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path: root/fs/xfs/xfs_aops.c
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Diffstat (limited to 'fs/xfs/xfs_aops.c')
-rw-r--r--fs/xfs/xfs_aops.c19
1 files changed, 16 insertions, 3 deletions
diff --git a/fs/xfs/xfs_aops.c b/fs/xfs/xfs_aops.c
index 21e2d70884e1..9c6a830da0ee 100644
--- a/fs/xfs/xfs_aops.c
+++ b/fs/xfs/xfs_aops.c
@@ -390,6 +390,19 @@ xfs_map_blocks(
if (XFS_FORCED_SHUTDOWN(mp))
return -EIO;
+ /*
+ * Truncate can race with writeback since writeback doesn't take the
+ * iolock and truncate decreases the file size before it starts
+ * truncating the pages between new_size and old_size. Therefore, we
+ * can end up in the situation where writeback gets a CoW fork mapping
+ * but the truncate makes the mapping invalid and we end up in here
+ * trying to get a new mapping. Bail out here so that we simply never
+ * get a valid mapping and so we drop the write altogether. The page
+ * truncation will kill the contents anyway.
+ */
+ if (type == XFS_IO_COW && offset > i_size_read(inode))
+ return 0;
+
ASSERT(type != XFS_IO_COW);
if (type == XFS_IO_UNWRITTEN)
bmapi_flags |= XFS_BMAPI_IGSTATE;
@@ -399,7 +412,7 @@ xfs_map_blocks(
(ip->i_df.if_flags & XFS_IFEXTENTS));
ASSERT(offset <= mp->m_super->s_maxbytes);
- if ((xfs_ufsize_t)offset + count > mp->m_super->s_maxbytes)
+ if (offset > mp->m_super->s_maxbytes - count)
count = mp->m_super->s_maxbytes - offset;
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + count);
offset_fsb = XFS_B_TO_FSBT(mp, offset);
@@ -791,7 +804,7 @@ xfs_aops_discard_page(
goto out_invalidate;
xfs_alert(ip->i_mount,
- "page discard on page %p, inode 0x%llx, offset %llu.",
+ "page discard on page "PTR_FMT", inode 0x%llx, offset %llu.",
page, ip->i_ino, offset);
xfs_ilock(ip, XFS_ILOCK_EXCL);
@@ -1312,7 +1325,7 @@ xfs_get_blocks(
lockmode = xfs_ilock_data_map_shared(ip);
ASSERT(offset <= mp->m_super->s_maxbytes);
- if ((xfs_ufsize_t)offset + size > mp->m_super->s_maxbytes)
+ if (offset > mp->m_super->s_maxbytes - size)
size = mp->m_super->s_maxbytes - offset;
end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)offset + size);
offset_fsb = XFS_B_TO_FSBT(mp, offset);