/*
* Copyright (c) 2026 Jiri Svoboda
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* - Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* - Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* - The name of the author may not be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
* IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
* INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
* NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
* DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
* THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
* THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
/** @addtogroup fmgt
* @{
*/
/** @file File system operations.
*
* These provide wrappers over normal file system operations that,
* in addition to basic functionality, query the user how to proceed
* in case of I/O error or if the destination file exists.
*/
#include <errno.h>
#include <stdbool.h>
#include <stdlib.h>
#include <vfs/vfs.h>
#include "fmgt.h"
#include "../private/fmgt.h"
#include "../private/fsops.h"
/** Open file.
*
* @param fmgt File management object
* @param fname File name
* @param rfd Place to store file descriptor
* @return EOK on success or an error code
*/
errno_t fmgt_open(fmgt_t *fmgt, const char *fname, int *rfd)
{
fmgt_io_error_t err;
fmgt_error_action_t action;
errno_t rc;
do {
rc = vfs_lookup_open(fname, WALK_REGULAR, MODE_READ, rfd);
if (rc == EOK)
break;
/* I/O error */
err.fname = fname;
err.optype = fmgt_io_open;
err.rc = rc;
fmgt_timer_stop(fmgt);
action = fmgt_io_error_query(fmgt, &err);
fmgt_timer_start(fmgt);
} while (action == fmgt_er_retry);
return rc;
}
/** Create file.
*
* @param fmgt File management object
* @param fname Destination file name
* @param rfd Place to store file descriptor
* @param rskip If @c true, skip existing file and continue
* @return EOK on success or an error code
*/
errno_t fmgt_create_file(fmgt_t *fmgt, const char *fname, int *rfd, bool *rskip)
{
fmgt_io_error_t err;
fmgt_error_action_t action;
fmgt_exists_t exists;
fmgt_exists_action_t exaction;
bool may_overwrite = false;
unsigned flags;
errno_t rc;
*rskip = false;
do {
flags = WALK_REGULAR | (may_overwrite ? WALK_MAY_CREATE :
WALK_MUST_CREATE);
rc = vfs_lookup_open(fname, flags, MODE_WRITE, rfd);
if (rc == EOK)
break;
if (rc == EEXIST) {
/* File exists */
exists.fname = fname;
fmgt_timer_stop(fmgt);
exaction = fmgt_exists_query(fmgt, &exists);
fmgt_timer_start(fmgt);
if (exaction == fmgt_exr_skip)
*rskip = true;
if (exaction != fmgt_exr_overwrite)
break;
may_overwrite = true;
} else {
/* I/O error */
err.fname = fname;
err.optype = fmgt_io_create;
err.rc = rc;
fmgt_timer_stop(fmgt);
action = fmgt_io_error_query(fmgt, &err);
fmgt_timer_start(fmgt);
if (action != fmgt_er_retry)
break;
}
} while (true);
return rc;
}
/** Create directory.
*
* @param fmgt File management object
* @param dname Directory name
* @return EOK on success or an error code
*/
errno_t fmgt_create_dir(fmgt_t *fmgt, const char *dname)
{
fmgt_io_error_t err;
fmgt_error_action_t action;
errno_t rc;
do {
rc = vfs_link_path(dname, KIND_DIRECTORY, NULL);
/* It is okay if the directory exists. */
if (rc == EOK || rc == EEXIST)
break;
/* I/O error */
err.fname = dname;
err.optype = fmgt_io_create;
err.rc = rc;
fmgt_timer_stop(fmgt);
action = fmgt_io_error_query(fmgt, &err);
fmgt_timer_start(fmgt);
} while (action == fmgt_er_retry);
if (rc == EEXIST)
return EOK;
return rc;
}
/** Read data from file.
*
* @param fmgt File management object
* @param fd File descriptor
* @param fname File name (for printing diagnostics)
* @param pos Pointer to current position (will be updated)
* @param buffer Data buffer
* @param nbytes Number of bytes to read
* @param nr Place to store number of bytes read
* @return EOK on success or an error code
*/
errno_t fmgt_read(fmgt_t *fmgt, int fd, const char *fname, aoff64_t *pos,
void *buffer, size_t nbytes, size_t *nr)
{
char *bp = (char *)buffer;
fmgt_io_error_t err;
fmgt_error_action_t action;
errno_t rc;
do {
rc = vfs_read(fd, pos, bp, nbytes, nr);
if (rc == EOK)
break;
/* I/O error */
err.fname = fname;
err.optype = fmgt_io_read;
err.rc = rc;
fmgt_timer_stop(fmgt);
action = fmgt_io_error_query(fmgt, &err);
fmgt_timer_start(fmgt);
} while (action == fmgt_er_retry);
/* Not recovered? */
if (rc != EOK)
return rc;
return EOK;
}
/** Write data to file.
*
* @param fmgt File management object
* @param fd File descriptor
* @param fname File name (for printing diagnostics)
* @param pos Pointer to current position (will be updated)
* @param buffer Pointer to data
* @param nbytes Number of bytes to write
* @return EOK on success or an error code
*/
errno_t fmgt_write(fmgt_t *fmgt, int fd, const char *fname, aoff64_t *pos,
void *buffer, size_t nbytes)
{
size_t total_written;
char *bp = (char *)buffer;
fmgt_io_error_t err;
fmgt_error_action_t action;
size_t nw;
errno_t rc;
total_written = 0;
while (total_written < nbytes) {
do {
rc = vfs_write(fd, pos, bp + total_written,
nbytes - total_written, &nw);
if (rc == EOK)
break;
/* I/O error */
err.fname = fname;
err.optype = fmgt_io_write;
err.rc = rc;
fmgt_timer_stop(fmgt);
action = fmgt_io_error_query(fmgt, &err);
fmgt_timer_start(fmgt);
} while (action == fmgt_er_retry);
/* Not recovered? */
if (rc != EOK)
return rc;
total_written += nw;
}
return EOK;
}
/** @}
*/