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Diffstat (limited to 'filesystem/fileystem_implmentation.rst')
| -rw-r--r-- | filesystem/fileystem_implmentation.rst | 593 |
1 files changed, 269 insertions, 324 deletions
diff --git a/filesystem/fileystem_implmentation.rst b/filesystem/fileystem_implmentation.rst index 0da79a9..f8b5a6a 100644 --- a/filesystem/fileystem_implmentation.rst +++ b/filesystem/fileystem_implmentation.rst @@ -1,5 +1,9 @@ .. comment SPDX-License-Identifier: CC-BY-SA-4.0 +.. COMMENT: COPYRIGHT (c) 1988-2002. +.. COMMENT: On-Line Applications Research Corporation (OAR). +.. COMMENT: All rights reserved. + Filesystem Implementation Requirements ###################################### @@ -9,45 +13,45 @@ implementations must adhere to. General ======= -The RTEMS filesystem framework was intended to be compliant with the -POSIX Files and Directories interface standard. The following filesystem +The RTEMS filesystem framework was intended to be compliant with the POSIX +Files and Directories interface standard. The following filesystem characteristics resulted in a functional switching layer. -.. code:: c + +.. code-block:: shell Figure of the Filesystem Functional Layering goes here. This figure includes networking and disk caching layering. -# Application programs are presented with a standard set of POSIX - compliant functions that allow them to interface with the files, devices - and directories in the filesystem. The interfaces to these routines do - not reflect the type of subordinate filesystem implementation in which - the file will be found. +# Application programs are presented with a standard set of POSIX compliant + functions that allow them to interface with the files, devices and + directories in the filesystem. The interfaces to these routines do not + reflect the type of subordinate filesystem implementation in which the file + will be found. -# The filesystem framework developed under RTEMS allows for mounting - filesystem of different types under the base filesystem. +# The filesystem framework developed under RTEMS allows for mounting filesystem + of different types under the base filesystem. -# The mechanics of locating file information may be quite different - between filesystem types. +# The mechanics of locating file information may be quite different between + filesystem types. -# The process of locating a file may require crossing filesystem - boundaries. +# The process of locating a file may require crossing filesystem boundaries. -# The transitions between filesystem and the processing required to - access information in different filesystem is not visible at the level - of the POSIX function call. +# The transitions between filesystem and the processing required to access + information in different filesystem is not visible at the level of the POSIX + function call. -# The POSIX interface standard provides file access by character - pathname to the file in some functions and through an integer file - descriptor in other functions. +# The POSIX interface standard provides file access by character pathname to + the file in some functions and through an integer file descriptor in other + functions. -# The nature of the integer file descriptor and its associated - processing is operating system and filesystem specific. +# The nature of the integer file descriptor and its associated processing is + operating system and filesystem specific. -# Directory and device information must be processed with some of the - same routines that apply to files. +# Directory and device information must be processed with some of the same + routines that apply to files. -# The form and content of directory and device information differs - greatly from that of a regular file. +# The form and content of directory and device information differs greatly from + that of a regular file. # Files, directories and devices represent elements (nodes) of a tree hierarchy. @@ -56,15 +60,16 @@ characteristics resulted in a functional switching layer. filesystem are node specific but are still not reflected in the POSIX interface routines. -.. code:: c +.. code-block:: shell Figure of the Filesystem Functional Layering goes here. This figure focuses on the Base Filesystem and IMFS. -.. code:: c +.. code-block:: shell