/*
* lookparent returns the last path component as a string and the
* directory it's in as a vnode.
*
* Since we don't support subdirectories, this is very easy -
* return the root dir and copy the path.
*/
static
int
sfs_lookparent(struct vnode *v, char *path, struct vnode **ret,
char *buf, size_t buflen)
{
struct sfs_vnode *sv = v->vn_data;
vfs_biglock_acquire();
if (sv->sv_i.sfi_type != SFS_TYPE_DIR) {
vfs_biglock_release();
return ENOTDIR;
}
if (strlen(path)+1 > buflen) {
vfs_biglock_release();
return ENAMETOOLONG;
}
strcpy(buf, path);
VOP_INCREF(&sv->sv_v);
*ret = &sv->sv_v;
vfs_biglock_release();
return 0;
}
/*
* Delete a file.
*/
static
int
sfs_remove(struct vnode *dir, const char *name)
{
struct sfs_vnode *sv = dir->vn_data;
struct sfs_vnode *victim;
int slot;
int result;
vfs_biglock_acquire();
/* Look for the file and fetch a vnode for it. */
result = sfs_lookonce(sv, name, &victim, &slot);
if (result) {
vfs_biglock_release();
return result;
}
/* Erase its directory entry. */
result = sfs_dir_unlink(sv, slot);
if (result==0) {
/* If we succeeded, decrement the link count. */
KASSERT(victim->sv_i.sfi_linkcount > 0);
victim->sv_i.sfi_linkcount--;
victim->sv_dirty = true;
}
/* Discard the reference that sfs_lookonce got us */
VOP_DECREF(&victim->sv_v);
vfs_biglock_release();
return result;
}
/*
* Unmount code.
*
* VFS calls FS_SYNC on the filesystem prior to unmounting it.
*/
static
int
sfs_unmount(struct fs *fs)
{
struct sfs_fs *sfs = fs->fs_data;
vfs_biglock_acquire();
/* Do we have any files open? If so, can't unmount. */
if (vnodearray_num(sfs->sfs_vnodes) > 0) {
vfs_biglock_release();
return EBUSY;
}
/* We should have just had sfs_sync called. */
KASSERT(sfs->sfs_superdirty == false);
KASSERT(sfs->sfs_freemapdirty == false);
/* Once we start nuking stuff we can't fail. */
vnodearray_destroy(sfs->sfs_vnodes);
bitmap_destroy(sfs->sfs_freemap);
/* The vfs layer takes care of the device for us */
(void)sfs->sfs_device;
/* Destroy the fs object */
kfree(sfs);
/* nothing else to do */
vfs_biglock_release();
return 0;
}
/*
* Make a hard link to a file.
* The VFS layer should prevent this being called unless both
* vnodes are ours.
*/
static
int
sfs_link(struct vnode *dir, const char *name, struct vnode *file)
{
struct sfs_vnode *sv = dir->vn_data;
struct sfs_vnode *f = file->vn_data;
int result;
KASSERT(file->vn_fs == dir->vn_fs);
vfs_biglock_acquire();
/* Just create a link */
result = sfs_dir_link(sv, name, f->sv_ino, NULL);
if (result) {
vfs_biglock_release();
return result;
}
/* and update the link count, marking the inode dirty */
f->sv_i.sfi_linkcount++;
f->sv_dirty = true;
vfs_biglock_release();
return 0;
}
/*
* Lookup gets a vnode for a pathname.
*
* Since we don't support subdirectories, it's easy - just look up the
* name.
*/
static
int
sfs_lookup(struct vnode *v, char *path, struct vnode **ret)
{
struct sfs_vnode *sv = v->vn_data;
struct sfs_vnode *final;
int result;
vfs_biglock_acquire();
if (sv->sv_i.sfi_type != SFS_TYPE_DIR) {
vfs_biglock_release();
return ENOTDIR;
}
result = sfs_lookonce(sv, path, &final, NULL);
if (result) {
vfs_biglock_release();
return result;
}
*ret = &final->sv_v;
vfs_biglock_release();
return 0;
}
/*
* VOP_RECLAIM
*
* Reclaim should make an effort to returning errors other than EBUSY.
