From ab29743117f9f4c22ac44c13c1647fb24fb2bafe Mon Sep 17 00:00:00 2001 From: Zhi Yong Wu Date: Wed, 18 Dec 2013 08:22:41 +0800 Subject: xfs: allow linkat() on O_TMPFILE files The VFS allows an anonymous temporary file to be named at a later time via a linkat() syscall. The inodes for O_TMPFILE files are are marked with a special flag I_LINKABLE and have a zero link count. To support this in XFS, xfs_link() detects if this flag I_LINKABLE is set and behaves appropriately when detected. So in this case, its transaciton reservation takes into account the additional overhead of removing the inode from the unlinked list. Then the inode is removed from the unlinked list and the directory entry is added. Finally its link count is bumped accordingly. Signed-off-by: Zhi Yong Wu Reviewed-by: Dave Chinner Reviewed-by: Christoph Hellwig Signed-off-by: Ben Myers --- fs/xfs/xfs_trans_resv.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'fs/xfs/xfs_trans_resv.c') diff --git a/fs/xfs/xfs_trans_resv.c b/fs/xfs/xfs_trans_resv.c index bd3b4b7831b..76f9a02bc36 100644 --- a/fs/xfs/xfs_trans_resv.c +++ b/fs/xfs/xfs_trans_resv.c @@ -203,6 +203,20 @@ xfs_calc_rename_reservation( XFS_FSB_TO_B(mp, 1)))); } +/* + * For removing an inode from unlinked list at first, we can modify: + * the agi hash list and counters: sector size + * the on disk inode before ours in the agi hash list: inode cluster size + */ +STATIC uint +xfs_calc_iunlink_remove_reservation( + struct xfs_mount *mp) +{ + return xfs_calc_buf_res(1, mp->m_sb.sb_sectsize) + + MAX((__uint16_t)XFS_FSB_TO_B(mp, 1), + (__uint16_t)XFS_INODE_CLUSTER_SIZE(mp)); +} + /* * For creating a link to an inode: * the parent directory inode: inode size @@ -220,6 +234,7 @@ xfs_calc_link_reservation( struct xfs_mount *mp) { return XFS_DQUOT_LOGRES(mp) + + xfs_calc_iunlink_remove_reservation(mp) + MAX((xfs_calc_inode_res(mp, 2) + xfs_calc_buf_res(XFS_DIROP_LOG_COUNT(mp), XFS_FSB_TO_B(mp, 1))), @@ -410,9 +425,9 @@ xfs_calc_ifree_reservation( { return XFS_DQUOT_LOGRES(mp) + xfs_calc_inode_res(mp, 1) + - xfs_calc_buf_res(2, mp->m_sb.sb_sectsize) + + xfs_calc_buf_res(1, mp->m_sb.sb_sectsize) + xfs_calc_buf_res(1, XFS_FSB_TO_B(mp, 1)) + - max_t(uint, XFS_FSB_TO_B(mp, 1), XFS_INODE_CLUSTER_SIZE(mp)) + + xfs_calc_iunlink_remove_reservation(mp) + xfs_calc_buf_res(1, 0) + xfs_calc_buf_res(2 + XFS_IALLOC_BLOCKS(mp) + mp->m_in_maxlevels, 0) + -- cgit v1.2.3-70-g09d2