[PATCH v4 00/21] Readdir enhancements

trondmy
2020-11-07T14:13:38Z

The following patch series performs a number of cleanups on the readdir
code.
It also adds support for 1MB readdir RPC calls on-the-wire, and modifies
the caching code to ensure that we cache the entire contents of that
1MB call (instead of discarding the data that doesn't fit into a single
page).
For filesystems that use ordered readdir cookie schemes (e.g. XFS), it
optimises searching for cookies in the client's page cache by skipping
over pages that contain cookie values that are not in the range we are
searching for.
Finally, it improves scalability when dealing with very large
directories by turning off caching when those directories are changing,
so as to avoid the need for a linear search on the client of the entire
directory when looking for the first entry pointed to by the current
file descriptor offset.

v2: Fix the handling of the NFSv3/v4 directory verifier.
v3: Optimise searching when the readdir cookies are seen to be ordered.
v4: Optimise performance for large directories that are changing.
Add in llseek dependency patches.

Trond Myklebust (21):
NFS: Remove unnecessary inode locking in nfs_llseek_dir()
NFS: Remove unnecessary inode lock in nfs_fsync_dir()
NFS: Ensure contents of struct nfs_open_dir_context are consistent
NFS: Clean up readdir struct nfs_cache_array
NFS: Clean up nfs_readdir_page_filler()
NFS: Clean up directory array handling
NFS: Don't discard readdir results
NFS: Remove unnecessary kmap in nfs_readdir_xdr_to_array()
NFS: Replace kmap() with kmap_atomic() in nfs_readdir_search_array()
NFS: Simplify struct nfs_cache_array_entry
NFS: Support larger readdir buffers
NFS: More readdir cleanups
NFS: nfs_do_filldir() does not return a value
NFS: Reduce readdir stack usage
NFS: Cleanup to remove nfs_readdir_descriptor_t typedef
NFS: Allow the NFS generic code to pass in a verifier to readdir
NFS: Handle NFS4ERR_NOT_SAME and NFSERR_BADCOOKIE from readdir calls
NFS: Improve handling of directory verifiers
NFS: Optimisations for monotonically increasing readdir cookies
NFS: Reduce number of RPC calls when doing uncached readdir
NFS: Do uncached readdir when we're seeking a cookie in an empty page
cache

fs/nfs/client.c | 4 +-
fs/nfs/dir.c | 702 +++++++++++++++++++++++++---------------
fs/nfs/inode.c | 7 -
fs/nfs/internal.h | 6 -
fs/nfs/nfs3proc.c | 35 +-
fs/nfs/nfs4proc.c | 40 +--
fs/nfs/proc.c | 18 +-
include/linux/nfs_fs.h | 9 +-
include/linux/nfs_xdr.h | 17 +-
9 files changed, 508 insertions(+), 330 deletions(-)

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2.28.0