*/
static
int
emufs_reclaim(struct vnode *v)
{
struct emufs_vnode *ev = v->vn_data;
struct emufs_fs *ef = v->vn_fs->fs_data;
unsigned ix, i, num;
int result;
/*
* Need both of these locks, e_lock to protect the device
* and vfs_biglock to protect the fs-related material.
*/
vfs_biglock_acquire();
lock_acquire(ef->ef_emu->e_lock);
if (ev->ev_v.vn_refcount != 1) {
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
return EBUSY;
}
/* emu_close retries on I/O error */
result = emu_close(ev->ev_emu, ev->ev_handle);
if (result) {
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
return result;
}
num = vnodearray_num(ef->ef_vnodes);
ix = num;
for (i=0; i<num; i++) {
struct vnode *vx;
vx = vnodearray_get(ef->ef_vnodes, i);
if (vx == v) {
ix = i;
break;
}
}
if (ix == num) {
panic("emu%d: reclaim vnode %u not in vnode pool\n",
ef->ef_emu->e_unit, ev->ev_handle);
}
vnodearray_remove(ef->ef_vnodes, ix);
VOP_CLEANUP(&ev->ev_v);
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
kfree(ev);
return 0;
}
/*
* Read a single filename from a directory into a uio.
*
*/
int
sfs_getdirentry(struct vnode *v, struct uio *uio)
{
struct sfs_vnode *sv = v->vn_data;
struct sfs_dir tsd;
int nentries = sfs_dir_nentries(sv);
int result;
vfs_biglock_acquire();
while (uio->uio_offset <= nentries) {
// Read directory entry
result = sfs_readdir(sv, &tsd, uio->uio_offset);
if (result) {
vfs_biglock_release();
return result;
}
if (tsd.sfd_ino != SFS_NOINO) {
break;
}
uio->uio_offset ++;
}
// If we still don't have a result, there must be nothing left
if (tsd.sfd_ino == SFS_NOINO) {
vfs_biglock_release();
return ENOMEM;
}
/* Ensure null termination, just in case */
tsd.sfd_name[sizeof(tsd.sfd_name)-1] = 0;
// Copy results to uio
result = uiomove(tsd.sfd_name, strlen(tsd.sfd_name), uio);
if (result) {
vfs_biglock_release();
return result;
}
uio->uio_offset ++;
vfs_biglock_release();
return 0;
}
/*
* Mount a filesystem. Once we've found the device, call MOUNTFUNC to
* set up the filesystem and hand back a struct fs.
*
* The DATA argument is passed through unchanged to MOUNTFUNC.
*/
int
vfs_mount(const char *devname, void *data,
int (*mountfunc)(void *data, struct device *, struct fs **ret))
{
const char *volname;
struct knowndev *kd;
struct fs *fs;
int result;
vfs_biglock_acquire();
result = findmount(devname, &kd);
if (result) {
vfs_biglock_release();
return result;
}
if (kd->kd_fs != NULL) {
vfs_biglock_release();
return EBUSY;
}
KASSERT(kd->kd_rawname != NULL);
KASSERT(kd->kd_device != NULL);
result = mountfunc(data, kd->kd_device, &fs);
if (result) {
vfs_biglock_release();
return result;
}
KASSERT(fs != NULL);
kd->kd_fs = fs;
volname = FSOP_GETVOLNAME(fs);
kprintf("vfs: Mounted %s: on %s\n",
volname ? volname : kd->kd_name, kd->kd_name);
vfs_biglock_release();
return 0;
}
int
sfs_getdirentry(struct vnode *v_node, struct uio *user_io)
{
struct sfs_vnode *s_node = v_node->vn_data;
struct sfs_dir sdir;
int offset = user_io->uio_offset;
vfs_biglock_acquire(); //acquire lock
int nentries = sfs_dir_nentries(s_node);
if (offset >= nentries) {
vfs_biglock_release(); //release lock
return ENOENT; //Error no entry
}
int result;
while(1) {
result = sfs_readdir(s_node, &sdir, user_io->uio_offset);
if (result) {
vfs_biglock_release(); //release lock
return result; //return this result
}
if (sdir.sfd_ino == SFS_NOINO) { //if this sdir is the inode # for free dir entry
offset++;
if(offset >= nentries) {
vfs_biglock_release(); //release lock
return ENOENT; //error no entry
}
user_io->uio_offset++;
continue;
}
break;
}
result = uiomove(sdir.sfd_name, strlen(sdir.sfd_name), user_io); //get the result
user_io->uio_offset = offset + 1; //update uio offset
vfs_biglock_release(); //release lock
return 0; //and return
}
/*
* Called for fsync(), and also on filesystem unmount, global sync(),
* and some other cases.
