The treeCache in SnapshotsDir was never cleared when snapshots were
reloaded. This caused the "latest" symlink to keep pointing to the
previous snapshot even after new snapshots were added.
Add a generation counter to SnapshotsDirStructure that is incremented
whenever the directory structure is rebuilt (in makeDirs). The
treeCache checks this generation on each lookup and resets itself
when the generation changes, ensuring cached nodes (including symlinks)
are refreshed after a snapshot reload.
A particular node should always be represented by a single instance.
This is necessary to allow the fuse library to assign a stable nodeId to
a node. macOS Sonoma trips over the previous, unstable behavior when
using fuse-t.
Hard links to the same file now get the same inode within the FUSE
mount. Also, inode generation is faster and, more importantly, no longer
allocates.
Benchmarked on Linux/amd64. Old means the benchmark with
sink = fs.GenerateDynamicInode(1, sub.node.Name)
instead of calling inodeFromNode. Results:
name old time/op new time/op delta
Inode/no_hard_links-8 137ns ± 4% 34ns ± 1% -75.20% (p=0.000 n=10+10)
Inode/hard_link-8 33.6ns ± 1% 9.5ns ± 0% -71.82% (p=0.000 n=9+8)
name old alloc/op new alloc/op delta
Inode/no_hard_links-8 48.0B ± 0% 0.0B -100.00% (p=0.000 n=10+10)
Inode/hard_link-8 0.00B 0.00B ~ (all equal)
name old allocs/op new allocs/op delta
Inode/no_hard_links-8 1.00 ± 0% 0.00 -100.00% (p=0.000 n=10+10)
Inode/hard_link-8 0.00 0.00 ~ (all equal)
bazil/fuse expects us to return context.Canceled to signal that a
syscall was successfully interrupted. Returning a wrapped version of
that error however causes the fuse library to signal an EIO (input/output
error). Thus unwrap context.Canceled errors before returning them.
Cleanly separate the directory presentation and the snapshot directory
structure. SnapshotsDir now translates the dirStruct into a format
usable by the fuse library and contains only minimal special case rules.
All decisions have moved into SnapshotsDirStructure which now creates a
fully preassembled tree data structure.
These commands filter the snapshots according to some criteria which
essentially requires loading the index before filtering the snapshots.
Thus create a copy of the snapshots list beforehand and use it later on.
This command can only be built on Darwin, FreeBSD and Linux
(and if we upgrade bazil.org/fuse, only FreeBSD and Linux:
https://github.com/bazil/fuse/issues/224).
Listing the few supported operating systems explicitly here makes
porting restic to new platforms easier.
The `dump`, `find`, `forget`, `ls`, `mount`, `restore`, `snapshots`,
`stats` and `tag` commands will now take into account multiple
`--host` and `-H` flags.