RTOS/rtems
1
0
Fork 0
forked from Imagelibrary/rtems
Code Pull Requests Activity

Documented the mount and umount routines.

Browse Source
This commit is contained in:
Wade A Smith
1998-09-28 22:09:12 +00:00
parent 487c5d58d7
commit 0f58ab42b6
1 changed files with 233 additions and 5 deletions
Download Patch File Download Diff File Expand all files Collapse all files

238
doc/new_chapters/io.t
View File

@@ -22,9 +22,11 @@ The directives provided by the input and output primitives manager are:
@item @code{read} - Reads from a file
@item @code{write} - Writes to a file
@item @code{fcntl} - Manipulates an open file descriptor
@item @code{lseek} - XXX
@item @code{lseek} - Reposition read/write file offset
@item @code{fsynch} - XXX
@item @code{fdatasynch} - XXX
@item @code{mount} - Mount a file system
@item @code{umount} - Unmount file systems
@item @code{aio_read} - YYY
@item @code{aio_write} - YYY
@item @code{lio_listio} - YYY
@@ -73,6 +75,9 @@ The
@subheading NOTES:
This routine is not currently supported by RTEMS but could be
in a future version.
@page
@subsection dup - Duplicates an open file descriptor
@@ -354,13 +359,16 @@ No locks available
@subheading NOTES:
@page
@subsection lseek -
@subsection lseek - Reposition read/write file offset
@subheading CALLING SEQUENCE:
@ifset is-C
@example
int lseek(
int fildes,
off_t offset,
int whence
);
@end example
@end ifset
@@ -371,14 +379,41 @@ int lseek(
@subheading STATUS CODES:
@table @b
@item E
The
@item EBADF
@code{Fildes} is not an open file descriptor.
@item ESPIPE
@code{Fildes} is associated with a pipe, socket or FIFO.
@item EINVAL
@code{Whence} is not a proper value.
@end table
@subheading DESCRIPTION:
@subheading NOTES:
The @code{lseek} function repositions the offset of the file descriptor
@code{fildes} to the argument offset according to the directive whence.
The argument @code{fildes} must be an open file descriptor. @code{Lseek}
repositions the file pointer fildes as follows:
If @code{whence} is SEEK_SET, the offset is set to @code{offset} bytes.
If @code{whence} is SEEK_CUR, the offset is set to its current location
plus offset bytes.
If @cdoe{whence} is SEEK_END, the offset is set to the size of the
file plus @cdoe{offset} bytes.
The @cdoe{lseek} function allows the file offset to be set beyond the end
of the existing end-of-file of the file. If data is later written at this
point, subsequent reads of the data in the gap return bytes of zeros
(until data is actually written into the gap).
Some devices are incapable of seeking. The value of the pointer asso-
ciated with such a device is undefined.
@subheading NOTES: None
@page
@subsection fsynch -
@@ -434,6 +469,178 @@ The
@subheading NOTES:
@page
@subsection mount - Mount a file system
@subheading CALLING SEQUENCE:
@ifset is-C
@example
#include <sys/mount.h>
#include <linux/fs.h>
int mount(
const char *specialfile,
const char * dir,
const char * filesystemtype,
unsigned long rwflag,
const void * data
);
@end example
@end ifset
@ifset is-Ada
@end ifset
@subheading STATUS CODES:
@table @b
@item EPERM
The user is not the super-user.
@item ENODEV
@code{Filesystemtype} not configured in the kernel.
@item ENOTBLK
@code{Specialfile} is not a block device (if a device was required).
@item EBUSY
@code{Specialfile} is already mounted. Or, it cannot be remounted
read-only, because it still holds files open for writing. Or, it
cannot be mounted on @code{dir} because @code{dir} is still busy
(it is the working directory of some task, the mount point of another
device, has open files, etc.).
@item EINVAL
@code{Specialfile had an invalid superblock. Or, a remount was
attempted, while @code{specialfile} was not already mounted on @code{dir}.
Or, an umount was attempted, while @code{dir} was not a mount point.
@item EFAULT
One of the pointer arguments points outside the user address space.
@item ENOMEM
The kernel could not allocate a free page to copy filenames or data into.
@item ENAMETOOLONG
A pathname was longer than MAXPATHLEN.
@item ENOTDIR
A pathname was empty or had a nonexistent component.
@item EACCES
