PUFFS_FLUSH(3) | Library Functions Manual | PUFFS_FLUSH(3) |
puffs_flush
—
#include <puffs.h>
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);
puffs_inval_namecache_dir
()
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.
April 7, 2007 | NetBSD 9.0 |