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Meetakshi Setiya 2c7d399e55 smb: client: reuse file lease key in compound operations
Currently, when a rename, unlink or set path size compound operation
is requested on a file that has a lot of dirty pages to be written
to the server, we do not send the lease key for these requests. As a
result, the server can assume that this request is from a new client, and
send a lease break notification to the same client, on the same
connection. As a response to the lease break, the client can consume
several credits to write the dirty pages to the server. Depending on the
server's credit grant implementation, the server can stop granting more
credits to this connection, and this can cause a deadlock (which can only
be resolved when the lease timer on the server expires).
One of the problems here is that the client is sending no lease key,
even if it has a lease for the file. This patch fixes the problem by
reusing the existing lease key on the file for rename, unlink and set path
size compound operations so that the client does not break its own lease.

A very trivial example could be a set of commands by a client that
maintains open handle (for write) to a file and then tries to copy the
contents of that file to another one, eg.,

tail -f /dev/null > myfile &
mv myfile myfile2

Presently, the network capture on the client shows that the move (or
rename) would trigger a lease break on the same client, for the same file.
With the lease key reused, the lease break request-response overhead is
eliminated, thereby reducing the roundtrips performed for this set of
operations.

The patch fixes the bug described above and also provides perf benefit.

Signed-off-by: Meetakshi Setiya <msetiya@microsoft.com>
Signed-off-by: Steve French <stfrench@microsoft.com>
2024-03-10 19:33:54 -05:00
arch KVM GUEST_MEMFD fixes for 6.8: 2024-03-10 09:27:39 -07:00
block block: sed-opal: handle empty atoms when parsing response 2024-02-16 15:52:45 -07:00
certs This update includes the following changes: 2023-11-02 16:15:30 -10:00
crypto crypto: lskcipher - Copy IV in lskcipher glue code always 2024-02-24 08:37:24 +08:00
Documentation KVM GUEST_MEMFD fixes for 6.8: 2024-03-10 09:27:39 -07:00
drivers phy third set of fixes for 6.8 2024-03-10 11:39:48 -07:00
fs smb: client: reuse file lease key in compound operations 2024-03-10 19:33:54 -05:00
include Tracing fixes for v6.8-rc7: 2024-03-10 11:53:21 -07:00
init init/Kconfig: lower GCC version check for -Warray-bounds 2024-03-04 16:40:33 -08:00
io_uring io_uring/net: fix multishot accept overflow handling 2024-02-14 18:30:19 -07:00
ipc shm: Slim down dependencies 2023-12-20 19:26:31 -05:00
kernel Tracing fixes for v6.8-rc7: 2024-03-10 11:53:21 -07:00
lib iov_iter: get rid of 'copy_mc' flag 2024-03-06 10:52:12 +01:00
LICENSES LICENSES: Add the copyleft-next-0.3.1 license 2022-11-08 15:44:01 +01:00
mm 6 hotfixes. 4 are cc:stable and the remainder pertain to post-6.7 2024-03-07 17:16:38 -08:00
net A follow-up for sparse read fixes that went into -rc4 -- msgr2 case was 2024-03-08 18:05:21 -08:00
rust Rust changes for v6.8 2024-01-11 13:05:41 -08:00
samples work around gcc bugs with 'asm goto' with outputs 2024-02-09 15:57:48 -08:00
scripts 6 hotfixes. 4 are cc:stable and the remainder pertain to post-6.7 2024-03-07 17:16:38 -08:00
security integrity-v6.8-fix 2024-03-05 13:21:30 -08:00
sound ASoC: Fixes for v6.8 2024-03-08 08:53:36 +01:00
tools KVM GUEST_MEMFD fixes for 6.8: 2024-03-10 09:27:39 -07:00
usr Kbuild updates for v6.8 2024-01-18 17:57:07 -08:00
virt KVM: Make KVM_MEM_GUEST_MEMFD mutually exclusive with KVM_MEM_READONLY 2024-02-22 17:07:06 -08:00
.clang-format clang-format: Update with v6.7-rc4's for_each macro list 2023-12-08 23:54:38 +01:00
.cocciconfig
.editorconfig Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.get_maintainer.ignore get_maintainer: add Alan to .get_maintainer.ignore 2022-08-20 15:17:44 -07:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore Add .editorconfig file for basic formatting 2023-12-28 16:22:47 +09:00
.mailmap drm fixes for 6.8 final 2024-03-08 12:44:56 -08:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING COPYING: state that all contributions really are covered by this file 2020-02-10 13:32:20 -08:00
CREDITS MAINTAINERS: supplement of zswap maintainers update 2024-01-25 23:52:21 -08:00
Kbuild Kbuild updates for v6.1 2022-10-10 12:00:45 -07:00
Kconfig kbuild: ensure full rebuild when the compiler is updated 2020-05-12 13:28:33 +09:00
MAINTAINERS cifs: minor update to list of reviewers 2024-03-10 19:33:53 -05:00
Makefile Linux 6.8 2024-03-10 13:38:09 -07:00
README

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.