More fixes.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39009 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fix build.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39007 a95241bf-73f2-0310-859d-f6bbb57e9c96

Changed the type of the "op" parameter of the fs_vnode_ops::ioctl() hook and
the _kern_ioctl() syscall from ulong to uint32.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36927 a95241bf-73f2-0310-859d-f6bbb57e9c96

Make use of the entry cache.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35641 a95241bf-73f2-0310-859d-f6bbb57e9c96

Replaced the rootfs mutex by an rw_lock. To avoid race conditions in the
directory iteration code, a mutex to protect the iteration cookie and one
to protect the cookie list have been introduced.
Overall this reduces the contention of the rootfs lock significantly. The
Haiku image -j8 build gets only marginally faster though.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34831 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Moved the VM headers into subdirectory vm/.
* Renamed vm_cache.h/vm_address_space.h to VMCache.h/VMAddressSpace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34449 a95241bf-73f2-0310-859d-f6bbb57e9c96

Added TODO about solving the renaming /boot problem differently as discussed
with Ingo.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32856 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Prevent the /boot entry from ever being renamed. You couldn't even try to
switch /boot to a different volume in two operations, unless you have first
linked /system/lib into /bin. This patch assumes that / will always have the
ID 1. Don't know if that is proper. Note that I also thought about solving
this in the VFS, since perhaps it isn't the job of root-fs to know about
/boot, but that would of course introduce another check for every rename
operation, which I decided against.

+alphabranch


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32806 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Made the internal file systems correctly handle the timespec struct stat
times.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31059 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Fixed two bugs in rootfs_rename(): the check of the result of
rootfs_find_in_dir() was wrong, leading to never be able to find the fromName
in the directory. Furthermore, the parent of the root directory is itself, but
the check to see whether or not the target is valid did not take this into
account, and therefore ran into an endless loop. This fixes bug #3864.
* Rearranged rootfs_rename() to be clearer.
* Style cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30633 a95241bf-73f2-0310-859d-f6bbb57e9c96

Removed the fs_vnode_ops::create_dir() parameter for returning the ID of the
newly created dir. The VFS really doesn't need it and for some file systems
it might not be easy to get by. Several file systems (e.g. rootfs and fat)
were ignoring the parameter anyway.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29719 a95241bf-73f2-0310-859d-f6bbb57e9c96

Remove the additional fs_vnode_ops arugment from get_vnode() again as it's not
needed at all when used as intended. Thanks Ingo for the explanation on how this
is intended to work. Adjusted the overlay fs accordingly and updated/reverted
the changes to the other filesystems.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29250 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Add an additional argument to get_vnode() that gets the fs_vnode_ops of the
node. That is needed for a layered filesystem to be able to construct a full
fs_vnode out of a volume/inode pair.
* Adapt places where get_vnode is used. Sadly this is a C API and we can't just
use a default NULL for that argument.
* Introduce a flag B_VNODE_WANTS_OVERLAY_SUB_NODE that can be returned in the
flags field of a fs get_vnode call. A filesystem can use this flag to indicate
that it doesn't support the full set of fs features (attributes, write support)
and it'd like to have unsupported calls emulated by an overlay sub node.
* Add a perliminary overlay filesystem that emulates file attributes using files
on a filesystem where attributes aren't supported. It does currently only
support reading attributes/attribute directories though. All other calls are
just passed through to the super filesystem.
* Adjust places where a HAS_FS_CALL() is taken as a guarantee that the operation
is supported. For the overlay filesystem we may later return a B_UNSUPPORTED,
so make sure that in that case proper fallback options are taken.
* Make the iso9660 filesystem request overlay sub nodes. This can be fine tuned
later to only trigger where there are features on a CD that need emulation
at all.

If you happened to know the attribute file format and location you could build
an iso with read-only attribute support now. Note that this won't be enough to
get a bootable iso-only image as the query and index support is yet missing.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29177 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Most of the other file systems now maintain the st_blocks value. It might not
always be correct, but should be at least close.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27793 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added FS interface hooks io() and cancel_io(). The former is supposed
to provide asynchrounous (or only synchronous, if asynchronous is not
supported) I/O request support. It will eventually replace
{read,write}_pages(). None of the FS implementations implement them
yet.
* Implemented some support functions for request-based I/O. File system
implementations can use do_fd_io() which passes an I/O request to the
layer responsible for a given FD, and do_iterative_fd_io(), which
translates a request for a file to subrequests for the underlying
device and passes them on. Both fall back to synchrounous processing
when the io() hook is not supported.
Furthermore added vfs_synchronous_io() which should be handy for the
devfs to perform io_requests synchronously for devices that don't
support the io() hook.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26655 a95241bf-73f2-0310-859d-f6bbb57e9c96