*/
static
int
sfs_fsync(struct vnode *v)
{
struct sfs_vnode *sv = v->vn_data;
int result;
vfs_biglock_acquire();
result = sfs_sync_inode(sv);
vfs_biglock_release();
return result;
}
/*
* Routine to retrieve the volume name. Filesystems can be referred
* to by their volume name followed by a colon as well as the name
* of the device they're mounted on.
*/
static
const char *
sfs_getvolname(struct fs *fs)
{
struct sfs_fs *sfs = fs->fs_data;
const char *ret;
vfs_biglock_acquire();
ret = sfs->sfs_super.sp_volname;
vfs_biglock_release();
return ret;
}
/*
* Return the type of the file (types as per kern/stat.h)
*/
static
int
sfs_gettype(struct vnode *v, uint32_t *ret)
{
struct sfs_vnode *sv = v->vn_data;
vfs_biglock_acquire();
switch (sv->sv_i.sfi_type) {
case SFS_TYPE_FILE:
*ret = S_IFREG;
vfs_biglock_release();
return 0;
case SFS_TYPE_DIR:
*ret = S_IFDIR;
vfs_biglock_release();
return 0;
}
panic("sfs: gettype: Invalid inode type (inode %u, type %u)\n",
sv->sv_ino, sv->sv_i.sfi_type);
return EINVAL;
}
/*
* Called for write(). sfs_io() does the work.
*/
static
int
sfs_write(struct vnode *v, struct uio *uio)
{
struct sfs_vnode *sv = v->vn_data;
int result;
KASSERT(uio->uio_rw==UIO_WRITE);
vfs_biglock_acquire();
result = sfs_io(sv, uio);
vfs_biglock_release();
return result;
}
/*
* Get vnode for the root of the filesystem.
* The root vnode is always found in block 1 (SFS_ROOT_LOCATION).
*/
struct vnode *
sfs_getroot(struct fs *fs)
{
struct sfs_fs *sfs = fs->fs_data;
struct sfs_vnode *sv;
int result;
vfs_biglock_acquire();
result = sfs_loadvnode(sfs, SFS_ROOT_LOCATION, SFS_TYPE_INVAL, &sv);
if (result) {
panic("sfs: getroot: Cannot load root vnode\n");
}
vfs_biglock_release();
return &sv->sv_v;
}
/*
* Unmount a filesystem/device by name.
* First calls FSOP_SYNC on the filesystem; then calls FSOP_UNMOUNT.
*/
int
vfs_unmount(const char *devname)
{
struct knowndev *kd;
int result;
vfs_biglock_acquire();
result = findmount(devname, &kd);
if (result) {
goto fail;
}
if (kd->kd_fs == NULL) {
result = EINVAL;
goto fail;
}
KASSERT(kd->kd_rawname != NULL);
KASSERT(kd->kd_device != NULL);
/* sync the fs */
result = FSOP_SYNC(kd->kd_fs);
if (result) {
goto fail;
}
result = FSOP_UNMOUNT(kd->kd_fs);
if (result) {
goto fail;
}
kprintf("vfs: Unmounted %s:\n", kd->kd_name);
/* now drop the filesystem */
kd->kd_fs = NULL;
KASSERT(result==0);
fail:
vfs_biglock_release();
return result;
}
/*
* Global sync function - call FSOP_SYNC on all devices.
*/
int
vfs_sync(void)
{
struct knowndev *dev;
unsigned i, num;
vfs_biglock_acquire();
num = knowndevarray_num(knowndevs);
for (i=0; i<num; i++) {
dev = knowndevarray_get(knowndevs, i);
if (dev->kd_fs != NULL) {
/*result =*/ FSOP_SYNC(dev->kd_fs);
}
}
vfs_biglock_release();
return 0;
}
/*
* Add a new device to the VFS layer's device table.
