Orion
Barry Importing existing Orion kernel d41a53c (2 years, 4 months ago)diff --git a/vfs/tmpfs/file.c b/vfs/tmpfs/file.c new file mode 100644 index 0000000..252c88f --- /dev/null +++ b/vfs/tmpfs/file.c @@ -0,0 +1,126 @@ +/* + * This file controls access to TmpFS Files. It contains the functions called + * by the VFS for any operation on a File struct belonging to TmpFS. + */ + +#include <stddef.h> +#include <string.h> +#include <errno.h> +#include "fs.h" +#include "../vfs.h" +#include "../cache.h" +#include "../../mem/paging.h" +#include "../../mem/frame.h" + +size_t tmpfs_read(File *file, char *buf, size_t size, off_t offset); +size_t tmpfs_write(File *file, char *buf, size_t size, off_t offset); +int tmpfs_readdir(File *file, DirEnt *dent, off_t index); +int tmpfs_open(File *file); + +FileOps tmpfsFileOps = { + .read = tmpfs_read, + .write = tmpfs_write, + .readdir = tmpfs_readdir, + .open = tmpfs_open, +}; + +/* Read a file */ +size_t +tmpfs_read(File *file, char *buf, size_t size, off_t offset) +{ + if (offset > file->inode->size) + return 0; + if (size + offset > file->inode->size) + size = file->inode->size - offset; + + uint16_t min; + size_t count = 0; + Page *page; + page_t oldPage; + while (size) { + min = (size > 0x1000) ? 0x1000 : size; + page = page_find(file->inode, offset); + if (!page) + break; + acquire(&quickPageLock); + oldPage = quick_page(page->frame); + memcpy(buf + count, QUICK_PAGE, min); + quick_page(oldPage); + release(&quickPageLock); + size -= min; + count += min; + } + return count; +} + +/* Write a file */ +size_t +tmpfs_write(File *file, char *buf, size_t size, off_t offset) +{ + if (size + offset > file->inode->size) + file->inode->size = size + offset; + + uint16_t min; + size_t count = 0; + Page *page; + page_t oldPage; + while (size) { + min = (size > 0x1000) ? 0x1000 : size; + page = page_find(file->inode, offset); + if (!page) + page = page_create(file->inode, alloc_frames(1), + offset); + acquire(&quickPageLock); + oldPage = quick_page(page->frame); + memcpy(QUICK_PAGE, buf + count, min); + quick_page(oldPage); + release(&quickPageLock); + size -= min; + count += min; + } + return count; +} + +/* Read a directory entry */ +int +tmpfs_readdir(File *file, DirEnt *dent, off_t index) +{ + DirEntry *de; + + if (!index--) { + dent->ino = file->inode->ino; + dent->type = DT_DIR; + dent->namelen = 2; + strncpy(dent->name, ".", dent->namelen); + return 0; + } + + for (de = file->inode->dirEntries; de && index; de = de->next, index--); + if (!de) + return -ENOENT; + dent->ino = de->inode->ino; + if (S_ISBLK(de->inode->mode)) + dent->type = DT_BLK; + if (S_ISCHR(de->inode->mode)) + dent->type = DT_CHR; + if (S_ISDIR(de->inode->mode)) + dent->type = DT_DIR; + if (S_ISFIFO(de->inode->mode)) + dent->type = DT_FIFO; + if (S_ISLNK(de->inode->mode)) + dent->type = DT_LNK; + if (S_ISREG(de->inode->mode)) + dent->type = DT_REG; + if (S_ISSOCK(de->inode->mode)) + dent->type = DT_SOCK; + dent->namelen = strnlen(de->name, NAME_MAX) + 1; + strncpy(dent->name, de->name, NAME_MAX); + return 0; +} + +/* Open a file */ +int +tmpfs_open(File *file) +{ + return 0; +}