Figure of the IMFS Memfile control blocks +.. _file-and-directory-removal-constraints: File and Directory Removal Constraints ====================================== @@ -73,15 +78,15 @@ The following POSIX constraints must be honored by all filesystems. - If a node is a directory with children it cannot be removed. -- The root node of any filesystem, whether the base filesystem or a - mounted filesystem, cannot be removed. +- The root node of any filesystem, whether the base filesystem or a mounted + filesystem, cannot be removed. -- A node that is a directory that is acting as the mount point of a file - system cannot be removed. +- A node that is a directory that is acting as the mount point of a file system + cannot be removed. -- On filesystems supporting hard links, a link count is maintained. - Prior to node removal, the node's link count is decremented by one. The - link count must be less than one to allow for removal of the node. +- On filesystems supporting hard links, a link count is maintained. Prior to + node removal, the node's link count is decremented by one. The link count + must be less than one to allow for removal of the node. API Layering ============ @@ -89,16 +94,16 @@ API Layering Mapping of Generic System Calls to Filesystem Specific Functions ---------------------------------------------------------------- -The list of generic system calls includes the routines open(), read(), -write(), close(), etc.. +The list of generic system calls includes the routines open(), read(), write(), +close(), etc.. -The Files and Directories section of the POSIX Application Programs -Interface specifies a set of functions with calling arguments that are -used to gain access to the information in a filesystem. To the -application program, these functions allow access to information in any -mounted filesystem without explicit knowledge of the filesystem type or -the filesystem mount configuration. The following are functions that are -provided to the application: +The Files and Directories section of the POSIX Application Programs Interface +specifies a set of functions with calling arguments that are used to gain +access to the information in a filesystem. To the application program, these +functions allow access to information in any mounted filesystem without +explicit knowledge of the filesystem type or the filesystem mount +configuration. The following are functions that are provided to the +application: # access() @@ -170,89 +175,85 @@ provided to the application: # write() -The filesystem's type as well as the node type within the filesystem -determine the nature of the processing that must be performed for each of -the functions above. The RTEMS filesystem provides a framework that -allows new filesystem to be developed and integrated without alteration -to the basic framework. +The filesystem's type as well as the node type within the filesystem determine +the nature of the processing that must be performed for each of the functions +above. The RTEMS filesystem provides a framework that allows new filesystem to +be developed and integrated without alteration to the basic framework. -To provide the functional switching that is required, each of the POSIX -file and directory functions have been implemented as a shell function. -The shell function adheres to the POSIX interface standard. Within this -functional shell, filesystem and node type information is accessed which -is then used to invoke the appropriate filesystem and node type specific -routine to process the POSIX function call. +To provide the functional switching that is required, each of the POSIX file +and directory functions have been implemented as a shell function. The shell +function adheres to the POSIX interface standard. Within this functional shell, +filesystem and node type information is accessed which is then used to invoke +the appropriate filesystem and node type specific routine to process the POSIX +function call. File/Device/Directory function access via file control block - rtems_libio_t structure -------------------------------------------------------------------------------------- -The POSIX open() function returns an integer file descriptor that is used -as a reference to file control block information for a specific file. The -file