[rtems commit] dosfs: Add skip_alignment for msdos_format()
Sebastian Huber
sebh at rtems.org
Wed Dec 5 14:22:59 UTC 2012
Module: rtems
Branch: master
Commit: 5b8d935ab3b9b70302d53292f024999a2259ca7b
Changeset: http://git.rtems.org/rtems/commit/?id=5b8d935ab3b9b70302d53292f024999a2259ca7b
Author: Ralf Kirchner <ralf.kirchner at embedded-brains.de>
Date: Wed Dec 5 14:11:26 2012 +0100
dosfs: Add skip_alignment for msdos_format()
Add skip_alignment parameter of msdos_format_request_param_t. Delete
cluster_align parameter of msdos_format_request_param_t.
By default the FAT, data cluster, and root directory for FAT12 and FAT16
is aligned on a cluster boundary to optimize performance.
Format changes throughout.
---
cpukit/libfs/src/dosfs/dosfs.h | 9 +--
cpukit/libfs/src/dosfs/fat.h | 1 +
cpukit/libfs/src/dosfs/msdos_format.c | 111 ++++++++++++++++++------
cpukit/libmisc/shell/main_msdosfmt.c | 4 +-
testsuites/fstests/mdosfs_support/fs_support.c | 2 +-
5 files changed, 93 insertions(+), 34 deletions(-)
diff --git a/cpukit/libfs/src/dosfs/dosfs.h b/cpukit/libfs/src/dosfs/dosfs.h
index 93d7789..530d23e 100644
--- a/cpukit/libfs/src/dosfs/dosfs.h
+++ b/cpukit/libfs/src/dosfs/dosfs.h
@@ -49,12 +49,9 @@ typedef struct {
uint8_t fattype; /* request value: MSDOS_FMT_FAT12/16/32 */
uint8_t media; /* media code. default: 0xF8 */
bool quick_format; /* true: do not clear out data sectors */
- uint32_t cluster_align; /* requested value: cluster alignment */
- /* make sector number of first sector */
- /* of first cluster divisible by this */
- /* value. This can optimize clusters */
- /* to be located at start of track */
- /* or start of flash block */
+ bool skip_alignment; /* do not align FAT, data cluster, and */
+ /* root directory for FAT12 and FAT16 to */
+ /* a cluster boundary */
int info_level; /* The amount of info to output */
} msdos_format_request_param_t;
diff --git a/cpukit/libfs/src/dosfs/fat.h b/cpukit/libfs/src/dosfs/fat.h
index 260d8aa..dab2471 100644
--- a/cpukit/libfs/src/dosfs/fat.h
+++ b/cpukit/libfs/src/dosfs/fat.h
@@ -271,6 +271,7 @@ extern "C" {
#define FAT_TOTAL_FSINFO_SIZE 512
#define MS_BYTES_PER_CLUSTER_LIMIT 0x8000 /* 32K */
+#define MS_BYTES_PER_CLUSTER_LIMIT_FAT12 0x1000 /* 4K */
#define FAT_BR_EXT_FLAGS_MIRROR 0x0080
diff --git a/cpukit/libfs/src/dosfs/msdos_format.c b/cpukit/libfs/src/dosfs/msdos_format.c
index 1c31b98..69bba0c 100644
--- a/cpukit/libfs/src/dosfs/msdos_format.c
+++ b/cpukit/libfs/src/dosfs/msdos_format.c
@@ -64,9 +64,24 @@ typedef struct {
char VolLabel[FAT_BR_VOLLAB_SIZE+1];
bool VolLabel_present;
uint32_t vol_id;
+ bool skip_alignment;
} msdos_format_param_t;
/*
+ * Align to cluster borders
+ */
+static uint32_t
+ loc_align_object (const uint32_t sectors,
+ const uint32_t clustersize,
+ const bool skip_alignment)
+{
+ if (! skip_alignment)
+ return (sectors + clustersize - 1) & ~(clustersize - 1);
+ else
+ return sectors;
+}
+
+/*
* Formatted output.
