Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-16 Thread Vladimir Sementsov-Ogievskiy
16.07.2021 21:47, Vladimir Sementsov-Ogievskiy wrote: 16.07.2021 19:21, Vladimir Sementsov-Ogievskiy wrote: 15.07.2021 23:00, Vladimir Sementsov-Ogievskiy wrote: 03.07.2021 16:50, Vladimir Sementsov-Ogievskiy wrote: +Permission bytes. If permission byte is rd-locked, it means that some process

Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-16 Thread Vladimir Sementsov-Ogievskiy
16.07.2021 19:21, Vladimir Sementsov-Ogievskiy wrote: 15.07.2021 23:00, Vladimir Sementsov-Ogievskiy wrote: 03.07.2021 16:50, Vladimir Sementsov-Ogievskiy wrote: +Permission bytes. If permission byte is rd-locked, it means that some process +uses corresponding permission on that file. + +Byte  

Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-16 Thread Vladimir Sementsov-Ogievskiy
15.07.2021 23:00, Vladimir Sementsov-Ogievskiy wrote: 03.07.2021 16:50, Vladimir Sementsov-Ogievskiy wrote: +Permission bytes. If permission byte is rd-locked, it means that some process +uses corresponding permission on that file. + +Byte    Operation +100 read +  Lock holder can re

Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-15 Thread Vladimir Sementsov-Ogievskiy
03.07.2021 16:50, Vladimir Sementsov-Ogievskiy wrote: +Permission bytes. If permission byte is rd-locked, it means that some process +uses corresponding permission on that file. + +ByteOperation +100 read + Lock holder can read +101 write + Lock holder can write +102

Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-15 Thread Daniel P . Berrangé
On Thu, Jul 15, 2021 at 08:13:40PM +0300, Vladimir Sementsov-Ogievskiy wrote: > 03.07.2021 17:50, Nir Soffer wrote: > > On Sat, Jul 3, 2021 at 4:51 PM Vladimir Sementsov-Ogievskiy > > wrote: > > [..] > > > > + > > > +Important notice: Qemu may fallback to POSIX file locks only if OFD locks > > >

Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-15 Thread Vladimir Sementsov-Ogievskiy
03.07.2021 17:50, Nir Soffer wrote: On Sat, Jul 3, 2021 at 4:51 PM Vladimir Sementsov-Ogievskiy wrote: [..] + +Important notice: Qemu may fallback to POSIX file locks only if OFD locks +unavailable. Other programs should behave similarly: use POSIX file locks +only if OFD locks unavailable a

Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-05 Thread Denis V. Lunev
On 7/5/21 10:55 AM, Vladimir Sementsov-Ogievskiy wrote: > 03.07.2021 17:50, Nir Soffer wrote: >> On Sat, Jul 3, 2021 at 4:51 PM Vladimir Sementsov-Ogievskiy >> wrote: >>> >>> Let's document how we use file locks in file-posix driver, to allow >>> external programs to "communicate" in this way with

Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-05 Thread Vladimir Sementsov-Ogievskiy
03.07.2021 17:50, Nir Soffer wrote: On Sat, Jul 3, 2021 at 4:51 PM Vladimir Sementsov-Ogievskiy wrote: Let's document how we use file locks in file-posix driver, to allow external programs to "communicate" in this way with Qemu. This makes the locking implementation public, so qemu can never

Re: [PATCH v2] docs: document file-posix locking protocol

2021-07-03 Thread Nir Soffer
On Sat, Jul 3, 2021 at 4:51 PM Vladimir Sementsov-Ogievskiy wrote: > > Let's document how we use file locks in file-posix driver, to allow > external programs to "communicate" in this way with Qemu. This makes the locking implementation public, so qemu can never change it without breaking externa

[PATCH v2] docs: document file-posix locking protocol

2021-07-03 Thread Vladimir Sementsov-Ogievskiy
Let's document how we use file locks in file-posix driver, to allow external programs to "communicate" in this way with Qemu. Signed-off-by: Vladimir Sementsov-Ogievskiy --- v2: improve some descriptions add examples add notice about old bad POSIX file locks docs/system/qemu-block-driv