X-Git-Url: https://git.ucc.asn.au/?a=blobdiff_plain;f=Kernel%2Finclude%2Fvfs.h;h=73161a1c857aafc30af0dad831c3da24b4d35976;hb=8657dc5b4f380b2c45e1f54b9843f8a80a0cd49e;hp=6fc2491dba5e9077c30df036e7a42c5f19442ca7;hpb=75e87cf46a3899f76bae5c64e130cfc033562e9a;p=tpg%2Facess2.git diff --git a/Kernel/include/vfs.h b/Kernel/include/vfs.h index 6fc2491d..73161a1c 100644 --- a/Kernel/include/vfs.h +++ b/Kernel/include/vfs.h @@ -5,118 +5,307 @@ /** * \file vfs.h * \brief Acess VFS Layer + * + * The Acess Virtual File System (VFS) provides abstraction of multiple + * physical filesystems, network storage and devices (both hardware and + * virtual) to the user. + * + * The core of the VFS is the concept of a \ref tVFS_Node "VFS Node". + * A VFS Node represents a "file" in the VFS tree, this can be any sort + * of file (an ordinary file, a directory, a symbolic link or a device) + * depending on the bits set in the \ref tVFS_Node.Flags Flags field. + * - For more information see "VFS Node Flags" */ #ifndef _VFS_H #define _VFS_H -#include +#include -//! \name ACL Permissions -//! \{ /** - * \brief Readable + * \brief Thread list datatype for VFS_Select */ -#define VFS_PERM_READ 0x00000001 +typedef struct sVFS_SelectList tVFS_SelectList; + /** - * \brief Writeable + * \name tVFS_Node Flags + * \brief Flag values for tVFS_Node.Flags + * \{ */ -#define VFS_PERM_WRITE 0x00000002 +//! \todo Is this still needed +#define VFS_FFLAG_READONLY 0x01 //!< Readonly File /** - * \brief Append allowed + * \brief Directory Flag + * + * This flag marks the tVFS_Node as describing a directory, and says + * that the tVFS_Node.FindDir, tVFS_Node.ReadDir, tVFS_Node.MkNod and + * tVFS_Node.Relink function pointers are valid. + * For a directory the tVFS_Node.Size field contains the number of files + * within the directory, or -1 for undetermined. */ -#define VFS_PERM_APPEND 0x00000004 +#define VFS_FFLAG_DIRECTORY 0x02 /** - * \brief Executable + * \brief Symbolic Link Flag + * + * Marks a file as a symbolic link */ -#define VFS_PERM_EXECUTE 0x00000008 +#define VFS_FFLAG_SYMLINK 0x04 /** - * \brief All permissions granted + * \brief Set User ID Flag + * + * Allows an executable file to change it's executing user to the file's + * owner. + * In the case of a directory, it means that all immediate children will + * inherit the UID of the parent. */ -#define VFS_PERM_ALL 0x7FFFFFFF // Mask for permissions +#define VFS_FFLAG_SETUID 0x08 /** - * \brief Denies instead of granting permissions - * \note Denials take precedence + * \brief Set Group ID Flag + * + * Allows an executable file to change it's executing group to the file's + * owning group. + * In the case of a directory, it means that all immediate children will + * inherit the GID of the parent. */ -#define VFS_PERM_DENY 0x80000000 // Inverts permissions -//! \} +#define VFS_FFLAG_SETGID 0x10 /** - * \brief ACL Defintion Structure - */ -typedef struct sVFS_ACL -{ - struct { - unsigned Group: 1; //!< Group (as opposed to user) flag - unsigned ID: 31; //!< ID of Group/User (-1 for nobody/world) - }; - struct { - unsigned Inv: 1; //!< Invert Permissions - unsigned Perms: 31; //!< Permission Flags - }; -} tVFS_ACL; - -/** - * \name VFS Node Flags - * \{ + * \brief "Don't do Write-Back" Flag + * + * Stops the VFS from calling tVFS_Node.Write on dirty pages when a region + * is unmapped. Nice for read-only files and memory-only files (or + * pseudo-readonly filesystems) */ -#define VFS_FFLAG_READONLY 0x01 //!< Read-only file -#define VFS_FFLAG_DIRECTORY 0x02 //!