VFS: design for the name cache system

core/elf.c

@@ -17,7 +17,7 @@
 uaddr_t loadElfProg(const char *prog, struct process *proc)
 {
     int i;
-    uaddr_t lastUserAddr  = 0;
+    uaddr_t lastUserAddr = 0;
     struct uAddrSpace *as = processGetAddrSpace(proc);
 
 /* e_ident value */

core/fs.c

@@ -1,27 +1,13 @@
 #include "fs.h"
-#include "list.h"
-#include "stddef.h"
-
-// List of all fs supported (e.g. EXT4, FAT32 ...)
-struct file_system *fsList = NULL;
-
-
-int fsRegister(struct file_system *fs){
-    list_add_tail(fsList, fs);
-
-    return 0;
-}
 
 int fsInodeUnref(struct inode *inode)
 {
-    //TODO
     (void)inode;
     return 0;
 };
 
 int fsInodeRef(struct inode *inode)
 {
-    //TODO
     (void)inode;
     return 0;
 };

core/fs.h

@@ -1,139 +1,7 @@
 #pragma once
-#include "fsEntry.h"
-#include "process.h"
-#include "stdint.h"
-#include <stddef.h>
-#include <stdint.h>
-
-#define FS_NAME_MAXLEN 32
-
-// Forward declaration
-struct file_system;
-struct file_system_instance;
-struct fs_stat;
-struct file;
-
-typedef enum {
-    FS_INODE_REGULAR_FILE = 0x01,
-    FS_INODE_DIRECTORY    = 0x02,
-    FS_INODE_SYMLINK      = 0x04,
-    FS_INODE_DEVICE_CHAR  = 0x08,
-    FS_INODE_DEVICE_BLOCK = 0x10
-} fs_inode_type_t;
-
-struct inode_operation {
-};
-
-struct inode { // inode_operation
-    struct file_system_instance *fs;
-
-    uint64_t location;
-    size_t ondiskRef;
-    size_t inmemRef;
-    fs_inode_type_t type;
-
-#define FS_READABLE 00400
-#define FS_WRITABLE 00200
-#define FS_EXECUTABLE 00100
-    uint32_t mode;
-
-    bool_t dirty;
-    struct inode_operation *ops;
-
-    union {
-        struct inode_dir_ops *opsDir;
-
-        struct inode_dir_symlink *opsSymlink;
-    };
-
-    int (*destructor)(struct inode *this);
-    int (*new_opened_file)(struct inode *this, const struct process *owner,
-                           uint32_t open_flags, struct file **result_of);
-    int (*close_opened_file)(struct inode *this, struct file *of);
-    void *custom;
-
-    struct inode *prev_dirty, *next_dirty;
-};
-
-struct file_system_instance_ops { // super_operations
-    // From the inode location, instantiace a struct inode
-    int (*getInodeFromDevice)(struct file_system_instance *this, uint64_t storage_location,
-                              struct inode **result);
-
-    int (*allocateNewInode)(struct file_system_instance *this, fs_inode_type_t type,
-                            const struct process *creator, uint32_t access_rights,
-                            uint32_t open_creat_flags, struct inode **result);
-
-    int (*statfs)(struct file_system_instance *this, struct fs_stat *result);
-};
-
-struct file_system_instance {
-
-    struct file_system *fsType; // this instance is of this type of file_system
-    struct inode *device; // device (like block one) could have a disk associated
-
-#define FS_MOUNT_SYNC (1 << 0)
-#define FS_MOUNT_READONLY (1 << 1)
-#define FS_MOUNT_NOEXEC (1 << 2)
-    uint32_t flags;
-
-    struct fsEntry *root; // root fsEntry for this fs instance
-    struct indoe *dirtyNodes; // list of inodes that are out of sync
-    void *custom; // custom
-    const struct file_system_instance_ops *ops;
 
