kernel.git/fs/nfsd/filecache.c, branch linux-6.5.y

nfsd: Handle EOPENSTALE correctly in the filecache

2023-11-20T10:56:43Z

[ Upstream commit d59b3515ab021e010fdc58a8f445ea62dd2f7f4c ] The nfsd_open code handles EOPENSTALE correctly, by retrying the call to fh_verify() and __nfsd_open(). However the filecache just drops the error on the floor, and immediately returns nfserr_stale to the caller. This patch ensures that we propagate the EOPENSTALE code back to nfsd_file_do_acquire, and that we handle it correctly. Fixes: 65294c1f2c5e ("nfsd: add a new struct file caching facility to nfsd") Signed-off-by: Trond Myklebust Reviewed-by: Jeff Layton Message-Id: <20230911183027.11372-1-trond.myklebust@hammerspace.com> Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin

NFSD: Fix problem of COMMIT and NFS4ERR_DELAY in infinite loop

2023-04-27T22:49:24Z

The following request sequence to the same file causes the NFS client and server getting into an infinite loop with COMMIT and NFS4ERR_DELAY: OPEN REMOVE WRITE COMMIT Problem reported by recall11, recall12, recall14, recall20, recall22, recall40, recall42, recall48, recall50 of nfstest suite. This patch restores the handling of race condition in nfsd_file_do_acquire with unlink to that prior of the regression. Fixes: ac3a2585f018 ("nfsd: rework refcounting in filecache") Signed-off-by: Dai Ngo Reviewed-by: Jeff Layton Signed-off-by: Chuck Lever

nfsd: simplify the delayed disposal list code

2023-04-26T13:05:01Z

When queueing a dispose list to the appropriate "freeme" lists, it pointlessly queues the objects one at a time to an intermediate list. Remove a few helpers and just open code a list_move to make it more clear and efficient. Better document the resulting functions with kerneldoc comments. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

NFSD: Convert filecache to rhltable

2023-04-26T13:04:59Z

While we were converting the nfs4_file hashtable to use the kernel's resizable hashtable data structure, Neil Brown observed that the list variant (rhltable) would be better for managing nfsd_file items as well. The nfsd_file hash table will contain multiple entries for the same inode -- these should be kept together on a list. And, it could be possible for exotic or malicious client behavior to cause the hash table to resize itself on every insertion. A nice simplification is that rhltable_lookup() can return a list that contains only nfsd_file items that match a given inode, which enables us to eliminate specialized hash table helper functions and use the default functions provided by the rhashtable implementation). Since we are now storing nfsd_file items for the same inode on a single list, that effectively reduces the number of hash entries that have to be tracked in the hash table. The mininum bucket count is therefore lowered. Light testing with fstests generic/531 show no regressions. Suggested-by: Neil Brown Signed-off-by: Chuck Lever

nfsd: allow reaping files still under writeback

2023-04-26T13:04:59Z

On most filesystems, there is no reason to delay reaping an nfsd_file just because its underlying inode is still under writeback. nfsd just relies on client activity or the local flusher threads to do writeback. The main exception is NFS, which flushes all of its dirty data on last close. Add a new EXPORT_OP_FLUSH_ON_CLOSE flag to allow filesystems to signal that they do this, and only skip closing files under writeback on such filesystems. Also, remove a redundant NULL file pointer check in nfsd_file_check_writeback, and clean up nfs's export op flag definitions. Signed-off-by: Jeff Layton Acked-by: Anna Schumaker Signed-off-by: Chuck Lever

nfsd: update comment over __nfsd_file_cache_purge

2023-04-26T13:04:59Z

Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

nfsd: don't take/put an extra reference when putting a file

2023-04-26T13:04:59Z

The last thing that filp_close does is an fput, so don't bother taking and putting the extra reference. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

nfsd: add some comments to nfsd_file_do_acquire

2023-04-26T13:04:58Z

David Howells mentioned that he found this bit of code confusing, so sprinkle in some comments to clarify. Reported-by: David Howells Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

nfsd: don't kill nfsd_files because of lease break error

2023-04-26T13:04:58Z

An error from break_lease is non-fatal, so we needn't destroy the nfsd_file in that case. Just put the reference like we normally would and return the error. Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever

nfsd: simplify test_bit return in NFSD_FILE_KEY_FULL comparator

2023-04-26T13:04:58Z

test_bit returns bool, so we can just compare the result of that to the key->gc value without the "!!". Signed-off-by: Jeff Layton Signed-off-by: Chuck Lever