*
* If "mountable" is set, the device will be treated as one that expects
* to have a filesystem mounted on it, and a raw device will be created
* for direct access.
*/
static
int
vfs_doadd(const char *dname, int mountable, struct device *dev, struct fs *fs)
{
char *name=NULL, *rawname=NULL;
struct knowndev *kd=NULL;
struct vnode *vnode=NULL;
const char *volname=NULL;
unsigned index;
int result;
vfs_biglock_acquire();
name = kstrdup(dname);
if (name==NULL) {
goto nomem;
}
if (mountable) {
rawname = mkrawname(name);
if (rawname==NULL) {
goto nomem;
}
}
vnode = dev_create_vnode(dev);
if (vnode==NULL) {
goto nomem;
}
kd = kmalloc(sizeof(struct knowndev));
if (kd==NULL) {
goto nomem;
}
kd->kd_name = name;
kd->kd_rawname = rawname;
kd->kd_device = dev;
kd->kd_vnode = vnode;
kd->kd_fs = fs;
if (fs!=NULL) {
volname = FSOP_GETVOLNAME(fs);
}
if (badnames(name, rawname, volname)) {
vfs_biglock_release();
return EEXIST;
}
result = knowndevarray_add(knowndevs, kd, &index);
if (result == 0 && dev != NULL) {
/* use index+1 as the device number, so 0 is reserved */
dev->d_devnumber = index+1;
}
vfs_biglock_release();
return result;
nomem:
if (name) {
kfree(name);
}
if (rawname) {
kfree(rawname);
}
if (vnode) {
kfree(vnode);
}
if (kd) {
kfree(kd);
}
vfs_biglock_release();
return ENOMEM;
}
static
int
sfs_domount(void *options, struct device *dev, struct fs **ret)
{
int result;
struct sfs_fs *sfs;
vfs_biglock_acquire();
/* We don't pass any options through mount */
(void)options;
/*
* Make sure our on-disk structures aren't messed up
*/
KASSERT(sizeof(struct sfs_super)==SFS_BLOCKSIZE);
KASSERT(sizeof(struct sfs_inode)==SFS_BLOCKSIZE);
KASSERT(SFS_BLOCKSIZE % sizeof(struct sfs_dir) == 0);
/*
* We can't mount on devices with the wrong sector size.
*
* (Note: for all intents and purposes here, "sector" and
* "block" are interchangeable terms. Technically a filesystem
* block may be composed of several hardware sectors, but we
* don't do that in sfs.)
*/
if (dev->d_blocksize != SFS_BLOCKSIZE) {
vfs_biglock_release();
return ENXIO;
}
/* Allocate object */
sfs = kmalloc(sizeof(struct sfs_fs));
if (sfs==NULL) {
vfs_biglock_release();
return ENOMEM;
}
/* Allocate array */
sfs->sfs_vnodes = vnodearray_create();
if (sfs->sfs_vnodes == NULL) {
kfree(sfs);
vfs_biglock_release();
return ENOMEM;
}
/* Set the device so we can use sfs_rblock() */
sfs->sfs_device = dev;
/* Load superblock */
result = sfs_rblock(sfs, &sfs->sfs_super, SFS_SB_LOCATION);
if (result) {
vnodearray_destroy(sfs->sfs_vnodes);
kfree(sfs);
vfs_biglock_release();
return result;
}
/* Make some simple sanity checks */
if (sfs->sfs_super.sp_magic != SFS_MAGIC) {
kprintf("sfs: Wrong magic number in superblock "
"(0x%x, should be 0x%x)\n",
sfs->sfs_super.sp_magic,
SFS_MAGIC);
vnodearray_destroy(sfs->sfs_vnodes);
kfree(sfs);
vfs_biglock_release();
return EINVAL;
}
if (sfs->sfs_super.sp_nblocks > dev->d_blocks) {
kprintf("sfs: warning - fs has %u blocks, device has %u\n",
