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| author | Michael Kerrisk <mtk.manpages@gmail.com> | 2016-09-12 19:10:28 +0100 |
|---|---|---|
| committer | Michael Kerrisk <mtk.manpages@gmail.com> | 2016-09-12 20:34:22 +0100 |
| commit | 47c906e5c4df647bda8d93a51268baeabc1496c8 (patch) | |
| tree | e076ae00036849c7a2e66e287f21454efd22f083 | |
| parent | 58afe6afe122b1fac2dffa67cf0818c27426c251 (diff) | |
| download | man-pages-47c906e5c4df647bda8d93a51268baeabc1496c8.tar.gz | |
open.2: Clarify user namespace capability requirements for O_NOATIME
Signed-off-by: Michael Kerrisk <mtk.manpages@gmail.com>
| -rw-r--r-- | man2/open.2 | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/man2/open.2 b/man2/open.2 index 28b92954f2..4752b972f0 100644 --- a/man2/open.2 +++ b/man2/open.2 @@ -483,6 +483,20 @@ Do not update the file last access time in the inode) when the file is .BR read (2). + +This flag can be employed only if one of the following conditions is true: +.RS +.IP * 3 +The effective UID of the process +.\" Strictly speaking: the filesystem UID +matches the owner UID of the file. +.IP * +The calling process has the +.BR CAP_FOWNER +capability in its user namespace and +the owner UID of the file has a mapping in the namespace. +.RE +.IP This flag is intended for use by indexing or backup programs, where its use can significantly reduce the amount of disk activity. This flag may not be effective on all filesystems. @@ -1018,8 +1032,7 @@ The .B O_NOATIME flag was specified, but the effective user ID of the caller .\" Strictly speaking, it's the filesystem UID... (MTK) -did not match the owner of the file and the caller was not privileged -.RB ( CAP_FOWNER ). +did not match the owner of the file and the caller was not privileged. .TP .B EPERM The operation was prevented by a file seal; see |