*/
static void
@@ -278,9 +293,12 @@ static int msdos_format_eval_sectors_per_cluster
\*-------------------------------------------------------------------------*/
int fattype, /* type code of FAT (FAT_FAT12 ...) */
uint32_t bytes_per_sector, /* byte count per sector (512) */
- uint32_t fatdata_sec_cnt, /* sectors available for FAT and data */
+ const uint32_t total_sector_cnt, /* total number of secters per volume */
+ const uint32_t rsvd_sector_cnt, /* number of reserved sectors */
+ const uint32_t root_dir_sector_cnt,/* number of sectors for the root dir */
uint8_t fat_num, /* number of fat copies */
uint32_t sectors_per_cluster, /* sectors per cluster (requested) */
+ const bool skip_alignment, /* true for no cluster alignment */
uint32_t *sectors_per_cluster_adj, /* ret: sec per cluster (granted) */
uint32_t *sectors_per_fat_ptr /* ret: sectors needed for one FAT */
)
@@ -296,6 +314,8 @@ static int msdos_format_eval_sectors_per_cluster
uint32_t fat_capacity;
uint32_t sectors_per_fat;
uint32_t data_cluster_cnt;
+ uint32_t fatdata_sect_cnt;
+ uint32_t fat_sectors_cnt;
/*
* ensure, that maximum cluster size (32KByte) is not exceeded
*/
@@ -310,27 +330,39 @@ static int msdos_format_eval_sectors_per_cluster
* - compute storage size for FAT
* - subtract from total cluster count
*/
- fatdata_cluster_cnt = fatdata_sec_cnt/sectors_per_cluster;
+ fatdata_sect_cnt = total_sector_cnt
+ - loc_align_object (rsvd_sector_cnt, sectors_per_cluster, skip_alignment);
if (fattype == FAT_FAT12) {
- fat_capacity = fatdata_cluster_cnt * 3 / 2;
+ fatdata_sect_cnt = fatdata_sect_cnt
+ - loc_align_object (root_dir_sector_cnt, sectors_per_cluster, skip_alignment);
+ fatdata_cluster_cnt = fatdata_sect_cnt/sectors_per_cluster;
+ fat_capacity = fatdata_cluster_cnt * 3 / 2;
}
else if (fattype == FAT_FAT16) {
- fat_capacity = fatdata_cluster_cnt * 2;
+ fatdata_sect_cnt = fatdata_sect_cnt
+ - loc_align_object (root_dir_sector_cnt, sectors_per_cluster, skip_alignment);
+ fatdata_cluster_cnt = fatdata_sect_cnt/sectors_per_cluster;
+ fat_capacity = fatdata_cluster_cnt * 2;
}
else { /* FAT32 */
- fat_capacity = fatdata_cluster_cnt * 4;
+ fatdata_cluster_cnt = fatdata_sect_cnt/sectors_per_cluster;
+ fat_capacity = fatdata_cluster_cnt * 4;
}
sectors_per_fat = ((fat_capacity
+ (bytes_per_sector - 1))
/ bytes_per_sector);
+ fat_sectors_cnt = loc_align_object (sectors_per_fat * fat_num,
+ sectors_per_cluster,
+ skip_alignment);
+
data_cluster_cnt = (fatdata_cluster_cnt -
- (((sectors_per_fat * fat_num)
+ ((fat_sectors_cnt
+ (sectors_per_cluster - 1))
/ sectors_per_cluster));
/*
- * data cluster count too big? then make sectors bigger
+ * data cluster count too big? Then make clusters bigger
*/
if (((fattype == FAT_FAT12) && (data_cluster_cnt > FAT_FAT12_MAX_CLN)) ||
((fattype == FAT_FAT16) && (data_cluster_cnt > FAT_FAT16_MAX_CLN))) {
@@ -342,7 +374,12 @@ static int msdos_format_eval_sectors_per_cluster
/*
* when maximum cluster size is exceeded, we have invalid data, abort...
*/
- if ((sectors_per_cluster * bytes_per_sector)
+ if (fattype == FAT_FAT12) {
+ if (MS_BYTES_PER_CLUSTER_LIMIT_FAT12 < (sectors_per_cluster * bytes_per_sector)) {
+ ret_val = EINVAL;
+ finished = true;
+ }
+ } else if ((sectors_per_cluster * bytes_per_sector)
> MS_BYTES_PER_CLUSTER_LIMIT) {
ret_val = EINVAL;
finished = true;
@@ -352,11 +389,11 @@ static int msdos_format_eval_sectors_per_cluster
if (ret_val != 0) {
rtems_set_errno_and_return_minus_one(ret_val);
}
- else {
- *sectors_per_cluster_adj = sectors_per_cluster;
- *sectors_per_fat_ptr = sectors_per_fat;
- return 0;
- }
+
+ *sectors_per_cluster_adj = sectors_per_cluster;
+ *sectors_per_fat_ptr = fat_sectors_cnt / fat_num;
+
+ return 0;
}
@@ -381,7 +418,6 @@ static int msdos_format_determine_fmt_params
\*=========================================================================*/
{
int ret_val = 0;
- uint32_t fatdata_sect_cnt;
uint32_t onebit;
uint32_t sectors_per_cluster_adj = 0;
uint64_t total_size = 0;
@@ -393,7 +429,8 @@ static int msdos_format_determine_fmt_params
* At least one thing we don't have to magically guess...
