Commit Graph

21 Commits

Author SHA1 Message Date
Norman Feske
ca0d3757cc vfs: make 'File_io_service::read_ready' const
... and replace pointer argument to const reference.

Issue #4706
2023-01-24 12:07:29 +01:00
Norman Feske
ff2176a586 vfs,libc: support write fds in select
By adding a 'write_ready' interface following the lines of the existing
'read_ready', VFS plugins become able to propagate the (de-)saturation
of I/O buffers to the VFS user. This information is important when using
a non-blocking file descriptor for writing into a TCP socket. Once the
application observes EAGAIN, it expects a subsequent 'select' call to
return as soon as new I/O buffer space becomes available.

Before this patch, the select call would always return under this
condition, causing an unnecessarily busy write loop.

Issue #4697
2023-01-24 12:07:28 +01:00
Johannes Schlatow
19958eafcf vfs: add notify_read_ready() to Single_vfs_handle
The Single_file_system now forwards the
`File_io_service::notify_read_ready` method to the
handle as it already did for most of the other methods.

genodelabs/genode#4394
2022-02-15 17:14:34 +01:00
Norman Feske
2912096f6e vfs: distinguish NO_PERM from NO_ENTRY in unlink
This patch changes the 'Single_file_system' to return NO_PERM only if
the to-be-unlinked file corresponds to the single file. This way, a
<rom> co-mounted with a <ram> file-system does not stand in the way of
unlinking files from the <ram>. The concrete symptom occurred the
following scenario:

  <vfs>
    <dir name="home">
      <ram/>
      <rom name="..."/>
    </dir>
  </vfs>

The following sequence of commands wrongly resulted in "Operation not
permitted":

 $ mkdir -p /home/a/b/c
 $ rm -f /home/a/b/c/d

In this case, rm should not fail (unlink should return ENOENT)

Fixes #3690
2020-03-26 11:38:55 +01:00
Norman Feske
5ab1505d43 file system: enhanced file status info
This patch extends the 'File_system::Status',
'File_system::Directory_entry', and the related 'Vfs' types with
the following additional information:

- Distinction between continuous and transactional files (Node_type)
  (issue #3507)
- Readable, writeable, and executable attributes (Node_rwx),
  replacing the former 'mode' bits
  (issue #3030)

The types 'Node_rwx', 'Node_type' are defined twice,
once for the VFS (vfs/types.h) and once for the 'File_system'
session (file_system_session/file_system_session.h).
Similarly, there is a direct correspondance between
'Vfs::Directory_service::Dirent' and 'File_system::Directory_entry'.

This duplication of types follows the existing pattern of keeping the
VFS and file-system session independent from each other.
2019-11-19 14:23:56 +01:00
Norman Feske
b3727a9b46 Add missing override annotations
Issue #3159
2019-02-19 11:12:11 +01:00
Norman Feske
6b94e65a95 os: avoid using deprecated APIs
Issue #1987
Issue #3125
2019-01-30 13:49:54 +01:00
Christian Prochaska
fd7ab79fe0 vfs: implement 'complete_sync()' in 'Single_file_system'
Fixes #3047
2018-11-27 11:38:13 +01:00
Emery Hemingway
c7d0accac0 VFS: catch Out_of_ram and Out_of_cap exceptions
Catch out of RAM and capability exceptions and return error values.
Abort opening a composite directory at Dir_file_system where an
opendir call on any child file-system returns an OUT_OF_RAM or
OUT_OF_CAPS error.

Ref #2642
2018-02-14 20:41:07 +01:00
Norman Feske
eba9c15746 Follow practices suggested by "Effective C++"
The patch adjust the code of the base, base-<kernel>, and os repository.
To adapt existing components to fix violations of the best practices
suggested by "Effective C++" as reported by the -Weffc++ compiler
argument. The changes follow the patterns outlined below:

* A class with virtual functions can no longer publicly inherit base
  classed without a vtable. The inherited object may either be moved
  to a member variable, or inherited privately. The latter would be
  used for classes that inherit 'List::Element' or 'Avl_node'. In order
  to enable the 'List' and 'Avl_tree' to access the meta data, the
  'List' must become a friend.

* Instead of adding a virtual destructor to abstract base classes,
  we inherit the new 'Interface' class, which contains a virtual
  destructor. This way, single-line abstract base classes can stay
  as compact as they are now. The 'Interface' utility resides in
  base/include/util/interface.h.

* With the new warnings enabled, all member variables must be explicitly
  initialized. Basic types may be initialized with '='. All other types
  are initialized with braces '{ ... }' or as class initializers. If
  basic types and non-basic types appear in a row, it is nice to only
  use the brace syntax (also for basic types) and align the braces.

* If a class contains pointers as members, it must now also provide a
  copy constructor and assignment operator. In the most cases, one
  would make them private, effectively disallowing the objects to be
  copied. Unfortunately, this warning cannot be fixed be inheriting
  our existing 'Noncopyable' class (the compiler fails to detect that
  the inheriting class cannot be copied and still gives the error).
  For now, we have to manually add declarations for both the copy
  constructor and assignment operator as private class members. Those
  declarations should be prepended with a comment like this:

        /*
         * Noncopyable
         */
        Thread(Thread const &);
        Thread &operator = (Thread const &);

  In the future, we should revisit these places and try to replace
  the pointers with references. In the presence of at least one
  reference member, the compiler would no longer implicitly generate
  a copy constructor. So we could remove the manual declaration.

Issue #465
2018-01-17 12:14:35 +01:00
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
Norman Feske
29b8d609c9 Adjust file headers to refer to the AGPLv3 2017-02-28 12:59:29 +01:00
Emery Hemingway
bae4ce5360 lib/vfs: deduplicate symlink and single_file
Issue #1891
2016-11-08 15:26:31 +01:00
Christian Helmuth
d8c34237bf vfs: default constructor for Dirent and Stat
Fixes #1743
2016-06-28 11:09:27 +02:00
Norman Feske
807be83b1b Remove inconsistent use of 'is_' prefix
Fixes #1963
2016-05-23 15:52:39 +02:00
Emery Hemingway
1d301e9c14 lib/vfs: consistent device and inode enumeration
Issue #1751
2016-04-25 10:47:54 +02:00
Emery Hemingway
82a7799638 lib/vfs: pass handle allocator to open(...)
Opening a VFS handle previously involved allocating from the global heap
at each VFS file system. By amending open with an allocator argument,
dynamic allocation can be partitioned.

A new close method is used to deallocate open handles.

Issue #1751
Issue #1891
2016-04-11 12:56:54 +02:00
Emery Hemingway
23c1d4c66d libc, vfs: rename improvements
Perform POSIX rename checks at the libc VFS plugin.
Clarify rename at VFS fs, ram, single, and tar file systems.

Issue #1900
Fixes #1782
2016-03-07 12:40:04 +01:00
Alexander Boettcher
8b8c2713ae vfs: use 64bit for file offset and size
Fixes #1246
2014-10-10 13:02:28 +02:00
Josef Söntgen
51b6c4b508 vfs: add vfs handle header to single_file header
Fixes #1238.
2014-08-22 16:16:40 +02:00
Norman Feske
ca971bbfd8 Move repositories to 'repos/' subdirectory
This patch changes the top-level directory layout as a preparatory
step for improving the tools for managing 3rd-party source codes.
The rationale is described in the issue referenced below.

Issue #1082
2014-05-14 16:08:00 +02:00