On Fri, Aug 16, 2013 at 04:22:09PM -0700, Andy Lutomirski wrote:
> This is like file_update_time, except that it acts on a struct inode *
> instead of a struct file *.
>
> Signed-off-by: Andy Lutomirski <luto@xxxxxxxxxxxxxx>
> ---
> fs/inode.c | 72 ++++++++++++++++++++++++++++++++++++++++++------------
> include/linux/fs.h | 1 +
> 2 files changed, 58 insertions(+), 15 deletions(-)
>
> diff --git a/fs/inode.c b/fs/inode.c
> index d6dfb09..bc90c12 100644
> --- a/fs/inode.c
> +++ b/fs/inode.c
> @@ -1637,6 +1637,34 @@ int file_remove_suid(struct file *file)
> }
> EXPORT_SYMBOL(file_remove_suid);
>
> +/*
> + * This does the work that's common to file_update_time and
> + * inode_update_time.
> + */
> +static int prepare_update_cmtime(struct inode *inode, struct timespec *now)
> +{
> + int sync_it;
> +
> + /* First try to exhaust all avenues to not sync */
> + if (IS_NOCMTIME(inode))
> + return 0;
> +
> + *now = current_fs_time(inode->i_sb);
> + if (!timespec_equal(&inode->i_mtime, now))
> + sync_it = S_MTIME;
> +
> + if (!timespec_equal(&inode->i_ctime, now))
> + sync_it |= S_CTIME;
> +
> + if (IS_I_VERSION(inode))
> + sync_it |= S_VERSION;
> +
> + if (!sync_it)
> + return 0;
> +
> + return sync_it;
> +}
> +
> /**
> * file_update_time - update mtime and ctime time
> * @file: file accessed
> @@ -1654,23 +1682,9 @@ int file_update_time(struct file *file)
> {
> struct inode *inode = file_inode(file);
> struct timespec now;
> - int sync_it = 0;
> + int sync_it = prepare_update_cmtime(inode, &now);
> int ret;
>
> - /* First try to exhaust all avenues to not sync */
> - if (IS_NOCMTIME(inode))
> - return 0;
> -
> - now = current_fs_time(inode->i_sb);
> - if (!timespec_equal(&inode->i_mtime, &now))
> - sync_it = S_MTIME;
> -
> - if (!timespec_equal(&inode->i_ctime, &now))
> - sync_it |= S_CTIME;
> -
> - if (IS_I_VERSION(inode))
> - sync_it |= S_VERSION;
> -
> if (!sync_it)
> return 0;
>
> @@ -1685,6 +1699,34 @@ int file_update_time(struct file *file)
> }
> EXPORT_SYMBOL(file_update_time);
>
> +/**
> + * inode_update_time_writable - update mtime and ctime time
> + * @inode: inode accessed
> + *
> + * This is like file_update_time, but it assumes the mnt is writable
> + * and takes an inode parameter instead. (We need to assume the mnt
> + * was writable because inodes aren't associated with any particular
> + * mnt.
> + */
> +
> +int inode_update_time_writable(struct inode *inode)
> +{
> + struct timespec now;
> + int sync_it = prepare_update_cmtime(inode, &now);
> + int ret;
> +
> + if (!sync_it)
> + return 0;
> +
> + /* sb_start_pagefault and update_time can both sleep. */
> + sb_start_pagefault(inode->i_sb);
> + ret = update_time(inode, &now, sync_it);
> + sb_end_pagefault(inode->i_sb);
This gets called from the writeback path - you can't use
sb_start_pagefault/sb_end_pagefault in that path.
Cheers,
Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
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