vfs_setlease(9) sets a lease on an open file

SYNOPSIS

int vfs_setlease(struct file * filp, long arg, struct file_lock ** lease);

ARGUMENTS

filp

file pointer

arg

type of lease to obtain

lease

file_lock to use

DESCRIPTION

Call this to establish a lease on the file. The (*lease)->fl_lmops->lm_break operation must be set; if not, break_lease will oops!

This will call the filesystem's setlease file method, if defined. Note that there is no getlease method; instead, the filesystem setlease method should call back to setlease to add a lease to the inode's lease list, where fcntl_getlease can find it. Since fcntl_getlease only reports whether the current task holds a lease, a cluster filesystem need only do this for leases held by processes on this node.

There is also no break_lease method; filesystems that handle their own leases should break leases themselves from the filesystem's open, create, and (on truncate) setattr methods.

WARNING

the only current setlease methods exist only to disable leases in certain cases. More vfs changes may be required to allow a full filesystem lease implementation.

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