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().
Besides adapting the components to the use of base/log.h, the patch
cleans up a few base headers, i.e., it removes unused includes from
root/component.h, specifically base/heap.h and
ram_session/ram_session.h. Hence, components that relied on the implicit
inclusion of those headers have to manually include those headers now.
While adjusting the log messages, I repeatedly stumbled over the problem
that printing char * arguments is ambiguous. It is unclear whether to
print the argument as pointer or null-terminated string. To overcome
this problem, the patch introduces a new type 'Cstring' that allows the
caller to express that the argument should be handled as null-terminated
string. As a nice side effect, with this type in place, the optional len
argument of the 'String' class could be removed. Instead of supplying a
pair of (char const *, size_t), the constructor accepts a 'Cstring'.
This, in turn, clears the way let the 'String' constructor use the new
output mechanism to assemble a string from multiple arguments (and
thereby getting rid of snprintf within Genode in the near future).
To enforce the explicit resolution of the char * ambiguity, the 'char *'
overload of the 'print' function is marked as deleted.
Issue #1987
These warnings are triggered by requests either using byte offsets or
reading a number of bytes that is not a multiple of the block size as
well as by components using the plugin with a different block size than
the backend block session provides.
Fixes#1964.
We report UNLINK_ERR_NO_PERM only for files in TAR archive, otherwise
UNLINK_ERR_NO_ENTRY is returned. This permits the arbitrary layering of
file systems with support for proper ENOENT reporting, for example,
when using 'rm -f non_existent_file' that aborts if EPERM is wrongly
reported.
Replace the Out_of_node_handles exception with Out_of_metadata.
Clients need to know when the server is out of internal resources,
but not why.
Cleanup and sort the errors at file_system_session.h.
Remove 'Size_limit_reached exception' from File_system, which was
internal to ram_fs.
Issue #1751Fixes#1909
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
strip_last_element at Path removes everything after the trailing slash,
which causes lookup failures at the VFS server when opening directories.
Issue #1648
Throw Invalid_name, No_space, and Out_of_node_handles where appropriate.
Catch the new range of errors thrown by at the VFS.
Catch Out_of_node_handles at the VFS, but print a message and re-throw.
Issue #1648
The intention of Packet_ref was to allow clients to place opaque
references into the packet descriptor itself, which could be observed on
packet completion. Currently no component in our sources uses this
feature and beyond that it is questionable if it should be used at all:
If the server tampers with the ref the client may easily be confused
into observing an incorrect or invalid context. It seems better to
remove the opaque context from the descriptor and leave the actual
implementation to the client and its needs.
Move FS Node implementations from server/ram_fs to include/ram_fs.
Support embedded ram_fs instances in VFS configurations using <ram/>.
Add 'no space' handling to VFS symlink ops.
Fixes#1635
This patch moves the VFS file-system factory to a separate vfs library
that is independent from libc. This enables libc-less Genode programs to
easily use the VFS infrastructure.
Fixes#1561
When returning early on directory operations, file systems that might
be able to handle the request but come after the current one are not
tried.
Fixes#1400.