control block contains information that is used to locate node, file -system, mount table and functional handler information. The diagram in -Figure 8 depicts the relationship between and among the following -components. +The POSIX open() function returns an integer file descriptor that is used as a +reference to file control block information for a specific file. The file +control block contains information that is used to locate node, file system, +mount table and functional handler information. The diagram in Figure 8 depicts +the relationship between and among the following components. # File Descriptor Table This is an internal RTEMS structure that tracks all currently defined file descriptors in the system. The index that is returned by the file open() - operation references a slot in this table. The slot contains a pointer to - the file descriptor table entry for this file. The rtems_libio_t structure + operation references a slot in this table. The slot contains a pointer to the + file descriptor table entry for this file. The rtems_libio_t structure represents the file control block. # Allocation of entry in the File Descriptor Table - Access to the file descriptor table is controlled through a semaphore that - is implemented using the rtems_libio_allocate() function. This routine - will grab a semaphore and then scan the file control blocks to determine - which slot is free for use. The first free slot is marked as used and the - index to this slot is returned as the file descriptor for the open() - request. After the alterations have been made to the file control block - table, the semaphore is released to allow further operations on the table. - -# Maximum number of entries in the file descriptor table is - configurable through the src/exec/sapi/headers/confdefs.h file. If the - CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS constant is defined its value - will represent the maximum number of file descriptors that are allowed. - If CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS is not specified a default - value of 20 will be used as the maximum number of file descriptors - allowed. + Access to the file descriptor table is controlled through a semaphore that is + implemented using the rtems_libio_allocate() function. This routine will grab + a semaphore and then scan the file control blocks to determine which slot is + free for use. The first free slot is marked as used and the index to this + slot is returned as the file descriptor for the open() request. After the + alterations have been made to the file control block table, the semaphore is + released to allow further operations on the table. + +# Maximum number of entries in the file descriptor table is configurable + through the src/exec/sapi/headers/confdefs.h file. If the + CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS constant is defined its value will + represent the maximum number of file descriptors that are allowed. If + CONFIGURE_LIBIO_MAXIMUM_FILE_DESCRIPTORS is not specified a default value of + 20 will be used as the maximum number of file descriptors allowed. # File control block - rtems_libio_t structure - .. code:: c + .. code-block:: c struct rtems_libio_tt { - rtems_driver_name_t \*driver; - off_t size; - off_t offset; - unsigned32 flags; - rtems_filesystem_location_info_t pathinfo; - Objects_Id sem; - unsigned32 data0; - void data1; - void file_info; - rtems_filesystem_file_handlers_r handlers; + rtems_driver_name_t *driver; + off_t size; + off_t offset; + unsigned32 flags; + rtems_filesystem_location_info_t pathinfo; + Objects_Id sem; + unsigned32 data0; + void data1; + void file_info; + rtems_filesystem_file_handlers_r handlers; }; A file control block can exist for regular files, devices and directories. The following fields are important for regular file and directory access: - - Size - For a file this represents the number of bytes currently - stored in a file. For a directory this field is not filled in. + - Size - For a file this represents the number of bytes currently stored in a + file. For a directory this field is not filled in. - - Offset - For a file this is the byte file position index relative to - the start of the file. For a directory this is the byte offset into a - sequence of dirent