Commit Graph

6 Commits

Author SHA1 Message Date
Jamie Liu 9b5e305e05 Remove filesystem structure from vfs.Dentry.
This change:

- Drastically simplifies the synchronization model: filesystem structure is
  both implementation-defined and implementation-synchronized.

- Allows implementations of vfs.DentryImpl to use implementation-specific
  dentry types, reducing casts during path traversal.

- Doesn't require dentries representing non-directory files to waste space on a
  map of children.

- Allows dentry revalidation and mount lookup to be correctly ordered (fixed
  FIXME in fsimpl/gofer/filesystem.go).

- Removes the need to have two separate maps in gofer.dentry
  (dentry.vfsd.children and dentry.negativeChildren) for positive and negative
  lookups respectively.

//pkg/sentry/fsimpl/tmpfs/benchmark_test.go:
name                        old time/op  new time/op  delta
VFS2TmpfsStat/1-112          172ns ± 4%   165ns ± 3%   -4.08%  (p=0.002 n=9+9)
VFS2TmpfsStat/2-112          199ns ± 3%   195ns ±10%     ~     (p=0.132 n=8+9)
VFS2TmpfsStat/3-112          230ns ± 2%   216ns ± 2%   -6.15%  (p=0.000 n=8+8)
VFS2TmpfsStat/8-112          390ns ± 2%   358ns ± 4%   -8.33%  (p=0.000 n=9+8)
VFS2TmpfsStat/64-112        2.20µs ± 3%  2.01µs ± 3%   -8.48%  (p=0.000 n=10+8)
VFS2TmpfsStat/100-112       3.42µs ± 9%  3.08µs ± 2%   -9.82%  (p=0.000 n=9+8)
VFS2TmpfsMountStat/1-112     278ns ± 1%   286ns ±15%     ~     (p=0.712 n=8+10)
VFS2TmpfsMountStat/2-112     311ns ± 4%   298ns ± 2%   -4.27%  (p=0.000 n=9+8)
VFS2TmpfsMountStat/3-112     339ns ± 3%   330ns ± 9%     ~     (p=0.070 n=8+9)
VFS2TmpfsMountStat/8-112     503ns ± 3%   466ns ± 3%   -7.38%  (p=0.000 n=8+8)
VFS2TmpfsMountStat/64-112   2.53µs ±16%  2.17µs ± 7%  -14.19%  (p=0.000 n=10+9)
VFS2TmpfsMountStat/100-112  3.60µs ± 4%  3.30µs ± 8%   -8.33%  (p=0.001 n=8+9)

Updates #1035

PiperOrigin-RevId: 307655892
2020-04-21 12:18:07 -07:00
Jamie Liu e72ce8cce4 Change lingering uses of "memfs" in fsimpl/tmpfs to "tmpfs".
PiperOrigin-RevId: 307422746
2020-04-20 10:10:35 -07:00
gVisor bot e4c7f3e6f6 Inline vfs.VirtualFilesystem in Kernel struct
This saves one pointer dereference per VFS access.

Updates #1623

PiperOrigin-RevId: 295216176
2020-02-14 13:40:39 -08:00
Fabricio Voznika dcffddf0ca Remove argument from vfs.MountNamespace.DecRef()
Updates #1035

PiperOrigin-RevId: 293194631
2020-02-04 11:48:36 -08:00
Adin Scannell 0e2f1b7abd Update package locations.
Because the abi will depend on the core types for marshalling (usermem,
context, safemem, safecopy), these need to be flattened from the sentry
directory. These packages contain no sentry-specific details.

PiperOrigin-RevId: 291811289
2020-01-27 15:31:32 -08:00
Nicolas Lacasse 51f3ab85e0 Convert memfs into proto-tmpfs.
- Renamed memfs to tmpfs.
- Copied fileRangeSet bits from fs/fsutil/ to fsimpl/tmpfs/
- Changed tmpfs to be backed by filemem instead of byte slice.
- regularFileReadWriter uses a sync.Pool, similar to gofer client.

PiperOrigin-RevId: 288356380
2020-01-06 12:52:55 -08:00