From 64671bafbdd984535aa382bccadd91fbe7be0e80 Mon Sep 17 00:00:00 2001 From: Eryu Guan Date: Mon, 18 Sep 2017 11:38:58 -0700 Subject: xfs: kill meaningless variable 'zero' In xfs_file_aio_write_checks(), variable 'zero' is there only to satisfy xfs_zero_eof(), the result of it is ignored. Now, with iomap_zero_range() based xfs_zero_eof(), we can safely pass NULL as the last param of it and kill 'zero'. Signed-off-by: Eryu Guan Reviewed-by: Carlos Maiolino Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_file.c | 4 +--- 1 file changed, 1 insertion(+), 3 deletions(-) (limited to 'fs/xfs/xfs_file.c') diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index ebdd0bd2b261..261d83f1db76 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -377,8 +377,6 @@ restart: */ spin_lock(&ip->i_flags_lock); if (iocb->ki_pos > i_size_read(inode)) { - bool zero = false; - spin_unlock(&ip->i_flags_lock); if (!drained_dio) { if (*iolock == XFS_IOLOCK_SHARED) { @@ -399,7 +397,7 @@ restart: drained_dio = true; goto restart; } - error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), &zero); + error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), NULL); if (error) return error; } else -- cgit v1.2.2 From d20a5e3851969fa685f118a80e4df670255a4e8d Mon Sep 17 00:00:00 2001 From: Eryu Guan Date: Mon, 18 Sep 2017 11:39:23 -0700 Subject: xfs: report zeroed or not correctly in xfs_zero_range() The 'did_zero' param of xfs_zero_range() was not passed to iomap_zero_range() correctly. This was introduced by commit 7bb41db3ea16 ("xfs: handle 64-bit length in xfs_iozero"), and found by code inspection. Signed-off-by: Eryu Guan Reviewed-by: Carlos Maiolino Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_file.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'fs/xfs/xfs_file.c') diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 261d83f1db76..350b6d43ba23 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -58,7 +58,7 @@ xfs_zero_range( xfs_off_t count, bool *did_zero) { - return iomap_zero_range(VFS_I(ip), pos, count, NULL, &xfs_iomap_ops); + return iomap_zero_range(VFS_I(ip), pos, count, did_zero, &xfs_iomap_ops); } int -- cgit v1.2.2 From ee70daaba82d70766d0723b743d9fdeb3b06102a Mon Sep 17 00:00:00 2001 From: Eryu Guan Date: Thu, 21 Sep 2017 11:26:18 -0700 Subject: xfs: update i_size after unwritten conversion in dio completion Since commit d531d91d6990 ("xfs: always use unwritten extents for direct I/O writes"), we start allocating unwritten extents for all direct writes to allow appending aio in XFS. But for dio writes that could extend file size we update the in-core inode size first, then convert the unwritten extents to real allocations at dio completion time in xfs_dio_write_end_io(). Thus a racing direct read could see the new i_size and find the unwritten extents first and read zeros instead of actual data, if the direct writer also takes a shared iolock. Fix it by updating the in-core inode size after the unwritten extent conversion. To do this, introduce a new boolean argument to xfs_iomap_write_unwritten() to tell if we want to update in-core i_size or not. Suggested-by: Brian Foster Reviewed-by: Brian Foster Signed-off-by: Eryu Guan Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong --- fs/xfs/xfs_file.c | 33 +++++++++++++++++++-------------- 1 file changed, 19 insertions(+), 14 deletions(-) (limited to 'fs/xfs/xfs_file.c') diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 350b6d43ba23..309e26c9dddb 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -434,7 +434,6 @@ xfs_dio_write_end_io( struct inode *inode = file_inode(iocb->ki_filp); struct xfs_inode *ip = XFS_I(inode); loff_t offset = iocb->ki_pos; - bool update_size = false; int error = 0; trace_xfs_end_io_direct_write(ip, offset, size); @@ -445,6 +444,21 @@ xfs_dio_write_end_io( if (size <= 0) return size; + if (flags & IOMAP_DIO_COW) { + error = xfs_reflink_end_cow(ip, offset, size); + if (error) + return error; + } + + /* + * Unwritten conversion updates the in-core isize after extent + * conversion but before updating the on-disk size. Updating isize any + * earlier allows a racing dio read to find unwritten extents before + * they are converted. + */ + if (flags & IOMAP_DIO_UNWRITTEN) + return xfs_iomap_write_unwritten(ip, offset, size, true); + /* * We need to update the in-core inode size here so that we don't end up * with the on-disk inode size being outside the in-core inode size. We @@ -459,20 +473,11 @@ xfs_dio_write_end_io( spin_lock(&ip->i_flags_lock); if (offset + size > i_size_read(inode)) { i_size_write(inode, offset + size); - update_size = true; - } - spin_unlock(&ip->i_flags_lock); - - if (flags & IOMAP_DIO_COW) { - error = xfs_reflink_end_cow(ip, offset, size); - if (error) - return error; - } - - if (flags & IOMAP_DIO_UNWRITTEN) - error = xfs_iomap_write_unwritten(ip, offset, size); - else if (update_size) + spin_unlock(&ip->i_flags_lock); error = xfs_setfilesize(ip, offset, size); + } else { + spin_unlock(&ip->i_flags_lock); + } return error; } -- cgit v1.2.2