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feat: build out vfs

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dualfroz committed 2026-09-08 20:47:02 +02:00
1 parent 3124635682
commit 4640fb5eb5
1 file changed
+140 -18
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src/vfs.c
+140 -18
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@@ -1122,15 +1122,17 @@ int64 vfsRead(int fd, void* buffer, uint64 length)
return sfsFdRead(d, buffer, length);
if (d->kind == fdConsole) {
char* text = (char*)buffer;
uint64 count = 0;
while (count < length) {
char c = keyboardReadChar();
text[count++] = c;
if (c == '\n')
break;
}
return (int64)count;
/* Non-blocking, like every other real fd kind above: -1 (queue
currently empty) is the "would block" signal syscall.c's sysRead
retries via vfsBlockingChannel's channel + the restart-syscall
trick, instead of this function looping/halting in place the way
the old single-global-buffer keyboardReadChar() used to. Returns
whatever is queued right now (possibly fewer than length bytes,
same partial-read contract pipeRead already has) rather than
insisting on a full line -- nothing in this kernel relied on the
old line-buffering behavior (grep shows no caller ever read fd 0
before this wave). */
return keyboardReaderRead(d->pipeHandle, buffer, length);
}
VfsNode* node = d->node;
@@ -1149,7 +1151,7 @@ int64 vfsRead(int fd, void* buffer, uint64 length)
int64 vfsLseek(int fd, int64 offset, int whence)
{
FileDescriptor* d = fdAt(fd);
if (!d || d->kind != fdFile)
if (!d || (d->kind != fdFile && d->kind != fdBlockDev && d->kind != fdSfs))
return -1;
int64 base;
@@ -1157,9 +1159,14 @@ int64 vfsLseek(int fd, int64 offset, int whence)
base = 0;
else if (whence == seekCur)
base = (int64)d->offset;
else if (whence == seekEnd)
base = (int64)d->node->size;
else
else if (whence == seekEnd) {
if (d->kind == fdBlockDev)
base = (int64)blockDevTotalBytes();
else if (d->kind == fdSfs)
base = (int64)sfsSizeOf(d->pipeHandle);
else
base = (int64)d->node->size;
} else
return -1;
int64 target = base + offset;
@@ -1171,20 +1178,75 @@ int64 vfsLseek(int fd, int64 offset, int whence)
int vfsStat(const char* path, FbStat* out)
{
char resolvedPath[fsPathMax];
vfsResolvePath(path, resolvedPath, sizeof(resolvedPath));
path = resolvedPath;
const char* rel;
if (isSfsPath(path, &rel)) {
int32 inodeNum = sfsLookup(rel);
if (inodeNum < 0)
return -1;
out->size = sfsSizeOf(inodeNum);
out->type = sfsTypeToFsType(sfsTypeOf(inodeNum));
out->mode = sfsModeOf(inodeNum);
out->uid = sfsUidOf(inodeNum);
out->gid = sfsGidOf(inodeNum);
out->mtime = sfsMtimeOf(inodeNum);
out->ctime = sfsCtimeOf(inodeNum);
return 0;
}
if (strcmp(path, blockDevPath) == 0) {
out->size = blockDevTotalBytes();
out->type = fsTypeFile;
out->mode = 0666;
out->uid = 0;
out->gid = 0;
out->mtime = 0;
out->ctime = 0;
return 0;
}
VfsNode* node = lookupNode(path);
if (!node)
return -1;
out->size = node->size;
out->type = node->type;
out->mode = node->writable ? 0666 : 0444;
out->mode = node->mode;
out->uid = node->uid;
out->gid = node->gid;
out->mtime = 0;
out->ctime = 0;
return 0;
}
int64 vfsGetdents(int fd, void* buffer, uint64 length)
{
FileDescriptor* d = fdAt(fd);
if (!d || d->kind != fdFile)
if (!d || (d->kind != fdFile && d->kind != fdSfs))
return -1;
if (d->kind == fdSfs) {
if (sfsTypeOf(d->pipeHandle) != sfsTypeDir)
return -1;
FbDirent* out = (FbDirent*)buffer;
uint64 written = 0;
char name[fsNameMax];
uint32 type;
while (written + sizeof(FbDirent) <= length &&
sfsReaddirAt(d->pipeHandle, (uint32)d->offset, name, sizeof(name), &type)) {
uint64 nameLen = strlen(name);
out->type = sfsTypeToFsType(type);
out->nameLength = (unsigned int)nameLen;
memcpy(out->name, name, nameLen + 1);