< Directory -#define VFS_FFLAG_SYMLINK 0x04 //!< Symbolic Link +#define VFS_FFLAG_NOWRITEBACK /** * \} */ /** - * \brief VFS Node + * \brief Represents a node (file or directory) in the VFS tree + * + * This structure provides the VFS with the functions required to read/write + * the file (or directory) that it represents. */ -typedef struct sVFS_Node { - Uint64 Inode; //!< Inode ID +typedef struct sVFS_Node +{ + /** + * \name Identifiers + * \brief Fields used by the driver to identify what data this node + * corresponds to. + * \{ + */ + Uint64 Inode; //!< Inode ID (Essentially another ImplInt) Uint ImplInt; //!< Implementation Usable Integer void *ImplPtr; //!< Implementation Usable Pointer + /** + * \} + */ + /** + * \name Node State + * \brief Stores the misc information about the node + * \{ + */ int ReferenceCount; //!< Number of times the node is used Uint64 Size; //!< File Size Uint32 Flags; //!< File Flags + /** + * \brief Pointer to cached data (FS Specific) + * \note The Inode_* functions will free when the node is uncached + * this if needed + */ + void *Data; + + /** + * \brief Node mutex + * \note Provided for the Filesystem driver's use + */ + tMutex Lock; + + /** + * \} + */ + + /** + * \name Times + * \{ + */ Sint64 ATime; //!< Last Accessed Time Sint64 MTime; //!< Last Modified Time Sint64 CTime; //!< Creation Time + /** + * \} + */ - Uint UID; //!< Owning User - Uint GID; //!< Owning Group + /** + * \name Access control + * \{ + */ + tUID UID; //!< ID of Owning User + tGID GID; //!< ID of Owning Group int NumACLs; //!< Number of ACL entries - tVFS_ACL *ACLs; //!< ACL Entries + tVFS_ACL *ACLs; //!< Access Controll List pointer + /** + * \} + */ + + /** + * \name VFS_Select() fields + * \note Used by the VFS internals, drivers should use VFS_Mark* + * \{ + */ + int DataAvaliable; + tVFS_SelectList *ReadThreads; //!< Threads waiting to read + int BufferFull; + tVFS_SelectList *WriteThreads; //!< Threads waiting to write + int ErrorOccurred; + tVFS_SelectList *ErrorThreads; //!< Threads waiting for an error + /** + * \} + */ + + /** + * \name VFS_MMap() fields + * \{ + */ + void *MMapInfo; + /** + * \} + */ - //! Reference the node + /** + * \name Common Functions + * \brief Functions that are used no matter the value of .Flags + * \{ + */ + /** + * \brief Reference the node + * \param Node Pointer to this node + */ void (*Reference)(struct sVFS_Node *Node); - //! Close (dereference) the node + /** + * \brief Close (dereference) the node + * \param Node Pointer to this node + * + * Usually .Close is used to write any changes to the node back to + * the persistent storage. + */ void (*Close)(struct sVFS_Node *Node); - //! Send an IO Control + + /** + * \brief Send an IO Control + * \param Node Pointer to this node + * \param Id IOCtl call number + * \param Data Pointer to data to pass to the driver + * \return Implementation defined + */ int (*IOCtl)(struct sVFS_Node *Node, int Id, void *Data); - //! \brief Read from the file + /** + * \} + */ + + /** + * \name Buffer Functions + * \brief Functions for accessing a buffer-type file (normal file or + * symbolic link) + * \{ + */ + + /** + * \brief Read from the file + * \param Node Pointer to this node + * \param Offset Byte offset in the file + * \param Length Number of bytes to read + * \param Buffer Destination for read data + * \return Number of bytes read + */ Uint64 (*Read)(struct sVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer); - //! \brief Write