/*
* 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;
}
/* Setup . and .. in root directory if this is the first mount */
int
sfs_setup_root(struct sfs_fs *sfs)
{
struct fs *fs = &sfs->sfs_absfs;
struct vnode *root_vv;
struct sfs_vnode *root_sv;
int result;
root_vv = sfs_getroot(fs);
root_sv = root_vv->vn_data;
if(sfs_dir_nentries(root_sv) != 0){
VOP_DECREF(root_vv);
return 0;
}
result = sfs_dir_link(root_sv, ".", SFS_ROOT_LOCATION, NULL);
if (result) {
VOP_DECREF(root_vv);
return result;
}
root_sv->sv_i.sfi_linkcount++;
root_sv->sv_dirty = 1;
result = sfs_dir_link(root_sv, "..", SFS_ROOT_LOCATION, NULL);
if (result) {
sfs_dir_unlink(root_sv, 0); /* Hope this doesn't fail?? */
root_sv->sv_i.sfi_linkcount--;
root_sv->sv_dirty = 1;
VOP_DECREF(root_vv);
return result;
}
root_sv->sv_i.sfi_linkcount++;
root_sv->sv_dirty = 1;
/* Decrement reference that sfs_getroot incremented */
VOP_DECREF(root_vv);
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, int excl, struct vnode **ret)
{
struct sfs_fs *sfs = v->vn_fs->fs_data;
struct sfs_vnode *sv = v->vn_data;
struct sfs_vnode *newguy;
u_int32_t ino;
int result;
/* Look up the name */
result = sfs_dir_findname(sv, name, &ino, NULL, NULL);
if (result!=0 && result!=ENOENT) {
return result;
}
/* If it exists and we didn't want it to, fail */
if (result==0 && excl) {
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) {
return result;
}
*ret = &newguy->sv_v;
return 0;
}
/* Didn't exist - create it */
result = sfs_makeobj(sfs, SFS_TYPE_FILE, &newguy);
if (result) {
return result;
}
/* Link it into the directory */
result = sfs_dir_link(sv, name, newguy->sv_ino, NULL);
if (result) {
VOP_DECREF(&newguy->sv_v);
return result;
}
/* Update the linkcount of the new file */
newguy->sv_i.sfi_linkcount++;
/* and consequently mark it dirty. */
newguy->sv_dirty = 1;
*ret = &newguy->sv_v;
return 0;
}
/*
* Make a hard link to a file.
* The VFS layer should prevent this being called unless both
* vnodes are ours.
*
* Locking: locks both vnodes, parent first. Since we aren't allowed
* to hardlink directories, the target can't be an ancestor of the
* directory we're working in.
*
* Requires up to 4 buffers.
*/
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;
struct sfs_dinode *inodeptr;
int result;
KASSERT(file->vn_fs == dir->vn_fs);
/* Hard links to directories aren't allowed. */
if (f->sv_type == SFS_TYPE_DIR) {
return EINVAL;
}
KASSERT(file != dir);
reserve_buffers(SFS_BLOCKSIZE);
/* directory must be locked first */
lock_acquire(sv->sv_lock);
lock_acquire(f->sv_lock);
result = sfs_dinode_load(f);
if (result) {
lock_release(f->sv_lock);
lock_release(sv->sv_lock);
unreserve_buffers(SFS_BLOCKSIZE);
return result;
}
/* Create the link */
result = sfs_dir_link(sv, name, f->sv_ino, NULL);
if (result) {
sfs_dinode_unload(f);
lock_release(f->sv_lock);
lock_release(sv->sv_lock);
unreserve_buffers(SFS_BLOCKSIZE);
return result;
}
/* and update the link count, marking the inode dirty */
inodeptr = sfs_dinode_map(f);
inodeptr->sfi_linkcount++;
sfs_dinode_mark_dirty(f);
sfs_dinode_unload(f);
lock_release(f->sv_lock);
lock_release(sv->sv_lock);
