[PATCH 13/15] xfs: use xfs_zero_range in xfs_zero_eof

Christoph Hellwig
2016-05-09T08:48:19Z

We now skip holes in it, so no need to have the caller do it as well.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
fs/xfs/xfs_file.c | 128 +-----------------------------------------------------
1 file changed, 1 insertion(+), 127 deletions(-)

diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
index 85369a9..6ad30dd 100644
--- a/fs/xfs/xfs_file.c
+++ b/fs/xfs/xfs_file.c
@@ -381,49 +381,6 @@ out:
}

/*
- * This routine is called to handle zeroing any space in the last block of the
- * file that is beyond the EOF. We do this since the size is being increased
- * without writing anything to that block and we don't want to read the
- * garbage on the disk.
- */
-STATIC int /* error (positive) */
-xfs_zero_last_block(
- struct xfs_inode *ip,
- xfs_fsize_t offset,
- xfs_fsize_t isize,
- bool *did_zeroing)
-{
- struct xfs_mount *mp = ip->i_mount;
- xfs_fileoff_t last_fsb = XFS_B_TO_FSBT(mp, isize);
- int zero_offset = XFS_B_FSB_OFFSET(mp, isize);
- int zero_len;
- int nimaps = 1;
- int error = 0;
- struct xfs_bmbt_irec imap;
-
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- if (error)
- return error;
-
- ASSERT(nimaps > 0);
-
- /*
- * If the block underlying isize is just a hole, then there
- * is nothing to zero.
- */
- if (imap.br_startblock == HOLESTARTBLOCK)
- return 0;
-
- zero_len = mp->m_sb.sb_blocksize - zero_offset;
- if (isize + zero_len > offset)
- zero_len = offset - isize;
- *did_zeroing = true;
- return xfs_zero_range(ip, isize, zero_len, NULL);
-}
-
-/*
* Zero any on disk space between the current EOF and the new, larger EOF.
*
* This handles the normal case of zeroing the remainder of the last block in
@@ -441,94 +398,11 @@ xfs_zero_eof(
xfs_fsize_t isize, /* current inode size */
bool *did_zeroing)
{
- struct xfs_mount *mp = ip->i_mount;
- xfs_fileoff_t start_zero_fsb;
- xfs_fileoff_t end_zero_fsb;
- xfs_fileoff_t zero_count_fsb;
- xfs_fileoff_t last_fsb;
- xfs_fileoff_t zero_off;
- xfs_fsize_t zero_len;
- int nimaps;
- int error = 0;
- struct xfs_bmbt_irec imap;
-
ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
ASSERT(offset > isize);

trace_xfs_zero_eof(ip, isize, offset - isize);
-
- /*
- * First handle zeroing the block on which isize resides.
- *
- * We only zero a part of that block so it is handled specially.
- */
- if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
- error = xfs_zero_last_block(ip, offset, isize, did_zeroing);
- if (error)
- return error;
- }
-
- /*
- * Calculate the range between the new size and the old where blocks
- * needing to be zeroed may exist.
- *
- * To get the block where the last byte in the file currently resides,
- * we need to subtract one from the size and truncate back to a block
- * boundary. We subtract 1 in case the size is exactly on a block
- * boundary.
- */
- last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
- start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
- end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
- ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
- if (last_fsb == end_zero_fsb) {
- /*
- * The size was only incremented on its last block.
- * We took care of that above, so just return.
- */
- return 0;
- }
-
- ASSERT(start_zero_fsb <= end_zero_fsb);
- while (start_zero_fsb <= end_zero_fsb) {
- nimaps = 1;
- zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
-
- xfs_ilock(ip, XFS_ILOCK_EXCL);
- error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
- &imap, &nimaps, 0);
- xfs_iunlock(ip, XFS_ILOCK_EXCL);
- if (error)
- return error;
-
- ASSERT(nimaps > 0);
-
- if (imap.br_state == XFS_EXT_UNWRITTEN ||
- imap.br_startblock == HOLESTARTBLOCK) {
- start_zero_fsb = imap.br_startoff + imap.br_blockcount;
- ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
- continue;
- }
-
- /*
- * There are blocks we need to zero.
- */
- zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
- zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
-
- if ((zero_off + zero_len) > offset)
- zero_len = offset - zero_off;
-
- error = xfs_zero_range(ip, zero_off, zero_len, NULL);
- if (error)
- return error;
-
- *did_zeroing = true;
- start_zero_fsb = imap.br_startoff + imap.br_blockcount;
- ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
- }
-
- return 0;
+ return xfs_zero_range(ip, isize, offset - isize, did_zeroing);
}

/*