[PATCH 04/14] xfs: detach dquots from inode if we don't need to inactivate it

Darrick J. Wong
2021-08-05T02:06:46Z

From: Darrick J. Wong <djwong@kernel.org>

If we don't need to inactivate an inode, we can detach the dquots and
move on to reclamation. This isn't strictly required here; it's a
preparation patch for deferred inactivation per reviewer request[1] to
move the creation of xfs_inode_needs_inactivation into a separate
change. Eventually this !need_inactive chunk will turn into the code
path for inodes that skip xfs_inactive and go straight to memory
reclaim.

[1] https://lore.kernel.org/linux-xfs/20210609012838.GW2945738@locust/T/#mca6d958521cb88bbc1bfe1a30767203328d410b5
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
---
fs/xfs/xfs_icache.c | 8 +++++++-
fs/xfs/xfs_inode.c | 53 +++++++++++++++++++++++++++++++++++++++++++++++++++
fs/xfs/xfs_inode.h | 2 ++
3 files changed, 62 insertions(+), 1 deletion(-)

diff --git a/fs/xfs/xfs_icache.c b/fs/xfs/xfs_icache.c
index f0e77ed0b8bb..b9214733d0c3 100644
--- a/fs/xfs/xfs_icache.c
+++ b/fs/xfs/xfs_icache.c
@@ -1752,8 +1752,14 @@ xfs_inode_mark_reclaimable(
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_perag *pag;
+ bool need_inactive = xfs_inode_needs_inactive(ip);

- xfs_inactive(ip);
+ if (!need_inactive) {
+ /* Going straight to reclaim, so drop the dquots. */
+ xfs_qm_dqdetach(ip);
+ } else {
+ xfs_inactive(ip);
+ }

if (!XFS_FORCED_SHUTDOWN(mp) && ip->i_delayed_blks) {
xfs_check_delalloc(ip, XFS_DATA_FORK);
diff --git a/fs/xfs/xfs_inode.c b/fs/xfs/xfs_inode.c
index 990b72ae3635..3c6ce1f6f643 100644
--- a/fs/xfs/xfs_inode.c
+++ b/fs/xfs/xfs_inode.c
@@ -1654,6 +1654,59 @@ xfs_inactive_ifree(
return 0;
}

+/*
+ * Returns true if we need to update the on-disk metadata before we can free
+ * the memory used by this inode. Updates include freeing post-eof
+ * preallocations; freeing COW staging extents; and marking the inode free in
+ * the inobt if it is on the unlinked list.
+ */
+bool
+xfs_inode_needs_inactive(
+ struct xfs_inode *ip)
+{
+ struct xfs_mount *mp = ip->i_mount;
+ struct xfs_ifork *cow_ifp = XFS_IFORK_PTR(ip, XFS_COW_FORK);
+
+ /*
+ * If the inode is already free, then there can be nothing
+ * to clean up here.
+ */
+ if (VFS_I(ip)->i_mode == 0)
+ return false;
+
+ /* If this is a read-only mount, don't do this (would generate I/O) */
+ if (mp->m_flags & XFS_MOUNT_RDONLY)
+ return false;
+
+ /* If the log isn't running, push inodes straight to reclaim. */
+ if (XFS_FORCED_SHUTDOWN(mp) || (mp->m_flags & XFS_MOUNT_NORECOVERY))
+ return false;
+
+ /* Metadata inodes require explicit resource cleanup. */
+ if (xfs_is_metadata_inode(ip))
+ return false;
+
+ /* Want to clean out the cow blocks if there are any. */
+ if (cow_ifp && cow_ifp->if_bytes > 0)
+ return true;
+
+ /* Unlinked files must be freed. */
+ if (VFS_I(ip)->i_nlink == 0)
+ return true;
+
+ /*
+ * This file isn't being freed, so check if there are post-eof blocks
+ * to free. @force is true because we are evicting an inode from the
+ * cache. Post-eof blocks must be freed, lest we end up with broken
+ * free space accounting.
+ *
+ * Note: don't bother with iolock here since lockdep complains about
+ * acquiring it in reclaim context. We have the only reference to the
+ * inode at this point anyways.
+ */
+ return xfs_can_free_eofblocks(ip, true);
+}
+
/*
* xfs_inactive
*
diff --git a/fs/xfs/xfs_inode.h b/fs/xfs/xfs_inode.h
index 4b6703dbffb8..e3137bbc7b14 100644
--- a/fs/xfs/xfs_inode.h
+++ b/fs/xfs/xfs_inode.h
@@ -493,6 +493,8 @@ extern struct kmem_zone *xfs_inode_zone;
/* The default CoW extent size hint. */
#define XFS_DEFAULT_COWEXTSZ_HINT 32

+bool xfs_inode_needs_inactive(struct xfs_inode *ip);
+
int xfs_iunlink_init(struct xfs_perag *pag);
void xfs_iunlink_destroy(struct xfs_perag *pag);