Searched hist:eb60ff1ee16a7d22415d6065d808ddf0b5c13d7a (Results 1 – 4 of 4) sorted by relevance
| /freebsd/sys/fs/unionfs/ |
| H A D | union.h | diff eb60ff1ee16a7d22415d6065d808ddf0b5c13d7a Wed Feb 28 18:45:56 CET 2024 Jason A. Harmening <jah@FreeBSD.org> unionfs: rework locking scheme to only lock a single vnode
Instead of locking both the lower and upper vnodes, which is both
complex and deadlock-prone, only lock the upper vnode, or the lower
vnode if no upper vnode is present.
In most cases this is all that is needed; for the cases in which
both vnodes do need to be locked, this change also employs deadlock-
avoiding techniques such as LK_NOWAIT and vn_lock_pair().
There are still some corner cases in which the current implementation
ends up taking multiple vnode locks across different filesystems
without taking special steps to avoid deadlock; those cases have
been noted in the comments.
Differential Revision: https://reviews.freebsd.org/D45398
Reviewed by: olce
Tested by: pho
|
| H A D | union_vfsops.c | diff eb60ff1ee16a7d22415d6065d808ddf0b5c13d7a Wed Feb 28 18:45:56 CET 2024 Jason A. Harmening <jah@FreeBSD.org> unionfs: rework locking scheme to only lock a single vnode
Instead of locking both the lower and upper vnodes, which is both
complex and deadlock-prone, only lock the upper vnode, or the lower
vnode if no upper vnode is present.
In most cases this is all that is needed; for the cases in which
both vnodes do need to be locked, this change also employs deadlock-
avoiding techniques such as LK_NOWAIT and vn_lock_pair().
There are still some corner cases in which the current implementation
ends up taking multiple vnode locks across different filesystems
without taking special steps to avoid deadlock; those cases have
been noted in the comments.
Differential Revision: https://reviews.freebsd.org/D45398
Reviewed by: olce
Tested by: pho
|
| H A D | union_subr.c | diff eb60ff1ee16a7d22415d6065d808ddf0b5c13d7a Wed Feb 28 18:45:56 CET 2024 Jason A. Harmening <jah@FreeBSD.org> unionfs: rework locking scheme to only lock a single vnode
Instead of locking both the lower and upper vnodes, which is both
complex and deadlock-prone, only lock the upper vnode, or the lower
vnode if no upper vnode is present.
In most cases this is all that is needed; for the cases in which
both vnodes do need to be locked, this change also employs deadlock-
avoiding techniques such as LK_NOWAIT and vn_lock_pair().
There are still some corner cases in which the current implementation
ends up taking multiple vnode locks across different filesystems
without taking special steps to avoid deadlock; those cases have
been noted in the comments.
Differential Revision: https://reviews.freebsd.org/D45398
Reviewed by: olce
Tested by: pho
|
| H A D | union_vnops.c | diff eb60ff1ee16a7d22415d6065d808ddf0b5c13d7a Wed Feb 28 18:45:56 CET 2024 Jason A. Harmening <jah@FreeBSD.org> unionfs: rework locking scheme to only lock a single vnode
Instead of locking both the lower and upper vnodes, which is both
complex and deadlock-prone, only lock the upper vnode, or the lower
vnode if no upper vnode is present.
In most cases this is all that is needed; for the cases in which
both vnodes do need to be locked, this change also employs deadlock-
avoiding techniques such as LK_NOWAIT and vn_lock_pair().
There are still some corner cases in which the current implementation
ends up taking multiple vnode locks across different filesystems
without taking special steps to avoid deadlock; those cases have
been noted in the comments.
Differential Revision: https://reviews.freebsd.org/D45398
Reviewed by: olce
Tested by: pho
|