structures. + - Offset - For a file this is the byte file position index relative to the + start of the file. For a directory this is the byte offset into a sequence + of dirent structures. - - Pathinfo - This is a structure that provides a pointer to node - information, OPS table functions, Handler functions and the mount table - entry associated with this node. + - Pathinfo - This is a structure that provides a pointer to node information, + OPS table functions, Handler functions and the mount table entry associated + with this node. - - file_info - A pointer to node information that is used by Handler - functions + - file_info - A pointer to node information that is used by Handler functions - - handlers - A pointer to a table of handler functions that operate on - a file, device or directory through a file descriptor index + - handlers - A pointer to a table of handler functions that operate on a + file, device or directory through a file descriptor index File/Directory function access via rtems_filesystem_location_info_t structure ----------------------------------------------------------------------------- @@ -260,63 +261,60 @@ File/Directory function access via rtems_filesystem_location_info_t structure The rtems_filesystem_location_info_tt structure below provides sufficient information to process nodes under a mounted filesystem. -.. code:: c +.. code-block:: c struct rtems_filesystem_location_info_tt { - void \*node_access; - rtems_filesystem_file_handlers_r \*handlers; - rtems_filesystem_operations_table \*ops; - rtems_filesystem_mount_table_entry_t \*mt_entry; + void *node_access; + rtems_filesystem_file_handlers_r *handlers; + rtems_filesystem_operations_table *ops; + rtems_filesystem_mount_table_entry_t *mt_entry; }; -It contains a void pointer to filesystem specific nodal structure, -pointers to the OPS table for the filesystem that contains the node, the -node type specific handlers for the node and a reference pointer to the -mount table entry associated with the filesystem containing the node +It contains a void pointer to filesystem specific nodal structure, pointers to +the OPS table for the filesystem that contains the node, the node type specific +handlers for the node and a reference pointer to the mount table entry +associated with the filesystem containing the node Operation Tables ================ -Filesystem specific operations are invoked indirectly. The set of -routines that implement the filesystem are configured into two tables. -The Filesystem Handler Table has routines that are specific to a -filesystem but remain constant regardless of the actual file type. -The File Handler Table has routines that are both filesystem and file type -specific. +Filesystem specific operations are invoked indirectly. The set of routines +that implement the filesystem are configured into two tables. The Filesystem +Handler Table has routines that are specific to a filesystem but remain +constant regardless of the actual file type. The File Handler Table has +routines that are both filesystem and file type specific. Filesystem Handler Table Functions ---------------------------------- OPS table functions are defined in a ``rtems_filesystem_operations_table`` -structure. It defines functions that are specific to a given filesystem. -One table exists for each filesystem that is supported in the RTEMS +structure. It defines functions that are specific to a given filesystem. One +table exists for each filesystem that is supported in the RTEMS configuration. The structure definition appears below and is followed by general developmental information on each of the functions contained in this function management structure. -.. code:: c +.. code-block:: c typedef struct { - rtems_filesystem_evalpath_t evalpath; - rtems_filesystem_evalmake_t evalformake; - rtems_filesystem_link_t link; - rtems_filesystem_unlink_t unlink; - rtems_filesystem_node_type_t node_type; - rtems_filesystem_mknod_t mknod; - rtems_filesystem_rmnod_t rmnod; - rtems_filesystem_chown_t chown; - rtems_filesystem_freenode_t freenod; - rtems_filesystem_mount_t mount; - rtems_filesystem_fsmount_me_t fsmount_me; - rtems_filesystem_unmount_t unmount; - rtems_filesystem_fsunmount_me_t fsunmount_me; - rtems_filesystem_utime_t utime; - rtems_filesystem_evaluate_link_t