/*
* Copyright 2018, Intel Corporation
*
* 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.
*
* * Neither the name of the copyright holder nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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 COPYRIGHT
* OWNER OR CONTRIBUTORS 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.
*/
/*
* extent_linux.c - implementation of the linux fs extent query API
*/
#include <string.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <linux/fs.h>
#include <linux/fiemap.h>
#include "file.h"
#include "out.h"
#include "extent.h"
/*
* os_extents_common -- (internal) common part of getting extents
* of the given file
*
* Returns: number of extents the file consists of or -1 in case of an error.
* Sets: file descriptor, struct fiemap and struct extents.
*/
static long
os_extents_common(const char *path, struct extents *exts,
int *pfd, struct fiemap **pfmap)
{
LOG(3, "path %s exts %p pfd %p pfmap %p", path, exts, pfd, pfmap);
int fd = open(path, O_RDONLY);
if (fd == -1) {
ERR("!open %s", path);
return -1;
}
enum file_type type = util_fd_get_type(fd);
if (type < 0)
goto error_close;
struct stat st;
if (fstat(fd, &st) < 0) {
ERR("!fstat %d", fd);
goto error_close;
}
if (exts->extents_count == 0) {
LOG(10, "%s: block size: %li", path, (long int)st.st_blksize);
exts->blksize = (uint64_t)st.st_blksize;
}
/* devdax does not have any extents */
if (type == TYPE_DEVDAX) {
close(fd);
return 0;
}
struct fiemap *fmap = Zalloc(sizeof(struct fiemap));
if (fmap == NULL) {
ERR("!malloc");
goto error_close;
}
fmap->fm_start = 0;
fmap->fm_length = (size_t)st.st_size;
fmap->fm_flags = 0;
fmap->fm_extent_count = 0;
if (ioctl(fd, FS_IOC_FIEMAP, fmap) != 0) {
ERR("!ioctl %d", fd);
goto error_free;
}
if (exts->extents_count == 0) {
exts->extents_count = fmap->fm_mapped_extents;
LOG(4, "%s: number of extents: %u", path, exts->extents_count);
} else if (exts->extents_count != fmap->fm_mapped_extents) {
ERR("number of extents differs (was: %u, is: %u)",
exts->extents_count, fmap->fm_mapped_extents);
goto error_free;
}
*pfd = fd;
*pfmap = fmap;
return exts->extents_count;
error_free:
Free(fmap);
error_close:
close(fd);
return -1;
}
/*
* os_extents_count -- get number of extents of the given file
* (and optionally read its block size)
*/
long
os_extents_count(const char *path, struct extents *exts)
{
LOG(3, "path %s extents %p", path, exts);
struct fiemap *fmap = NULL;
int fd = -1;
ASSERTne(exts, NULL);
memset(exts, 0, sizeof(*exts));
long ret = os_extents_common(path, exts, &fd, &fmap);
Free(fmap);
if (fd != -1)
close(fd);
return ret;
}
/*
* os_extents_get -- get extents of the given file
* (and optionally read its block size)
*/
int
os_extents_get(const char *path, struct extents *exts)
{
LOG(3, "path %s extents %p", path, exts);
struct fiemap *fmap = NULL;
int fd = -1;
int ret = -1;
ASSERTne(exts, NULL);
if (exts->extents_count == 0)
return 0;
ASSERTne(exts->extents, NULL);
if (os_extents_common(path, exts, &fd, &fmap) <= 0)
goto error_free;
struct fiemap *newfmap = Realloc(fmap, sizeof(struct fiemap) +
fmap->fm_mapped_extents *
sizeof(struct fiemap_extent));
if (newfmap == NULL) {
ERR("!Realloc");
goto error_free;
}
fmap = newfmap;
fmap->fm_extent_count = fmap->fm_mapped_extents;
memset(fmap->fm_extents, 0, fmap->fm_mapped_extents *
sizeof(struct fiemap_extent));
if (ioctl(fd, FS_IOC_FIEMAP, fmap) != 0) {
ERR("!ioctl %d", fd);
goto error_free;
}
if (fmap->fm_extent_count > 0) {
LOG(10, "file %s has %u extents:", path, fmap->fm_extent_count);
}
unsigned e;
for (e = 0; e < fmap->fm_extent_count; e++) {
exts->extents[e].offset_physical =
fmap->fm_extents[e].fe_physical;
exts->extents[e].offset_logical =
fmap->fm_extents[e].fe_logical;
exts->extents[e].length = fmap->fm_extents[e].fe_length;
LOG(10, " #%u: off_phy: %lu off_log: %lu len: %lu",
e,
exts->extents[e].offset_physical,
exts->extents[e].offset_logical,
exts->extents[e].length);
}
ret = 0;
error_free:
Free(fmap);
if (fd != -1)
close(fd);
return ret;
}