* bfs_fsync() was the only place which could cause the
fs_vnode_ops::write_pages() to be called with fsReenter = true. Since
this is no longer the case, the argument has become superfluous. For
read_pages() it always was. Removed the argument from the functions
and all functions that propagated it.
* Some whitespace at the end of lines was removed.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26579 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Both, rootfs, and devfs did not correctly report the number of entries
returned by fs_read_dir().
* Removed superfluous white space.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26338 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Made the private kernel locking primitives available to file systems as well.
* Applied Korli's mutex_unlock() fix to block_cache.cpp.
* Removed block_cache_priv.h, as it's no longer needed (moved its definitions
into block_cache.cpp, as in the kernel file).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26296 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added BDiskSystem::ShortName() and everything needed to get it there.
* Added BDiskDeviceRoster::GetDiskSystem() method, that can get a disk system
by short/pretty/module name - since they should all be unique, I put them
in a single namespace, please complain if you don't like that :-)
* Cleaned up DiskSystem.h and DiskDeviceRoster.h according to the updated
header guidelines.
* Renamed ntfs pretty name from "ntfs File System" to "Windows NT File System".


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25414 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Removed old mutex implementation and renamed cutex to mutex.
* Trivial adjustments of code using mutexes. Mostly removing the
mutex_init() return value check.
* Added mutex_lock_threads_locked(), which is called with the threads
spinlock being held. The spinlock is released while waiting, of
course. This function is useful in cases where the existence of the
mutex object is ensured by holding the threads spinlock.
* Changed the two instances in the VFS code where an IO context of
another team needs to be locked to use mutex_lock_threads_locked().
Before it required a semaphore-based mutex implementation.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25283 a95241bf-73f2-0310-859d-f6bbb57e9c96

create_special_node() supports creating a special node without entry,
now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24822 a95241bf-73f2-0310-859d-f6bbb57e9c96

The rootfs was calling remove_vnode() on nodes for which it might not
have had a reference.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24818 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Reorganized the FS interface a little:
- Moved most file_system_module_info hooks into separate structures.
Those that operate on mounted volumes to fs_volume_ops, those
operating on a vnode to fs_vnode_ops.
- Got rid of the fs_volume, fs_cookie, fs_vnode typedefs. We use void*
again.
- Instead of a void* volume and node cookie hooks are passed a
fs_volume and fs_vnode structure pointer, which contain the cookie
and an ops pointer (fs_volume a few more things).
- The VFS {new,publish,get,...}_vnode() functions take a fs_volume*
instead of the volume ID. So does vfs_get_fs_node_from_path().
- Added type and flags arguments to publish_vnode() and the
get_vnode() hook and removed the type argument from lookup() hook.
Added vnode::type using formerly unused bits to store the node type.
Simplified a few things in the VFS due to the now always available
node type.
- Added fs_volume_ops::{create,delete}_sub_vnode() and
fs_vnode_ops::get_super_vnode() hooks. They are used to support file
system layers, e.g. allowing to extend an FS not supporting BeOS
attribute with attribute support. Needs some more work in the VFS.
- Added fs_vnode_ops::create_special_node() hook for creating special
nodes (e.g. FIFOs).
* Adjusted the built-in file systems and BFS according to the interface
changes. Removed all other FSs from the image for the time being.
We'll see whether further API changes are necessary before porting
them.
* Adjusted the bfs_shell accordingly.
* Implemented create_special_node() in rootfs to support special nodes.
* Added support for FIFOs:
- Added syscall _kern_create_fifo() (used by mkfifo()), which creates
a special node (type S_IFIFO) in the respective file system.
- When a special node is published the VFS creates a respective sub
node. Currently only FIFOs are supported.
- Added a little support for FIFO subnodes by using functionality from
the pipefs.
- Added mkfifo to the image. It can create FIFOs in the rootfs, but
the FIFOs aren't really usable ATM, since they still work like
pipes, i.e. readers and writers need to have them open at the same
time.
* Some smaller changes in the VFS:
- Made the *_CALL macros nicer to use (vargs).
- Refactored FS entry lookup into new function lookup_dir_entry().
- create_vnode() no longer just calls the FS create() hook. First it
looks up the entry and uses open_vnode(), if it already exists. This
is necessary for two reasons: 1) The FS might not support create()
while still allowing to open() entries. 2) When the FS has other
layers on to of it (or the respective node) it might not be
responsible for opening the node.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24816 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Aligned the semantics of the read_symlink() FS module hook with the
readlink() function. It is no longer required to null-terminate the
string, shall not fail, if the buffer is too small, and shall return
the length of the string actually written into the buffer.
* Adjusted rootfs, devfs, and bfs accordingly. Also adjusted their
read_stat() hooks to return the correct symlink length in st_size.
* Our readlink() does now comply to the standard (and BeOS).
Additionally if the buffer is big enough it is nice to non-conforming
apps and null-terminates it.
* BSymLink::ReadLink() explicitly null-terminates the string now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24425 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Extracted file_map API out of the file cache - it's now an optional service
that can be used by file systems.
* Changed the way the file cache works: instead of reading/writing to the
underlying device directly, it can now be used for any data source, ie.
also network file systems.
* As a result, the former pages_io() moved to the VFS layer, and can now be
called by a file system via {read|write}_file_io_vec_pages() (naming
suggestions are always welcomed :-)). It now gets an FD, and uses that to
communicate with the device (via its fs_{read|write}_pages() hooks).
* The file_cache_{read|write}() functions must now be called without holding
an I/O relevant file system lock. That allows the file cache to prepare the
pages without colliding with the page writer, IOW the "mayBlock" flag can
go into the attic again (yay!).
* This also results in a much better performance when the system does I/O and
is low on memory, as the page writer can now finally write back some pages,
and that even without maxing out the CPU :)
* The API changes put slightly more burden on the fs_{read|write}_pages()
hooks, but in combination with the file_map it's still pretty straight
forward. It just will have to dispatch the call to the underlying device
directly, usually it will just call its fs_{read|write}_pages() hooks
via the above mentioned calls.
* Ported BFS and FAT to the new API, the latter has not been tested, though.
* Also ported the API changes to the fs_shell. I also completely removed its
file cache level page handling - the downside is that device access is no
longer cached (ie. depends on the host OS now), the upside is that the code
is greatly simplified.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22886 a95241bf-73f2-0310-859d-f6bbb57e9c96

