removed unused variable 'grandparent'
factored out the call to name_cache_entry_update() from root/non-root paths
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
renamed name_cache_entry_refresh() to name_cache_entry_updated(). this function resets the entry's expiration timer. new function name_cache_entry_accessed() deals with moving the entry to the end of exp_entries to prevent eviction
name_cache_entry_accessed() now does the same for its parents as well. cache consistency of the parents is maintained because their expiration timers are unchanged. by 'refreshing' the parents of each name cache entry inserted, the eviction policy will always prefer child nodes (which are far less costly to evict)
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
open_update_cache() wasn't retrying insert after the open_delegation_return() error case
nfs41_name_cache_delegreturn() needs a check for if (attributes->delegated) to avoid an extra deref when the call to nfs41_name_cache_insert() failed
added a TODO comment to nfs41_client_delegation_return_lru() for improvements to the naive algorithm
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
to prevent delegations from claiming all available slots in the attribute cache, nfs41_name_cache_insert() now returns ERROR_TOO_MANY_OPEN_FILES when the number of delegated entries reaches 50% of the cache capacity. see comment 'delegations and cache feedback' in name_cache.c for details
when nfs41_open() sees this error from nfs41_name_cache_insert(), it calls new function nfs41_client_delegation_return_lru() to return the least-recently-used delegation and, if successful, loops back to nfs41_name_cache_insert(). nfs41_client_delegation_return_lru() returns NFS4ERR_BADHANDLE if all delegations are currently in use (associated with an existing open), in which case nfs41_open() returns the newly-granted delegation
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
on opens that grant a delegation, return the delegation immediately if attribute cache insertion fails
nfs41_name_cache_insert() now returns success in the 'out_err_deleg' case, where name cache insertion failed but attr cache insertion was successful
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
once the attribute cache fills up with delegated entries, attr_cache_find_or_create() will start returning ERROR_OUTOFMEMORY. this is a problem for nfs41_name_cache_insert(), because name_cache_find_or_create() will succeed and then name_cache_entry_update() will fail. this leaves behind a name cache entry with attributes=NULL, which is treated like a negative entry and causes later lookups to fail with ERROR_FILE_NOT_FOUND
added a call to name_cache_entry_invalidate() to clean up this entry if name_cache_entry_update() fails
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
added 2011 year to the copyright line
added authors info to the license
added UofM license to libtirpc files that we modified
(but i probably missed some)
when a delegation is granted by OPEN, its delegation type is passed to nfs41_name_cache_insert(). as long as the delegation is held, its name_cache_entry is kept out of the cache.exp_entries list to prevent it from expiring. an extra reference is held on the attr_cache_entry as well, so it sticks around even if the name_cache_entry is removed (a parent expires, for example). new function nfs41_name_cache_delegreturn() adds the name_cache_entry back to the list, and releases the extra attr_cache_entry reference
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
nfs41_name_cache_lookup() was returning FILE_NOT_FOUND on negative entries, but still copying the target filehandle
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
avoid the recursive case where state recovery operations (OPEN for reclaim and RECLAIM_COMPLETE) return BADSESSION, which kicks off another round of recovery
added a 'bool_t try_recovery' argument to compound_encode_send_decode() in place of its unused 'bufsize_in' and 'bufsize_out'. when try_recovery=FALSE, return BADSESSION/STALE_CLIENTID errors instead of attempting recovery. nfs41_open_reclaim(), nfs41_reclaim_complete(), and nfs41_destroy_session() now pass try_recovery=FALSE
during state recovery, we can now check the return values of nfs41_open_reclaim() and nfs41_reclaim_complete() for BADSESSION, and use a goto to restart session recovery
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
fixed a few cases of warning 4242: possible loss of data
wincrypt.h appears to come with windows.h in later versions of the ddk, but nfs41_client.c fails to compile in WDK 6001 without #include <wincrypt.h>
Signed-off-by: Casey Bodley <cbodley@citi.umich.edu>
symptom: in certain cases, name_cache_find_or_create() was returning ERROR_FILE_EXISTS, which should never happen!
cause: the string comparisons in name_cache_search() and name_cache_insert() were returning different results when the argument to name_cache_search() is a) not null-terminated, and b) shorter than the other string. this caused name_cache_search() to search the wrong branch of the rbtree and fail to find the component, while name_cache_insert() would correctly find it and return ERROR_FILE_EXISTS
fix: compare the string lengths before calling strncmp() to avoid comparing past the end of the component. moved the comparisons to a separate component_cmp() function called by both name_cache_search() and name_cache_insert() to make sure they get the same result!
Signed-off-by: Casey Bodley <cbodley@umich.edu>
/* negative lookup caching
*
* by caching lookups that result in NOENT, we can avoid sending subsequent
* lookups over the wire. a name cache entry is negative when its attributes
* pointer is NULL. negative entries are created by three functions:
* nfs41_name_cache_remove(), _insert() when called with NULL for the fh and
* attributes, and _rename() for the source entry
*/
Signed-off-by: Casey Bodley <cbodley@umich.edu>
previously, when the name cache encountered a missing/negative/expired entry, it returned the previous two entries as 'target' and 'parent', and nfs41_lookup() started new lookups from the filehandle in 'target'. this differs from nfs41_lookup(), which on NOENT will return NULL for the 'target' and the previous entry as 'parent'. modified name_cache_lookup() to do the same, and updated nfs41_lookup() to start new lookups from the filehandle in 'parent'
now when nfs41_lookup() gets the is_negative flag from nfs41_name_cache_lookup(), it can just return the error without needing to copy the 'target' to 'parent'
Signed-off-by: Casey Bodley <cbodley@umich.edu>
as before, we move the src entry from src_parent to dst_parent. but instead of unlinking the destination entry if it exists, we recycle it as a negative entry where src used to be. if the destination entry doesn't exist, we create a new one for this negative entry
if the dst_parent entry is invalidated by the change_info, we just leave the original src entry in place and make it negative
Signed-off-by: Casey Bodley <cbodley@umich.edu>
negative lookup entries don't have attributes, so we won't invalidate them based on 'change'. name_cache_entry_changed() returns false if entry->attributes == NULL
Signed-off-by: Casey Bodley <cbodley@umich.edu>
instead of calling name_cache_entry_unlink(), nfs41_name_cache_remove() calls name_cache_entry_update() with NULL for fh and info to make it a negative entry, then name_cache_unlink_children_recursive() to remove any children
Signed-off-by: Casey Bodley <cbodley@umich.edu>
marked nfs41_name_cache_insert() parameters fh and info as OPTIONAL; passing NULL designates a negative lookup entry
name_cache_entry_create() no longer calls attr_cache_find_or_create(), and doesn't need the 'fileid' argument
name_cache_entry_update() also makes fh and info OPTIONAL, and handles the cases where we switch from a negative <-> positive entry, calling attr_cache_find_or_create() or attr_cache_entry_deref() as appropriate
removed unused function name_cache_find_or_create(); everything uses name_cache_entry_find_or_create() instead, so renamed that to name_cache_find_or_create()
Signed-off-by: Casey Bodley <cbodley@umich.edu>
added function entry_invis() in addition to entry_has_expired(). entry_invis() returns true if entry_has_expired() or for negative entries. the is_negative flag is set for negative entries (defined as having entry->attributes == NULL), and returned by nfs41_name_cache_lookup(). when nfs41_lookup() sees this flag set, it returns the status without attempting to do any more lookups
Signed-off-by: Casey Bodley <cbodley@umich.edu>
