svn_rev_338
add rmdir and unlink, make creat more like posix, add common function for prerequites checking
This commit is contained in:
Sascha Hauer
Sascha Hauer
parent
96b3a92454
commit
9df483a88f
253
fs/fs.c
253
fs/fs.c
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@ -6,6 +6,7 @@
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#include <malloc.h>
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#include <linux/stat.h>
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#include <fcntl.h>
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#include <xfuncs.h>
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char *mkmodestr(unsigned long mode, char *str)
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{
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@ -96,6 +97,13 @@ struct mtab_entry *get_mtab_entry_by_path(const char *_path)
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return match ? match : mtab;
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}
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struct mtab_entry *mtab_next_entry(struct mtab_entry *e)
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{
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if (!e)
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return mtab;
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return e->next;
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}
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FILE files[MAX_FILES];
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FILE *get_file(void)
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@ -118,39 +126,105 @@ void put_file(FILE *f)
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files[f->no].in_use = 0;
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}
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static FILE* get_file_by_pathname(const char *pathname)
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static struct device_d *get_device_by_path(char **path)
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{
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FILE *f;
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struct device_d *dev;
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struct mtab_entry *e;
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f = get_file();
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if (!f) {
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errno = -EMFILE;
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normalise_path(*path);
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e = get_mtab_entry_by_path(*path);
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if (!e)
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return NULL;
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}
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if (e != mtab)
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*path += strlen(e->path);
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return f;
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dev = e->dev;
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return dev;
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}
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int creat(const char *pathname, mode_t mode)
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int dir_is_empty(const char *pathname)
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{
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struct mtab_entry *e;
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struct device_d *dev;
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struct fs_driver_d *fsdrv;
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struct dir *dir;
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struct dirent *d;
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int ret = 1;
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e = get_mtab_entry_by_path(pathname);
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if (!e) {
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dir = opendir(pathname);
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if (!dir) {
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errno = -ENOENT;
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return -ENOENT;
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}
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while ((d = readdir(dir))) {
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if (!strcmp(d->name, ".") || !strcmp(d->name, ".."))
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continue;
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ret = 0;
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break;
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}
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closedir(dir);
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return ret;
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}
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// S_IFREG
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// S_IFDIR
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#define S_UB_IS_EMPTY (1<<31)
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#define S_UB_EXISTS (1<<30)
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#define S_UB_DOES_NOT_EXIST (1<<29)
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//
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static int path_check_prereq(const char *path, unsigned int flags)
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{
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struct stat s;
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unsigned int m;
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if (stat(path, &s)) {
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if (flags & S_UB_DOES_NOT_EXIST)
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return 0;
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errno = -ENOENT;
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return errno;
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}
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if (e != mtab)
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pathname += strlen(e->path);
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if (flags == S_UB_EXISTS)
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return 0;
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dev = e->dev;
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m = s.st_mode;
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if (S_ISDIR(m)) {
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if (flags & S_IFREG) {
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errno = -EISDIR;
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return errno;
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}
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if ((flags & S_UB_IS_EMPTY) && !dir_is_empty(path)) {
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errno = -ENOTEMPTY;
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return errno;
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}
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}
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if ((flags & S_IFDIR) && S_ISREG(m)) {
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errno = -ENOTDIR;
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return errno;
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}
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return 0;
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}
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int unlink(const char *pathname)
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{
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struct device_d *dev;
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struct fs_driver_d *fsdrv;
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char *p = strdup(pathname);
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char *freep = p;
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if (path_check_prereq(pathname, S_IFREG))
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return errno;
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dev = get_device_by_path(&p);
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if (!dev)
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goto out;
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fsdrv = (struct fs_driver_d *)dev->driver->type_data;
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errno = fsdrv->create(dev, pathname, S_IFREG);
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errno = fsdrv->unlink(dev, p);
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out:
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free(freep);
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return errno;
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}
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@ -158,32 +232,36 @@ int open(const char *pathname, int flags)
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{
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struct device_d *dev;
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struct fs_driver_d *fsdrv;
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struct mtab_entry *e;
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FILE *f;
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int exist;
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struct stat s;
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char *path;
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exist = stat(pathname, &s) == 0 ? 1 : 0;
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exist = (stat(pathname, &s) == 0) ? 1 : 0;
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if (!exist && !(flags & O_CREAT))
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return -EEXIST;
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f = get_file_by_pathname(pathname);
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e = get_mtab_entry_by_path(pathname);
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if (!e) {
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/* This can only happen when nothing is mounted */
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errno = -ENOENT;
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goto out;
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if (exist && (s.st_mode & S_IFDIR)) {
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errno = -EISDIR;
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return errno;
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}
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/* Adjust the pathname to the root of the device */
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if (e != mtab)
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pathname += strlen(e->path);
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if (!exist && !(flags & O_CREAT)) {
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errno = -ENOENT;
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return errno;
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}
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dev = e->dev;
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f = get_file();
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if (!f) {
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errno = -EMFILE;
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return errno;
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}
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path = strdup(pathname);
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dev = get_device_by_path(&path);
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if (!dev)
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goto out;
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fsdrv = (struct fs_driver_d *)dev->driver->type_data;
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f->dev = dev;
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f->flags = flags;
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@ -201,22 +279,28 @@ int open(const char *pathname, int flags)
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if (errno)
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goto out;
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if (flags & O_APPEND)
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f->pos = f->size;
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if (flags & O_TRUNC) {
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errno = fsdrv->truncate(dev, f, 0);