 
-    struct file_system_instance *prev, *next;
+struct inode {//TODO
-};
+              };
-
-struct file_system {
-    char name[FS_NAME_MAXLEN];
-    struct file_system_instance *instances;
-    void *custom;
-
-    int (*mount)(struct file_system *this, struct inode *device, const char *args,
-                 struct file_system_instance **mounted_fs);
-
-    int (*umount)(struct file_system *this, struct file_system_instance *mounted_fs);
-
-    struct file_system *prev, *next;
-};
-
-struct file_operations{
-};
-
-struct file {
-    const struct process *owner;
-
-    struct fs_entry *direntry;
-    uint ref;
-    int64_t position;
-
-#define O_ACCMODE	   0003
-#define O_RDONLY	     00
-#define O_WRONLY	     01
-#define O_RDWR		     02
-
-#define O_CREAT 0100  /* Not fcntl.  */
-#define O_EXCL 0200   /* Not fcntl.  */
-#define O_NOCTTY 0400 /* Not fcntl.  */
-#define O_TRUNC 01000 /* Not fcntl.  */
-#define O_APPEND 02000
-#define O_DIRECTORY 0200000 /* Must be a directory.  */ 
-#define O_NOFOLLOW 0400000 /* Do not follow links.  */
-#define O_SYNC 04010000
-#define O_CLOEXEC 02000000 /* Set close_on_exec.  */
-
-    uint32_t flags;
-    const struct file_operations	*ops;
-
-    int (*duplicate)(struct file *this, const struct process *for_owner,
-                     struct file **result);
-
-    void *custom;
-};
-
-int fsRegister(struct file_system *fs);
-
 int fsInodeUnref(struct inode *inode);
 int fsInodeRef(struct inode *inode);

core/fsEntry.c

@@ -4,6 +4,7 @@
 #include "errno.h"
 #include "list.h"
 #include "mem.h"
+#include "stdint.h"
 
 bool_t pstringSplipPath(struct pstr *path, struct pstr *upper, struct pstr *lower)
 {
@@ -37,28 +38,23 @@ bool_t pstringSplipPath(struct pstr *path, struct pstr *upper, struct pstr *lowe
     return lower->len > 0;
 }
 
-bool_t pstringIsEq(const struct pstr *p1, const struct pstr *p2)
+bool_t pstringIsEq(struct pstr *p1, struct pstr *p2)
 {
-    return p1->len == p2->len && (memcmp(p1->name, p2->name, p1->len) == 0);
+    return p1->len == p2->len && (memcmp(p1, p2, p1->len) == 0);
 }
 
-bool_t pstringIsStr(const struct pstr *p, char *s)
+int fsEntryRef(struct fsEntry *entry)
-{
-    size_t slen = strlen(s);
-    return p->len == slen && (memcmp(p->name, s, slen) == 0);
-}
-
-int fsEntryRef(struct fs_entry *entry)
 {
     entry->ref++;
     return 0;
 }
 
-int fsEntryUnref(struct fs_entry **entry)
+int fsEntryUnref(struct fsEntry **entry)
 {
-    struct fs_entry *toDelete = NULL, *entryTmp;
+    struct fsEntry *toDelete = NULL, *entryTmp;
 
     entryTmp = *entry;
+    *entry   = NULL;
 
     while (entryTmp) {
         assert(entryTmp->ref > 0);
@@ -68,10 +64,10 @@ int fsEntryUnref(struct fs_entry **entry)
             break;
 
         if (entryTmp == *entry)
-            *entry = NULL;
+            entry = NULL;
 
         if (entryTmp->parent) {
-            struct fs_entry *parent = entryTmp->parent;
+            struct fsEntry *parent = entryTmp->parent;
 
             assert(entryTmp->parent->ref >= 1);
 
@@ -96,19 +92,20 @@ int fsEntryUnref(struct fs_entry **entry)
     return 0;
 }
 
-struct fs_entry *fsEntryAlloc(struct fs_entry *parent, const struct pstr *name, struct inode *inode)
+int fsEntryNewChild(struct fsEntry *parent, const struct pstr *name, struct inode *inode,
+                    struct fsEntry **result)
 {
-    struct fs_entry *entry = zalloc(sizeof(struct fs_entry));
+    struct fsEntry *entry = malloc(sizeof(struct fsEntry));
 
     if (!entry)
-        return NULL;
+        return -ENOMEM;
 
     if (name && name->len > 0) {
         char *allocName = malloc(name->len);
 
         if (!allocName) {
             free(entry);
-            return NULL;
+            return -ENOMEM;
         }
 
         memcpy(allocName, name->name, name->len);
@@ -121,95 +118,16 @@ struct fs_entry *fsEntryAlloc(struct fs_entry *parent, const struct pstr *name,
     entry->parent = parent;
 
     fsInodeRef(inode);
-
     if (parent) {
         fsEntryRef(parent);
         list_add_head_named(parent->childs, entry, prevSiblings, nextSiblings);
     }
 
