F_DIRTY;
- if (shared)
- iomap->flags |= IOMAP_F_SHARED;
return 0;
}

@@ -540,6 +539,7 @@ xfs_file_iomap_begin_delay(
struct xfs_iext_cursor icur, ccur;
xfs_fsblock_t prealloc_blocks = 0;
bool eof = false, cow_eof = false, shared = false;
+ u16 iomap_flags = 0;
int whichfork = XFS_DATA_FORK;
int error = 0;

@@ -707,7 +707,7 @@ xfs_file_iomap_begin_delay(
* Flag newly allocated delalloc blocks with IOMAP_F_NEW so we punch
* them out if the write happens to fail.
*/
- iomap->flags |= IOMAP_F_NEW;
+ iomap_flags |= IOMAP_F_NEW;
trace_xfs_iomap_alloc(ip, offset, count, whichfork,
whichfork == XFS_DATA_FORK ? &imap : &cmap);
done:
@@ -715,14 +715,17 @@ xfs_file_iomap_begin_delay(
if (imap.br_startoff > offset_fsb) {
xfs_trim_extent(&cmap, offset_fsb,
imap.br_startoff - offset_fsb);
- error = xfs_bmbt_to_iomap(ip, iomap, &cmap, true);
+ error = xfs_bmbt_to_iomap(ip, iomap, &cmap,
+ IOMAP_F_SHARED);
goto out_unlock;
}
/* ensure we only report blocks we have a reservation for */
xfs_trim_extent(&imap, cmap.br_startoff, cmap.br_blockcount);
shared = true;
}
- error = xfs_bmbt_to_iomap(ip, iomap, &imap, shared);
+ if (shared)
+ iomap_flags |= IOMAP_F_SHARED;
+ error = xfs_bmbt_to_iomap(ip, iomap, &imap, iomap_flags);
out_unlock:
xfs_iunlock(ip, XFS_ILOCK_EXCL);
return error;
@@ -930,6 +933,7 @@ xfs_file_iomap_begin(
xfs_fileoff_t offset_fsb, end_fsb;
int nimaps = 1, error = 0;
bool shared = false;
+ u16 iomap_flags = 0;
unsigned lockmode;

if (XFS_FORCED_SHUTDOWN(mp))
@@ -1045,11 +1049,13 @@ xfs_file_iomap_begin(
if (error)
return error;

- iomap->flags |= IOMAP_F_NEW;
+ iomap_flags |= IOMAP_F_NEW;
trace_xfs_iomap_alloc(ip, offset, length, XFS_DATA_FORK, &imap);

out_finish:
- return xfs_bmbt_to_iomap(ip, iomap, &imap, shared);
+ if (shared)
+ iomap_flags |= IOMAP_F_SHARED;
+ return xfs_bmbt_to_iomap(ip, iomap, &imap, iomap_flags);

out_found:
ASSERT(nimaps);
@@ -1193,7 +1199,7 @@ xfs_seek_iomap_begin(
if (data_fsb < cow_fsb + cmap.br_blockcount)
end_fsb = min(end_fsb, data_fsb);
xfs_trim_extent(&cmap, offset_fsb, end_fsb);
- error = xfs_bmbt_to_iomap(ip, iomap, &cmap, true);
+ error = xfs_bmbt_to_iomap(ip, iomap, &cmap, IOMAP_F_SHARED);
/*
* This is a COW extent, so we must probe the page cache
* because there could be dirty page cache being backed
@@ -1215,7 +1221,7 @@ xfs_seek_iomap_begin(
imap.br_state = XFS_EXT_NORM;
done:
xfs_trim_extent(&imap, offset_fsb, end_fsb);
- error = xfs_bmbt_to_iomap(ip, iomap, &imap, false);
+ error = xfs_bmbt_to_iomap(ip, iomap, &imap, 0);
out_unlock:
xfs_iunlock(ip, lockmode);
return error;
@@ -1261,7 +1267,7 @@ xfs_xattr_iomap_begin(
if (error)
return error;
ASSERT(nimaps);
- return xfs_bmbt_to_iomap(ip, iomap, &imap, false);
+ return xfs_bmbt_to_iomap(ip, iomap, &imap, 0);
}

const struct iomap_ops xfs_xattr_iomap_ops = {
diff --git a/fs/xfs/xfs_iomap.h b/fs/xfs/xfs_iomap.h
index 5c2f6aa6d78f..71d0ae460c44 100644
--- a/fs/xfs/xfs_iomap.h
+++ b/fs/xfs/xfs_iomap.h
@@ -16,7 +16,7 @@ int xfs_iomap_write_direct(struct xfs_inode *, xfs_off_t, size_t,
int xfs_iomap_write_unwritten(struct xfs_inode *, xfs_off_t, xfs_off_t, bool);

int xfs_bmbt_to_iomap(struct xfs_inode *, struct iomap *,
- struct xfs_bmbt_irec *, bool shared);
+ struct xfs_bmbt_irec *, u16);
xfs_extlen_t xfs_eof_alignment(struct xfs_inode *ip, xfs_extlen_t extsize);

static inline xfs_filblks_t
diff --git a/fs/xfs/xfs_pnfs.c b/fs/xfs/xfs_pnfs.c
index a339bd5fa260..9c96493be9e0 100644
--- a/fs/xfs/xfs_pnfs.c
+++ b/fs/xfs/xfs_pnfs.c
@@ -178,7 +178,7 @@ xfs_fs_map_blocks(
}
xfs_iunlock(ip, XFS_IOLOCK_EXCL);

- error = xfs_bmbt_to_iomap(ip, iomap, &imap, false);
+ error = xfs_bmbt_to_iomap(ip, iomap, &imap, 0);
*device_generation = mp->m_generation;
return error;
out_unlock:
--
2.20.1