int
puffs_inval_namecache_dir(
struct puffs_usermount *pu
puffs_cookie_t cookie
)
int
puffs_inval_namecache_all(
struct puffs_usermount *pu
)
int
puffs_inval_pagecache_node(
struct puffs_usermount *pu
puffs_cookie_t cookie
)
int
puffs_inval_pagecache_node_range(
struct puffs_usermount *pu
puffs_cookie_t cookie
off_t start
off_t end
)
int
puffs_flush_pagecache_node(
struct puffs_usermount *pu
puffs_cookie_t cookie
)
int
puffs_flush_pagecache_node_range(
struct puffs_usermount *pu
puffs_cookie_t cookie
off_t start
off_t end
)
)
invalidates the name cache for a given directory.
The argument
cookie
should describe an existing and valid directory cookie for the file
system.
Similarly,
puffs_inval_namecache_all(
)
invalidates the name cache for the entire file system
(this routine might go away).
The cached pages (file contents) for a regular file described by
cookie
are invalidated using
puffs_inval_pagecache_node().
A specific range can be invalidated using
puffs_inval_pagecache_node_range(
)
for a platform specific page level granularity.
The offset
start
will be
truncated
to a page boundary while
end
will be
rounded up
to the next page boundary.
As a special case, specifying 0 as
end
will invalidate all contents from
start
to the end of the file.
It is especially important to note that these routines will not only invalidate data in the "read cache", but also data in the "write back" cache (conceptually speaking; in reality they are the same cache), which has not yet been flushed to the file server. Therefore any unflushed data will be lost.
The counterparts of the invalidation routines are the flushing routines
puffs_flush_pagecache_node()
and
puffs_flush_pagecache_node_range(
),
which force unwritten data from the kernel page cache to be written.
For the flush range version, the same range rules as with the
invalidation routine apply.
The data is flushed asynchronously, i.e. if the routine returns
successfully, all the caller knows is that the data has been queued
for writing.