Commit 32b43ab6 authored by Alex Lyakas's avatar Alex Lyakas Committed by Dave Chinner

xfs: optimise xfs_iext_destroy

When unmounting XFS, we call:

xfs_inode_free => xfs_idestroy_fork => xfs_iext_destroy

This goes over the whole indirection array and calls
xfs_iext_irec_remove for each one of the erps (from the last one to
the first one). As a result, we keep shrinking (reallocating
actually) the indirection array until we shrink out all of its
elements. When we have files with huge numbers of extents, umount
takes 30-80 sec, depending on the amount of files that XFS loaded
and the amount of indirection entries of each file. The unmount
stack looks like:

[<ffffffffc0b6d200>] xfs_iext_realloc_indirect+0x40/0x60 [xfs]
[<ffffffffc0b6cd8e>] xfs_iext_irec_remove+0xee/0xf0 [xfs]
[<ffffffffc0b6cdcd>] xfs_iext_destroy+0x3d/0xb0 [xfs]
[<ffffffffc0b6cef6>] xfs_idestroy_fork+0xb6/0xf0 [xfs]
[<ffffffffc0b87002>] xfs_inode_free+0xb2/0xc0 [xfs]
[<ffffffffc0b87260>] xfs_reclaim_inode+0x250/0x340 [xfs]
[<ffffffffc0b87583>] xfs_reclaim_inodes_ag+0x233/0x370 [xfs]
[<ffffffffc0b8823d>] xfs_reclaim_inodes+0x1d/0x20 [xfs]
[<ffffffffc0b96feb>] xfs_unmountfs+0x7b/0x1a0 [xfs]
[<ffffffffc0b98e4d>] xfs_fs_put_super+0x2d/0x70 [xfs]
[<ffffffff811e9e36>] generic_shutdown_super+0x76/0x100
[<ffffffff811ea207>] kill_block_super+0x27/0x70
[<ffffffff811ea519>] deactivate_locked_super+0x49/0x60
[<ffffffff811eaaee>] deactivate_super+0x4e/0x70
[<ffffffff81207593>] cleanup_mnt+0x43/0x90
[<ffffffff81207632>] __cleanup_mnt+0x12/0x20
[<ffffffff8108f8e7>] task_work_run+0xa7/0xe0
[<ffffffff81014ff7>] do_notify_resume+0x97/0xb0
[<ffffffff81717c6f>] int_signal+0x12/0x17

Further, this reallocation prevents us from freeing the extent list
from a RCU callback as allocation can block. Hence if the extent
list is in indirect format, optimise the freeing of the extent list
to only use kmem_free calls by freeing entire extent buffer pages at
a time, rather than extent by extent.

[dchinner: simplified freeing loop based on Christoph's suggestion]
Signed-off-by: default avatarAlex Lyakas <alex@zadarastorage.com>
Reviewed-by: default avatarDave Chinner <dchinner@redhat.com>
Signed-off-by: default avatarDave Chinner <david@fromorbit.com>
parent 7d3aa7fe
......@@ -1496,6 +1496,24 @@ xfs_iext_indirect_to_direct(
}
}
/*
* Remove all records from the indirection array.
*/
STATIC void
xfs_iext_irec_remove_all(
struct xfs_ifork *ifp)
{
int nlists;
int i;
ASSERT(ifp->if_flags & XFS_IFEXTIREC);
nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
for (i = 0; i < nlists; i++)
kmem_free(ifp->if_u1.if_ext_irec[i].er_extbuf);
kmem_free(ifp->if_u1.if_ext_irec);
ifp->if_flags &= ~XFS_IFEXTIREC;
}
/*
* Free incore file extents.
*/
......@@ -1504,14 +1522,7 @@ xfs_iext_destroy(
xfs_ifork_t *ifp) /* inode fork pointer */
{
if (ifp->if_flags & XFS_IFEXTIREC) {
int erp_idx;
int nlists;
nlists = ifp->if_real_bytes / XFS_IEXT_BUFSZ;
for (erp_idx = nlists - 1; erp_idx >= 0 ; erp_idx--) {
xfs_iext_irec_remove(ifp, erp_idx);
}
ifp->if_flags &= ~XFS_IFEXTIREC;
xfs_iext_irec_remove_all(ifp);
} else if (ifp->if_real_bytes) {
kmem_free(ifp->if_u1.if_extents);
} else if (ifp->if_bytes) {
......
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