Minki/linux
1
0
Fork 1
mirror of https://github.com/torvalds/linux.git synced 2024-11-24 21:21:41 +00:00
Code Issues Packages Projects Releases Wiki Activity
A mirror of the official Linux kernel repository just in case
1,310,019 Commits 7 Branches 862 Tags 6.4 GiB
C 97.6%
Assembly 1%
Shell 0.5%
Python 0.3%
Makefile 0.3%
be2ca38253
Go to file
Dominique Martinet be2ca38253 Revert "fs/9p: simplify iget to remove unnecessary paths" 
This reverts commit 724a08450f.

This code simplification introduced significant regressions on servers
that do not remap inode numbers when exporting multiple underlying
filesystems with colliding inodes, as can be illustrated with simple
tmpfs exports in qemu with remapping disabled:
```
# host side
cd /tmp/linux-test
mkdir m1 m2
mount -t tmpfs tmpfs m1
mount -t tmpfs tmpfs m2
mkdir m1/dir m2/dir
echo foo > m1/dir/foo
echo bar > m2/dir/bar

# guest side
# started with -virtfs local,path=/tmp/linux-test,mount_tag=tmp,security_model=mapped-file
mount -t 9p -o trans=virtio,debug=1 tmp /mnt/t

ls /mnt/t/m1/dir
# foo
ls /mnt/t/m2/dir
# bar (works ok if directry isn't open)

# cd to keep first dir's inode alive
cd /mnt/t/m1/dir
ls /mnt/t/m2/dir
# foo (should be bar)
```
Other examples can be crafted with regular files with fscache enabled,
in which case I/Os just happen to the wrong file leading to
corruptions, or guest failing to boot with:
  | VFS: Lookup of 'com.android.runtime' in 9p 9p would have caused loop

In theory, we'd want the servers to be smart enough and ensure they
never send us two different files with the same 'qid.path', but while
qemu has an option to remap that is recommended (and qemu prints a
warning if this case happens), there are many other servers which do
not (kvmtool, nfs-ganesha, probably diod...), we should at least ensure
we don't cause regressions on this:
- assume servers can't be trusted and operations that should get a 'new'
inode properly do so. commit d05dcfdf5e (" fs/9p: mitigate inode
collisions") attempted to do this, but v9fs_fid_iget_dotl() was not
called so some higher level of caching got in the way; this needs to be
fixed properly before we can re-apply the patches.
- if we ever want to really simplify this code, we will need to add some
negotiation with the server at mount time where the server could claim
they handle this properly, at which point we could optimize this out.
(but that might not be needed at all if we properly handle the 'new'
check?)

Fixes: 724a08450f ("fs/9p: simplify iget to remove unnecessary paths")
Reported-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/all/20240408141436.GA17022@redhat.com/
Link: https://lkml.kernel.org/r/20240923100508.GA32066@willie-the-truck
Cc: stable@vger.kernel.org # v6.9+
Message-ID: <20241024-revert_iget-v1-4-4cac63d25f72@codewreck.org>
Signed-off-by: Dominique Martinet <asmadeus@codewreck.org>
2024-10-25 06:26:09 +09:00
arch - Explicitly disable the TSC deadline timer when going idle to address 2024-10-20 12:04:32 -07:00
block block-6.12-20241018 2024-10-18 15:53:00 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto This push fixes the following issues: 2024-10-16 08:42:54 -07:00
Documentation Char/Misc/IIO fixes for 6.12-rc4 2024-10-20 13:10:44 -07:00
drivers bluetooth pull request for net: 2024-10-20 14:08:17 -07:00
fs Revert "fs/9p: simplify iget to remove unnecessary paths" 2024-10-25 06:26:09 +09:00
include TTY/Serial driver fixes for 6.12-rc4 2024-10-20 13:03:30 -07:00
init cfi: fix conditions for HAVE_CFI_ICALL_NORMALIZE_INTEGERS 2024-10-13 22:23:13 +02:00
io_uring io_uring/rw: fix wrong NOWAIT check in io_rw_init_file() 2024-10-19 09:25:45 -06:00
ipc struct fd layout change (and conversion to accessor helpers) 2024-09-23 09:35:36 -07:00
kernel - Add PREEMPT_RT maintainers 2024-10-20 11:30:56 -07:00
lib Rust fixes for v6.12 (2nd) 2024-10-19 08:32:47 -07:00
LICENSES LICENSES: add 0BSD license text 2024-09-01 20:43:24 -07:00
mm mm: fix follow_pfnmap API lockdep assert 2024-10-18 09:50:05 -07:00
net bluetooth pull request for net: 2024-10-20 14:08:17 -07:00
rust Driver core fix for 6.12-rc3 2024-10-13 09:10:52 -07:00
samples [tree-wide] finally take no_llseek out 2024-09-27 08:18:43 -07:00
scripts kbuild: rust: add CONFIG_RUSTC_LLVM_VERSION 2024-10-13 22:22:28 +02:00
security ipe: fallback to platform keyring also if key in trusted keyring is rejected 2024-10-18 12:14:53 -07:00
sound ALSA: hda/conexant - Use cached pin control for Node 0x1d on HP EliteOne 1000 G2 2024-10-16 10:29:57 +02:00
tools BPF fixes: 2024-10-18 16:27:14 -07:00
usr initramfs: shorten cmd_initfs in usr/Makefile 2024-07-16 01:07:52 +09:00
virt sched/fair: Fix external p->on_rq users 2024-10-14 09:14:35 +02:00
.clang-format clang-format: Update with v6.11-rc1's for_each macro list 2024-08-02 13:20:31 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore Add Jeff Kirsher to .get_maintainer.ignore 2024-03-08 11:36:54 +00:00
.gitattributes
.gitignore Kbuild updates for v6.12 2024-09-24 13:02:06 -07:00
.mailmap mailmap: add an entry for Andy Chiu 2024-10-17 00:28:08 -07:00
.rustfmt.toml
COPYING
CREDITS CREDITS: sort alphabetically by name 2024-10-09 12:47:19 -07:00
Kbuild
Kconfig
MAINTAINERS Char/Misc/IIO fixes for 6.12-rc4 2024-10-20 13:10:44 -07:00
Makefile Linux 6.12-rc4 2024-10-20 15:19:38 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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 reStructuredText 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.