unimore/kernel-hacking-2024-linux-steffo
unimore/kernel-hacking-2024-linux-steffo
1
Fork 0
Code Pull requests 5 Wiki Activity

fs: add kernel doc for mnt_{hold,unhold}_writers()

Browse source 
When I introduced mnt_{hold,unhold}_writers() in commit fbdc2f6c40
("fs: split out functions to hold writers") I did not add kernel doc for
them. Fix this and introduce proper documentation.

Link: https://lore.kernel.org/r/20220203131411.3093040-4-brauner@kernel.org
Fixes: fbdc2f6c40 ("fs: split out functions to hold writers")
Cc: Seth Forshee <seth.forshee@digitalocean.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Christian Brauner 2022-02-03 14:14:07 +01:00
parent 97acd70118
commit 538f4f022a
No known key found for this signature in database
GPG key ID: 91C61BC06578DCA2
1 changed files with 30 additions and 0 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

30
fs/namespace.c
View file

@ -469,6 +469,24 @@ void mnt_drop_write_file(struct file *file)
}
EXPORT_SYMBOL(mnt_drop_write_file);
/**
* mnt_hold_writers - prevent write access to the given mount
* @mnt: mnt to prevent write access to
*
* Prevents write access to @mnt if there are no active writers for @mnt.
* This function needs to be called and return successfully before changing
* properties of @mnt that need to remain stable for callers with write access
* to @mnt.
*
* After this functions has been called successfully callers must pair it with
* a call to mnt_unhold_writers() in order to stop preventing write access to
* @mnt.
*
* Context: This function expects lock_mount_hash() to be held serializing
* setting MNT_WRITE_HOLD.
* Return: On success 0 is returned.
* On error, -EBUSY is returned.
*/
static inline int mnt_hold_writers(struct mount *mnt)
{
mnt->mnt.mnt_flags |= MNT_WRITE_HOLD;
@ -500,6 +518,18 @@ static inline int mnt_hold_writers(struct mount *mnt)
return 0;
}
/**
* mnt_unhold_writers - stop preventing write access to the given mount
* @mnt: mnt to stop preventing write access to
*
* Stop preventing write access to @mnt allowing callers to gain write access
* to @mnt again.
*
* This function can only be called after a successful call to
* mnt_hold_writers().
*
* Context: This function expects lock_mount_hash() to be held.
*/
static inline void mnt_unhold_writers(struct mount *mnt)
{
/*