unreserve_buffers(SFS_BLOCKSIZE);
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;
assert(file->vn_fs == dir->vn_fs);
/* Just create a link */
result = sfs_dir_link(sv, name, f->sv_ino, NULL);
if (result) {
return result;
}
/* and update the link count, marking the inode dirty */
f->sv_i.sfi_linkcount++;
f->sv_dirty = 1;
return 0;
}
static
int
sfs_mkdir(struct vnode *vv, const char *name){
struct sfs_fs *sfs = vv->vn_fs->fs_data;
struct sfs_vnode *sv = vv->vn_data;
struct sfs_vnode *newguy;
u_int32_t ino;
int result, result2, slot1, slot2;
/* Look up the name */
result = sfs_dir_findname(sv, name, &ino, NULL, NULL);
if (result!=0 && result!=ENOENT) {
return result;
}
if (result==0) {
/* Directory or file of same name already exists */
return EINVAL;
}
/* Didn't exist - create it */
result = sfs_makeobj(sfs, SFS_TYPE_DIR, &newguy);
if (result) {
return result;
}
/* Link it into the directory */
result = sfs_dir_link(sv, name, newguy->sv_ino, &slot1);
if (result) {
VOP_DECREF(&newguy->sv_v);
return result;
}
/* Increment linkcount of the new directory and mark it dirty */
newguy->sv_i.sfi_linkcount++;
newguy->sv_dirty = 1;
/* Link . and .. into our directory */
result = sfs_dir_link(newguy, ".", newguy->sv_ino, &slot2);
if (result) {
result2 = sfs_dir_unlink(sv, slot1);
if(result2){
VOP_DECREF(&newguy->sv_v);
return result2;
}
newguy->sv_i.sfi_linkcount--;
newguy->sv_dirty = 1;
VOP_DECREF(&newguy->sv_v);
return result;
}
newguy->sv_i.sfi_linkcount++;
newguy->sv_dirty = 1;
result = sfs_dir_link(newguy, "..", sv->sv_ino, NULL);
if (result) {
result2 = sfs_dir_unlink(newguy, slot2);
if(result2){
VOP_DECREF(&newguy->sv_v);
return result2;
}
newguy->sv_i.sfi_linkcount--;
newguy->sv_dirty = 1;
result2 = sfs_dir_unlink(sv, slot1);
if(result2){
VOP_DECREF(&newguy->sv_v);
return result2;
}
newguy->sv_i.sfi_linkcount--;
newguy->sv_dirty = 1;
VOP_DECREF(&newguy->sv_v);
return result;
}
sv->sv_i.sfi_linkcount++;
sv->sv_dirty = 1;
VOP_DECREF(&newguy->sv_v);
return 0;
}
/*
* Rename a file.
*/
static
int
sfs_rename(struct vnode *d1, const char *n1,
struct vnode *d2, const char *n2)
{
struct sfs_vnode *sv1 = d1->vn_data;
struct sfs_vnode *sv2 = d2->vn_data;
struct sfs_vnode *g1;
int slot1, slot2;
int result, result2;
/* Look up the old name of the file and get its inode and slot number*/
result = sfs_lookonce(sv1, n1, &g1, &slot1);
if (result) {
return result;
}
/*
* Link it to the 'new' directory 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(sv2, 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 = 1;
/* Unlink the old slot */
result = sfs_dir_unlink(sv1, 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.
*/
assert(g1->sv_i.sfi_linkcount>0);
g1->sv_i.sfi_linkcount--;
g1->sv_dirty = 1;
/* Let go of the reference to g1 */
VOP_DECREF(&g1->sv_v);
return 0;
puke_harder:
/*
* Error recovery: try to undo what we already did
*/
result2 = sfs_dir_unlink(sv2, 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);
return result;
}
/*
* Delete a directory.
*
* Locking: Acquires vnode lock for parent dir and then vnode lock for
* victim dir. Releases both.
*
* Requires 4 buffers.