sfs->sfs_super.sp_nblocks, dev->d_blocks);
}
/* Ensure null termination of the volume name */
sfs->sfs_super.sp_volname[sizeof(sfs->sfs_super.sp_volname)-1] = 0;
/* Load free space bitmap */
sfs->sfs_freemap = bitmap_create(SFS_FS_BITMAPSIZE(sfs));
if (sfs->sfs_freemap == NULL) {
vnodearray_destroy(sfs->sfs_vnodes);
kfree(sfs);
vfs_biglock_release();
return ENOMEM;
}
result = sfs_mapio(sfs, UIO_READ);
if (result) {
bitmap_destroy(sfs->sfs_freemap);
vnodearray_destroy(sfs->sfs_vnodes);
kfree(sfs);
vfs_biglock_release();
return result;
}
/* Set up abstract fs calls */
sfs->sfs_absfs.fs_sync = sfs_sync;
sfs->sfs_absfs.fs_getvolname = sfs_getvolname;
sfs->sfs_absfs.fs_getroot = sfs_getroot;
sfs->sfs_absfs.fs_unmount = sfs_unmount;
sfs->sfs_absfs.fs_data = sfs;
/* the other fields */
sfs->sfs_superdirty = false;
sfs->sfs_freemapdirty = false;
/* Hand back the abstract fs */
*ret = &sfs->sfs_absfs;
vfs_biglock_release();
return 0;
}
static
int
sfs_sync(struct fs *fs)
{
struct sfs_fs *sfs;
unsigned i, num;
int result;
vfs_biglock_acquire();
/*
* Get the sfs_fs from the generic abstract fs.
*
* Note that the abstract struct fs, which is all the VFS
* layer knows about, is actually a member of struct sfs_fs.
* The pointer in the struct fs points back to the top of the
* struct sfs_fs - essentially the same object. This can be a
* little confusing at first.
*
* The following diagram may help:
*
* struct sfs_fs <-------------\
* : |
* : sfs_absfs (struct fs) | <------\
* : : | |
* : : various members | |
* : : | |
* : : fs_data ----------/ |
* : : ...|...
* : . VFS .
* : . layer .
* : other members .......
* :
* :
*
* This construct is repeated with vnodes and devices and other
* similar things all over the place in OS/161, so taking the
* time to straighten it out in your mind is worthwhile.
*/
sfs = fs->fs_data;
/* Go over the array of loaded vnodes, syncing as we go. */
num = vnodearray_num(sfs->sfs_vnodes);
for (i=0; i<num; i++) {
struct vnode *v = vnodearray_get(sfs->sfs_vnodes, i);
VOP_FSYNC(v);
}
/* If the free block map needs to be written, write it. */
if (sfs->sfs_freemapdirty) {
result = sfs_mapio(sfs, UIO_WRITE);
if (result) {
vfs_biglock_release();
return result;
}
sfs->sfs_freemapdirty = false;
}
/* If the superblock needs to be written, write it. */
if (sfs->sfs_superdirty) {
result = sfs_wblock(sfs, &sfs->sfs_super, SFS_SB_LOCATION);
if (result) {
vfs_biglock_release();
return result;
}
sfs->sfs_superdirty = false;
}
vfs_biglock_release();
return 0;
}
/*
* Called when the vnode refcount (in-memory usage count) hits zero.
*
* This function should try to avoid returning errors other than EBUSY.
*/
static
int
sfs_reclaim(struct vnode *v)
{
struct sfs_vnode *sv = v->vn_data;
struct sfs_fs *sfs = v->vn_fs->fs_data;
unsigned ix, i, num;
int result;
vfs_biglock_acquire();
/*
* Make sure someone else hasn't picked up the vnode since the
* decision was made to reclaim it. (You must also synchronize
* this with sfs_loadvnode.)
