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Upstream-Status: Inappropriate [Backport]
From e6bd18d8938986c997c45f0ea95b221d4edec095 Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Thu, 21 Apr 2011 16:24:07 -0400
Subject: [PATCH 15/15] btrfs-progs: add discard support to mkfs
Discard the whole device before starting to create the filesystem structures.
Modelled after similar support in mkfs.xfs.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
---
btrfs_cmds.c | 21 +++++++++++++++++----
utils.c | 21 +++++++++++++++++++++
2 files changed, 38 insertions(+), 4 deletions(-)
diff --git a/btrfs_cmds.c b/btrfs_cmds.c
index 6de73f4..32f6b25 100644
--- a/btrfs_cmds.c
+++ b/btrfs_cmds.c
@@ -732,13 +732,26 @@ int do_add_volume(int nargs, char **args)
return 12;
}
- for(i=1 ; i < (nargs-1) ; i++ ){
+ for (i = 1; i < (nargs-1); i++ ){
struct btrfs_ioctl_vol_args ioctl_args;
int devfd, res;
u64 dev_block_count = 0;
struct stat st;
int mixed = 0;
+ res = check_mounted(args[i]);
+ if (res < 0) {
+ fprintf(stderr, "error checking %s mount status\n",
+ args[i]);
+ ret++;
+ continue;
+ }
+ if (res == 1) {
+ fprintf(stderr, "%s is mounted\n", args[i]);
+ ret++;
+ continue;
+ }
+
devfd = open(args[i], O_RDWR);
if (!devfd) {
fprintf(stderr, "ERROR: Unable to open device '%s'\n", args[i]);
@@ -746,8 +759,8 @@ int do_add_volume(int nargs, char **args)
ret++;
continue;
}
- ret = fstat(devfd, &st);
- if (ret) {
+ res = fstat(devfd, &st);
+ if (res) {
fprintf(stderr, "ERROR: Unable to stat '%s'\n", args[i]);
close(devfd);
ret++;
@@ -781,7 +794,7 @@ int do_add_volume(int nargs, char **args)
}
close(fdmnt);
- if( ret)
+ if (ret)
return ret+20;
else
return 0;
diff --git a/utils.c b/utils.c
index 13373c9..17e5afe 100644
--- a/utils.c
+++ b/utils.c
@@ -50,6 +50,20 @@
static inline int ioctl(int fd, int define, u64 *size) { return 0; }
#endif
+#ifndef BLKDISCARD
+#define BLKDISCARD _IO(0x12,119)
+#endif
+
+static int
+discard_blocks(int fd, u64 start, u64 len)
+{
+ u64 range[2] = { start, len };
+
+ if (ioctl(fd, BLKDISCARD, &range) < 0)
+ return errno;
+ return 0;
+}
+
static u64 reference_root_table[] = {
[1] = BTRFS_ROOT_TREE_OBJECTID,
[2] = BTRFS_EXTENT_TREE_OBJECTID,
@@ -537,6 +551,13 @@ int btrfs_prepare_device(int fd, char *file, int zero_end, u64 *block_count_ret,
printf("SMALL VOLUME: forcing mixed metadata/data groups\n");
*mixed = 1;
}
+
+ /*
+ * We intentionally ignore errors from the discard ioctl. It is
+ * not necessary for the mkfs functionality but just an optimization.
+ */
+ discard_blocks(fd, 0, block_count);
+
ret = zero_dev_start(fd);
if (ret) {
fprintf(stderr, "failed to zero device start %d\n", ret);
--
1.7.2.3
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