On Wed, 2011-09-21 at 10:58 -0400, J. Bruce Fields wrote:
> Eventually we should probably do the same thing to the file operations
> as well.
>
> Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
> ---
> fs/locks.c | 98 ++++++++++++++++++++++++++++++++++++++----------------------
> 1 files changed, 62 insertions(+), 36 deletions(-)
>
> diff --git a/fs/locks.c b/fs/locks.c
> index 9b8408e..b342902 100644
> --- a/fs/locks.c
> +++ b/fs/locks.c
> @@ -1352,18 +1352,7 @@ int fcntl_getlease(struct file *filp)
> return type;
> }
>
> -/**
> - * generic_setlease - sets a lease on an open file
> - * @filp: file pointer
> - * @arg: type of lease to obtain
> - * @flp: input - file_lock to use, output - file_lock inserted
> - *
> - * The (input) flp->fl_lmops->lm_break function is required
> - * by break_lease().
> - *
> - * Called with file_lock_lock held.
> - */
> -int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
> +int generic_add_lease(struct file *filp, long arg, struct file_lock **flp)
> {
> struct file_lock *fl, **before, **my_before = NULL, *lease;
> struct dentry *dentry = filp->f_path.dentry;
> @@ -1372,30 +1361,14 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
>
> lease = *flp;
>
> - error = -EACCES;
> - if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE))
> - goto out;
> - error = -EINVAL;
> - if (!S_ISREG(inode->i_mode))
> + error = -EAGAIN;
> + if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
> goto out;
> - error = security_file_lock(filp, arg);
> - if (error)
> + if ((arg == F_WRLCK)
> + && ((dentry->d_count > 1)
> + || (atomic_read(&inode->i_count) > 1)))
> goto out;
>
> - time_out_leases(inode);
> -
> - BUG_ON(!(*flp)->fl_lmops->lm_break);
> -
> - if (arg != F_UNLCK) {
> - error = -EAGAIN;
> - if ((arg == F_RDLCK) && (atomic_read(&inode->i_writecount) > 0))
> - goto out;
> - if ((arg == F_WRLCK)
> - && ((dentry->d_count > 1)
> - || (atomic_read(&inode->i_count) > 1)))
> - goto out;
> - }
> -
> /*
> * At this point, we know that if there is an exclusive
> * lease on this file, then we hold it on this filp
> @@ -1433,9 +1406,6 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
> goto out;
> }
>
> - if (arg == F_UNLCK)
> - goto out;
> -
> error = -EINVAL;
> if (!leases_enable)
> goto out;
> @@ -1446,6 +1416,62 @@ int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
> out:
> return error;
> }
> +
> +int generic_delete_lease(struct file *filp, struct file_lock **flp)
> +{
> + struct file_lock *fl, **before;
> + struct dentry *dentry = filp->f_path.dentry;
> + struct inode *inode = dentry->d_inode;
> +
> + for (before = &inode->i_flock;
> + ((fl = *before) != NULL) && IS_LEASE(fl);
> + before = &fl->fl_next) {
> + if (fl->fl_file != filp)
> + continue;
> + return (*flp)->fl_lmops->lm_change(before, F_UNLCK);
> + }
> + return -EAGAIN;
> +}
> +
> +/**
> + * generic_setlease - sets a lease on an open file
> + * @filp: file pointer
> + * @arg: type of lease to obtain
> + * @flp: input - file_lock to use, output - file_lock inserted
> + *
> + * The (input) flp->fl_lmops->lm_break function is required
> + * by break_lease().
> + *
> + * Called with file_lock_lock held.
> + */
> +int generic_setlease(struct file *filp, long arg, struct file_lock **flp)
> +{
> + struct dentry *dentry = filp->f_path.dentry;
> + struct inode *inode = dentry->d_inode;
> + int error;
> +
> + if ((current_fsuid() != inode->i_uid) && !capable(CAP_LEASE))
> + return -EACCES;
> + if (!S_ISREG(inode->i_mode))
> + return -EINVAL;
> + error = security_file_lock(filp, arg);
> + if (error)
> + return error;
> +
> + time_out_leases(inode);
> +
> + BUG_ON(!(*flp)->fl_lmops->lm_break);
> +
> + switch (arg) {
> + case F_UNLCK:
> + return generic_delete_lease(filp, flp);
> + case F_RDLCK:
> + case F_WRLCK:
> + return generic_add_lease(filp, arg, flp);
> + default:
> + BUG();
> + }
> +}
> EXPORT_SYMBOL(generic_setlease);
>
> static int __vfs_setlease(struct file *filp, long arg, struct file_lock **lease)
Nice, the code refactoring makes it a lot more readable.
thanks,
Mimi
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