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Enable the IO hook for both attribute and write overlay. Attribute overlay isn't 

concerned by it as it does not do file data, it simply passes the hook through.
In the write_overlay case we check for write operations and for modified nodes.
In both cases we return B_NOT_SUPPORTED which will cause a fallback to
synchronous IO. The main problem with the fallback is not that it is synchronous
but that the physical buffers of the request will be mapped and filled page
wise, which makes it slow for various reasons. In any case with this setup all
reads to write_overlay that can go through unmodified now do. This should speed
up CD boot as there is no physical to virtual translation overhead and no limit
to page wise reads. In the best case it should now read 256 blocks at the time
instead of always falling back to 2. My tests show no side effects on creating,
writing or partially modifying nodes so far.


git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@32897 a95241bf-73f2-0310-859d-f6bbb57e9c96
This commit is contained in:
Michael Lotz 2009-09-01 21:22:37 +00:00
parent ee0be828e4
commit 271b9ad49a
2 changed files with 18 additions and 11 deletions
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6
src/add-ons/kernel/file_systems/layers/attribute_overlay/attribute_overlay.cpp
View File

@ -1187,14 +1187,12 @@ overlay_write_pages(fs_volume *volume, fs_vnode *vnode, void *cookie, off_t pos,
}
#if 0
static status_t
overlay_io(fs_volume *volume, fs_vnode *vnode, void *cookie,
io_request *request)
{
OVERLAY_CALL(io, cookie, request)
}
#endif
static status_t
@ -1641,9 +1639,7 @@ static fs_vnode_ops sOverlayVnodeOps = {
&overlay_read_pages,
&overlay_write_pages,
// TODO: the io scheduler uses it when available but we may simply
// return B_UNSUPPORTED and I'm not sure it then falls back correctly
NULL, //&overlay_io,
&overlay_io,
&overlay_cancel_io,
&overlay_get_file_map,

23
src/add-ons/kernel/file_systems/layers/write_overlay/write_overlay.cpp
View File

@ -17,6 +17,7 @@
#include <fs_cache.h>
#include <fs_info.h>
#include <fs_interface.h>
#include <io_requests.h>
#include <debug.h>
#include <KernelExport.h>
@ -1294,14 +1295,26 @@ overlay_write_pages(fs_volume *volume, fs_vnode *vnode, void *cookie, off_t pos,
}
#if 0
static status_t
overlay_io(fs_volume *volume, fs_vnode *vnode, void *cookie,
io_request *request)
{
OVERLAY_CALL(io, cookie, request)
if (io_request_is_write(request))
return B_UNSUPPORTED;
OverlayInode *node = (OverlayInode *)vnode->private_node;
if (node->IsModified())
return B_UNSUPPORTED;
TRACE("relaying op: io\n");
fs_vnode *superVnode = node->SuperVnode();
if (superVnode->ops->io != NULL) {
return superVnode->ops->io(volume->super_volume, superVnode, cookie,
request);
}
return B_UNSUPPORTED;
}
#endif
static status_t
@ -1714,9 +1727,7 @@ static fs_vnode_ops sOverlayVnodeOps = {
&overlay_read_pages,
&overlay_write_pages,
// TODO: the io scheduler uses it when available but we may simply
// return B_UNSUPPORTED and I'm not sure it then falls back correctly
NULL, //&overlay_io,
&overlay_io,
&overlay_cancel_io,
&overlay_get_file_map,