A component of a path was not searchable. Or, mounting a read-only
filesystem was attempted without giving the MS_RDONLY flag. Or, the
block device Specialfile is located on a filesystem mounted with
the MS_NODEV option.
@item ENXIO
The major number of the block device @code{specialfile} is out of
range.
@item EMFILE
(In case no block device is required:) Table of dummy devices is full.
@end table
@subheading DESCRIPTION:
@code{Mount} attaches the filesystem specified by @code{specialfile}
(which is often a device name) to the directory specified by @code{dir}.
Only the super-user may mount filesystems.
The @code{filesystemtype} argument may take one of the values listed in
/proc/filesystems (link "minix", "ext2", "msdos", "proc", "nfs",
"iso9660" etc.).
The @code{rwflag} argument has the magic number 0xCOED in the top 16 bits,
and various mount flags in the low order 16 bits. If the magic number is
absent, then the last two arguments are not used.
The @code{data} argument is interpreted by the different file systems.
@subheading NOTES: None
@page
@subsection umount - Umount file systems
@subheading CALLING SEQUENCE:
@ifset is-C
@example
#include <sys/mount.h>
#include <linux/fs.h>
int umount(
const char *specialfile
);
@end example
@end ifset
@ifset is-Ada
@end ifset
@subheading STATUS CODES:
@table @b
@item EPERM
The user is not the super-user.
@item ENODEV
@code{Filesystemtype} not configured in the kernel.
@item ENOTBLK
@code{Specialfile} is not a block device (if a device was required).
@item EBUSY
@code{Specialfile} is already mounted. Or, it cannot be remounted
read-only, because it still holds files open for writing. Or, it
cannot be mounted on @code{dir} because @code{dir} is still busy
(it is the working directory of some task, the mount point of another
device, has open files, etc.).
@item EINVAL
@code{Specialfile had an invalid superblock. Or, a remount was
attempted, while @code{specialfile} was not already mounted on @code{dir}.
Or, an umount was attempted, while @code{dir} was not a mount point.
@item EFAULT
One of the pointer arguments points outside the user address space.
@item ENOMEM
The kernel could not allocate a free page to copy filenames or data into.
@item ENAMETOOLONG
A pathname was longer than MAXPATHLEN.
@item ENOTDIR
A pathname was empty or had a nonexistent component.
@item EACCES
A component of a path was not searchable. Or, mounting a read-only
filesystem was attempted without giving the MS_RDONLY flag. Or, the
block device Specialfile is located on a filesystem mounted with
the MS_NODEV option.
@item ENXIO
The major number of the block device @code{specialfile} is out of
range.
@item EMFILE
(In case no block device is required:) Table of dummy devices is full.
@end table
@subheading DESCRIPTION:
@code{Umount} removes the attachment of the filesystem specified
by @code{specialfile} or @code{dir}.
Only the super-user may umount filesystems.
@subheading NOTES: None
@page
@subsection aio_read -
@@ -461,6 +668,9 @@ The
@subheading NOTES:
This routine is not currently supported by RTEMS but could be
in a future version.
@page
@subsection aio_write -
@@ -488,6 +698,9 @@ The
@subheading NOTES:
This routine is not currently supported by RTEMS but could be
in a future version.
@page
@subsection lio_listio -
@@ -515,6 +728,9 @@ The
@subheading NOTES:
This routine is not currently supported by RTEMS but could be
in a future version.
@page
@subsection aio_error -
@@ -542,6 +758,9 @@ The
@subheading NOTES:
This routine is not currently supported by RTEMS but could be
in a future version.
@page
@subsection aio_return -
@@ -569,6 +788,9 @@ The
@subheading NOTES:
This routine is not currently supported by RTEMS but could be
in a future version.
@page
@subsection aio_cancel -
@@ -596,6 +818,9 @@ The
@subheading NOTES:
This routine is not currently supported by RTEMS but could be
in a future version.
@page
@subsection aio_suspend -
@@ -623,6 +848,9 @@ The
@subheading NOTES:
This routine is not currently supported by RTEMS but could be
in a future version.
@page
@subsection aio_fsync -