Commit Graph

15 Commits

Author SHA1 Message Date
Christian Prochaska
b0935ef9b2 VFS: nonblocking interface
The VFS library can be used in single-threaded or multi-threaded
environments and depending on that, signals are handled by the same thread
which uses the VFS library or possibly by a different thread. If a VFS
plugin needs to block to wait for a signal, there is currently no way
which works reliably in both environments.

For this reason, this commit makes the interface of the VFS library
nonblocking, similar to the File_system session interface.

The most important changes are:

- Directories are created and opened with the 'opendir()' function and the
  directory entries are read with the recently introduced 'queue_read()'
  and 'complete_read()' functions.

- Symbolic links are created and opened with the 'openlink()' function and
  the link target is read with the 'queue_read()' and 'complete_read()'
  functions and written with the 'write()' function.

- The 'write()' function does not wait for signals anymore. This can have
  the effect that data written by a VFS library user has not been
  processed by a file system server yet when the library user asks for the
  size of the file or closes it (both done with RPC functions at the file
  system server). For this reason, a user of the VFS library should
  request synchronization before calling 'stat()' or 'close()'. To make
  sure that a file system server has processed all write request packets
  which a client submitted before the synchronization request,
  synchronization is now requested at the file system server with a
  synchronization packet instead of an RPC function. Because of this
  change, the synchronization interface of the VFS library is now split
  into 'queue_sync()' and 'complete_sync()' functions.

Fixes #2399
2017-08-28 16:49:38 +02:00
Emery Hemingway
2deddf1e6d Check for symlink target length errors
Check for symlink length errors at the VFS library and the ram_fs and
vfs servers.

Fix #2462
2017-08-17 11:04:21 +02:00
Christian Prochaska
6a43f3c11a file system: use Id_space instead of Node_handle_registry
Fixes #2436
2017-08-17 10:59:43 +02:00
Norman Feske
4d442bca30 Streamline exception types
This patch reduces the number of exception types by facilitating
globally defined exceptions for common usage patterns shared by most
services. In particular, RPC functions that demand a session-resource
upgrade not longer reflect this condition via a session-specific
exception but via the 'Out_of_ram' or 'Out_of_caps' types.

Furthermore, the 'Parent::Service_denied', 'Parent::Unavailable',
'Root::Invalid_args', 'Root::Unavailable', 'Service::Invalid_args',
'Service::Unavailable', and 'Local_service::Factory::Denied' types have
been replaced by the single 'Service_denied' exception type defined in
'session/session.h'.

This consolidation eases the error handling (there are fewer exceptions
to handle), alleviates the need to convert exceptions along the
session-creation call chain, and avoids possible aliasing problems
(catching the wrong type with the same name but living in a different
scope).
2017-05-31 13:16:07 +02:00
Emery Hemingway
24a9537a27 File_system: replace per-handle signals with notification packets
Replace registration and signaling of per-handle signal capabilities
with CONTENT_CHANGED notification packets.

Fix #2397
2017-05-31 13:16:01 +02:00
Christian Helmuth
1d99e7ede9 base: classify signals as I/O and application level
Fixes #2363
2017-05-31 13:15:58 +02:00
Norman Feske
29b8d609c9 Adjust file headers to refer to the AGPLv3 2017-02-28 12:59:29 +01:00
Alexander Boettcher
328da2975f vfs: fix races in fs_file_system with pthreads
Change metadata before submitting a packet. If the submitting thread is a
pthread, the metadata may be immediately change by the signal handler running
in the context of the entrypoint thread.
2017-02-28 12:59:23 +01:00
Martin Stein
0b5db07948 vfs fs: ignore dead handle IDs on handle_ack
When a directory gets destructed it dissolves the handles of each contained file
but the acknowledgement might be still in-flight. If we finally receive it,
it leads to an Unknown_id exception on the Handles ID Space in 'handle_ack'.
Now we catch it, print a warning, and go on.
2017-02-27 15:37:49 +01:00
Christian Helmuth
61b6dccf13 Queued read/write/read_ready in VFS and servers 2017-02-23 15:03:28 +01:00
Sebastian Sumpf
aa602032dd vfs: dynamic configuration support 2017-02-23 14:54:48 +01:00
Christian Helmuth
f9389109bf Support select in libc VFS plugin by read_ready() 2017-02-07 11:12:29 +01:00
Christian Helmuth
c0d61858c3 Support for suspendable read in VFS and libC
The support has two parts. First, a VFS plugin now gets passed an
I/O-response handler callback on construction, which informs users of the
VFS that an I/O event occurred. This enables, for example, the libC to
check if blocking read can be completed. Further, the VFS file I/O
interface provides now functions for suspendable reads, i.e.,
queue_read() and complete_read().
2017-02-07 11:12:27 +01:00
Emery Hemingway
ddf3716cff vfs: pass Env and allocator when creating file-systems
Fix #1891
2016-11-08 15:26:31 +01:00
Emery Hemingway
beebd394fc lib/vfs: seperate implemention and API headers
Issue #1891
2016-11-08 15:26:30 +01:00