The 'file_size' type denotes the size of files on disk in bytes. On
32-bit architectures it is larger than the size_t, which refers to
in-memory object sizes.
Whereas the use of 'file_size' is appropriate for ftruncate and seek, it
is not a suitable type for the parameters of read/write operations
because those operations refer to in-memory buffers.
This patch replaces the use of 'file_size' by size_t. However, since it
affects all sites where the read/write interface is uses, it takes the
opportunity to replace the C-style (pointer, size) arguments by
'Byte_range_ptr' and 'Const_byte_range_ptr'.
Issue #4706
The old 'Io_response_handler::io_progress_response' interface has been
replaced by the 'Vfs::Env::User::wakeup_vfs_user' (issue #4697). The
remaining 'read_ready_response' method is now hosted in the
appropriately named 'Read_ready_response_handler'.
Issue #4706
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
The new interface is meant to replace the 'Vfs::Io_response_handler'.
In contrast to the 'Io_response_handler', which had to be called
on a 'Vfs_handle', the new interface does not require any specific
'Vfs_handle'. It is merely meant to prompt the VFS user (like the libc)
to re-attempt stalled I/O operations but it does not provide any
immediate hint, about which of the handles have become ready for
reading/writing.
Issue #4697
This patch removes the 'Insufficient_buffer' exception by returning the
WRITE_ERR_WOULD_BLOCK result value instead. It also eliminates the
superfluous WRITE_ERR_AGAIN and WRITE_ERR_INTERRUPT codes.
Issue #4697
This patch fosters the batching of network packets transferred by the
lwIP stack over the NIC connection. It replaces the eager submission of
the packet-stream's data-flow signals by explicit wakeup notifications.
The commit also increases the NIC session's buffer size from 128 to 1024
packets.
Issue #4697
...and tighten constness in adjacent code parts.
The VFS-internal synchronization via mutexes is no longer needed because
the access to the VFS is serialized by the VFS client, i.e., the libc.
Issue #4697
This patch facilitates the batching of I/O operations in the VFS library
by replacing the implicit wakeup of remote peer (via the traditional
packet-stream interface like 'submit_packet') by explicit wakeup
signalling.
The wakeup signalling is triggered not before the VFS user settles down.
E.g., for libc-based applications, this is the case if the libc goes
idle, waiting for external I/O.
In the case of a busy writer to a non-blocking file descriptor or socket
(e.g., lighttpd), the remote peers are woken up once a write operation
yields an out-count of 0.
The deferring of wakeup signals is accommodated by the new 'Remote_io'
mechanism (vfs/remote_io.h) that is designated to be used by all VFS
plugins that interact with asynchronous Genode services for I/O.
Issue #4697
XML allows attribute values like <node attr="\"/>. The XML parser
wrongly reflects this case as 'Invalid_syntax'. This behavior stems from
the implicit use of the 'end_of_quote' function, which considers the
sequence of '\"' as a quoted '"' rather than the end of a quoted string.
The patch solves this problem by making the 'end_of_quote' part of
the tokenizer's scanner policy.
The patch removes the 'end_of_quote' function from 'util/string.h'
because it is not universal, and to avoid the ambiguity with
'SCANNER_POLICY::end_of_quote'.
Fixes#4431
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
Clang likes to complain when lambdas capture parameters without
actually using them. This patch fixes a couple of such problems in VFS
related os module code.
Issue #4421
Adapts Dir_file_system::open_composite_dirs in a way that it returns "success"
when the leaf node of the path is an empty directory but "lookup failed", as
usual, if one of the other directories on the way to the leaf node is empty.
I couldn't find a technical reason why we used to return "lookup failed" when
only the leaf node was empty.
The commit also adds a test for en empty root directory and empty
sub-directories to the fs_query run script.
Fixes#4198
- Since Genode::strncpy is not 100% compatible with the POSIX
strncpy function, better use a distinct name.
- Remove bogus return value from the function, easing the potential
enforcement of mandatory return-value checks later.
Fixes#3752
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
This is a follow-up patch for issue #1784 that solves two
inconsistencies.
- The Vfs::Timestamp::INVALID matches File_system::Timestamp::INVALID
- The Noux libc plugin tests for Timestamp::INVALID instead of a
positive value.
The patch fixes the mtime info as shown in directory listings in
Sculpt's inspect window.
Add a new plugin for creating pipes between pairs of VFS handles. It is
intended to replace the libc_pipe plugin, one of the last remaining libc
plugins.
In contrast to the libc_pipe plugin, this plugin defers cross-handle
notification until I/O signal handling rather than block and unblock
readers using a semaphore. This is a performance regression in the case
of multiple threads blocking on a pipe, but shall be an intermediate
mechanism pending renovations within the libc VFS and threading layers.
As a side effect, threads blocked on a pipe might not be resumed until
the main thread suspends and dispatches I/O signals.
The "test-libc_pipe" test has been adjusted to use the VFS pipe plugin
and tests both local pipes and pipes hosted remotely in the VFS server.
Merge adaptations (such as EOF handling, adjustment to VFS/libc
interface changes) by Norman Feske.
Fix#2303
This patch adds support for watch notifications for the
'Readonly_value_file_system', which is often used by VFS plugins to
implement pseudo files. It thereby enables VFS clients to respond to
VFS-plugin events (think of terminal resize) dynamically.
Fixes#3523
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.
Replace the I/O response handler that is passed to the VFS at
construction with an object that is dynamically attached to handles.
This object shall also accept read-ready notifications, and plugins are
encouraged to keep handles awaiting ready-ready notifications separate
from handles that await I/O progress.
Replace the use of handle lists in plugins with handle queues, this
makes the code easier to understand and the ordering of notifications to
the application more explicit.
These changes replace the use of the Post_signal_hook from all VFS
plugins, applications must assume that read-ready and I/O notifications
occur during I/O signal dispatch and use an Io_progress_handler at its
entrypoints to defer response until after signal dispatching.
Fix#3257
The "Vfs::Vfs_handle" type should not contain any public members that
can be initialized by the VFS internally and by the application, so
remove inheritance from the "Genode::list::Element" class. The VFS
plugins must instead use lists of "Vfs::Vfs_handle" sub-classes, the
lifetime of which are always managed by the plugin.
Ref #3036
Calling 'handle_io_response()' in a regular VFS function (in contrast to a
post-signal hook) can cause problems if the caller of the VFS function holds
a lock which prevents the io response handler from returning.
With this commit, the user of the VFS becomes responsible for unblocking
threads which might be blocking after a failed 'queue_read()', 'queue_sync()'
or 'write()' call.
Fixes#2896