* rootfs.c -> rootfs.cpp
* Made the kernel rootfs reusable by the FS Shell and removed the
copy in the FS Shell sources.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22436 a95241bf-73f2-0310-859d-f6bbb57e9c96

More fixes.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39009 a95241bf-73f2-0310-859d-f6bbb57e9c96

Fix build.



git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@39007 a95241bf-73f2-0310-859d-f6bbb57e9c96

Changed the type of the "op" parameter of the fs_vnode_ops::ioctl() hook and
the _kern_ioctl() syscall from ulong to uint32.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@36927 a95241bf-73f2-0310-859d-f6bbb57e9c96

Make use of the entry cache.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@35641 a95241bf-73f2-0310-859d-f6bbb57e9c96

Replaced the rootfs mutex by an rw_lock. To avoid race conditions in the
directory iteration code, a mutex to protect the iteration cookie and one
to protect the cookie list have been introduced.
Overall this reduces the contention of the rootfs lock significantly. The
Haiku image -j8 build gets only marginally faster though.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34831 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Moved the VM headers into subdirectory vm/.
* Renamed vm_cache.h/vm_address_space.h to VMCache.h/VMAddressSpace.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@34449 a95241bf-73f2-0310-859d-f6bbb57e9c96

Added TODO about solving the renaming /boot problem differently as discussed
with Ingo.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32856 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Prevent the /boot entry from ever being renamed. You couldn't even try to
switch /boot to a different volume in two operations, unless you have first
linked /system/lib into /bin. This patch assumes that / will always have the
ID 1. Don't know if that is proper. Note that I also thought about solving
this in the VFS, since perhaps it isn't the job of root-fs to know about
/boot, but that would of course introduce another check for every rename
operation, which I decided against.

+alphabranch


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32806 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Made the internal file systems correctly handle the timespec struct stat
times.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@31059 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Fixed two bugs in rootfs_rename(): the check of the result of
rootfs_find_in_dir() was wrong, leading to never be able to find the fromName
in the directory. Furthermore, the parent of the root directory is itself, but
the check to see whether or not the target is valid did not take this into
account, and therefore ran into an endless loop. This fixes bug #3864.
* Rearranged rootfs_rename() to be clearer.
* Style cleanup.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30633 a95241bf-73f2-0310-859d-f6bbb57e9c96

Removed the fs_vnode_ops::create_dir() parameter for returning the ID of the
newly created dir. The VFS really doesn't need it and for some file systems
it might not be easy to get by. Several file systems (e.g. rootfs and fat)
were ignoring the parameter anyway.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29719 a95241bf-73f2-0310-859d-f6bbb57e9c96

