From: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx>
This uses a struct to cache the block size for aligned reads/writes,
to avoid repeated ioctl(BLKSSZGET) calls.
Signed-off-by: Jes Sorensen <Jes.Sorensen@xxxxxxxxxx>
---
super1.c | 75 ++++++++++++++++++++++++++++++++++++++++++++-----------------
1 files changed, 54 insertions(+), 21 deletions(-)
diff --git a/super1.c b/super1.c
index 513f406..350e27a 100644
--- a/super1.c
+++ b/super1.c
@@ -137,8 +137,25 @@ static unsigned int calc_sb_1_csum(struct mdp_superblock_1 * sb)
return __cpu_to_le32(csum);
}
+/*
+ * Information related to file descriptor used for aligned reads/writes.
+ * Cache the block size.
+ */
+struct align_fd {
+ int fd;
+ int blk_sz;
+};
+
+static void init_afd(struct align_fd *afd, int fd)
+{
+ afd->fd = fd;
+
+ if (ioctl(afd->fd, BLKSSZGET, &afd->blk_sz) != 0)
+ afd->blk_sz = 512;
+}
+
static char abuf[4096+4096];
-static int aread(int fd, void *buf, int len)
+static int aread(struct align_fd *afd, void *buf, int len)
{
/* aligned read.
* On devices with a 4K sector size, we need to read
@@ -148,26 +165,30 @@ static int aread(int fd, void *buf, int len)
int bsize, iosize;
char *b;
int n;
- if (ioctl(fd, BLKSSZGET, &bsize) != 0)
- bsize = 512;
- if (bsize > 4096 || len > 4096)
+ bsize = afd->blk_sz;
+
+ if (!bsize || bsize > 4096 || len > 4096) {
+ if (!bsize)
+ fprintf(stderr, "WARNING - aread() called with "
+ "invalid block size\n");
return -1;
+ }
b = (char*)(((long)(abuf+4096))&~4095UL);
for (iosize = 0; iosize < len; iosize += bsize)
;
- n = read(fd, b, iosize);
+ n = read(afd->fd, b, iosize);
if (n <= 0)
return n;
- lseek(fd, len - n, 1);
+ lseek(afd->fd, len - n, 1);
if (n > len)
n = len;
memcpy(buf, b, n);
return n;
}
-static int awrite(int fd, void *buf, int len)
+static int awrite(struct align_fd *afd, void *buf, int len)
{
/* aligned write.
* On devices with a 4K sector size, we need to write
@@ -178,27 +199,31 @@ static int awrite(int fd, void *buf, int len)
int bsize, iosize;
char *b;
int n;
- if (ioctl(fd, BLKSSZGET, &bsize) != 0)
- bsize = 512;
- if (bsize > 4096 || len > 4096)
+
+ bsize = afd->blk_sz;
+ if (!bsize || bsize > 4096 || len > 4096) {
+ if (!bsize)
+ fprintf(stderr, "WARNING - awrite() called with "
+ "invalid block size\n");
return -1;
+ }
b = (char*)(((long)(abuf+4096))&~4095UL);
for (iosize = 0; iosize < len ; iosize += bsize)
;
if (len != iosize) {
- n = read(fd, b, iosize);
+ n = read(afd->fd, b, iosize);
if (n <= 0)
return n;
- lseek(fd, -n, 1);
+ lseek(afd->fd, -n, 1);
}
memcpy(b, buf, len);
- n = write(fd, b, iosize);
+ n = write(afd->fd, b, iosize);
if (n <= 0)
return n;
- lseek(fd, len - n, 1);
+ lseek(afd->fd, len - n, 1);
return len;
}
@@ -962,6 +987,7 @@ static int store_super1(struct supertype *st, int fd)
{
struct mdp_superblock_1 *sb = st->sb;
unsigned long long sb_offset;
+ struct align_fd afd;
int sbsize;
unsigned long long dsize;
@@ -973,6 +999,8 @@ static int store_super1(struct supertype *st, int fd)
if (dsize < 24)
return 2;
+ init_afd(&afd, fd);
+
/*
* Calculate the position of the superblock.
* It is always aligned to a 4K boundary and
@@ -1012,7 +1040,7 @@ static int store_super1(struct supertype *st, int fd)
sbsize = sizeof(*sb) + 2 * __le32_to_cpu(sb->max_dev);
sbsize = (sbsize+511)&(~511UL);
- if (awrite(fd, sb, sbsize) != sbsize)
+ if (awrite(&afd, sb, sbsize) != sbsize)
return 4;
if (sb->feature_map & __cpu_to_le32(MD_FEATURE_BITMAP_OFFSET)) {
@@ -1020,9 +1048,8 @@ static int store_super1(struct supertype *st, int fd)
(((char*)sb)+1024);
if (__le32_to_cpu(bm->magic) == BITMAP_MAGIC) {
locate_bitmap1(st, fd);
- if (awrite(fd, bm, sizeof(*bm)) !=
- sizeof(*bm))
- return 5;
+ if (awrite(&afd, bm, sizeof(*bm)) != sizeof(*bm))
+ return 5;
}
}
fsync(fd);
@@ -1250,9 +1277,12 @@ static int load_super1(struct supertype *st, int fd, char *devname)
int uuid[4];
struct bitmap_super_s *bsb;
struct misc_dev_info *misc;
+ struct align_fd afd;
free_super1(st);
+ init_afd(&afd, fd);
+
if (st->ss == NULL || st->minor_version == -1) {
int bestvers = -1;
struct supertype tst;
@@ -1338,7 +1368,7 @@ static int load_super1(struct supertype *st, int fd, char *devname)
return 1;
}
- if (aread(fd, super, 1024) != 1024) {
+ if (aread(&afd, super, 1024) != 1024) {
if (devname)
fprintf(stderr, Name ": Cannot read superblock on %s\n",
devname);
@@ -1383,7 +1413,7 @@ static int load_super1(struct supertype *st, int fd, char *devname)
* should get that written out.
*/
locate_bitmap1(st, fd);
- if (aread(fd, bsb, 512) != 512)
+ if (aread(&afd, bsb, 512) != 512)
goto no_bitmap;
uuid_from_super1(st, uuid);
@@ -1643,6 +1673,9 @@ static int write_bitmap1(struct supertype *st, int fd)
int rv = 0;
void *buf;
int towrite, n;
+ struct align_fd afd;
+
+ init_afd(&afd, fd);
locate_bitmap1(st, fd);
@@ -1660,7 +1693,7 @@ static int write_bitmap1(struct supertype *st, int fd)
n = towrite;
if (n > 4096)
n = 4096;
- n = awrite(fd, buf, n);
+ n = awrite(&afd, buf, n);
if (n > 0)
towrite -= n;
else
--
1.7.7.6
--
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