*/
if (ret_val == 0) {
- ret_val = rtems_disk_fd_get_block_size(fd, &fmt_params->bytes_per_sector);
+ ret_val = rtems_disk_fd_get_media_block_size(fd, &fmt_params->bytes_per_sector);
+
}
if (ret_val == 0) {
ret_val = rtems_disk_fd_get_block_count(fd, &fmt_params->totl_sector_cnt);
@@ -542,6 +579,10 @@ static int msdos_format_determine_fmt_params
}
}
+ if (ret_val == 0 && rqdata != NULL) {
+ fmt_params->skip_alignment = rqdata->skip_alignment;
+ }
+
if (ret_val == 0) {
msdos_format_printf (rqdata, MSDOS_FMT_INFO_LEVEL_DETAIL,
"sectors per cluster: %d\n", fmt_params->sectors_per_cluster);
@@ -588,10 +629,6 @@ static int msdos_format_determine_fmt_params
/ fmt_params->bytes_per_sector);
}
if (ret_val == 0) {
- fatdata_sect_cnt = (fmt_params->totl_sector_cnt -
- fmt_params->rsvd_sector_cnt -
- fmt_params->root_dir_sectors);
-
/*
* check values to get legal arrangement of FAT type and cluster count
*/
@@ -599,14 +636,32 @@ static int msdos_format_determine_fmt_params
ret_val = msdos_format_eval_sectors_per_cluster
(fmt_params->fattype,
fmt_params->bytes_per_sector,
- fatdata_sect_cnt,
+ fmt_params->totl_sector_cnt,
+ fmt_params->rsvd_sector_cnt,
+ fmt_params->root_dir_sectors,
fmt_params->fat_num,
fmt_params->sectors_per_cluster,
+ fmt_params->skip_alignment,
§ors_per_cluster_adj,
&(fmt_params->sectors_per_fat));
fmt_params->sectors_per_cluster = sectors_per_cluster_adj;
}
+ if (0 == ret_val)
+ {
+ if (FAT_FAT32 != fmt_params->fattype)
+ {
+ fmt_params->files_per_root_dir = loc_align_object (fmt_params->root_dir_sectors,
+ fmt_params->sectors_per_cluster,
+ fmt_params->skip_alignment)
+ * (fmt_params->bytes_per_sector / FAT_DIRENTRY_SIZE);
+ }
+
+ fmt_params->rsvd_sector_cnt = loc_align_object (fmt_params->rsvd_sector_cnt,
+ fmt_params->sectors_per_cluster,
+ fmt_params->skip_alignment);
+ }
+
/*
* determine media code
*/
@@ -1064,6 +1119,8 @@ int msdos_format
* allocate directory in a FAT32 FS
*/
if (ret_val == 0) {
+ uint32_t start_sector;
+
/*
* empty sector: all clusters are free/do not link further on
*/
@@ -1106,15 +1163,19 @@ int msdos_format
*/
FAT_SET_VAL32(tmp_sec,8,FAT_FAT32_EOC);
}
+
+ start_sector = loc_align_object (fmt_params.rsvd_sector_cnt,
+ fmt_params.sectors_per_cluster,
+ fmt_params.skip_alignment);
for (i = 0;
(i < fmt_params.fat_num) && (ret_val == 0);
i++) {
ret_val = msdos_format_write_sec
- (fd,
- fmt_params.rsvd_sector_cnt
- + (i * fmt_params.sectors_per_fat),
- fmt_params.bytes_per_sector,
- tmp_sec);
+ (fd,
+ start_sector
+ + (i * fmt_params.sectors_per_fat),
+ fmt_params.bytes_per_sector,
+ tmp_sec);
}
}
/*
diff --git a/cpukit/libmisc/shell/main_msdosfmt.c b/cpukit/libmisc/shell/main_msdosfmt.c
index e684246..000b8e8 100644
--- a/cpukit/libmisc/shell/main_msdosfmt.c
+++ b/cpukit/libmisc/shell/main_msdosfmt.c
@@ -36,7 +36,7 @@ static int rtems_shell_main_msdos_format(
.fattype = MSDOS_FMT_FATANY,
.media = 0,
.quick_format = TRUE,
- .cluster_align = 0,
+ .skip_alignment = 0,
.info_level = 0
};
@@ -149,7 +149,7 @@ static int rtems_shell_main_msdos_format(
printf (" %-20s: %i\n", "fat type", rqdata.fattype);
printf (" %-20s: %d\n", "media", rqdata.media);
printf (" %-20s: %d\n", "quick_format", rqdata.quick_format);
- printf (" %-20s: %" PRIu32 "\n", "cluster align", rqdata.cluster_align);
+ printf (" %-20s: %s\n", "skip_alignment", (0 == rqdata.skip_alignment) ? "false" : "true");
}
if (msdos_format (driver, &rqdata) < 0) {
diff --git a/testsuites/fstests/mdosfs_support/fs_support.c b/testsuites/fstests/mdosfs_support/fs_support.c
index ef4356e..c58379a 100644
--- a/testsuites/fstests/mdosfs_support/fs_support.c
+++ b/testsuites/fstests/mdosfs_support/fs_support.c
@@ -34,7 +34,7 @@ msdos_format_request_param_t rqdata = {
fattype: MSDOS_FMT_FATANY,
media: 0,
quick_format: FALSE,
- cluster_align: 0,
+ skip_alignment: 0,
info_level: 0
};
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