eval_link; - rtems_filesystem_symlink_t symlink; + rtems_filesystem_evalpath_t evalpath; + rtems_filesystem_evalmake_t evalformake; + rtems_filesystem_link_t link; + rtems_filesystem_unlink_t unlink; + rtems_filesystem_node_type_t node_type; + rtems_filesystem_mknod_t mknod; + rtems_filesystem_rmnod_t rmnod; + rtems_filesystem_chown_t chown; + rtems_filesystem_freenode_t freenod; + rtems_filesystem_mount_t mount; + rtems_filesystem_fsmount_me_t fsmount_me; + rtems_filesystem_unmount_t unmount; + rtems_filesystem_fsunmount_me_t fsunmount_me; + rtems_filesystem_utime_t utime; + rtems_filesystem_evaluate_link_t eval_link; + rtems_filesystem_symlink_t symlink; } rtems_filesystem_operations_table; -.. COMMENT: @page - evalpath Handler ~~~~~~~~~~~~~~~~ @@ -326,27 +324,25 @@ evalpath **Arguments:** -.. code:: c +.. code-block:: c - const char \*pathname, /* IN \*/ - int flags, /* IN \*/ - rtems_filesystem_location_info_t \*pathloc /* IN/OUT \*/ + const char *pathname, /* IN */ + int flags, /* IN */ + rtems_filesystem_location_info_t *pathloc /* IN/OUT */ **Description:** -This routine is responsible for evaluating the pathname passed in -based upon the flags and the valid ``rthems_filesystem_location_info_t``. -Additionally, it must make any changes to pathloc necessary to identify -the pathname node. This should include calling the evalpath for a mounted -filesystem, if the given filesystem supports the mount command. +This routine is responsible for evaluating the pathname passed in based upon +the flags and the valid ``rthems_filesystem_location_info_t``. Additionally, +it must make any changes to pathloc necessary to identify the pathname node. +This should include calling the evalpath for a mounted filesystem, if the given +filesystem supports the mount command. -This routine returns a 0 if the evaluation was successful. -Otherwise, it returns a -1 and sets errno to the correct error. +This routine returns a 0 if the evaluation was successful. Otherwise, it +returns a -1 and sets errno to the correct error. This routine is required and should NOT be set to NULL. -.. COMMENT: @page - evalformake Handler ~~~~~~~~~~~~~~~~~~~ @@ -356,29 +352,27 @@ evalformake **Arguments:** -.. code:: c +.. code-block:: c - const char \*path, /* IN \*/ - rtems_filesystem_location_info_t \*pathloc, /* IN/OUT \*/ - const char \**name /* OUT \*/ + const char *path, /* IN */ + rtems_filesystem_location_info_t *pathloc, /* IN/OUT */ + const char **name /* OUT */ **Description:** -This method is given a path to evaluate and a valid start location. It -is responsible for finding the parent node for a requested make command, -setting pathloc information to identify the parent node, and setting -the name pointer to the first character of the name of the new node. -Additionally, if the filesystem supports the mount command, this method -should call the evalformake routine for the mounted filesystem. +This method is given a path to evaluate and a valid start location. It is +responsible for finding the parent node for a requested make command, setting +pathloc information to identify the parent node, and setting the name pointer +to the first character of the name of the new node. Additionally, if the +filesystem supports the mount command, this method should call the evalformake +routine for the mounted filesystem. This routine returns a 0 if the evaluation was successful. Otherwise, it returns a -1 and sets errno to the correct error. -This routine is required and should NOT be set to NULL. However, if -the filesystem does not support user creation of a new node, it may -set errno to ENOSYS and return -1. - -.. COMMENT: @page +This routine is required and should NOT be set to NULL. However, if the +filesystem does not support user creation of a new node, it may set errno to +ENOSYS and return -1. link Handler ~~~~~~~~~~~~ @@ -389,26 +383,24 @@ link **Arguments:** -.. code:: c +.. code-block:: c - rtems_filesystem_location_info_t \*to_loc, /* IN \*/ - rtems_filesystem_location_info_t \*parent_loc, /* IN \*/ - const char \*token /* IN \*/ + rtems_filesystem_location_info_t *to_loc, /* IN */ + rtems_filesystem_location_info_t *parent_loc, /* IN */ + const char *token /* IN */ **Description:** This routine is used to create a hard-link. -It will first examine the