*/
static
int
sfs_rmdir(struct vnode *v, const char *name)
{
struct sfs_vnode *sv = v->vn_data;
struct sfs_fs *sfs = sv->sv_absvn.vn_fs->fs_data;
struct sfs_vnode *victim;
struct sfs_dinode *dir_inodeptr;
struct sfs_dinode *victim_inodeptr;
int result, result2;
int slot;
/* Cannot remove the . or .. entries from a directory! */
if (!strcmp(name, ".") || !strcmp(name, "..")) {
return EINVAL;
}
lock_acquire(sv->sv_lock);
reserve_buffers(SFS_BLOCKSIZE);
result = sfs_dinode_load(sv);
if (result) {
goto die_loadsv;
}
dir_inodeptr = sfs_dinode_map(sv);
if (dir_inodeptr->sfi_linkcount == 0) {
result = ENOENT;
goto die_linkcount;
}
result = sfs_lookonce(sv, name, &victim, &slot);
if (result) {
goto die_linkcount;
}
lock_acquire(victim->sv_lock);
result = sfs_dinode_load(victim);
if (result) {
goto die_loadvictim;
}
victim_inodeptr = sfs_dinode_map(victim);
if (victim->sv_ino == SFS_ROOTDIR_INO) {
result = EPERM;
goto die_total;
}
/* Only allowed on directories */
if (victim_inodeptr->sfi_type != SFS_TYPE_DIR) {
result = ENOTDIR;
goto die_total;
}
result = sfs_dir_checkempty(victim);
if (result) {
goto die_total;
}
result = sfs_dir_unlink(sv, slot);
if (result) {
goto die_total;
}
KASSERT(dir_inodeptr->sfi_linkcount > 1);
KASSERT(victim_inodeptr->sfi_linkcount==2);
dir_inodeptr->sfi_linkcount--;
sfs_dinode_mark_dirty(sv);
victim_inodeptr->sfi_linkcount -= 2;
sfs_dinode_mark_dirty(victim);
result = sfs_itrunc(victim, 0);
if (result) {
victim_inodeptr->sfi_linkcount += 2;
dir_inodeptr->sfi_linkcount++;
result2 = sfs_dir_link(sv, name, victim->sv_ino, NULL);
if (result2) {
/* XXX: would be better if this case didn't exist */
panic("sfs: %s: rmdir: %s; while recovering: %s\n",
sfs->sfs_sb.sb_volname,
strerror(result), strerror(result2));
}
goto die_total;
}
die_total:
sfs_dinode_unload(victim);
die_loadvictim:
lock_release(victim->sv_lock);
VOP_DECREF(&victim->sv_absvn);
die_linkcount:
sfs_dinode_unload(sv);
die_loadsv:
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return result;
}
static
int
sfs_mkdir(struct vnode *v, const char *name, mode_t mode)
{
struct sfs_fs *sfs = v->vn_fs->fs_data;
struct sfs_vnode *sv = v->vn_data;
int result;
uint32_t ino;
struct sfs_dinode *dir_inodeptr;
struct sfs_dinode *new_inodeptr;
struct sfs_vnode *newguy;
(void)mode;
lock_acquire(sv->sv_lock);
reserve_buffers(SFS_BLOCKSIZE);
result = sfs_dinode_load(sv);
if (result) {
goto die_early;
}
dir_inodeptr = sfs_dinode_map(sv);
if (dir_inodeptr->sfi_linkcount == 0) {
result = ENOENT;
goto die_simple;
}
/* Look up the name */
result = sfs_dir_findname(sv, name, &ino, NULL, NULL);
if (result!=0 && result!=ENOENT) {
goto die_simple;
}
/* If it exists, fail */
if (result==0) {
result = EEXIST;
goto die_simple;
}
/*
* If we're trying to create . or .. and we get this far
* (meaning the entry in question is missing), the fs is
* corrupted. Let's not make it worse. Best at this point to
* bail out and run fsck.
