xfs: take the ilock shared if possible in xfs_file_iomap_begin (66642c5c) · Commits · 戴 / test

fs/xfs/xfs_iomap.c

+6 −4

Original line number	Diff line number	Diff line
		@@ -954,6 +954,7 @@ xfs_file_iomap_begin(
		struct xfs_bmbt_irec imap;
		xfs_fileoff_t offset_fsb, end_fsb;
		int nimaps = 1, error = 0;
		unsigned lockmode;

		if (XFS_FORCED_SHUTDOWN(mp))
		return -EIO;
		@@ -963,7 +964,7 @@ xfs_file_iomap_begin(
		iomap);
		}

		xfs_ilock(ip, XFS_ILOCK_EXCL);
		lockmode = xfs_ilock_data_map_shared(ip);

		ASSERT(offset <= mp->m_super->s_maxbytes);
		if ((xfs_fsize_t)offset + length > mp->m_super->s_maxbytes)
		@@ -974,7 +975,7 @@ xfs_file_iomap_begin(
		error = xfs_bmapi_read(ip, offset_fsb, end_fsb - offset_fsb, &imap,
		&nimaps, XFS_BMAPI_ENTIRE);
		if (error) {
		xfs_iunlock(ip, XFS_ILOCK_EXCL);
		xfs_iunlock(ip, lockmode);
		return error;
		}

		@@ -994,7 +995,8 @@ xfs_file_iomap_begin(
		* xfs_iomap_write_direct() expects the shared lock. It
		* is unlocked on return.
		*/
		xfs_ilock_demote(ip, XFS_ILOCK_EXCL);
		if (lockmode == XFS_ILOCK_EXCL)
		xfs_ilock_demote(ip, lockmode);
		error = xfs_iomap_write_direct(ip, offset, length, &imap,
		nimaps);
		if (error)
		@@ -1005,7 +1007,7 @@ xfs_file_iomap_begin(
		} else {
		ASSERT(nimaps);

		xfs_iunlock(ip, XFS_ILOCK_EXCL);
		xfs_iunlock(ip, lockmode);
		trace_xfs_iomap_found(ip, offset, length, 0, &imap);
		}