mirror of
https://github.com/torvalds/linux
synced 2024-07-05 18:00:39 +00:00
Rather than use remap_pfn_range() for this and manually free later, switch to using vm_insert_page() and have it Just Work. This requires a bit of effort on the mmap lookup side, as the ctx uring_lock isn't held, which otherwise protects buffer_lists from being torn down, and it's not safe to grab from mmap context that would introduce an ABBA deadlock between the mmap lock and the ctx uring_lock. Instead, lookup the buffer_list under RCU, as the the list is RCU freed already. Use the existing reference count to determine whether it's possible to safely grab a reference to it (eg if it's not zero already), and drop that reference when done with the mapping. If the mmap reference is the last one, the buffer_list and the associated memory can go away, since the vma insertion has references to the inserted pages at that point. Signed-off-by: Jens Axboe <axboe@kernel.dk> |
||
---|---|---|
.. | ||
acpi | ||
asm-generic | ||
clocksource | ||
crypto | ||
drm | ||
dt-bindings | ||
keys | ||
kunit | ||
kvm | ||
linux | ||
math-emu | ||
media | ||
memory | ||
misc | ||
net | ||
pcmcia | ||
ras | ||
rdma | ||
rv | ||
scsi | ||
soc | ||
sound | ||
target | ||
trace | ||
uapi | ||
ufs | ||
vdso | ||
video | ||
xen |