*/
if (!strcmp(name, ".") || !strcmp(name, "..")) {
panic("sfs: %s: No %s entry in dir %u; please fsck\n",
sfs->sfs_sb.sb_volname, name, sv->sv_ino);
}
result = sfs_makeobj(sfs, SFS_TYPE_DIR, &newguy);
if (result) {
goto die_simple;
}
new_inodeptr = sfs_dinode_map(newguy);
result = sfs_dir_link(newguy, ".", newguy->sv_ino, NULL);
if (result) {
goto die_uncreate;
}
result = sfs_dir_link(newguy, "..", sv->sv_ino, NULL);
if (result) {
goto die_uncreate;
}
result = sfs_dir_link(sv, name, newguy->sv_ino, NULL);
if (result) {
goto die_uncreate;
}
/*
* Increment link counts (Note: not until after the names are
* added - that way if one fails, the link count will be zero,
* and reclaim will dispose of the new directory.
*
* Note also that the name in the parent directory gets added
* last, so there's no case in which we have to go back and
* remove it.
*/
new_inodeptr->sfi_linkcount += 2;
dir_inodeptr->sfi_linkcount++;
sfs_dinode_mark_dirty(newguy);
sfs_dinode_mark_dirty(sv);
sfs_dinode_unload(newguy);
sfs_dinode_unload(sv);
lock_release(newguy->sv_lock);
lock_release(sv->sv_lock);
VOP_DECREF(&newguy->sv_absvn);
unreserve_buffers(SFS_BLOCKSIZE);
KASSERT(result==0);
return result;
die_uncreate:
sfs_dinode_unload(newguy);
lock_release(newguy->sv_lock);
VOP_DECREF(&newguy->sv_absvn);
die_simple:
sfs_dinode_unload(sv);
die_early:
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return result;
}
/*
* Create a file. If EXCL is set, insist that the filename not already
* exist; otherwise, if it already exists, just open it.
*
* Locking: Gets/releases the vnode lock for v. Does not lock the new vnode,
* as nobody else can get to it except by searching the directory it's in,
* which is locked.
*
* Requires up to 4 buffers as VOP_DECREF invocations may take 3.
*/
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;
struct sfs_dinode *sv_dino;
struct sfs_dinode *new_dino;
uint32_t ino;
int result;
lock_acquire(sv->sv_lock);
reserve_buffers(SFS_BLOCKSIZE);
result = sfs_dinode_load(sv);
if (result) {
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return result;
}
sv_dino = sfs_dinode_map(sv);
if (sv_dino->sfi_linkcount == 0) {
sfs_dinode_unload(sv);
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return ENOENT;
}
sfs_dinode_unload(sv);
/* Look up the name */
result = sfs_dir_findname(sv, name, &ino, NULL, NULL);
if (result!=0 && result!=ENOENT) {
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return result;
}
/* If it exists and we didn't want it to, fail */
if (result==0 && excl) {
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return EEXIST;
}
if (result==0) {
/* We got something; load its vnode and return */
result = sfs_loadvnode(sfs, ino, SFS_TYPE_INVAL, &newguy);
if (result) {
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return result;
}
*ret = &newguy->sv_absvn;
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return 0;
}
/* Didn't exist - create it */
result = sfs_makeobj(sfs, SFS_TYPE_FILE, &newguy);
if (result) {
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(sv->sv_lock);
return result;
}
/* sfs_makeobj loads the inode for us */
new_dino = sfs_dinode_map(newguy);
/* 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) {
sfs_dinode_unload(newguy);
lock_release(newguy->sv_lock);
VOP_DECREF(&newguy->sv_absvn);
lock_release(sv->sv_lock);
unreserve_buffers(SFS_BLOCKSIZE);
return result;
}
/* Update the linkcount of the new file */
new_dino->sfi_linkcount++;
/* and consequently mark it dirty. */
sfs_dinode_mark_dirty(newguy);
*ret = &newguy->sv_absvn;
sfs_dinode_unload(newguy);
unreserve_buffers(SFS_BLOCKSIZE);
lock_release(newguy->sv_lock);
lock_release(sv->sv_lock);
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;
}
