From acfbac776496f2093e9facf7876b4015ef8c3d1d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Tue, 8 Oct 2024 10:59:16 +0200 Subject: [PATCH] xfs: take XFS_MMAPLOCK_EXCL xfs_file_write_zero_eof xfs_file_write_zero_eof is the only caller of xfs_zero_range that does not take XFS_MMAPLOCK_EXCL (aka the invalidate lock). Currently that is actually the right thing, as an error in the iomap zeroing code will also take the invalidate_lock to clean up, but to fix that deadlock we need a consistent locking pattern first. The only extra thing that XFS_MMAPLOCK_EXCL will lock out are read pagefaults, which isn't really needed here, but also not actively harmful. Signed-off-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Carlos Maiolino --- fs/xfs/xfs_file.c | 8 +++++++- fs/xfs/xfs_iomap.c | 2 ++ 2 files changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 3efb0da2a910..b19916b11fd5 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -364,6 +364,7 @@ xfs_file_write_zero_eof( { struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host); loff_t isize; + int error; /* * We need to serialise against EOF updates that occur in IO completions @@ -411,7 +412,12 @@ xfs_file_write_zero_eof( } trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize); - return xfs_zero_range(ip, isize, iocb->ki_pos - isize, NULL); + + xfs_ilock(ip, XFS_MMAPLOCK_EXCL); + error = xfs_zero_range(ip, isize, iocb->ki_pos - isize, NULL); + xfs_iunlock(ip, XFS_MMAPLOCK_EXCL); + + return error; } /* diff --git a/fs/xfs/xfs_iomap.c b/fs/xfs/xfs_iomap.c index 01324da63fcf..4fa4d66dc377 100644 --- a/fs/xfs/xfs_iomap.c +++ b/fs/xfs/xfs_iomap.c @@ -1449,6 +1449,8 @@ xfs_zero_range( { struct inode *inode = VFS_I(ip); + xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL); + if (IS_DAX(inode)) return dax_zero_range(inode, pos, len, did_zero, &xfs_dax_write_iomap_ops);