-    return entry;
+    *result = entry;
-}
-
-int fsEntryLookup(struct fs_entry *entry, const struct pstr *name, const struct fs_entry *root, struct fs_entry **result)
-{
-    if (pstringIsStr(name, ".")) {
-        *result = entry;
-    } else if (pstringIsStr(name, "..")) {
-        if (entry == root) {
-            *result = entry;
-        } else {
-            // If this entry is mounted, get the mountpoint
-            for (; entry->mountpoint; entry = entry->mountpoint) {
-                // No-op
-            }
-
-            assert(NULL != entry->parent);
-            *result = entry->parent;
-        }
-        fsEntryRef(*result);
-        return 0;
-    } else {
-        struct fs_entry *child;
-        int childIdx;
-        list_foreach_forward_named(entry->childs, child, childIdx, prevSiblings, nextSiblings)
-        {
-            if (pstringIsEq(&child->name, name)) {
-                break;
-            }
-        }
-
-        if (!list_foreach_early_break(entry->childs, child, childIdx))
-            return -ENOENT;
-
-        *result = child;
-    }
-
-    // Follow the mount chain
-    for (; (*result)->mountedFs; *result = (*result)->mountedFs)
-        ;
-
-    fsEntryRef(*result);
 
     return 0;
 }
 
-int fsEntrySetup(void)
+int fsEntrySetup(void){
-{
+    return allocBookSlab(sizeof(struct fsEntry), PAGE_SIZE, 0, 0);
-    return allocBookSlab(sizeof(struct fs_entry), PAGE_SIZE, 0, 0);
-}
-
-int fsEntryMount(struct fs_entry *mountpoint, struct fs_entry *mounted)
-{
-    if (mountpoint->mountedFs != NULL || mounted->mountpoint != NULL) {
-        return -EBUSY;
-    }
-
-    mountpoint->mountedFs = mounted;
-    mounted->mountpoint = mountpoint;
-
-    fsEntryRef(mounted);
-    fsEntryRef(mountpoint);
-
-    return 0;
-}
-
-int fsEntryUmount(struct fs_entry *mounted)
-{
-    if (!mounted->mountpoint || !mounted->mountpoint->mountedFs || mounted->mountpoint->mountedFs != mounted)
-        return -ENOENT;
-
-    if (mounted->mountedFs)
-        return -EBUSY;
-
-    // self + mounted
-    if (mounted->ref != 2)
-        return -EBUSY;
-
-
-    mounted->mountpoint->mountedFs = NULL;
-    fsEntryUnref(&mounted->mountpoint);
-    mounted->mountpoint = NULL;
-    fsEntryUnref(&mounted);
-
-    return 0;
 }

core/fsEntry.h

@@ -22,10 +22,6 @@ struct pstr {
         .len = l, .name = n                                                                   \
     }
 
-#define PSTR_STATIC_INIT(n)                                                                   \
-    {                                                                                         \
-        .len = sizeof(n) - 1, .name = n                                                       \
-    }
 
 /**
  * @brief Structure representing a file system entry.
@@ -34,16 +30,16 @@ struct pstr {
  * including its name, associated inode, relationships within
  * the file system hierarchy, and reference count.
  */
-struct fs_entry {
+struct fsEntry {
     struct pstr name;
     struct inode *node;
 
-    struct fs_entry *parent;     // parent directory
+    struct fsEntry *parent;     // parent directory
-    struct fs_entry *mountpoint; // if this is a mounted fs, point to mountpoint
+    struct fsEntry *mountpoint; // if this is a mounted fs, point to mountpoint
-    struct fs_entry *mountedFs;  // Fs possibly mounted on this fsEntry
+    struct fsEntry *mountedFs;  // Fs possibly mounted on this fsEntry
 
