From ea0630ef550a3ed7bc38d54c8acab6c7ed075aba Mon Sep 17 00:00:00 2001
From: Ian Moffett <ian@osmora.org>
Date: Tue, 26 Mar 2024 21:49:29 -0400
Subject: kernel: Use 'sio_txn' for file I/O

Signed-off-by: Ian Moffett <ian@osmora.org>
---
 sys/fs/initramfs.c       |  7 ++++---
 sys/include/sys/vfs.h    |  3 ++-
 sys/include/sys/vnode.h  |  5 +++--
 sys/kern/kern_filedesc.c | 14 +++++++++++---
 sys/kern/vfs_subr.c      |  4 ++--
 5 files changed, 22 insertions(+), 11 deletions(-)

(limited to 'sys')

diff --git a/sys/fs/initramfs.c b/sys/fs/initramfs.c
index 5b31bf9..897a3d4 100644
--- a/sys/fs/initramfs.c
+++ b/sys/fs/initramfs.c
@@ -121,11 +121,12 @@ vop_vget(struct vnode *parent, const char *name, struct vnode **vp)
 }
 
 static int
-vop_read(struct vnode *vp, char *buf, size_t count)
+vop_read(struct vnode *vp, struct sio_txn *sio)
 {
     struct tar_hdr *hdr;
     size_t size;
     char *contents;
+    char *buf = sio->buf;
 
     if (vp->data == NULL) {
         return -EIO;
@@ -135,14 +136,14 @@ vop_read(struct vnode *vp, char *buf, size_t count)
     size = getsize(hdr->size);
     contents = hdr_to_contents(hdr);
 
-    for (size_t i = 0; i < count; ++i) {
+    for (size_t i = sio->offset; i < sio->len; ++i) {
         if (i >= size) {
             return i + 1;
         }
         buf[i] = contents[i];
     }
 
-    return count;
+    return sio->len;
 }
 
 static char *
diff --git a/sys/include/sys/vfs.h b/sys/include/sys/vfs.h
index e219cf7..b454d39 100644
--- a/sys/include/sys/vfs.h
+++ b/sys/include/sys/vfs.h
@@ -33,6 +33,7 @@
 #include <sys/mount.h>
 #include <sys/vnode.h>
 #include <sys/types.h>
+#include <sys/sio.h>
 
 /* Max path length */
 #define PATH_MAX 1024
@@ -50,7 +51,7 @@ char *vfs_get_fname_at(const char *path, size_t idx);
 int vfs_rootname(const char *path, char **new_path);
 bool vfs_is_valid_path(const char *path);
 ssize_t vfs_hash_path(const char *path);
-ssize_t vfs_read(struct vnode *vp, char *buf, size_t count);
+ssize_t vfs_read(struct vnode *vp, struct sio_txn *sio);
 
 #endif /* defined(_KERNEL) */
 
diff --git a/sys/include/sys/vnode.h b/sys/include/sys/vnode.h
index 11bbf99..0352312 100644
--- a/sys/include/sys/vnode.h
+++ b/sys/include/sys/vnode.h
@@ -33,13 +33,14 @@
 #include <sys/types.h>
 #include <sys/queue.h>
 #include <sys/mount.h>
+#include <sys/sio.h>
 
 struct vnode;
 
 struct vops {
     int(*vget)(struct vnode *parent, const char *name, struct vnode **vp);
-    int(*read)(struct vnode *vp, char *buf, size_t count);
-    int(*write)(struct vnode *vp, const char *buf, size_t count);
+    int(*read)(struct vnode *vp, struct sio_txn *sio);
+    int(*write)(struct vnode *vp, struct sio_txn *sio);
 };
 
 struct vnode {
diff --git a/sys/kern/kern_filedesc.c b/sys/kern/kern_filedesc.c
index 80ab094..63ffa98 100644
--- a/sys/kern/kern_filedesc.c
+++ b/sys/kern/kern_filedesc.c
@@ -29,6 +29,7 @@
 
 #include <sys/filedesc.h>
 #include <sys/proc.h>
+#include <sys/sio.h>
 #include <sys/sched.h>
 #include <sys/errno.h>
 #include <sys/system.h>
@@ -90,8 +91,9 @@ make_write_buf(struct proc *td, const void *data, char **buf_out, size_t count)
  * Helper function for write()
  */
 static ssize_t
-do_write(struct vnode *vp, const char *buf, size_t count)
+do_write(struct vnode *vp, char *buf, size_t count)
 {
+    struct sio_txn sio = { .buf = buf, .len = count };
     struct vops *vops = vp->vops;
     int status;
 
@@ -103,7 +105,7 @@ do_write(struct vnode *vp, const char *buf, size_t count)
     }
 
     /* Attempt a write */
-    if ((status = vops->write(vp, buf, count)) < 0) {
+    if ((status = vops->write(vp, &sio)) < 0) {
         return status;
     }
 
@@ -313,8 +315,14 @@ read(int fd, void *buf, size_t count)
     ssize_t bytes_read;
     struct vnode *vnode;
     struct filedesc *fd_desc;
+    struct sio_txn sio = {
+        .buf = buf,
+        .len = count,
+        .type = SIO_NONE
+    };
 
     fd_desc = fd_from_fdnum(this_td(), fd);
+    sio.offset = fd_desc->offset;
 
     if (fd_desc == NULL) {
         return -EBADF;
@@ -326,7 +334,7 @@ read(int fd, void *buf, size_t count)
         return -EINVAL;
     }
 
-    bytes_read = vfs_read(vnode, buf, count);
+    bytes_read = vfs_read(vnode, &sio);
     return bytes_read;
 }
 
diff --git a/sys/kern/vfs_subr.c b/sys/kern/vfs_subr.c
index 5155c9a..bbaec12 100644
--- a/sys/kern/vfs_subr.c
+++ b/sys/kern/vfs_subr.c
@@ -225,7 +225,7 @@ vfs_vget(struct vnode *parent, const char *name, struct vnode **vp)
 }
 
 ssize_t
-vfs_read(struct vnode *vp, char *buf, size_t count)
+vfs_read(struct vnode *vp, struct sio_txn *sio)
 {
-    return vp->vops->read(vp, buf, count);
+    return vp->vops->read(vp, sio);
 }
-- 
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