Remove the additional fs_vnode_ops arugment from get_vnode() again as it's not
needed at all when used as intended. Thanks Ingo for the explanation on how this
is intended to work. Adjusted the overlay fs accordingly and updated/reverted
the changes to the other filesystems.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29250 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Add an additional argument to get_vnode() that gets the fs_vnode_ops of the
node. That is needed for a layered filesystem to be able to construct a full
fs_vnode out of a volume/inode pair.
* Adapt places where get_vnode is used. Sadly this is a C API and we can't just
use a default NULL for that argument.
* Introduce a flag B_VNODE_WANTS_OVERLAY_SUB_NODE that can be returned in the
flags field of a fs get_vnode call. A filesystem can use this flag to indicate
that it doesn't support the full set of fs features (attributes, write support)
and it'd like to have unsupported calls emulated by an overlay sub node.
* Add a perliminary overlay filesystem that emulates file attributes using files
on a filesystem where attributes aren't supported. It does currently only
support reading attributes/attribute directories though. All other calls are
just passed through to the super filesystem.
* Adjust places where a HAS_FS_CALL() is taken as a guarantee that the operation
is supported. For the overlay filesystem we may later return a B_UNSUPPORTED,
so make sure that in that case proper fallback options are taken.
* Make the iso9660 filesystem request overlay sub nodes. This can be fine tuned
later to only trigger where there are features on a CD that need emulation
at all.

If you happened to know the attribute file format and location you could build
an iso with read-only attribute support now. Note that this won't be enough to
get a bootable iso-only image as the query and index support is yet missing.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@29177 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Most of the other file systems now maintain the st_blocks value. It might not
always be correct, but should be at least close.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@27793 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added FS interface hooks io() and cancel_io(). The former is supposed
to provide asynchrounous (or only synchronous, if asynchronous is not
supported) I/O request support. It will eventually replace
{read,write}_pages(). None of the FS implementations implement them
yet.
* Implemented some support functions for request-based I/O. File system
implementations can use do_fd_io() which passes an I/O request to the
layer responsible for a given FD, and do_iterative_fd_io(), which
translates a request for a file to subrequests for the underlying
device and passes them on. Both fall back to synchrounous processing
when the io() hook is not supported.
Furthermore added vfs_synchronous_io() which should be handy for the
devfs to perform io_requests synchronously for devices that don't
support the io() hook.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26655 a95241bf-73f2-0310-859d-f6bbb57e9c96

* bfs_fsync() was the only place which could cause the
fs_vnode_ops::write_pages() to be called with fsReenter = true. Since
this is no longer the case, the argument has become superfluous. For
read_pages() it always was. Removed the argument from the functions
and all functions that propagated it.
* Some whitespace at the end of lines was removed.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26579 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Both, rootfs, and devfs did not correctly report the number of entries
returned by fs_read_dir().
* Removed superfluous white space.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26338 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Made the private kernel locking primitives available to file systems as well.
* Applied Korli's mutex_unlock() fix to block_cache.cpp.
* Removed block_cache_priv.h, as it's no longer needed (moved its definitions
into block_cache.cpp, as in the kernel file).


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26296 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Added BDiskSystem::ShortName() and everything needed to get it there.
* Added BDiskDeviceRoster::GetDiskSystem() method, that can get a disk system
by short/pretty/module name - since they should all be unique, I put them
in a single namespace, please complain if you don't like that :-)
* Cleaned up DiskSystem.h and DiskDeviceRoster.h according to the updated
header guidelines.
* Renamed ntfs pretty name from "ntfs File System" to "Windows NT File System".


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25414 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Removed old mutex implementation and renamed cutex to mutex.
* Trivial adjustments of code using mutexes. Mostly removing the
mutex_init() return value check.
* Added mutex_lock_threads_locked(), which is called with the threads
spinlock being held. The spinlock is released while waiting, of
course. This function is useful in cases where the existence of the
mutex object is ensured by holding the threads spinlock.
* Changed the two instances in the VFS code where an IO context of
another team needs to be locked to use mutex_lock_threads_locked().
Before it required a semaphore-based mutex implementation.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25283 a95241bf-73f2-0310-859d-f6bbb57e9c96

create_special_node() supports creating a special node without entry,
now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24822 a95241bf-73f2-0310-859d-f6bbb57e9c96