to the file + /** + * \brief Write to the file + * \param Node Pointer to this node + * \param Offset Byte offser in the file + * \param Length Number of bytes to write + * \param Buffer Source of written data + * \return Number of bytes read + */ Uint64 (*Write)(struct sVFS_Node *Node, Uint64 Offset, Uint64 Length, void *Buffer); + + /** + * \brief Map a region of a file into memory + * \param Node Pointer to this node + * \param Offset Start of the region (page aligned) + * \param Length Length of the region (page aligned) + * \param Dest Location to which to map + * \return Boolean Failure + * \note If NULL, the VFS implements it using .Read + */ + int (*MMap)(struct sVFS_Node *Node, Uint64 Offset, int Length, void *Dest); + + /** + * \} + */ - //! \brief Find an directory entry by name - //! \note The node returned must be accessable until ::tVFS_Node.Close is called - struct sVFS_Node *(*FindDir)(struct sVFS_Node *Node, char *Name); + /** + * \name Directory Functions + * \{ + */ + /** + * \brief Find an directory entry by name + * \param Node Pointer to this node + * \param Name Name of the file wanted + * \return Pointer to the requested node or NULL if it cannot be found + * \note The node returned must be accessable until ::tVFS_Node.Close + * is called and ReferenceCount reaches zero. + */ + struct sVFS_Node *(*FindDir)(struct sVFS_Node *Node, const char *Name); - //! \brief Read from a directory - //! \note MUST return a heap address + /** + * \brief Read from a directory + * \param Node Pointer to this node + * \param Pos Offset in the directory + * \return Pointer to the name of the item on the heap (will be freed + * by the caller). If the directory end has been reached, NULL + * will be returned. + * If an item is required to be skipped either &::NULLNode, + * ::VFS_SKIP or ::VFS_SKIPN(0...1023) will be returned. + */ char *(*ReadDir)(struct sVFS_Node *Node, int Pos); - //! \brief Create a node in a directory - int (*MkNod)(struct sVFS_Node *Node, char *Name, Uint Flags); + /** + * \brief Create a node in a directory + * \param Node Pointer to this node + * \param Name Name of the new child + * \param Flags Flags to apply to the new child (directory or symlink) + * \return Zero on Success, non-zero on error (see errno.h) + */ + int (*MkNod)(struct sVFS_Node *Node, const char *Name, Uint Flags); - //! \brief Relink (Rename/Remove) a file/directory - int (*Relink)(struct sVFS_Node *Node, char *OldName, char *NewName); + /** + * \brief Relink (Rename/Remove) a file/directory + * \param Node Pointer to this node + * \param OldName Name of the item to move/delete + * \param NewName New name (or NULL if unlinking is wanted) + * \return Zero on Success, non-zero on error (see errno.h) + */ + int (*Relink)(struct sVFS_Node *Node, const char *OldName, const char *NewName); - //!< \todo Complete + /** + * \brief Link a node to a name + * \param Node Pointer to this node (directory) + * \param Child Node to create a new link to + * \param NewName Name for the new link + * \return Zeron on success, non-zero on error (see errno.h) + */ + int (*Link)(struct sVFS_Node *Node, struct sVFS_Node *Child, const char *NewName); + + /** + * \} + */ } tVFS_Node; /** @@ -125,12 +314,12 @@ typedef struct sVFS_Node { typedef struct sVFS_Driver { //! \brief Unique Identifier for this filesystem type - char *Name; + const char *Name; //! \brief Flags applying to this driver Uint Flags; //! \brief Callback to mount a device - tVFS_Node *(*InitDevice)(char *Device, char **Options); + tVFS_Node *(*InitDevice)(const char *Device, const char **Options); //! \brief Callback to unmount a device void (*Unmount)(tVFS_Node *Node); //! \brief Used internally (next driver in the chain) @@ -147,7 +336,8 @@ typedef struct sVFS_Driver extern tVFS_Node NULLNode; //!