main: add "-kernel_cache" flag

This option is similar to fuse(8) kernel_cache

Verified using vmtouch.

Without -kernel_cache:

$ dd if=/dev/zero of=foo bs=1M count=10 ; vmtouch -t foo ; vmtouch foo
10+0 records in
10+0 records out
10485760 bytes (10 MB, 10 MiB) copied, 0,0242321 s, 433 MB/s
           Files: 1
     Directories: 0
   Touched Pages: 2560 (10M)
         Elapsed: 0.011159 seconds
           Files: 1
     Directories: 0
  Resident Pages: 0/2560  0/10M  0%
         Elapsed: 0.000993 seconds

With -kernel_cache:

$ dd if=/dev/zero of=foo bs=1M count=10 ; vmtouch -t foo ; vmtouch foo
10+0 records in
10+0 records out
10485760 bytes (10 MB, 10 MiB) copied, 0,0244015 s, 430 MB/s
           Files: 1
     Directories: 0
   Touched Pages: 2560 (10M)
         Elapsed: 0.011564 seconds
           Files: 1
     Directories: 0
  Resident Pages: 2560/2560  10M/10M  100%
         Elapsed: 0.000369 seconds
This commit is contained in:
gmd20 2020-12-08 15:27:23 +08:00 committed by Jakob Unterwurzacher
parent 14dac373c2
commit c20c7992a0
5 changed files with 12 additions and 1 deletions

View File

@ -241,6 +241,9 @@ Only for forward mode: automatically unmount the filesystem if it has been idle
for the specified duration. Durations can be specified like "500s" or "2h45m".
0 (the default) means stay mounted indefinitely.
#### -kernel_cache
Enable the kernel_cache option of the FUSE filesystem, see fuse(8) for details.
#### -ko
Pass additional mount options to the kernel (comma-separated list).
FUSE filesystems are mounted with "nodev,nosuid" by default. If gocryptfs

View File

@ -30,7 +30,7 @@ type argContainer struct {
noprealloc, speed, hkdf, serialize_reads, forcedecode, hh, info,
sharedstorage, devrandom, fsck bool
// Mount options with opposites
dev, nodev, suid, nosuid, exec, noexec, rw, ro bool
dev, nodev, suid, nosuid, exec, noexec, rw, ro, kernel_cache bool
masterkey, mountpoint, cipherdir, cpuprofile,
memprofile, ko, ctlsock, fsname, force_owner, trace, fido2 string
// -extpass, -badname, -passfile can be passed multiple times
@ -179,6 +179,7 @@ func parseCliOpts() (args argContainer) {
flagSet.BoolVar(&args.noexec, "noexec", false, "Deny executables")
flagSet.BoolVar(&args.rw, "rw", false, "Mount the filesystem read-write")
flagSet.BoolVar(&args.ro, "ro", false, "Mount the filesystem read-only")
flagSet.BoolVar(&args.kernel_cache, "kernel_cache", false, "Enable the FUSE kernel_cache option")
flagSet.StringVar(&args.masterkey, "masterkey", "", "Mount with explicit master key")
flagSet.StringVar(&args.cpuprofile, "cpuprofile", "", "Write cpu profile to specified file")

View File

@ -44,4 +44,6 @@ type Args struct {
// which are a performance problem for writes. See
// https://github.com/rfjakob/gocryptfs/issues/515 for details.
Suid bool
// Enable the FUSE kernel_cache option
KernelCache bool
}

View File

@ -190,6 +190,10 @@ func (n *Node) Open(ctx context.Context, flags uint32) (fh fs.FileHandle, fuseFl
rn.openWriteOnlyLock.RLock()
defer rn.openWriteOnlyLock.RUnlock()
if rn.args.KernelCache {
fuseFlags = fuse.FOPEN_KEEP_CACHE
}
// Open backing file
fd, err := syscallcompat.Openat(dirfd, cName, newFlags, 0)
// Handle a few specific errors

View File

@ -267,6 +267,7 @@ func initFuseFrontend(args *argContainer) (rootNode fs.InodeEmbedder, wipeKeys f
ExcludeWildcard: args.excludeWildcard,
ExcludeFrom: args.excludeFrom,
Suid: args.suid,
KernelCache: args.kernel_cache,
}
// confFile is nil when "-zerokey" or "-masterkey" was used
if confFile != nil {