st_nlink count of the node that we are trying to. -If the link count exceeds LINK_MAX an error will be returned. +It will first examine the st_nlink count of the node that we are trying to. If +the link count exceeds LINK_MAX an error will be returned. The name of the link will be normalized to remove extraneous separators from the end of the name. This routine is not required and may be set to NULL. -.. COMMENT: @page - unlink Handler ~~~~~~~~~~~~~~ @@ -424,8 +416,6 @@ XXX XXX -.. COMMENT: @page - node_type Handler ~~~~~~~~~~~~~~~~~ @@ -435,16 +425,14 @@ node_type() **Arguments:** -.. code:: c +.. code-block:: c - rtems_filesystem_location_info_t \*pathloc /* IN \*/ + rtems_filesystem_location_info_t *pathloc /* IN */ **Description:** XXX -.. COMMENT: @page - mknod Handler ~~~~~~~~~~~~~ @@ -454,19 +442,17 @@ mknod() **Arguments:** -.. code:: c +.. code-block:: c - const char \*token, /* IN \*/ - mode_t mode, /* IN \*/ - dev_t dev, /* IN \*/ - rtems_filesystem_location_info_t \*pathloc /* IN/OUT \*/ + const char *token, /* IN */ + mode_t mode, /* IN */ + dev_t dev, /* IN */ + rtems_filesystem_location_info_t *pathloc /* IN/OUT */ **Description:** XXX -.. COMMENT: @page - rmnod Handler ~~~~~~~~~~~~~ @@ -482,8 +468,6 @@ XXX XXX -.. COMMENT: @page - chown Handler ~~~~~~~~~~~~~ @@ -493,11 +477,11 @@ chown() **Arguments:** -.. code:: c +.. code-block:: c - rtems_filesystem_location_info_t \*pathloc /* IN \*/ - uid_t owner /* IN \*/ - gid_t group /* IN \*/ + rtems_filesystem_location_info_t *pathloc /* IN */ + uid_t owner /* IN */ + gid_t group /* IN */ **Description:** @@ -514,21 +498,19 @@ freenod() **Arguments:** -.. code:: c +.. code-block:: c - rtems_filesystem_location_info_t \*pathloc /* IN \*/ + rtems_filesystem_location_info_t *pathloc /* IN */ **Description:** -This routine is used by the generic code to allow memory to be allocated -during the evaluate routines, and set free when the generic code is finished -accessing a node. If the evaluate routines allocate memory to identify -a node this routine should be utilized to free that memory. +This routine is used by the generic code to allow memory to be allocated during +the evaluate routines, and set free when the generic code is finished accessing +a node. If the evaluate routines allocate memory to identify a node this +routine should be utilized to free that memory. This routine is not required and may be set to NULL. -.. COMMENT: @page - mount Handler ~~~~~~~~~~~~~ @@ -538,16 +520,14 @@ mount() **Arguments:** -.. code:: c +.. code-block:: c - rtems_filesystem_mount_table_entry_t \*mt_entry + rtems_filesystem_mount_table_entry_t *mt_entry **Description:** XXX -.. COMMENT: @page - fsmount_me Handler ~~~~~~~~~~~~~~~~~~ @@ -557,15 +537,15 @@ XXX **Arguments:** -.. code:: c +.. code-block:: c - rtems_filesystem_mount_table_entry_t \*mt_entry + rtems_filesystem_mount_table_entry_t *mt_entry **Description:** This function is provided with a filesystem to take care of the internal -filesystem management details associated with mounting that filesystem -under the RTEMS environment. +filesystem management details associated with mounting that filesystem under +the RTEMS environment. It is not responsible for the mounting details associated the filesystem containing the mount point. @@ -573,37 +553,46 @@ containing the mount point. The rtems_filesystem_mount_table_entry_t structure contains the key elements below: -rtems_filesystem_location_info_t \*mt_point_node, +.. code-block:: c + + rtems_filesystem_location_info_t *mt_point_node, This structure contains information about the mount point. This allows us to find the ops-table and the handling functions associated with the filesystem containing the mount point. -rtems_filesystem_location_info_t \*fs_root_node, +.. code-block:: c + + rtems_filesystem_location_info_t *fs_root_node, This structure contains information about the root node in the file system to be mounted. It allows us to find the ops-table and the handling functions associated with the filesystem to be mounted. -rtems_filesystem_options_t options, +.. code-block:: c + + rtems_filesystem_options_t options, Read only or read/write access -void \*fs_info, +.. code-block:: c -This points to an allocated block of memory the will be used to -hold any filesystem specific