The rootfs was calling remove_vnode() on nodes for which it might not
have had a reference.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24818 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Reorganized the FS interface a little:
- Moved most file_system_module_info hooks into separate structures.
Those that operate on mounted volumes to fs_volume_ops, those
operating on a vnode to fs_vnode_ops.
- Got rid of the fs_volume, fs_cookie, fs_vnode typedefs. We use void*
again.
- Instead of a void* volume and node cookie hooks are passed a
fs_volume and fs_vnode structure pointer, which contain the cookie
and an ops pointer (fs_volume a few more things).
- The VFS {new,publish,get,...}_vnode() functions take a fs_volume*
instead of the volume ID. So does vfs_get_fs_node_from_path().
- Added type and flags arguments to publish_vnode() and the
get_vnode() hook and removed the type argument from lookup() hook.
Added vnode::type using formerly unused bits to store the node type.
Simplified a few things in the VFS due to the now always available
node type.
- Added fs_volume_ops::{create,delete}_sub_vnode() and
fs_vnode_ops::get_super_vnode() hooks. They are used to support file
system layers, e.g. allowing to extend an FS not supporting BeOS
attribute with attribute support. Needs some more work in the VFS.
- Added fs_vnode_ops::create_special_node() hook for creating special
nodes (e.g. FIFOs).
* Adjusted the built-in file systems and BFS according to the interface
changes. Removed all other FSs from the image for the time being.
We'll see whether further API changes are necessary before porting
them.
* Adjusted the bfs_shell accordingly.
* Implemented create_special_node() in rootfs to support special nodes.
* Added support for FIFOs:
- Added syscall _kern_create_fifo() (used by mkfifo()), which creates
a special node (type S_IFIFO) in the respective file system.
- When a special node is published the VFS creates a respective sub
node. Currently only FIFOs are supported.
- Added a little support for FIFO subnodes by using functionality from
the pipefs.
- Added mkfifo to the image. It can create FIFOs in the rootfs, but
the FIFOs aren't really usable ATM, since they still work like
pipes, i.e. readers and writers need to have them open at the same
time.
* Some smaller changes in the VFS:
- Made the *_CALL macros nicer to use (vargs).
- Refactored FS entry lookup into new function lookup_dir_entry().
- create_vnode() no longer just calls the FS create() hook. First it
looks up the entry and uses open_vnode(), if it already exists. This
is necessary for two reasons: 1) The FS might not support create()
while still allowing to open() entries. 2) When the FS has other
layers on to of it (or the respective node) it might not be
responsible for opening the node.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24816 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Aligned the semantics of the read_symlink() FS module hook with the
readlink() function. It is no longer required to null-terminate the
string, shall not fail, if the buffer is too small, and shall return
the length of the string actually written into the buffer.
* Adjusted rootfs, devfs, and bfs accordingly. Also adjusted their
read_stat() hooks to return the correct symlink length in st_size.
* Our readlink() does now comply to the standard (and BeOS).
Additionally if the buffer is big enough it is nice to non-conforming
apps and null-terminates it.
* BSymLink::ReadLink() explicitly null-terminates the string now.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24425 a95241bf-73f2-0310-859d-f6bbb57e9c96

* Extracted file_map API out of the file cache - it's now an optional service
that can be used by file systems.
* Changed the way the file cache works: instead of reading/writing to the
underlying device directly, it can now be used for any data source, ie.
also network file systems.
* As a result, the former pages_io() moved to the VFS layer, and can now be
called by a file system via {read|write}_file_io_vec_pages() (naming
suggestions are always welcomed :-)). It now gets an FD, and uses that to
communicate with the device (via its fs_{read|write}_pages() hooks).
* The file_cache_{read|write}() functions must now be called without holding
an I/O relevant file system lock. That allows the file cache to prepare the
pages without colliding with the page writer, IOW the "mayBlock" flag can
go into the attic again (yay!).
* This also results in a much better performance when the system does I/O and
is low on memory, as the page writer can now finally write back some pages,
and that even without maxing out the CPU :)
* The API changes put slightly more burden on the fs_{read|write}_pages()
hooks, but in combination with the file_map it's still pretty straight
forward. It just will have to dispatch the call to the underlying device
directly, usually it will just call its fs_{read|write}_pages() hooks
via the above mentioned calls.
* Ported BFS and FAT to the new API, the latter has not been tested, though.
* Also ported the API changes to the fs_shell. I also completely removed its
file cache level page handling - the downside is that device access is no
longer cached (ie. depends on the host OS now), the upside is that the code
is greatly simplified.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22886 a95241bf-73f2-0310-859d-f6bbb57e9c96

* rootfs.c -> rootfs.cpp
* Made the kernel rootfs reusable by the FS Shell and removed the
copy in the FS Shell sources.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22436 a95241bf-73f2-0310-859d-f6bbb57e9c96