[PATCH] Use posix_memalign() for memory used to write bitmaps
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STALE5347d
From: <hidden>
Date: 2012-02-14 10:52:13
Subsystem:
the rest · Maintainer:
Linus Torvalds
From: Jes Sorensen <redacted> This makes super[01].c properly align buffers used for the bitmap using posix_memalign() to make sure the writes don't fail in case the bitmap is opened using O_DIRECT. This is based on https://bugzilla.redhat.com/show_bug.cgi?id=789898 and an initial patch by Alexander Murashkin. Signed-off-by: Jes Sorensen <redacted> --- super0.c | 8 +++++--- super1.c | 7 +++++-- 2 files changed, 10 insertions(+), 5 deletions(-)
diff --git a/super0.c b/super0.c
index dab85db..d53f025 100644
--- a/super0.c
+++ b/super0.c@@ -1065,13 +1065,11 @@ static int write_bitmap0(struct supertype *st, int fd) int rv = 0; int towrite, n; - char abuf[4096+4096]; - char *buf = (char*)(((long)(abuf+4096))&~4095L); + void *buf; if (!get_dev_size(fd, NULL, &dsize)) return 1; - if (dsize < MD_RESERVED_SECTORS*512) return -1;
@@ -1082,6 +1080,9 @@ static int write_bitmap0(struct supertype *st, int fd) if (lseek64(fd, offset + 4096, 0)< 0LL) return 3; + if (posix_memalign(&buf, 4096, 4096)) + return -ENOMEM; + memset(buf, 0xff, 4096); memcpy(buf, ((char*)sb)+MD_SB_BYTES, sizeof(bitmap_super_t)); towrite = 60*1024;
@@ -1100,6 +1101,7 @@ static int write_bitmap0(struct supertype *st, int fd) if (towrite) rv = -2; + free(buf); return rv; }
diff --git a/super1.c b/super1.c
index cfa237a..a18952a 100644
--- a/super1.c
+++ b/super1.c@@ -1641,12 +1641,14 @@ static int write_bitmap1(struct supertype *st, int fd) struct mdp_superblock_1 *sb = st->sb; bitmap_super_t *bms = (bitmap_super_t*)(((char*)sb)+1024); int rv = 0; - + void *buf; int towrite, n; - char buf[4096]; locate_bitmap1(st, fd); + if (posix_memalign(&buf, 4096, 4096)) + return -ENOMEM; + memset(buf, 0xff, 4096); memcpy(buf, ((char*)sb)+1024, sizeof(bitmap_super_t));
@@ -1669,6 +1671,7 @@ static int write_bitmap1(struct supertype *st, int fd) if (towrite) rv = -2; + free(buf); return rv; }
--
1.7.4.4