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authorFabricio Voznika <fvoznika@google.com>2020-08-04 19:04:12 -0700
committergVisor bot <gvisor-bot@google.com>2020-08-04 19:05:55 -0700
commit102735bfb45820dd840df14827b42744da77c9a0 (patch)
tree4b80cebce8c2c189091a793de039aaa598b0b1aa /pkg/sentry/fsimpl/gofer
parentb44408b40e3e8762a77ccf5eeb7f2ef567235c43 (diff)
Inline gofer.regularFileFD.pwriteLocked
Go compiler barely inlines anything, so inline by hand pwriteLocked since it's called from a single place. PiperOrigin-RevId: 324937734
Diffstat (limited to 'pkg/sentry/fsimpl/gofer')
-rw-r--r--pkg/sentry/fsimpl/gofer/regular_file.go102
1 files changed, 56 insertions, 46 deletions
diff --git a/pkg/sentry/fsimpl/gofer/regular_file.go b/pkg/sentry/fsimpl/gofer/regular_file.go
index 420e8efe2..db6bed4f6 100644
--- a/pkg/sentry/fsimpl/gofer/regular_file.go
+++ b/pkg/sentry/fsimpl/gofer/regular_file.go
@@ -184,6 +184,7 @@ func (fd *regularFileFD) pwrite(ctx context.Context, src usermem.IOSequence, off
d.metadataMu.Lock()
defer d.metadataMu.Unlock()
+
// Set offset to file size if the fd was opened with O_APPEND.
if fd.vfsfd.StatusFlags()&linux.O_APPEND != 0 {
// Holding d.metadataMu is sufficient for reading d.size.
@@ -194,70 +195,79 @@ func (fd *regularFileFD) pwrite(ctx context.Context, src usermem.IOSequence, off
return 0, offset, err
}
src = src.TakeFirst64(limit)
- n, err := fd.pwriteLocked(ctx, src, offset, opts)
- return n, offset + n, err
-}
-// Preconditions: fd.dentry().metatdataMu must be locked.
-func (fd *regularFileFD) pwriteLocked(ctx context.Context, src usermem.IOSequence, offset int64, opts vfs.WriteOptions) (int64, error) {
- d := fd.dentry()
if d.fs.opts.interop != InteropModeShared {
// Compare Linux's mm/filemap.c:__generic_file_write_iter() =>
// file_update_time(). This is d.touchCMtime(), but without locking
// d.metadataMu (recursively).
d.touchCMtimeLocked()
}
- if fd.vfsfd.StatusFlags()&linux.O_DIRECT != 0 {
- // Write dirty cached pages that will be touched by the write back to
- // the remote file.
- if err := d.writeback(ctx, offset, src.NumBytes()); err != nil {
- return 0, err
- }
- // Remove touched pages from the cache.
- pgstart := usermem.PageRoundDown(uint64(offset))
- pgend, ok := usermem.PageRoundUp(uint64(offset + src.NumBytes()))
- if !ok {
- return 0, syserror.EINVAL
- }
- mr := memmap.MappableRange{pgstart, pgend}
- var freed []memmap.FileRange
- d.dataMu.Lock()
- cseg := d.cache.LowerBoundSegment(mr.Start)
- for cseg.Ok() && cseg.Start() < mr.End {
- cseg = d.cache.Isolate(cseg, mr)
- freed = append(freed, memmap.FileRange{cseg.Value(), cseg.Value() + cseg.Range().Length()})
- cseg = d.cache.Remove(cseg).NextSegment()
- }
- d.dataMu.Unlock()
- // Invalidate mappings of removed pages.
- d.mapsMu.Lock()
- d.mappings.Invalidate(mr, memmap.InvalidateOpts{})
- d.mapsMu.Unlock()
- // Finally free pages removed from the cache.
- mf := d.fs.mfp.MemoryFile()
- for _, freedFR := range freed {
- mf.DecRef(freedFR)
- }
- }
+
rw := getDentryReadWriter(ctx, d, offset)
+ defer putDentryReadWriter(rw)
+
if fd.vfsfd.StatusFlags()&linux.O_DIRECT != 0 {
+ if err := fd.writeCache(ctx, d, offset, src); err != nil {
+ return 0, offset, err
+ }
+
// Require the write to go to the remote file.
rw.direct = true
}
+
n, err := src.CopyInTo(ctx, rw)
- putDentryReadWriter(rw)
- if n != 0 && fd.vfsfd.StatusFlags()&(linux.O_DSYNC|linux.O_SYNC) != 0 {
- // Write dirty cached pages touched by the write back to the remote
- // file.
+ if err != nil {
+ return n, offset, err
+ }
+ if n > 0 && fd.vfsfd.StatusFlags()&(linux.O_DSYNC|linux.O_SYNC) != 0 {
+ // Write dirty cached pages touched by the write back to the remote file.
if err := d.writeback(ctx, offset, src.NumBytes()); err != nil {
- return 0, err
+ return n, offset, err
}
// Request the remote filesystem to sync the remote file.
- if err := d.handle.file.fsync(ctx); err != nil {
- return 0, err
+ if err := d.handle.sync(ctx); err != nil {
+ return n, offset, err
}
}
- return n, err
+ return n, offset + n, nil
+}
+
+func (fd *regularFileFD) writeCache(ctx context.Context, d *dentry, offset int64, src usermem.IOSequence) error {
+ // Write dirty cached pages that will be touched by the write back to
+ // the remote file.
+ if err := d.writeback(ctx, offset, src.NumBytes()); err != nil {
+ return err
+ }
+
+ // Remove touched pages from the cache.
+ pgstart := usermem.PageRoundDown(uint64(offset))
+ pgend, ok := usermem.PageRoundUp(uint64(offset + src.NumBytes()))
+ if !ok {
+ return syserror.EINVAL
+ }
+ mr := memmap.MappableRange{pgstart, pgend}
+ var freed []memmap.FileRange
+
+ d.dataMu.Lock()
+ cseg := d.cache.LowerBoundSegment(mr.Start)
+ for cseg.Ok() && cseg.Start() < mr.End {
+ cseg = d.cache.Isolate(cseg, mr)
+ freed = append(freed, memmap.FileRange{cseg.Value(), cseg.Value() + cseg.Range().Length()})
+ cseg = d.cache.Remove(cseg).NextSegment()
+ }
+ d.dataMu.Unlock()
+
+ // Invalidate mappings of removed pages.
+ d.mapsMu.Lock()
+ d.mappings.Invalidate(mr, memmap.InvalidateOpts{})
+ d.mapsMu.Unlock()
+
+ // Finally free pages removed from the cache.
+ mf := d.fs.mfp.MemoryFile()
+ for _, freedFR := range freed {
+ mf.DecRef(freedFR)
+ }
+ return nil
}
// Write implements vfs.FileDescriptionImpl.Write.