*/
if (v->vn_refcount != 1) {
/* consume the reference VOP_DECREF gave us */
KASSERT(v->vn_refcount>1);
v->vn_refcount--;
vfs_biglock_release();
return EBUSY;
}
/* If there are no on-disk references to the file either, erase it. */
if (sv->sv_i.sfi_linkcount==0) {
result = VOP_TRUNCATE(&sv->sv_v, 0);
if (result) {
vfs_biglock_release();
return result;
}
}
/* Sync the inode to disk */
result = sfs_sync_inode(sv);
if (result) {
vfs_biglock_release();
return result;
}
/* If there are no on-disk references, discard the inode */
if (sv->sv_i.sfi_linkcount==0) {
sfs_bfree(sfs, sv->sv_ino);
}
/* Remove the vnode structure from the table in the struct sfs_fs. */
num = vnodearray_num(sfs->sfs_vnodes);
ix = num;
for (i=0; i<num; i++) {
struct vnode *v2 = vnodearray_get(sfs->sfs_vnodes, i);
struct sfs_vnode *sv2 = v2->vn_data;
if (sv2 == sv) {
ix = i;
break;
}
}
if (ix == num) {
panic("sfs: reclaim vnode %u not in vnode pool\n",
sv->sv_ino);
}
vnodearray_remove(sfs->sfs_vnodes, ix);
VOP_CLEANUP(&sv->sv_v);
vfs_biglock_release();
/* Release the storage for the vnode structure itself. */
kfree(sv);
/* Done */
return 0;
}
/*
* Function to load a vnode into memory.
*/
static
int
emufs_loadvnode(struct emufs_fs *ef, uint32_t handle, int isdir,
struct emufs_vnode **ret)
{
struct vnode *v;
struct emufs_vnode *ev;
unsigned i, num;
int result;
vfs_biglock_acquire();
lock_acquire(ef->ef_emu->e_lock);
num = vnodearray_num(ef->ef_vnodes);
for (i=0; i<num; i++) {
v = vnodearray_get(ef->ef_vnodes, i);
ev = v->vn_data;
if (ev->ev_handle == handle) {
/* Found */
VOP_INCREF(&ev->ev_v);
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
*ret = ev;
return 0;
}
}
/* Didn't have one; create it */
ev = kmalloc(sizeof(struct emufs_vnode));
if (ev==NULL) {
lock_release(ef->ef_emu->e_lock);
return ENOMEM;
}
ev->ev_emu = ef->ef_emu;
ev->ev_handle = handle;
result = VOP_INIT(&ev->ev_v, isdir ? &emufs_dirops : &emufs_fileops,
&ef->ef_fs, ev);
if (result) {
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
kfree(ev);
return result;
}
result = vnodearray_add(ef->ef_vnodes, &ev->ev_v, NULL);
if (result) {
/* note: VOP_CLEANUP undoes VOP_INIT - it does not kfree */
VOP_CLEANUP(&ev->ev_v);
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
kfree(ev);
return result;
}
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
*ret = ev;
return 0;
}
/*
* Rename a file.
*
* Since we don't support subdirectories, assumes that the two
* directories passed are the same.
*/
static
int
sfs_rename(struct vnode *d1, const char *n1,
struct vnode *d2, const char *n2)
{
struct sfs_vnode *sv = d1->vn_data;
struct sfs_vnode *g1;
int slot1, slot2;
int result, result2;
vfs_biglock_acquire();
KASSERT(d1==d2);
KASSERT(sv->sv_ino == SFS_ROOT_LOCATION);
/* Look up the old name of the file and get its inode and slot number*/
result = sfs_lookonce(sv, n1, &g1, &slot1);
if (result) {
vfs_biglock_release();
return result;
}
/* We don't support subdirectories */
KASSERT(g1->sv_i.sfi_type == SFS_TYPE_FILE);
/*
* Link it under the new name.
*
* We could theoretically just overwrite the original
* directory entry, except that we need to check to make sure
* the new name doesn't already exist; might as well use the
* existing link routine.
*/
result = sfs_dir_link(sv, n2, g1->sv_ino, &slot2);
if (result) {
goto puke;
}
/* Increment the link count, and mark inode dirty */
g1->sv_i.sfi_linkcount++;
g1->sv_dirty = true;
/* Unlink the old slot */
result = sfs_dir_unlink(sv, slot1);
if (result) {
goto puke_harder;
}
/*
* Decrement the link count again, and mark the inode dirty again,
* in case it's been synced behind our back.
