Re: [PATCH v3 1/2] name_to_handle_at.2: Document the AT_HANDLE_MNT_ID_UNIQUE flag
From: Alejandro Colomar <alx@kernel.org>
Date: 2025-03-31 08:38:27
Hi Amir, On Mon, Mar 31, 2025 at 10:16:41AM +0200, Amir Goldstein wrote:
A flag since v6.12 to indicate that the requested mount_id is a 64bit unique id. Cc: Chuck Lever <chuck.lever@oracle.com> Cc: Jeff Layton <redacted> Cc: Christian Brauner <brauner@kernel.org> Cc: Jan Kara <jack@suse.cz> Cc: Aleksa Sarai <redacted> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Thanks! I've applied the patch, with some minor amendments: diff --git i/man/man2/open_by_handle_at.2 w/man/man2/open_by_handle_at.2 index da0129dee..47405b118 100644 --- i/man/man2/open_by_handle_at.2 +++ w/man/man2/open_by_handle_at.2 @@ -127,7 +127,7 @@ .SS name_to_handle_at() .I flags argument is a bit mask constructed by ORing together zero or more of .BR AT_HANDLE_FID , -.BR AT_HANDLE_MNT_ID_UNIQUE, +.BR AT_HANDLE_MNT_ID_UNIQUE , .BR AT_EMPTY_PATH , and .BR AT_SYMLINK_FOLLOW , @@ -153,11 +153,11 @@ .SS name_to_handle_at() contain the .BR AT_HANDLE_MNT_ID_UNIQUE " (since Linux 6.12)" .\" commit 4356d575ef0f39a3e8e0ce0c40d84ce900ac3b61 -flag, the caller indicates that the size of the +flag, the caller indicates that the width of the .I mount_id -buffer is at least 64bit +buffer is at least 64 bits, and then the mount id returned in that buffer -is the unique mount id as the one returned by +is the unique mount id as returned by .BR statx (2) with the .BR STATX_MNT_ID_UNIQUE The most notable one is s/size/width/. In C23 there are the concepts of the width of a type and the size of a type. The width is measured in bits, and the size is measured in bytes. Let's be consistent with that. I have also proposed a new set of operators for ISO C2y, which are _Minof, _Maxof, and _Widthof, which yield the minimum and maximum values of a type, and its width in bits. <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n3518.txt> The C Committee seems in favour of that proposal, and I expect it will be accepted in August. Have a lovely day! Alex P.S.: I'm not using my @gmail account anymore. Please use [off-list ref].
quoted hunk ↗ jump to hunk
--- man/man2/open_by_handle_at.2 | 16 ++++++++++++++++ 1 file changed, 16 insertions(+)diff --git a/man/man2/open_by_handle_at.2 b/man/man2/open_by_handle_at.2 index 6b9758d42..e3ec70dd5 100644 --- a/man/man2/open_by_handle_at.2 +++ b/man/man2/open_by_handle_at.2@@ -127,6 +127,7 @@ The .I flags argument is a bit mask constructed by ORing together zero or more of .BR AT_HANDLE_FID , +.BR AT_HANDLE_MNT_ID_UNIQUE, .BR AT_EMPTY_PATH , and .BR AT_SYMLINK_FOLLOW ,@@ -147,6 +148,21 @@ with the returned .I file_handle may fail. .P +When +.I flags +contain the +.BR AT_HANDLE_MNT_ID_UNIQUE " (since Linux 6.12)" +.\" commit 4356d575ef0f39a3e8e0ce0c40d84ce900ac3b61 +flag, the caller indicates that the size of the +.I mount_id +buffer is at least 64bit +and then the mount id returned in that buffer +is the unique mount id as the one returned by +.BR statx (2) +with the +.BR STATX_MNT_ID_UNIQUE +flag. +.P Together, the .I pathname and-- 2.34.1
-- <https://www.alejandro-colomar.es/>
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