-    struct fs_entry *childs;                      // point to the list of children
+    struct fsEntry *childs;                      // point to the list of children
-    struct fs_entry *nextSiblings, *prevSiblings; // Sibling at the same level
+    struct fsEntry *nextSiblings, *prevSiblings; // Sibling at the same level
 
     uint ref; // reference counter
 };
@@ -71,15 +67,7 @@ bool_t pstringSplipPath(struct pstr *path, struct pstr *upper, struct pstr *lowe
  * @param b Pointer to the second pstr structure.
  * @return int Returns 1 if the structures are equal, 0 otherwise.
  */
-bool_t pstringIsEq(const struct pstr *p1, const struct pstr *p2);
+bool_t pstringIsEq(struct pstr *p1, struct pstr *p2);
-
-/**
- * @brief Checks if a pstr structure matches a given C string.
- *
- * @param s Pointer to the null-terminated C string to compare.
- * @return bool_t Returns true if the pstr matches the C string, false otherwise.
- */
-bool_t pstringIsStr(const struct pstr *p, char *s);
 
 /**
  * @brief Increments the reference count of a file system entry.
@@ -91,7 +79,7 @@ bool_t pstringIsStr(const struct pstr *p, char *s);
  * @param entry Pointer to the fsEntry structure whose reference count will be incremented.
  * @return int Returns 0 on success.
  */
-int fsEntryRef(struct fs_entry *entry);
+int fsEntryRef(struct fsEntry *entry);
 
 /**
  * @brief Decrements the reference count of a file system entry.
@@ -100,84 +88,31 @@ int fsEntryRef(struct fs_entry *entry);
  * entry. It is typically used to manage the lifecycle of file system
  * entries, ensuring that they are not prematurely deallocated.
  *
- * @param entry Pointer to the fsEntry structure whose reference count will be decremented.
+ * @param entry Pointer to the fsEntry structure whose reference count will be incremented.
  * @return int Returns 0 on success.
  */
-int fsEntryUnref(struct fs_entry **entry);
+int fsEntryUnref(struct fsEntry **entry);
 
 /**
- * @brief Allocates and initializes a new fsEntry.
+ * @brief Creates a new child fsEntry under the specified parent.
  *
- * This function allocates memory for a new `fsEntry` structure, initializes
+ * This function allocates and initializes a new fsEntry structure
- * it with the provided name and inode, and adds it to the parent's list of children.
+ * representing a file system entry. The new entry is added as a child
+ * of the specified parent. It also handles reference counting for
+ * the parent entry and the associated inode.
  *
- * @param parent Pointer to the parent `fsEntry` structure. Can be NULL if the new entry has no parent.
+ * @param parent Pointer to the parent fsEntry. Can be NULL if the new entry has no parent.
- * @param name Pointer to the `pstr` structure representing the name of the new entry. Can be NULL.
+ * @param name Pointer to the pstr structure representing the name of the new entry. Can be NULL.
- * @param inode Pointer to the `inode` structure associated with the new entry.
+ * @param inode Pointer to the inode associated with the new entry.
- *
+ * @param result Pointer to a location where the pointer to the newly created fsEntry will be stored.
- * @return struct fsEntry* Pointer to the newly allocated `fsEntry` structure, or NULL if allocation fails.
+ * @return int Returns 0 on success, or a negative error code on failure.
- *
+ *         -ENOMEM if memory allocation fails.
- * @note The reference count of the new entry is set to 1.
- * @note If a parent is provided, the new entry is added to the parent's list of children and the parent's reference count is incremented.
- * @note The inode's reference count is incremented.
  */
-struct fs_entry *fsEntryAlloc(struct fs_entry *parent, const struct pstr *name, struct inode *inode);
+int fsEntryNewChild(struct fsEntry *parent, const struct pstr *name, struct inode *inode,
+                    struct fsEntry **result);
 