information of a global nature. This -allocated region if important because it allows us to mount the -same filesystem type more than once under the RTEMS system. -Each instance of the mounted filesystem has its own set of global -management information that is separate from the global -management information associated with the other instances of the -mounted filesystem type. + void *fs_info, -rtems_filesystem_limits_and_options_t pathconf_info, +This points to an allocated block of memory the will be used to hold any +filesystem specific information of a global nature. This allocated region if +important because it allows us to mount the same filesystem type more than once +under the RTEMS system. Each instance of the mounted filesystem has its own +set of global management information that is separate from the global +management information associated with the other instances of the mounted +filesystem type. -The table contains the following set of values associated with the -mounted filesystem: +.. code-block:: c + + rtems_filesystem_limits_and_options_t pathconf_info, + +The table contains the following set of values associated with the mounted +filesystem: - link_max @@ -629,29 +618,29 @@ mounted filesystem: - posix_vdisable -These values are accessed with the pathconf() and the fpathconf () -functions. +These values are accessed with the pathconf() and the fpathconf () functions. + +.. code-block:: c -const char \*dev + const char *dev The is intended to contain a string that identifies the device that contains -the filesystem information. The filesystems that are currently implemented -are memory based and don't require a device specification. +the filesystem information. The filesystems that are currently implemented are +memory based and don't require a device specification. If the mt_point_node.node_access is NULL then we are mounting the base file system. -The routine will create a directory node for the root of the IMFS file -system. +The routine will create a directory node for the root of the IMFS file system. The node will have read, write and execute permissions for owner, group and others. The node's name will be a null string. -A filesystem information structure(fs_info) will be allocated and -initialized for the IMFS filesystem. The fs_info pointer in the mount table -entry will be set to point the filesystem information structure. +A filesystem information structure(fs_info) will be allocated and initialized +for the IMFS filesystem. The fs_info pointer in the mount table entry will be +set to point the filesystem information structure. The pathconf_info element of the mount table will be set to the appropriate table of path configuration constants (LIMITS_AND_OPTIONS). @@ -664,10 +653,8 @@ The fs_root_node structure will be filled in with the following: - OPS table functions for the IMFS -A 0 will be returned to the calling routine if the process succeeded, -otherwise a 1 will be returned. - -.. COMMENT: @page +A 0 will be returned to the calling routine if the process succeeded, otherwise +a 1 will be returned. unmount Handler ~~~~~~~~~~~~~~~ @@ -684,8 +671,6 @@ XXX XXX -.. COMMENT: @page - fsunmount_me Handler ~~~~~~~~~~~~~~~~~~~~ @@ -695,16 +680,14 @@ imfs_fsunmount_me() **Arguments:** -.. code:: c +.. code-block:: c - rtems_filesystem_mount_table_entry_t \*mt_entry + rtems_filesystem_mount_table_entry_t *mt_entry **Description:** XXX -.. COMMENT: @page - utime Handler ~~~~~~~~~~~~~ @@ -720,8 +703,6 @@ XXX XXX -.. COMMENT: @page - eval_link Handler ~~~~~~~~~~~~~~~~~ @@ -737,8 +718,6 @@ XXX XXX -.. COMMENT: @page - symlink Handler ~~~~~~~~~~~~~~~ @@ -754,8 +733,6 @@ XXX XXX -.. COMMENT: @page - File Handler Table Functions ---------------------------- @@ -763,28 +740,27 @@ Handler table functions are defined in a ``rtems_filesystem_file_handlers_r`` structure. It defines functions that are specific to a node type in a given filesystem. One table exists for each of the filesystem's node types. The structure definition appears below. It is followed by general developmental -information on each of the functions associated with regular files contained -in this function management structure. -.. code:: c +information on each of the functions associated with regular files contained in +this function management