*/
KASSERT(g1->sv_i.sfi_linkcount>0);
g1->sv_i.sfi_linkcount--;
g1->sv_dirty = true;
/* Let go of the reference to g1 */
VOP_DECREF(&g1->sv_v);
vfs_biglock_release();
return 0;
puke_harder:
/*
* Error recovery: try to undo what we already did
*/
result2 = sfs_dir_unlink(sv, slot2);
if (result2) {
kprintf("sfs: rename: %s\n", strerror(result));
kprintf("sfs: rename: while cleaning up: %s\n",
strerror(result2));
panic("sfs: rename: Cannot recover\n");
}
g1->sv_i.sfi_linkcount--;
puke:
/* Let go of the reference to g1 */
VOP_DECREF(&g1->sv_v);
vfs_biglock_release();
return result;
}
/*
* Called for ftruncate() and from sfs_reclaim.
*/
static
int
sfs_truncate(struct vnode *v, off_t len)
{
/*
* I/O buffer for handling the indirect block.
*
* Note: in real life (and when you've done the fs assignment)
* you would get space from the disk buffer cache for this,
* not use a static area.
*/
static uint32_t idbuf[SFS_DBPERIDB];
struct sfs_vnode *sv = v->vn_data;
struct sfs_fs *sfs = sv->sv_v.vn_fs->fs_data;
/* Length in blocks (divide rounding up) */
uint32_t blocklen = DIVROUNDUP(len, SFS_BLOCKSIZE);
uint32_t i, j, block;
uint32_t idblock, baseblock, highblock;
int result;
int hasnonzero, iddirty;
KASSERT(sizeof(idbuf)==SFS_BLOCKSIZE);
vfs_biglock_acquire();
/*
* Go through the direct blocks. Discard any that are
* past the limit we're truncating to.
*/
for (i=0; i<SFS_NDIRECT; i++) {
block = sv->sv_i.sfi_direct[i];
if (i >= blocklen && block != 0) {
sfs_bfree(sfs, block);
sv->sv_i.sfi_direct[i] = 0;
sv->sv_dirty = true;
}
}
/* Indirect block number */
idblock = sv->sv_i.sfi_indirect;
/* The lowest block in the indirect block */
baseblock = SFS_NDIRECT;
/* The highest block in the indirect block */
highblock = baseblock + SFS_DBPERIDB - 1;
if (blocklen < highblock && idblock != 0) {
/* We're past the proposed EOF; may need to free stuff */
/* Read the indirect block */
result = sfs_rblock(sfs, idbuf, idblock);
if (result) {
vfs_biglock_release();
return result;
}
hasnonzero = 0;
iddirty = 0;
for (j=0; j<SFS_DBPERIDB; j++) {
/* Discard any blocks that are past the new EOF */
if (blocklen < baseblock+j && idbuf[j] != 0) {
sfs_bfree(sfs, idbuf[j]);
idbuf[j] = 0;
iddirty = 1;
}
/* Remember if we see any nonzero blocks in here */
if (idbuf[j]!=0) {
hasnonzero=1;
}
}
if (!hasnonzero) {
/* The whole indirect block is empty now; free it */
sfs_bfree(sfs, idblock);
sv->sv_i.sfi_indirect = 0;
sv->sv_dirty = true;
}
else if (iddirty) {
/* The indirect block is dirty; write it back */
result = sfs_wblock(sfs, idbuf, idblock);
if (result) {
vfs_biglock_release();
return result;
}
}
}
/* Set the file size */
sv->sv_i.sfi_size = len;
/* Mark the inode dirty */
sv->sv_dirty = true;
vfs_biglock_release();
return 0;
}
/*
* Create a file. If EXCL is set, insist that the filename not already
* exist; otherwise, if it already exists, just open it.
*/
static
int
sfs_creat(struct vnode *v, const char *name, bool excl, mode_t mode,
struct vnode **ret)
{
struct sfs_fs *sfs = v->vn_fs->fs_data;
struct sfs_vnode *sv = v->vn_data;
struct sfs_vnode *newguy;
uint32_t ino;
int result;
vfs_biglock_acquire();
/* Look up the name */
result = sfs_dir_findname(sv, name, &ino, NULL, NULL);
if (result!=0 && result!=ENOENT) {
vfs_biglock_release();
return result;
}
/* If it exists and we didn't want it to, fail */
if (result==0 && excl) {
vfs_biglock_release();
return EEXIST;
}
if (result==0) {
/* We got a file; load its vnode and return */
result = sfs_loadvnode(sfs, ino, SFS_TYPE_INVAL, &newguy);
if (result) {
vfs_biglock_release();
return result;
}
*ret = &newguy->sv_v;
vfs_biglock_release();
return 0;
}
/* Didn't exist - create it */
result = sfs_makeobj(sfs, SFS_TYPE_FILE, &newguy);
if (result) {
vfs_biglock_release();
return result;
}
/* We don't currently support file permissions; ignore MODE */
(void)mode;
/* Link it into the directory */
result = sfs_dir_link(sv, name, newguy->sv_ino, NULL);
if (result) {
VOP_DECREF(&newguy->sv_v);
vfs_biglock_release();
return result;
}
/* Update the linkcount of the new file */
newguy->sv_i.sfi_linkcount++;
/* and consequently mark it dirty. */
newguy->sv_dirty = true;
*ret = &newguy->sv_v;
vfs_biglock_release();
return 0;
}
/*
* Global unmount function.