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if (errno)
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goto out;
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}
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if (flags & O_APPEND)
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f->pos = f->size;
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return f->no;
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out:
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put_file(f);
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free(path);
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return errno;
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}
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int creat(const char *pathname, mode_t mode)
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{
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return open(pathname, O_CREAT | O_WRONLY | O_TRUNC);
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}
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int read(int fd, void *buf, size_t count)
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{
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struct device_d *dev;
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@ -244,7 +328,7 @@ ssize_t write(int fd, const void *buf, size_t count)
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FILE *f = &files[fd];
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dev = f->dev;
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printf("WRITE: dev: %p\n",dev);
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// printf("WRITE: dev: %p\n",dev);
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fsdrv = (struct fs_driver_d *)dev->driver->type_data;
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if (f->pos + count > f->size) {
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errno = fsdrv->truncate(dev, f, f->pos + count);
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@ -305,13 +389,13 @@ int close(int fd)
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return errno;
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}
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int mount(struct device_d *dev, char *fsname, char *path)
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int mount(struct device_d *parent_device, char *fsname, char *path)
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{
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struct driver_d *drv;
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struct fs_driver_d *fs_drv;
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struct mtab_entry *entry;
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struct fs_device_d *fsdev;
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struct dir *dir;
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struct device_d *dev;
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int ret;
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errno = 0;
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@ -328,12 +412,8 @@ int mount(struct device_d *dev, char *fsname, char *path)
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}
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if (mtab) {
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/* check if path exists and is a directory */
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if (!(dir = opendir(path))) {
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errno = -ENOTDIR;
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if (path_check_prereq(path, S_IFDIR))
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goto out;
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}
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closedir(dir);
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} else {
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/* no mtab, so we only allow to mount on '/' */
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if (*path != '/' || *(path + 1)) {
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@ -345,8 +425,7 @@ int mount(struct device_d *dev, char *fsname, char *path)
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fs_drv = drv->type_data;
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if (fs_drv->flags & FS_DRIVER_NO_DEV) {
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dev = malloc(sizeof(struct device_d));
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memset(dev, 0, sizeof(struct device_d));
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dev = xzalloc(sizeof(struct device_d));
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sprintf(dev->name, "%s", fsname);
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dev->type = DEVICE_TYPE_FS;
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if ((ret = register_device(dev))) {
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@ -361,9 +440,13 @@ int mount(struct device_d *dev, char *fsname, char *path)
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goto out;
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}
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} else {
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fsdev = malloc(sizeof(struct fs_device_d));
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memset(fsdev, 0, sizeof(struct fs_device_d));
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fsdev->parent = dev;
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if (!parent_device) {
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printf("need device for driver %s\n", fsname);
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errno = -ENODEV;
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goto out;
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}
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fsdev = xzalloc(sizeof(struct fs_device_d));
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fsdev->parent = parent_device;
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sprintf(fsdev->dev.name, "%s", fsname);
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fsdev->dev.type = DEVICE_TYPE_FS;
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fsdev->dev.type_data = fsdev;
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@ -385,6 +468,7 @@ int mount(struct device_d *dev, char *fsname, char *path)
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entry = malloc(sizeof(struct mtab_entry));
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sprintf(entry->path, "%s", path);
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entry->dev = dev;
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entry->parent_device = parent_device;
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entry->next = NULL;
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if (!mtab)
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@ -432,25 +516,20 @@ int umount(const char *pathname)
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struct dir *opendir(const char *pathname)
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{
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struct dir *dir = NULL;
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struct device_d *dev;
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struct fs_driver_d *fsdrv;
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struct dir *dir = NULL;
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struct mtab_entry *e;
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char *p = strdup(pathname);
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char *freep = p;
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normalise_path(p);
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if (path_check_prereq(pathname, S_IFDIR))
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return NULL;
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e = get_mtab_entry_by_path(p);
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if (!e)
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dev = get_device_by_path(&p);
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if (!dev)
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goto out;
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if (e != mtab)
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p += strlen(e->path);
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dev = e->dev;
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// printf("opendir: dev: %p\n",dev);
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fsdrv = (struct fs_driver_d *)dev->driver->type_data;
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// printf("opendir: fsdrv: %p\n",fsdrv);
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dir = fsdrv->opendir(dev, p);
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@ -513,27 +592,51 @@ int mkdir (const char *pathname)
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{
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struct fs_driver_d *fsdrv;
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struct device_d *dev;
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struct mtab_entry *e;
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char *p = strdup(pathname);
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char *freep = p;
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e = get_mtab_entry_by_path(pathname);
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if (!e) {
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errno = -ENOENT;
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return -ENOENT;
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}
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if (e != mtab)
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pathname += strlen(e->path);
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dev = e->dev;
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if (path_check_prereq(pathname, S_UB_DOES_NOT_EXIST))
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return errno;
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dev = get_device_by_path(&p);
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if (!dev)
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goto out;
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fsdrv = (struct fs_driver_d *)dev->driver->type_data;
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if (fsdrv->mkdir) {
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errno = fsdrv->mkdir(dev, pathname);
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return errno;
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errno = fsdrv->mkdir(dev, p);
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goto out;
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}
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errno = -EROFS;
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return -EROFS;
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out:
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free(freep);
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return errno;
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}
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int rmdir (const char *pathname)
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{
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struct fs_driver_d *fsdrv;
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struct device_d *dev;
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char *p = strdup(pathname);
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char *freep = p;
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if (path_check_prereq(pathname, S_IFDIR | S_UB_IS_EMPTY))
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return errno;
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dev = get_device_by_path(&p);
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if (!dev)
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goto out;
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fsdrv = (struct fs_driver_d *)dev->driver->type_data;
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if (fsdrv->rmdir) {
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errno = fsdrv->rmdir(dev, p);
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goto out;
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}
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errno = -EROFS;
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out:
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free(freep);
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return errno;
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}
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