structure. + +.. code-block:: c typedef struct { - rtems_filesystem_open_t open; - rtems_filesystem_close_t close; - rtems_filesystem_read_t read; - rtems_filesystem_write_t write; - rtems_filesystem_ioctl_t ioctl; - rtems_filesystem_lseek_t lseek; - rtems_filesystem_fstat_t fstat; - rtems_filesystem_fchmod_t fchmod; - rtems_filesystem_ftruncate_t ftruncate; - rtems_filesystem_fpathconf_t fpathconf; - rtems_filesystem_fsync_t fsync; - rtems_filesystem_fdatasync_t fdatasync; - rtems_filesystem_fcntl_t fcntl; + rtems_filesystem_open_t open; + rtems_filesystem_close_t close; + rtems_filesystem_read_t read; + rtems_filesystem_write_t write; + rtems_filesystem_ioctl_t ioctl; + rtems_filesystem_lseek_t lseek; + rtems_filesystem_fstat_t fstat; + rtems_filesystem_fchmod_t fchmod; + rtems_filesystem_ftruncate_t ftruncate; + rtems_filesystem_fpathconf_t fpathconf; + rtems_filesystem_fsync_t fsync; + rtems_filesystem_fdatasync_t fdatasync; + rtems_filesystem_fcntl_t fcntl; } rtems_filesystem_file_handlers_r; -.. COMMENT: @page - open Handler ~~~~~~~~~~~~ @@ -794,10 +770,10 @@ open() **Arguments:** -.. code:: c +.. code-block:: c - rtems_libio_t \*iop, - const char \*pathname, + rtems_libio_t *iop, + const char *pathname, unsigned32 flag, unsigned32 mode @@ -805,8 +781,6 @@ open() XXX -.. COMMENT: @page - close Handler ~~~~~~~~~~~~~ @@ -816,9 +790,9 @@ close() **Arguments:** -.. code:: c +.. code-block:: c - rtems_libio_t \*iop + rtems_libio_t *iop **Description:** @@ -828,8 +802,6 @@ XXX XXX -.. COMMENT: @page - read Handler ~~~~~~~~~~~~ @@ -839,10 +811,10 @@ read() **Arguments:** -.. code:: c +.. code-block:: c - rtems_libio_t \*iop, - void \*buffer, + rtems_libio_t *iop, + void *buffer, unsigned32 count **Description:** @@ -853,8 +825,6 @@ XXX XXX -.. COMMENT: @page - write Handler ~~~~~~~~~~~~~ @@ -874,8 +844,6 @@ XXX XXX -.. COMMENT: @page - ioctl Handler ~~~~~~~~~~~~~ @@ -885,11 +853,11 @@ XXX **Arguments:** -.. code:: c +.. code-block:: c - rtems_libio_t \*iop, + rtems_libio_t *iop, unsigned32 command, - void \*buffer + void *buffer **Description:** @@ -899,8 +867,6 @@ XXX XXX -.. COMMENT: @page - lseek Handler ~~~~~~~~~~~~~ @@ -910,9 +876,9 @@ lseek() **Arguments:** -.. code:: c +.. code-block:: c - rtems_libio_t \*iop, + rtems_libio_t *iop, off_t offset, int whence @@ -924,8 +890,6 @@ XXX XXX -.. COMMENT: @page - fstat Handler ~~~~~~~~~~~~~ @@ -935,15 +899,15 @@ fstat() **Arguments:** -.. code:: c +.. code-block:: c - rtems_filesystem_location_info_t \*loc, - struct stat \*buf + rtems_filesystem_location_info_t *loc, + struct stat *buf **Description:** -The following information is extracted from the filesystem -specific node and placed in the ``stat`` structure: +The following information is extracted from the filesystem specific node and +placed in the ``stat`` structure: - st_mode @@ -963,16 +927,12 @@ specific node and placed in the ``stat`` structure: **NOTES:** -Both the ``stat()`` and ``lstat()`` services are -implemented directly using the ``fstat()`` handler. The -difference in behavior is determined by how the path is evaluated -prior to this handler being called on a particular -file entity. +Both the ``stat()`` and ``lstat()`` services are implemented directly using the +``fstat()`` handler. The difference in behavior is determined by how the path +is evaluated prior to this handler being called on a particular file entity. -The ``fstat()`` system call is implemented directly -on top of this filesystem handler. - -.. COMMENT: @page +The ``fstat()`` system call is implemented directly on top of this filesystem +handler. fchmod Handler ~~~~~~~~~~~~~~ @@ -983,10 +943,10 @@ fchmod() **Arguments:** -.. code:: c +.. code-block:: c - rtems_libio_t \*iop - mode_t mode + rtems_libio_t *iop + mode_t mode **Description:** @@ -996,8 +956,6 @@ XXX XXX -.. COMMENT: @page - ftruncate Handler ~~~~~~~~~~~~~~~~~ @@ -1036,8 +994,6 @@ XXX XXX -.. COMMENT: @page - fsync Handler ~~~~~~~~~~~~~ @@ -1057,8 +1013,6 @@ XXX XXX -.. COMMENT: @page - fdatasync Handler ~~~~~~~~~~~~~~~~~ @@ -1078,8 +1032,6 @@ XXX XXX -.. COMMENT: @page - fcntl Handler ~~~~~~~~~~~~~ @@ -1098,10 +1050,3 @@ XXX **NOTES:** XXX - -.. COMMENT: COPYRIGHT (c) 1988-2002. - -.. COMMENT: On-Line Applications Research Corporation (OAR). - -.. COMMENT: All rights reserved. - |