out++;
written += sizeof(FbDirent);
d->offset++;
}
return (int64)written;
}
VfsNode* node = d->node;
if (node->type != fsTypeDir)
return -1;
@@ -1214,28 +1276,88 @@ int64 vfsGetdents(int fd, void* buffer, uint64 length)
int vfsMkdir(const char* path)
{
char resolvedPath[fsPathMax];
vfsResolvePath(path, resolvedPath, sizeof(resolvedPath));
path = resolvedPath;
const char* rel;
if (isSfsPath(path, &rel))
return sfsCreateDir(rel) >= 0 ? 0 : -1;
if (lookupNode(path))
return -1;
char leaf[fsNameMax];
VfsNode* parent = splitParent(path, leaf, sizeof(leaf));
if (!parent || parent->type != fsTypeDir || !parent->writable)
if (!parent || parent->type != fsTypeDir || !parent->writable
|| !vfsPermitted(parent->mode, parent->uid, parent->gid, currentThreadUid(), currentThreadGid(), fsModeOwnerWrite))
return -1;
return makeChildDir(parent, leaf, strlen(leaf), true) ? 0 : -1;
return makeChildDir(parent, leaf, strlen(leaf), true, fsModeDefaultDir) ? 0 : -1;
}
int vfsUnlink(const char* path)
{
char resolvedPath[fsPathMax];
vfsResolvePath(path, resolvedPath, sizeof(resolvedPath));
path = resolvedPath;
const char* rel;
if (isSfsPath(path, &rel)) {
int32 inodeNum = sfsLookup(rel);
/* Real unlink(2) semantics: EISDIR on a directory, even an empty
one -- rmdir(2) (vfsRmdir below) is the only sanctioned way to
remove one. sfsRemove itself has no opinion here (it is the raw
on-disk primitive, also used by vfsRmdir below), so the type
check has to happen at this dispatch layer, matching the tmpfs
branch below which has always refused a directory this way. */
if (inodeNum < 0 || sfsTypeOf(inodeNum) == sfsTypeDir)
return -1;
/* Only the LAST directory entry pointing at a persistent fifo's
inode should ever tear down its live pipe.h binding (see
sfsFifoForget above) -- a hardlinked fifo (sfsLink does not
special-case sfsTypeFifo, unlike sfsTypeDir) losing one of
several names must leave any live session alone, exactly like
sfsRemove itself only actually frees the inode once linkCount
drops to 0. Checked and captured BEFORE sfsRemove, since a
successful removal may itself free the inode (readInode on it
afterwards would read whatever unrelated data now occupies that
slot, if anything). */
bool lastLinkOfFifo = sfsTypeOf(inodeNum) == sfsTypeFifo &&
sfsLinkCountOf(inodeNum) <= 1;
if (!sfsRemove(rel))
return -1;
if (lastLinkOfFifo)
sfsFifoForget(inodeNum);
return 0;
}
VfsNode* node = lookupNode(path);
if (!node || node->type != fsTypeFile || !node->writable)
if (!node || !node->writable || (node->type != fsTypeFile && node->type != fsTypeFifo))
return -1;
/* Real unlink(2) semantics: removing a directory ENTRY needs write
permission on the PARENT directory, not on the entry itself -- a
real Unix caller can delete a read-only file it can write into the
containing directory of, matching real Unix's own "the file's own
mode is irrelevant to unlink" rule. */
VfsNode* parent = node->parent;
if (!vfsPermitted(parent->mode, parent->uid, parent->gid, currentThreadUid(), currentThreadGid(), fsModeOwnerWrite))
return -1;
VfsNode** link = &parent->firstChild;
while (*link && *link != node)
link = &(*link)->nextSibling;
if (*link)
*link = node->nextSibling;
/* Any fd already opened on this fifo (fdPipeRead/fdPipeWrite) keeps
working off its own copy of node->pipeHandle -- it never dereferences
this node again, so freeing it here does not disturb a live reader or
writer, matching real unlink-while-open semantics. Only reclaim the
underlying pipe slot if nobody ever actually opened it; otherwise the
still-open ends must keep it alive until their own vfsClose. */
if (node->type == fsTypeFifo)
pipeDestroyIfUnattached(node->pipeHandle);
if (node->rwData)
kfree(node->rwData);
kfree(node);