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| author | David Howells <dhowells@redhat.com> | 2017-07-17 10:45:35 +0300 |
|---|---|---|
| committer | David Howells <dhowells@redhat.com> | 2017-07-17 10:45:35 +0300 |
| commit | e462ec50cb5fad19f6003a3d8087f4a0945dd2b1 (patch) | |
| tree | 7e56b715ce6b1c4ad13a4c3cfbce9462efe875bc /Documentation/filesystems/porting | |
| parent | bc98a42c1f7d0f886c0c1b75a92a004976a46d9f (diff) | |
| download | linux-e462ec50cb5fad19f6003a3d8087f4a0945dd2b1.tar.xz | |
VFS: Differentiate mount flags (MS_*) from internal superblock flags
Differentiate the MS_* flags passed to mount(2) from the internal flags set
in the super_block's s_flags. s_flags are now called SB_*, with the names
and the values for the moment mirroring the MS_* flags that they're
equivalent to.
In this patch, just the headers are altered and some kernel code where
blind automated conversion isn't necessarily correct.
Note that this shows up some interesting issues:
(1) Some MS_* flags get translated to MNT_* flags (such as MS_NODEV ->
MNT_NODEV) without passing this on to the filesystem, but some
filesystems set such flags anyway.
(2) The ->remount_fs() methods of some filesystems adjust the *flags
argument by setting MS_* flags in it, such as MS_NOATIME - but these
flags are then scrubbed by do_remount_sb() (only the occupants of
MS_RMT_MASK are permitted: MS_RDONLY, MS_SYNCHRONOUS, MS_MANDLOCK,
MS_I_VERSION and MS_LAZYTIME)
I'm not sure what's the best way to solve all these cases.
Suggested-by: Al Viro <viro@ZenIV.linux.org.uk>
Signed-off-by: David Howells <dhowells@redhat.com>
Diffstat (limited to 'Documentation/filesystems/porting')
| -rw-r--r-- | Documentation/filesystems/porting | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 5fb17f49f7a2..93e0a2404532 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -228,7 +228,7 @@ anything from oops to silent memory corruption. --- [mandatory] - FS_NOMOUNT is gone. If you use it - just set MS_NOUSER in flags + FS_NOMOUNT is gone. If you use it - just set SB_NOUSER in flags (see rootfs for one kind of solution and bdev/socket/pipe for another). --- |