-/**
- * @brief Looks up an entry in the file system.
- *
- * This function searches for a specified entry within the children
- * of a given directory entry. The search is limited to the entries
- * that are already in memory. If the entry is not found, it indicates
- * that the entry must be resolved using disk accesses.
- *
- * @param entry The node in which we are looking for the entry.
- * @param name The name of the entry we are looking for.
- * @param root The base node beyond which lookup must not go (to
- * support chroot): a kind of "barrier".
- * @param result The fsEntry for the given entry (set only when
- * the return value is 0).
- *
- * @return int Returns 0 if the entry is found, otherwise returns a non-zero error code.
- *         -ENOENT if the entry could not be found in the entry directory.
- *
- * @note The mountpoints are followed.
- * @note result is a NEW reference to the node. It should be unreferenced when unused.
- */
-int fsEntryLookup(struct fs_entry *entry, const struct pstr *name,
-                          const struct fs_entry *root, struct fs_entry **result);
 /**
  * @brief Setup the fsEntry subsystem
  *
  */
 int fsEntrySetup(void);
-
-/**
- * @brief Mounts a file system entry at a specified mount point.
- *
- * This function mounts a file system entry (`mounted`) at a specified mount point (`mountpoint`).
- * It updates the `mountedFs` field of the mount point and the `mountpoint` field of the mounted entry.
- *
- * @param mountpoint Pointer to the `fsEntry` structure representing the mount point.
- * @param mounted Pointer to the `fsEntry` structure representing the file system entry to be mounted.
- *
- * @return int Returns 0 on success, or -EBUSY if either the mount point is already occupied or the mounted entry is already mounted.
- *
- * @note The reference counts of both the mount point and the mounted entry are incremented.
- */
-int fsEntryMount(struct fs_entry *mountpoint, struct fs_entry *mounted);
-
-/**
- * @brief Unmounts a file system entry.
- *
- * This function unmounts a file system entry (`mounted`) from its mount point.
- * It updates the `mountedFs` field of the mount point and the `mountpoint` field of the mounted entry.
- *
- * @param mounted Pointer to the `fsEntry` structure representing the file system entry to be unmounted.
- *
- * @return int Returns 0 on success, -ENOENT if the entry is not mounted, or -EBUSY if the entry is busy.
- *
- * @note The unmount operation fails if the mounted entry has children or other references.
- * @note The reference counts of both the mount point and the mounted entry are decremented.
- */
-int fsEntryUmount(struct fs_entry *mounted);

core/klibc.c

@@ -171,7 +171,7 @@ void reverse(char s[])
 }
 
 /* K&R */
-size_t strlen(const char s[])
+int strlen(const char s[])
 {
     int i = 0;
     while (s[i] != '\0')

core/klibc.h

@@ -26,7 +26,7 @@ __attribute__ ((access (write_only, 1, 3))) void *memset(void *s, int c, size_t
 char *itoa(long long int value, char *str, int base);
 int atoi(const char *str);
 void reverse(char s[]);
-size_t strlen(const char s[]);
+int strlen(const char s[]);
 __attribute__ ((access (read_only, 1, 2))) unsigned int strnlen(const char *s, size_t count);
 int strcmp(const char s1[], const char s2[]);
 __attribute__ ((access (read_only, 2), access (write_only, 1, 3))) char *strzcpy(char *dst, const char *src, int len);

core/main.c

@@ -7,6 +7,7 @@
 #include "gdt.h"
 #include "idt.h"
 #include "interrupt.h"
+#include "io.h"
 #include "irq.h"
 #include "kernel.h"
 #include "keyboard.h"
@@ -19,6 +20,7 @@
 #include "process.h"
 #include "serial.h"
 #include "stack.h"
+#include "stdarg.h"
 #include "swintr.h"
 #include "thread.h"
 #ifdef RUN_TEST
@@ -40,6 +42,7 @@ void idleThread(void *arg)
     }
 }
 
+
 #define FILE_HEADER_SIZE   16
 #define FILE_MAX_SIZE   64 // In nb of sectors
 void loadUserSpace()
@@ -51,7 +54,7 @@ void loadUserSpace()
         return;
     }
 
-    char *buf = (char *)malloc(FILE_MAX_SIZE * DISK_SECTOR_SIZE);
+    char *buf = malloc(FILE_MAX_SIZE * DISK_SECTOR_SIZE);
     if (buf == NULL) {
         printf("ENOMEM\n");
         return;

tests/test.c

@@ -3,7 +3,6 @@
 #include "ata.h"
 #include "assert.h"
 #include "cpu_context.h"
-#include "errno.h"
 #include "fsEntry.h"
 #include "kernel.h"
 #include "klibc.h"
@@ -564,9 +563,10 @@ void testFsPstring()
 
