[PATCH] name_to_handle_at.2: Document the AT_HANDLE_CONNECTABLE flag
From: Amir Goldstein <amir73il@gmail.com>
Date: 2025-03-30 11:16:50
Also in:
linux-fsdevel
Subsystem:
the rest · Maintainer:
Linus Torvalds
A flag since v6.13 to indicate that the requested file_handle is intended to be used for open_by_handle_at(2) to obtain an open file with a known path. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- man/man2/open_by_handle_at.2 | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-)
diff --git a/man/man2/open_by_handle_at.2 b/man/man2/open_by_handle_at.2
index 6b9758d42..ce3a2cec8 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_CONNECTABLE, .BR AT_EMPTY_PATH , and .BR AT_SYMLINK_FOLLOW ,
@@ -147,6 +148,29 @@ with the returned .I file_handle may fail. .P +When +.I flags +contain the +.BR AT_HANDLE_CONNECTABLE " (since Linux 6.13)" +.\" commit a20853ab8296d4a8754482cb5e9adde8ab426a25 +flag, the caller indicates that the returned +.I file_handle +is needed to open a file with known path later, +so it should be expected that a subsequent call to +.BR open_by_handle_at () +with the returned +.I file_handle +may fail if the file was moved, +but otherwise, +the path of the opened file is expected to be visible +from the +.IR /proc/ pid /fd/* +magic link. +This flag can not be used in combination with the flags +.BR AT_HANDLE_FID , +and +.BR AT_EMPTY_PATH . +.P Together, the .I pathname and
@@ -311,7 +335,7 @@ points outside your accessible address space. .TP .B EINVAL .I flags -includes an invalid bit value. +includes an invalid bit value or an invalid bit combination. .TP .B EINVAL .I handle\->handle_bytes
@@ -398,6 +422,11 @@ was acquired using the .B AT_HANDLE_FID flag and the filesystem does not support .BR open_by_handle_at (). +This error can also occur if the +.I handle +was acquired using the +.B AT_HANDLE_CONNECTABLE +flag and the file was moved to a different parent. .SH VERSIONS FreeBSD has a broadly similar pair of system calls in the form of .BR getfh ()
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2.34.1