Hello everyone!
The attached patches to linux and btrfs-progs add support for filtering
based on the number of strips in a block when balancing.
This is my first attempt at kernel development, I'd love if you could
please point out any mistakes that I've made.
Thanks,
Gabríel
P.S. I could not figure out how to subscribe to this mailing list, so
please remember to include me in your replies.
diff --git a/Documentation/btrfs-balance.asciidoc b/Documentation/btrfs-balance.asciidoc
index 6d2fd0c..8663855 100644
--- a/Documentation/btrfs-balance.asciidoc
+++ b/Documentation/btrfs-balance.asciidoc
@@ -110,6 +110,10 @@ Process only given number of chunks, after all filters apply. This can be used
to specifically target a chunk in connection with other filters (drange,
vrange) or just simply limit the amount of work done by a single balance run.
+*stripes*::
+Balances only block groups which have the given number of stripes. The
+parameter is either a range specified as <start..end>, or a single integer.
+
*soft*::
Takes no parameters. Only has meaning when converting between profiles.
When doing convert from one profile to another and soft mode is on,
diff --git a/cmds-balance.c b/cmds-balance.c
index 9af218b..c47f8b7 100644
--- a/cmds-balance.c
+++ b/cmds-balance.c
@@ -226,6 +226,21 @@ static int parse_filters(char *filters, struct btrfs_balance_args *args)
return 1;
}
args->flags |= BTRFS_BALANCE_ARGS_LIMIT;
+ } else if (!strcmp(this_char, "stripes")) {
+ if (!value || !*value) {
+ fprintf(stderr,
+ "the stripes filter requires an argument\n");
+ return 1;
+ }
+ if (parse_u64(value, &args->sstart)) {
+ if (parse_range(value, &args->sstart, &args->send)) {
+ fprintf(stderr, "Invalid stripes argument\n");
+ return 1;
+ }
+ } else {
+ args->send = args->sstart;
+ }
+ args->flags |= BTRFS_BALANCE_ARGS_STRIPES;
} else {
fprintf(stderr, "Unrecognized balance option '%s'\n",
this_char);
@@ -262,6 +277,15 @@ static void dump_balance_args(struct btrfs_balance_args *args)
(unsigned long long)args->vend);
if (args->flags & BTRFS_BALANCE_ARGS_LIMIT)
printf(", limit=%llu", (unsigned long long)args->limit);
+ if (args->flags & BTRFS_BALANCE_ARGS_STRIPES) {
+ if (args->sstart == args->send) {
+ printf(", stripes=%llu", (unsigned long long)args->sstart);
+ } else {
+ printf(", stripes=%llu..%llu",
+ (unsigned long long)args->sstart,
+ (unsigned long long)args->send);
+ }
+ }
printf("\n");
}
diff --git a/ioctl.h b/ioctl.h
index dff015a..c1f6aec 100644
--- a/ioctl.h
+++ b/ioctl.h
@@ -228,7 +228,11 @@ struct btrfs_balance_args {
__u64 flags;
__u64 limit; /* limit number of processed chunks */
- __u64 unused[7];
+
+ __u64 sstart;
+ __u64 send;
+
+ __u64 unused[5];
} __attribute__ ((__packed__));
/* report balance progress to userspace */
diff --git a/volumes.h b/volumes.h
index 4ecb993..a809a78 100644
--- a/volumes.h
+++ b/volumes.h
@@ -136,6 +136,7 @@ struct map_lookup {
#define BTRFS_BALANCE_ARGS_DRANGE (1ULL << 3)
#define BTRFS_BALANCE_ARGS_VRANGE (1ULL << 4)
#define BTRFS_BALANCE_ARGS_LIMIT (1ULL << 5)
+#define BTRFS_BALANCE_ARGS_STRIPES (1ULL << 6)
/*
* Profile changing flags. When SOFT is set we won't relocate chunk if
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index 938efe3..78573e5 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -849,7 +849,11 @@ struct btrfs_disk_balance_args {
/* BTRFS_BALANCE_ARGS_LIMIT value */
__le64 limit;
- __le64 unused[7];
+ /* btrfs stripes filter */
+ __le64 sstart;
+ __le64 send;
+
+ __le64 unused[5];
} __attribute__ ((__packed__));
/*
diff --git a/fs/btrfs/volumes.c b/fs/btrfs/volumes.c
index 6fc73586..dc65fbb 100644
--- a/fs/btrfs/volumes.c
+++ b/fs/btrfs/volumes.c
@@ -3170,6 +3170,18 @@ static int chunk_vrange_filter(struct extent_buffer *leaf,
return 1;
}
+static int chunk_stripes_filter(struct extent_buffer *leaf,
+ struct btrfs_chunk *chunk,
+ struct btrfs_balance_args *bargs)
+{
+ int num_stripes = btrfs_chunk_num_stripes(leaf, chunk);
+
+ if (bargs->sstart <= num_stripes && num_stripes <= bargs->send)
+ return 0;
+
+ return 1;
+}
+
static int chunk_soft_convert_filter(u64 chunk_type,
struct btrfs_balance_args *bargs)
{
@@ -3236,6 +3248,12 @@ static int should_balance_chunk(struct btrfs_root *root,
return 0;
}
+ /* stripes filter */
+ if ((bargs->flags & BTRFS_BALANCE_ARGS_STRIPES) &&
+ chunk_stripes_filter(leaf, chunk, bargs)) {
+ return 0;
+ }
+
/* soft profile changing mode */
if ((bargs->flags & BTRFS_BALANCE_ARGS_SOFT) &&
chunk_soft_convert_filter(chunk_type, bargs)) {
diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 2ca784a..fb6b89a 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -375,6 +375,7 @@ struct map_lookup {
#define BTRFS_BALANCE_ARGS_DRANGE (1ULL << 3)
#define BTRFS_BALANCE_ARGS_VRANGE (1ULL << 4)
#define BTRFS_BALANCE_ARGS_LIMIT (1ULL << 5)
+#define BTRFS_BALANCE_ARGS_STRIPES (1ULL << 6)
/*
* Profile changing flags. When SOFT is set we won't relocate chunk if
diff --git a/include/uapi/linux/btrfs.h b/include/uapi/linux/btrfs.h
index b6dec05..a7819d0 100644
--- a/include/uapi/linux/btrfs.h
+++ b/include/uapi/linux/btrfs.h
@@ -218,7 +218,11 @@ struct btrfs_balance_args {
__u64 flags;
__u64 limit; /* limit number of processed chunks */
- __u64 unused[7];
+
+ __u64 sstart;
+ __u64 send;
+
+ __u64 unused[5];
} __attribute__ ((__packed__));
/* report balance progress to userspace */