*/
int
vfs_unmountall(void)
{
struct knowndev *dev;
unsigned i, num;
int result;
vfs_biglock_acquire();
num = knowndevarray_num(knowndevs);
for (i=0; i<num; i++) {
dev = knowndevarray_get(knowndevs, i);
if (dev->kd_rawname == NULL) {
/* not mountable/unmountable */
continue;
}
if (dev->kd_fs == NULL) {
/* not mounted */
continue;
}
kprintf("vfs: Unmounting %s:\n", dev->kd_name);
result = FSOP_SYNC(dev->kd_fs);
if (result) {
kprintf("vfs: Warning: sync failed for %s: %s, trying "
"again\n", dev->kd_name, strerror(result));
result = FSOP_SYNC(dev->kd_fs);
if (result) {
kprintf("vfs: Warning: sync failed second time"
" for %s: %s, giving up...\n",
dev->kd_name, strerror(result));
/*
* Do not attempt to complete the
* unmount as it will likely explode.
*/
continue;
}
}
result = FSOP_UNMOUNT(dev->kd_fs);
if (result == EBUSY) {
kprintf("vfs: Cannot unmount %s: (busy)\n",
dev->kd_name);
continue;
}
if (result) {
kprintf("vfs: Warning: unmount failed for %s:"
" %s, already synced, dropping...\n",
dev->kd_name, strerror(result));
continue;
}
/* now drop the filesystem */
dev->kd_fs = NULL;
}
vfs_biglock_release();
return 0;
}
/*
* VOP_RECLAIM
*
* Reclaim should make an effort to returning errors other than EBUSY.
*/
static
int
emufs_reclaim(struct vnode *v)
{
struct emufs_vnode *ev = v->vn_data;
struct emufs_fs *ef = v->vn_fs->fs_data;
unsigned ix, i, num;
int result;
/*
* Need all of these locks, e_lock to protect the device,
* vfs_biglock to protect the fs-related material, and
* vn_countlock for the reference count.
*/
vfs_biglock_acquire();
lock_acquire(ef->ef_emu->e_lock);
spinlock_acquire(&ev->ev_v.vn_countlock);
if (ev->ev_v.vn_refcount > 1) {
/* consume the reference VOP_DECREF passed us */
ev->ev_v.vn_refcount--;
spinlock_release(&ev->ev_v.vn_countlock);
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
return EBUSY;
}
KASSERT(ev->ev_v.vn_refcount == 1);
/*
* Since we hold e_lock and are the last ref, nobody can increment
* the refcount, so we can release vn_countlock.
*/
spinlock_release(&ev->ev_v.vn_countlock);
/* emu_close retries on I/O error */
result = emu_close(ev->ev_emu, ev->ev_handle);
if (result) {
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
return result;
}
num = vnodearray_num(ef->ef_vnodes);
ix = num;
for (i=0; i<num; i++) {
struct vnode *vx;
vx = vnodearray_get(ef->ef_vnodes, i);
if (vx == v) {
ix = i;
break;
}
}
if (ix == num) {
panic("emu%d: reclaim vnode %u not in vnode pool\n",
ef->ef_emu->e_unit, ev->ev_handle);
}
vnodearray_remove(ef->ef_vnodes, ix);
vnode_cleanup(&ev->ev_v);
lock_release(ef->ef_emu->e_lock);
vfs_biglock_release();
kfree(ev);
return 0;
}
