With cmd/mount2, reading a directory more than once returned the correct
entries on the first read but nothing on subsequent reads. Plain `ls`
triggers this: it does lseek(fd, 0, SEEK_SET) to rewind the directory
before a second getdents.
go-fuse v2.9.0 rewinds a directory stream by calling Seekdir on the
FileSeekdirer interface. dirStream did not implement it, so go-fuse
returned ENOTSUP and produced an empty listing on every read after the
first.
This implements Seekdir on dirStream: a rewind to offset 0 resets the
stream to the start, restoring correct listings on re-read. Non-zero
offsets are uncommon for in-memory listings and still return ENOTSUP,
matching go-fuse's own default. A compile-time interface assertion is
added so signature drift on future go-fuse updates is caught at build
time.
Before: second and subsequent reads of a directory returned no entries.
After: directories list correctly on every read.
See: https://github.com/hanwen/go-fuse/issues/549
Co-authored-by: Nick Craig-Wood <nick@craig-wood.com>
This change adds the --direct-io flag to the mount. This means the
page cache is completely bypassed for reads and writes. No read-ahead
takes place. Shared mmap is disabled.
This is useful to accurately read files which may change length
frequently on the source.
Before this change, the current working directory could disappear
according to the Linux kernel.
This was caused by mount returning different nodes with the same
information in.
This change uses vfs.Node.SetSys to cache the information so we always
return the same node.