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More progress on parsing elf files. Fixes to memfs file read/write

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Increased inode block pointers to 40. The current maximum allowed (and checked).
Updates to file size after every file write ensures subsequent writes can
correctly operate using updated file size information (i.e. not try to add
more pages that are already present). We cannot do this inside write() because
directory writes rely on byte-granularity updates on file buffers, whereas
file updates are by page-granularity (currently).
This commit is contained in:
Bahadir Balban
2008-11-21 19:26:10 +02:00
parent 27d331895b
commit 2d5a08ff32
15 changed files with 187 additions and 30 deletions
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68
tasks/mm0/src/file.c
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@@ -262,12 +262,12 @@ int insert_page_olist(struct page *this, struct vm_object *vmo)
/* If there's only one in list */
if (before->list.next == &vmo->page_cache) {
/* Add to end if greater */
/* Add as next if greater */
if (this->offset > before->offset)
list_add_tail(&this->list, &before->list);
/* Add to beginning if smaller */
else if (this->offset < before->offset)
list_add(&this->list, &before->list);
/* Add as previous if smaller */
else if (this->offset < before->offset)
list_add_tail(&this->list, &before->list);
else
BUG();
return 0;
@@ -276,7 +276,7 @@ int insert_page_olist(struct page *this, struct vm_object *vmo)
/* If this page is in-between two other, insert it there */
if (before->offset < this->offset &&
after->offset > this->offset) {
list_add_tail(&this->list, &before->list);
list_add(&this->list, &before->list);
return 0;
}
BUG_ON(this->offset == before->offset);
@@ -565,7 +565,7 @@ int new_file_pages(struct vm_file *f, unsigned long start, unsigned long end)
*/
/* Writes user data in buffer into pages in cache */
int write_cache_pages(struct vm_file *vmfile, struct tcb *task, void *buf,
int write_cache_pages_orig(struct vm_file *vmfile, struct tcb *task, void *buf,
unsigned long pfn_start, unsigned long pfn_end,
unsigned long cursor_offset, int count)
{
@@ -623,6 +623,62 @@ copy:
return count - left;
}
/*
* Writes user data in buffer into pages in cache. If a page is not
* found, it's a bug. The writeable page range must have been readied
* by read_file_pages()/new_file_pages().
*/
int write_cache_pages(struct vm_file *vmfile, struct tcb *task, void *buf,
unsigned long pfn_start, unsigned long pfn_end,
unsigned long cursor_offset, int count)
{
struct page *head;
unsigned long last_pgoff; /* Last copied page's offset */
unsigned long copy_offset; /* Current copy offset on the buffer */
int copysize, left;
/* Find the head of consecutive pages */
list_for_each_entry(head, &vmfile->vm_obj.page_cache, list) {
/* First page */
if (head->offset == pfn_start) {
left = count;
/* Copy the first page and unmap. */
copysize = (left < PAGE_SIZE) ? left : PAGE_SIZE;
copy_offset = (unsigned long)buf;
page_copy(head, task_virt_to_page(task, copy_offset),
cursor_offset, copy_offset & PAGE_MASK, copysize);
head->flags |= VM_DIRTY;
head->owner->flags |= VM_DIRTY;
left -= copysize;
last_pgoff = head->offset;
/* Rest of the consecutive pages */
} else if (head->offset > pfn_start && head->offset < pfn_end) {
/* Make sure we're advancing on pages consecutively */
BUG_ON(head->offset != last_pgoff + 1);
copysize = (left < PAGE_SIZE) ? left : PAGE_SIZE;
copy_offset = (unsigned long)buf + count - left;
/* Must be page aligned */
BUG_ON(!is_page_aligned(copy_offset));
page_copy(head, task_virt_to_page(task, copy_offset),
0, 0, copysize);
head->flags |= VM_DIRTY;
left -= copysize;
last_pgoff = head->offset;
} else if (head->offset == pfn_end || left == 0)
break;
}
BUG_ON(left != 0);
return count - left;
}
/*
* Reads a page range from an ordered list of pages into buffer.
*