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Message-ID: <4B7090B7.4060708@redhat.com>
Date: Mon, 08 Feb 2010 16:31:19 -0600
From: Eric Sandeen <sandeen@...hat.com>
To: ext4 development <linux-ext4@...r.kernel.org>
Subject: [PATCH] libext2fs: try to get physical sector size first in ext2fs_get_device_sectsize()
Some devices, notably 4k sector drives, may have a 512 logical
sector size, mapped onto a 4k physical sector size.
When mke2fs is ratcheting down the blocksize for small filesystems,
or when a blocksize is specified on the commandline, we should not
willingly go below the physical sector size of the device.
When a blocksize is specified, we -must- not go below
the logical sector size of the device.
Add a new library function, ext2fs_get_device_phys_sectsize()
to get the physical sector size if possible, and adjust the
logic in mke2fs to enforce the above rules.
Signed-off-by: Eric Sandeen <sandeen@...hat.com>
---
diff --git a/lib/ext2fs/ext2fs.h b/lib/ext2fs/ext2fs.h
index 213a819..9c06048 100644
--- a/lib/ext2fs/ext2fs.h
+++ b/lib/ext2fs/ext2fs.h
@@ -1086,6 +1086,7 @@ extern errcode_t ext2fs_get_device_size2(const char *file, int blocksize,
/* getsectsize.c */
errcode_t ext2fs_get_device_sectsize(const char *file, int *sectsize);
+errcode_t ext2fs_get_device_phys_sectsize(const char *file, int *sectsize);
/* i_block.c */
errcode_t ext2fs_iblk_add_blocks(ext2_filsys fs, struct ext2_inode *inode,
diff --git a/lib/ext2fs/getsectsize.c b/lib/ext2fs/getsectsize.c
index ae9139d..0c7fa82 100644
--- a/lib/ext2fs/getsectsize.c
+++ b/lib/ext2fs/getsectsize.c
@@ -26,15 +26,20 @@
#include <linux/fd.h>
#endif
-#if defined(__linux__) && defined(_IO) && !defined(BLKSSZGET)
+#if defined(__linux__) && defined(_IO)
+#if !defined(BLKSSZGET)
#define BLKSSZGET _IO(0x12,104)/* get block device sector size */
#endif
+#if !defined(BLKPBSZGET)
+#define BLKPBSZGET _IO(0x12,123)/* get block physical sector size */
+#endif
+#endif
#include "ext2_fs.h"
#include "ext2fs.h"
/*
- * Returns the number of blocks in a partition
+ * Returns the logical sector size of a device
*/
errcode_t ext2fs_get_device_sectsize(const char *file, int *sectsize)
{
@@ -58,3 +63,29 @@ errcode_t ext2fs_get_device_sectsize(const char *file, int *sectsize)
close(fd);
return 0;
}
+
+/*
+ * Returns the physical sector size of a device
+ */
+errcode_t ext2fs_get_device_phys_sectsize(const char *file, int *sectsize)
+{
+ int fd;
+
+#ifdef HAVE_OPEN64
+ fd = open64(file, O_RDONLY);
+#else
+ fd = open(file, O_RDONLY);
+#endif
+ if (fd < 0)
+ return errno;
+
+#ifdef BLKPBSZGET
+ if (ioctl(fd, BLKPBSZGET, sectsize) >= 0) {
+ close(fd);
+ return 0;
+ }
+#endif
+ *sectsize = 0;
+ close(fd);
+ return 0;
+}
diff --git a/lib/ext2fs/tst_getsectsize.c b/lib/ext2fs/tst_getsectsize.c
index cb1b8c6..31599d2 100644
--- a/lib/ext2fs/tst_getsectsize.c
+++ b/lib/ext2fs/tst_getsectsize.c
@@ -27,7 +27,7 @@
int main(int argc, char **argv)
{
- int sectsize;
+ int lsectsize, psectsize;
int retval;
if (argc < 2) {
@@ -35,13 +35,19 @@ int main(int argc, char **argv)
exit(1);
}
- retval = ext2fs_get_device_sectsize(argv[1], §size);
+ retval = ext2fs_get_device_sectsize(argv[1], &lsectsize);
if (retval) {
com_err(argv[0], retval,
"while calling ext2fs_get_device_sectsize");
exit(1);
}
- printf("Device %s has a hardware sector size of %d.\n",
- argv[1], sectsize);
+ retval = ext2fs_get_device_phys_sectsize(argv[1], &psectsize);
+ if (retval) {
+ com_err(argv[0], retval,
+ "while calling ext2fs_get_device_phys_sectsize");
+ exit(1);
+ }
+ printf("Device %s has logical/physical sector size of %d/%d.\n",
+ argv[1], lsectsize, psectsize);
exit(0);
}
diff --git a/misc/mke2fs.c b/misc/mke2fs.c
index 94b4c81..1a1307b 100644
--- a/misc/mke2fs.c
+++ b/misc/mke2fs.c
@@ -1068,7 +1068,7 @@ static void PRS(int argc, char *argv[])
int inode_size = 0;
unsigned long flex_bg_size = 0;
double reserved_ratio = 5.0;
- int sector_size = 0;
+ int lsector_size = 0, psector_size = 0;
int show_version_only = 0;
unsigned long long num_inodes = 0; /* unsigned long long to catch too-large input */
errcode_t retval;
@@ -1586,16 +1586,25 @@ got_size:
((tmp = getenv("MKE2FS_FIRST_META_BG"))))
fs_param.s_first_meta_bg = atoi(tmp);
- /* Get the hardware sector size, if available */
- retval = ext2fs_get_device_sectsize(device_name, §or_size);
+ /* Get the hardware sector sizes, if available */
+ retval = ext2fs_get_device_sectsize(device_name, &lsector_size);
if (retval) {
com_err(program_name, retval,
_("while trying to determine hardware sector size"));
exit(1);
}
+ retval = ext2fs_get_device_phys_sectsize(device_name, &psector_size);
+ if (retval) {
+ com_err(program_name, retval,
+ _("while trying to determine physical sector size"));
+ exit(1);
+ }
+ /* Older kernels may not have physical/logical distinction */
+ if (!psector_size)
+ psector_size = lsector_size;
if ((tmp = getenv("MKE2FS_DEVICE_SECTSIZE")) != NULL)
- sector_size = atoi(tmp);
+ psector_size = atoi(tmp);
if (blocksize <= 0) {
use_bsize = get_int_from_profile(fs_types, "blocksize", 4096);
@@ -1606,14 +1615,25 @@ got_size:
(use_bsize > 4096))
use_bsize = 4096;
}
- if (sector_size && use_bsize < sector_size)
- use_bsize = sector_size;
+ if (psector_size && use_bsize < psector_size)
+ use_bsize = psector_size;
if ((blocksize < 0) && (use_bsize < (-blocksize)))
use_bsize = -blocksize;
blocksize = use_bsize;
ext2fs_blocks_count_set(&fs_param,
ext2fs_blocks_count(&fs_param) /
(blocksize / 1024));
+ } else {
+ if (blocksize < lsector_size || /* Impossible */
+ (!force && (blocksize < psector_size))) { /* Suboptimal */
+ com_err(program_name, EINVAL,
+ _("while setting blocksize; too small for device\n"));
+ exit(1);
+ } else if (blocksize < psector_size) {
+ fprintf(stderr, _("Warning: specified blocksize %d is "
+ "less than device physical sectorsize %d, "
+ "forced to continue\n"), blocksize, psector_size);
+ }
}
if (inode_ratio == 0) {
--
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