< NULL VFS Node (Ignored/Skipped) /** - * \name Simple ACLs to aid writing drivers + * \name Static ACLs + * \brief Simple ACLs to aid writing drivers * \{ */ extern tVFS_ACL gVFS_ACL_EveryoneRWX; //!< Everyone Read/Write/Execute @@ -170,7 +360,21 @@ extern int VFS_AddDriver(tVFS_Driver *Info); * \brief Get the information structure of a driver given its name * \param Name Name of filesystem driver to find */ -extern tVFS_Driver *VFS_GetFSByName(char *Name); +extern tVFS_Driver *VFS_GetFSByName(const char *Name); + + +/** + * \brief Prepare a node for use + */ +extern void VFS_InitNode(tVFS_Node *Node); + +/** + * \brief Clean up a node, ready for deletion + * \note This should ALWAYS be called before a node is freed, as it + * cleans up VFS internal structures. + */ +extern void VFS_CleanupNode(tVFS_Node *Node); + /** * \fn tVFS_ACL *VFS_UnixToAcessACL(Uint Mode, Uint Owner, Uint Group) * \brief Transforms Unix Permssions into Acess ACLs @@ -181,15 +385,50 @@ extern tVFS_Driver *VFS_GetFSByName(char *Name); */ extern tVFS_ACL *VFS_UnixToAcessACL(Uint Mode, Uint Owner, Uint Group); +/** + * \brief Flags fro \a TypeFlag of VFS_SelectNode + * \{ + */ +#define VFS_SELECT_READ 0x01 +#define VFS_SELECT_WRITE 0x02 +#define VFS_SELECT_ERROR 0x04 +/** + * \} + */ + +/** + * \brief Wait for an event on a node + * \param Node Node to wait on + * \param Type Type of wait + * \param Timeout Time to wait (NULL for infinite wait) + * \param Name Name to show in debug output + * \return Number of nodes that actioned (0 or 1) + */ +extern int VFS_SelectNode(tVFS_Node *Node, int Type, tTime *Timeout, const char *Name); + +/** + * \brief Change the full flag on a node + */ +extern int VFS_MarkFull(tVFS_Node *Node, BOOL IsBufferFull); +extern int VFS_MarkAvaliable(tVFS_Node *Node, BOOL IsDataAvaliable); +extern int VFS_MarkError(tVFS_Node *Node, BOOL IsErrorState); + // --- Node Cache -- -//! \name Node Cache -//! \{ /** - * \fn int Inode_GetHandle() + * \name Node Cache + * \brief Functions to allow a node to be cached in memory by the VFS + * + * These functions store a node for the driver, to prevent it from having + * to re-generate the node on each call to FindDir. It also allows for + * fast cleanup when a filesystem is unmounted. + * \{ + */ +/** + * \fn int Inode_GetHandle(void) * \brief Gets a unique handle to the Node Cache * \return A unique handle for use for the rest of the Inode_* functions */ -extern int Inode_GetHandle(); +extern int Inode_GetHandle(void); /** * \fn tVFS_Node *Inode_GetCache(int Handle, Uint64 Inode) * \brief Gets an inode from the node cache @@ -207,7 +446,7 @@ extern tVFS_Node *Inode_GetCache(int Handle, Uint64 Inode); */ extern tVFS_Node *Inode_CacheNode(int Handle, tVFS_Node *Node); /** - * \fn void Inode_UncacheNode(int Handle, Uint64 Inode) + * \fn int Inode_UncacheNode(int Handle, Uint64 Inode) * \brief Dereferences (and removes if needed) a node from the cache * \param Handle A handle returned by Inode_GetHandle() * \param Inode Value of the Inode field of the ::tVFS_Node you want to remove @@ -220,6 +459,8 @@ extern void Inode_UncacheNode(int Handle, Uint64 Inode); */ extern void Inode_ClearCache(int Handle); -//! \} +/** + * \} + */ #endif