| commit | 46b71cbec8385411cb5105d75a02b8336c76b13e | |
| author | Matthew Dillon <dillon@apollo.backplane.com> | |
| Fri, 6 Oct 2017 05:59:40 +0000 (5 22:59 -0700) | ||
| committer | Matthew Dillon <dillon@apollo.backplane.com> | |
| Fri, 6 Oct 2017 06:25:06 +0000 (5 23:25 -0700) | ||
| tree | 29b26e72aaee64e0e966058a6e6abbd508c819f4 | treesnapshot (tar.gz zip) |
| parent | 24bdeb698d15c8ef4c3f92e348a0e7348ac89aeb | commitdiff |
kernel - Refuse to swapoff under certain conditions
* Both tmpfs and vn can't handle swapoff's method of bringing pages
back in from the swap partition being decomissioned.
* Fixing this properly is fairly involved. The normal swapoff procedure
is to page swap into the related VM object, but tmpfs and vn use their
VM objects ONLY to track swap blocks and not for vm_page manipulation,
so that just won't work. In addition, the swap code may associate
a swap block with a VM object before issuing the write I/O to page
out the data, and the swapoff code's asynchronous pagein might cause
problems.
For now, just make sure that swapoff refuses to remove the partition
under these conditions, so it doesn't blow up tmpfs or vn.
* Both tmpfs and vn can't handle swapoff's method of bringing pages
back in from the swap partition being decomissioned.
* Fixing this properly is fairly involved. The normal swapoff procedure
is to page swap into the related VM object, but tmpfs and vn use their
VM objects ONLY to track swap blocks and not for vm_page manipulation,
so that just won't work. In addition, the swap code may associate
a swap block with a VM object before issuing the write I/O to page
out the data, and the swapoff code's asynchronous pagein might cause
problems.
For now, just make sure that swapoff refuses to remove the partition
under these conditions, so it doesn't blow up tmpfs or vn.
| sys/dev/disk/vn/vn.c | diffblobblamehistory | |
| sys/vfs/tmpfs/tmpfs_subr.c | diffblobblamehistory | |
| sys/vm/swap_pager.c | diffblobblamehistory | |
| sys/vm/vm_object.h | diffblobblamehistory |