From eb77b23b565e7e1d2cc3a7d9e4cc186fb54e81a8 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 3 Sep 2019 08:13:13 -0700
Subject: [PATCH] xfs: add a xfs_valid_startblock helper
Add a helper that validates the startblock is valid. This checks for a
non-zero block on the main device, but skips that check for blocks on
the realtime device.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
---
fs/xfs/libxfs/xfs_bmap.c | 2 +-
fs/xfs/libxfs/xfs_bmap.h | 7 +++++++
fs/xfs/xfs_iomap.c | 6 +++---
3 files changed, 11 insertions(+), 4 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_bmap.c b/fs/xfs/libxfs/xfs_bmap.c
index 6d97794c97c0..054b4ce30033 100644
--- a/fs/xfs/libxfs/xfs_bmap.c
+++ b/fs/xfs/libxfs/xfs_bmap.c
@@ -4515,7 +4515,7 @@ xfs_bmapi_convert_delalloc(
if (WARN_ON_ONCE(bma.blkno == NULLFSBLOCK))
goto out_finish;
error = -EFSCORRUPTED;
- if (WARN_ON_ONCE(!bma.got.br_startblock && !XFS_IS_REALTIME_INODE(ip)))
+ if (WARN_ON_ONCE(!xfs_valid_startblock(ip, bma.got.br_startblock)))
goto out_finish;
XFS_STATS_ADD(mp, xs_xstrat_bytes, XFS_FSB_TO_B(mp, bma.length));
diff --git a/fs/xfs/libxfs/xfs_bmap.h b/fs/xfs/libxfs/xfs_bmap.h
index c409871a096e..5bb446d80542 100644
--- a/fs/xfs/libxfs/xfs_bmap.h
+++ b/fs/xfs/libxfs/xfs_bmap.h
@@ -171,6 +171,13 @@ static inline bool xfs_bmap_is_real_extent(struct xfs_bmbt_irec *irec)
!isnullstartblock(irec->br_startblock);
}
+/*
+ * Check the mapping for obviously garbage allocations that could trash the
+ * filesystem immediately.
+ */
+#define xfs_valid_startblock(ip, startblock) \
+ ((startblock) != 0 || XFS_IS_REALTIME_INODE(ip))
+
void xfs_trim_extent(struct xfs_bmbt_irec *irec, xfs_fileoff_t bno,
xfs_filblks_t len);
int xfs_bmap_add_attrfork(struct xfs_inode *ip, int size, int rsvd);
diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c
index 3a4310d7cb59..f780e223b118 100644
--- a/fs/xfs/xfs_iomap.c
+++ b/fs/xfs/xfs_iomap.c
@@ -58,7 +58,7 @@ xfs_bmbt_to_iomap(
{
struct xfs_mount *mp = ip->i_mount;
- if (unlikely(!imap->br_startblock && !XFS_IS_REALTIME_INODE(ip)))
+ if (unlikely(!xfs_valid_startblock(ip, imap->br_startblock)))
return xfs_alert_fsblock_zero(ip, imap);
if (imap->br_startblock == HOLESTARTBLOCK) {
@@ -297,7 +297,7 @@ xfs_iomap_write_direct(
goto out_unlock;
}
- if (!(imap->br_startblock || XFS_IS_REALTIME_INODE(ip)))
+ if (unlikely(!xfs_valid_startblock(ip, imap->br_startblock)))
error = xfs_alert_fsblock_zero(ip, imap);
out_unlock:
@@ -814,7 +814,7 @@ xfs_iomap_write_unwritten(
if (error)
return error;
- if (!(imap.br_startblock || XFS_IS_REALTIME_INODE(ip)))
+ if (unlikely(!xfs_valid_startblock(ip, imap.br_startblock)))
return xfs_alert_fsblock_zero(ip, &imap);
if ((numblks_fsb = imap.br_blockcount) == 0) {
--
2.30.9