     // Test 6
     const char *tmp   = "///home///file/test///";
+    const char *testS = "test";
     path.name = tmp;
     path.len = strlen(tmp);
-    struct pstr test  = PSTR_STATIC_INIT("test");
+    struct pstr test  = PSTR_INIT(testS, strlen(testS));
     struct pstr empty = PSTR_INIT("", 0);
     struct pstr slash = PSTR_INIT("/", 1);
     struct pstr dot = PSTR_INIT("..", 2);
@@ -603,82 +603,21 @@ void testFsPstring()
 void testFsEntry()
 {
     printf("Test fsEntry: create tree\n");
-
+    struct inode node;
-    struct inode inode;
+    struct fsEntry *root, *home, *usr;
-    struct pstr rootname    = PSTR_STATIC_INIT("/");
+    struct pstr rootname = PSTR_INIT("root", 4);
-    struct pstr homename    = PSTR_STATIC_INIT("home");
+    struct pstr homename = PSTR_INIT("home", 4);
-    struct pstr usrname     = PSTR_STATIC_INIT("usr");
+    struct pstr usrname  = PSTR_INIT("usr", 3);
-    struct pstr file1name   = PSTR_STATIC_INIT("file1");
+    assert(fsEntryNewChild(NULL, &rootname, &node, &root) == 0);
-    struct pstr mntname     = PSTR_STATIC_INIT("mnt");
+    assert(fsEntryNewChild(root, &homename, &node, &home) == 0);
-    struct pstr mntfilename = PSTR_STATIC_INIT("file2");
+    assert(fsEntryNewChild(root, &usrname, &node, &usr) == 0);
-    struct pstr dot         = PSTR_STATIC_INIT(".");
-    struct pstr dot2        = PSTR_STATIC_INIT("..");
-
-    // create fs with /home, /mnt, /usr/file1
-    struct fs_entry *root    = fsEntryAlloc(NULL, &rootname, &inode);
-    struct fs_entry *home    = fsEntryAlloc(root, &homename, &inode);
-    struct fs_entry *usr     = fsEntryAlloc(root, &usrname, &inode);
-    struct fs_entry *mnt     = fsEntryAlloc(root, &mntname, &inode);
-    struct fs_entry *file1   = fsEntryAlloc(home, &file1name, &inode);
-
-    // /file2
-    struct fs_entry *rootExt = fsEntryAlloc(NULL, &rootname, &inode);
-    struct fs_entry *mntfile = fsEntryAlloc(rootExt, &mntfilename, &inode);
-    struct fs_entry *res, *res2;
-
-    assert(root && home && usr);
-
-    printf("Test fsEntry: Lookup\n");
-    // find a child
-    assert(fsEntryLookup(root, &homename, NULL, &res) == 0);
-    assert(home == res);
-    fsEntryUnref(&res);
-
-    // cd .
-    assert(fsEntryLookup(home, &dot, NULL, &res) == 0);
-    assert(home == res);
-    fsEntryUnref(&res);
-
-    // cd ..
-    assert(fsEntryLookup(home, &dot2, NULL, &res) == 0);
-    assert(root == res);
-    fsEntryUnref(&res);
-
-    // find a non-child fail
-    assert(fsEntryLookup(home, &usrname, NULL, &res) == -ENOENT);
-
-    // find mnt and mount rootExt
-    assert(fsEntryLookup(root, &mntname, NULL, &res) == 0);
-    assert(res == mnt);
-    assert(fsEntryMount(res, rootExt)==0);
-    fsEntryUnref(&res); //lookup increase ref
-
-    // find on mounted
-    assert(fsEntryLookup(root, &mntname, NULL, &res) == 0);
-    fsEntryUnref(&res); //lookup increase ref
-    assert(fsEntryLookup(res, &mntfilename, NULL, &res2) == 0);
-    fsEntryUnref(&res2); //lookup increase ref
-
-    // Clen rootExt
-    fsEntryUnref(&mntfile);
-
-    // unmount rootExt
-    assert(fsEntryUmount(rootExt) == 0);
-
 
     printf("Test fsEntry: free tree\n");
     fsEntryUnref(&usr);
     assert(root->ref > 0);
     assert(usr == NULL);
     fsEntryUnref(&home);
-    assert(home != NULL);
+    assert(usr == NULL);
-    fsEntryUnref(&file1);
-    assert(file1 == NULL);
-    fsEntryUnref(&mnt);
-    assert(mnt == NULL);
-
-    fsEntryUnref(&mntfile);
-    fsEntryUnref(&rootExt);
 }
 
 void run_test(void)