diff options
Diffstat (limited to 'pkg/p9/client.go')
| -rw-r--r-- | pkg/p9/client.go | 56 |
1 files changed, 38 insertions, 18 deletions
diff --git a/pkg/p9/client.go b/pkg/p9/client.go index 221516c6c..71e944c30 100644 --- a/pkg/p9/client.go +++ b/pkg/p9/client.go @@ -17,12 +17,13 @@ package p9 import ( "errors" "fmt" - "sync" "syscall" "golang.org/x/sys/unix" "gvisor.dev/gvisor/pkg/flipcall" "gvisor.dev/gvisor/pkg/log" + "gvisor.dev/gvisor/pkg/pool" + "gvisor.dev/gvisor/pkg/sync" "gvisor.dev/gvisor/pkg/unet" ) @@ -74,10 +75,10 @@ type Client struct { socket *unet.Socket // tagPool is the collection of available tags. - tagPool pool + tagPool pool.Pool // fidPool is the collection of available fids. - fidPool pool + fidPool pool.Pool // messageSize is the maximum total size of a message. messageSize uint32 @@ -155,8 +156,8 @@ func NewClient(socket *unet.Socket, messageSize uint32, version string) (*Client } c := &Client{ socket: socket, - tagPool: pool{start: 1, limit: uint64(NoTag)}, - fidPool: pool{start: 1, limit: uint64(NoFID)}, + tagPool: pool.Pool{Start: 1, Limit: uint64(NoTag)}, + fidPool: pool.Pool{Start: 1, Limit: uint64(NoFID)}, pending: make(map[Tag]*response), recvr: make(chan bool, 1), messageSize: messageSize, @@ -173,7 +174,7 @@ func NewClient(socket *unet.Socket, messageSize uint32, version string) (*Client // our sendRecv function to use that functionality. Otherwise, // we stick to sendRecvLegacy. rversion := Rversion{} - err := c.sendRecvLegacy(&Tversion{ + _, err := c.sendRecvLegacy(&Tversion{ Version: versionString(requested), MSize: messageSize, }, &rversion) @@ -218,11 +219,11 @@ func NewClient(socket *unet.Socket, messageSize uint32, version string) (*Client c.sendRecv = c.sendRecvChannel } else { // Channel setup failed; fallback. - c.sendRecv = c.sendRecvLegacy + c.sendRecv = c.sendRecvLegacySyscallErr } } else { // No channels available: use the legacy mechanism. - c.sendRecv = c.sendRecvLegacy + c.sendRecv = c.sendRecvLegacySyscallErr } // Ensure that the socket and channels are closed when the socket is shut @@ -304,7 +305,7 @@ func (c *Client) openChannel(id int) error { ) // Open the data channel. - if err := c.sendRecvLegacy(&Tchannel{ + if _, err := c.sendRecvLegacy(&Tchannel{ ID: uint32(id), Control: 0, }, &rchannel0); err != nil { @@ -318,7 +319,7 @@ func (c *Client) openChannel(id int) error { defer rchannel0.FilePayload().Close() // Open the channel for file descriptors. - if err := c.sendRecvLegacy(&Tchannel{ + if _, err := c.sendRecvLegacy(&Tchannel{ ID: uint32(id), Control: 1, }, &rchannel1); err != nil { @@ -430,13 +431,28 @@ func (c *Client) waitAndRecv(done chan error) error { } } +// sendRecvLegacySyscallErr is a wrapper for sendRecvLegacy that converts all +// non-syscall errors to EIO. +func (c *Client) sendRecvLegacySyscallErr(t message, r message) error { + received, err := c.sendRecvLegacy(t, r) + if !received { + log.Warningf("p9.Client.sendRecvChannel: %v", err) + return syscall.EIO + } + return err +} + // sendRecvLegacy performs a roundtrip message exchange. // +// sendRecvLegacy returns true if a message was received. This allows us to +// differentiate between failed receives and successful receives where the +// response was an error message. +// // This is called by internal functions. -func (c *Client) sendRecvLegacy(t message, r message) error { +func (c *Client) sendRecvLegacy(t message, r message) (bool, error) { tag, ok := c.tagPool.Get() if !ok { - return ErrOutOfTags + return false, ErrOutOfTags } defer c.tagPool.Put(tag) @@ -456,12 +472,12 @@ func (c *Client) sendRecvLegacy(t message, r message) error { err := send(c.socket, Tag(tag), t) c.sendMu.Unlock() if err != nil { - return err + return false, err } // Co-ordinate with other receivers. if err := c.waitAndRecv(resp.done); err != nil { - return err + return false, err } // Is it an error message? @@ -469,14 +485,14 @@ func (c *Client) sendRecvLegacy(t message, r message) error { // For convenience, we transform these directly // into errors. Handlers need not handle this case. if rlerr, ok := resp.r.(*Rlerror); ok { - return syscall.Errno(rlerr.Error) + return true, syscall.Errno(rlerr.Error) } // At this point, we know it matches. // // Per recv call above, we will only allow a type // match (and give our r) or an instance of Rlerror. - return nil + return true, nil } // sendRecvChannel uses channels to send a message. @@ -485,7 +501,7 @@ func (c *Client) sendRecvChannel(t message, r message) error { c.channelsMu.Lock() if len(c.availableChannels) == 0 { c.channelsMu.Unlock() - return c.sendRecvLegacy(t, r) + return c.sendRecvLegacySyscallErr(t, r) } idx := len(c.availableChannels) - 1 ch := c.availableChannels[idx] @@ -525,7 +541,11 @@ func (c *Client) sendRecvChannel(t message, r message) error { } // Parse the server's response. - _, retErr := ch.recv(r, rsz) + resp, retErr := ch.recv(r, rsz) + if resp == nil { + log.Warningf("p9.Client.sendRecvChannel: p9.channel.recv: %v", retErr) + retErr = syscall.EIO + } // Release the channel. c.channelsMu.Lock() |