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Al Viro 7484e15dbb replace collect_mounts()/drop_collected_mounts() with a safer variant
collect_mounts() has several problems - one can't iterate over the results
directly, so it has to be done with callback passed to iterate_mounts();
it has an oopsable race with d_invalidate(); it creates temporary clones
of mounts invisibly for sync umount (IOW, you can have non-lazy umount
succeed leaving filesystem not mounted anywhere and yet still busy).

A saner approach is to give caller an array of struct path that would pin
every mount in a subtree, without cloning any mounts.

        * collect_mounts()/drop_collected_mounts()/iterate_mounts() is gone
        * collect_paths(where, preallocated, size) gives either ERR_PTR(-E...) or
a pointer to array of struct path, one for each chunk of tree visible under
'where' (i.e. the first element is a copy of where, followed by (mount,root)
for everything mounted under it - the same set collect_mounts() would give).
Unlike collect_mounts(), the mounts are *not* cloned - we just get pinning
references to the roots of subtrees in the caller's namespace.
        Array is terminated by {NULL, NULL} struct path.  If it fits into
preallocated array (on-stack, normally), that's where it goes; otherwise
it's allocated by kmalloc_array().  Passing 0 as size means that 'preallocated'
is ignored (and expected to be NULL).
        * drop_collected_paths(paths, preallocated) is given the array returned
by an earlier call of collect_paths() and the preallocated array passed to that
call.  All mount/dentry references are dropped and array is kfree'd if it's not
equal to 'preallocated'.
        * instead of iterate_mounts(), users should just iterate over array
of struct path - nothing exotic is needed for that.  Existing users (all in
audit_tree.c) are converted.

[folded a fix for braino reported by Venkat Rao Bagalkote <venkat88@linux.ibm.com>]

Fixes: 80b5dce8c5 ("vfs: Add a function to lazily unmount all mounts from any dentry")
Tested-by: Venkat Rao Bagalkote <venkat88@linux.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2025-06-23 14:01:49 -04:00
arch The delayed from_timer() API cleanup: 2025-06-08 11:33:00 -07:00
block treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto EFI updates for v6.16 2025-05-30 12:42:57 -07:00
Documentation replace collect_mounts()/drop_collected_mounts() with a safer variant 2025-06-23 14:01:49 -04:00
drivers The delayed from_timer() API cleanup: 2025-06-08 11:33:00 -07:00
fs replace collect_mounts()/drop_collected_mounts() with a safer variant 2025-06-23 14:01:49 -04:00
include replace collect_mounts()/drop_collected_mounts() with a safer variant 2025-06-23 14:01:49 -04:00
init Rust changes for v6.16 2025-06-04 21:18:37 -07:00
io_uring io_uring-6.16-20250606 2025-06-06 13:09:03 -07:00
ipc - The 3 patch series "hung_task: extend blocking task stacktrace dump to 2025-05-31 19:12:53 -07:00
kernel replace collect_mounts()/drop_collected_mounts() with a safer variant 2025-06-23 14:01:49 -04:00
lib 13 hotfixes. 6 are cc:stable and the remainder address post-6.15 issues 2025-06-06 21:45:45 -07:00
LICENSES LICENSES: add CC0-1.0 license text 2025-05-21 14:54:17 +02:00
mm treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
net treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
rust Char/Misc/IIO pull request for 6.16-rc1 2025-06-06 11:50:47 -07:00
samples - The 3 patch series "hung_task: extend blocking task stacktrace dump to 2025-05-31 19:12:53 -07:00
scripts Kbuild updates for v6.16 2025-06-07 10:05:35 -07:00
security require gcc-8 and binutils-2.30 2025-05-31 08:16:52 -07:00
sound treewide, timers: Rename from_timer() to timer_container_of() 2025-06-08 09:07:37 +02:00
tools turbostat v2025.06.08 2025-06-08 11:44:41 -07:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge branch 'kvm-lockdep-common' into HEAD 2025-05-28 06:29:17 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore .gitignore: ignore Python compiled bytecode 2025-04-24 10:12:46 -06:00
.mailmap fourteen smb3 client fixes, most smbdirect related 2025-06-08 10:20:21 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.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 Update Christoph's Email address and make it consistent 2025-05-12 23:50:31 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS fourteen smb3 client fixes, most smbdirect related 2025-06-08 10:20:21 -07:00
Makefile Linux 6.16-rc1 2025-06-08 13:44:43 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

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.