* [PATCH] Btrfs-progs: enhance btrfs subvol list to show read-only snapshots
@ 2012-08-02 10:13 zhoubo
2012-08-05 9:08 ` Goffredo Baroncelli
0 siblings, 1 reply; 2+ messages in thread
From: zhoubo @ 2012-08-02 10:13 UTC (permalink / raw)
To: linux-btrfs
From: Zhou Bo <zhoub-fnst@cn.fujitsu.com>
This patch enhances btrfs subvol list to show read-only snapshots.
You can use the -r option showing read-only snapshots, for example:
btrfs subvolume list -r <path>
Signed-off-by: Zhou Bo <zhoub-fnst@cn.fujitsu.com>
---
btrfs-list.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++------
cmds-subvolume.c | 15 ++++++++----
ctree.h | 2 +
3 files changed, 72 insertions(+), 13 deletions(-)
diff --git a/btrfs-list.c b/btrfs-list.c
index 693d241..9c10b9e 100644
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -608,7 +608,46 @@ out:
return 0;
}
-static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
+static int is_readonly_subvol(int fd, u64 objectid)
+{
+ int ret;
+ struct btrfs_ioctl_search_args args;
+ struct btrfs_ioctl_search_key *sk = &args.key;
+ struct btrfs_ioctl_search_header *sh;
+ unsigned long off = 0;
+ int found = 0;
+ struct btrfs_root_item *item;
+
+ memset(&args, 0, sizeof(args));
+
+ /* search in the tree of tree roots */
+ sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
+ sk->min_objectid = objectid;
+ sk->max_objectid = objectid;
+ sk->max_type = BTRFS_ROOT_ITEM_KEY;
+ sk->min_type = BTRFS_ROOT_ITEM_KEY;
+ sk->max_offset = (u64)-1;
+ sk->max_transid = (u64)-1;
+ sk->nr_items = 1;
+ ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
+ if (ret < 0)
+ return ret;
+ if (sk->nr_items == 0) {
+ errno = -ENOENT;
+ found = -1;
+ goto out;
+ }
+ sh = (struct btrfs_ioctl_search_header *)args.buf;
+ off += sizeof(*sh);
+ item = (struct btrfs_root_item *)(args.buf + off);
+ if (item->flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY))
+ found = 1;
+out:
+ return found;
+}
+
+static int __list_subvol_search(int fd, struct root_lookup *root_lookup,
+ int list_ro)
{
int ret;
struct btrfs_ioctl_search_args args;
@@ -668,9 +707,23 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
name_len = btrfs_stack_root_ref_name_len(ref);
name = (char *)(ref + 1);
dir_id = btrfs_stack_root_ref_dirid(ref);
-
- add_root(root_lookup, sh->objectid, sh->offset,
- dir_id, name, name_len);
+ if (list_ro) {
+ int subvol_readonly =
+ is_readonly_subvol(fd,
+ sh->objectid);
+ if (subvol_readonly < 0) {
+ return subvol_readonly;
+ } else if (subvol_readonly) {
+ add_root(root_lookup,
+ sh->objectid,
+ sh->offset, dir_id,
+ name, name_len);
+ }
+ } else {
+ add_root(root_lookup, sh->objectid,
+ sh->offset, dir_id,
+ name, name_len);
+ }
}
off += sh->len;
@@ -719,7 +772,7 @@ static int __list_subvol_fill_paths(int fd, struct root_lookup *root_lookup)
return 0;
}
-int list_subvols(int fd, int print_parent, int get_default)
+int list_subvols(int fd, int print_parent, int get_default, int list_ro)
{
struct root_lookup root_lookup;
struct rb_node *n;
@@ -745,7 +798,7 @@ int list_subvols(int fd, int print_parent, int get_default)
}
}
- ret = __list_subvol_search(fd, &root_lookup);
+ ret = __list_subvol_search(fd, &root_lookup, list_ro);
if (ret) {
fprintf(stderr, "ERROR: can't perform the search - %s\n",
strerror(errno));
@@ -788,7 +841,6 @@ int list_subvols(int fd, int print_parent, int get_default)
(unsigned long long)entry->root_id,
(unsigned long long)level, path);
}
-
free(path);
n = rb_prev(n);
}
@@ -983,7 +1035,7 @@ char *path_for_root(int fd, u64 root)
char *ret_path = NULL;
int ret;
- ret = __list_subvol_search(fd, &root_lookup);
+ ret = __list_subvol_search(fd, &root_lookup, 0);
if (ret < 0)
return ERR_PTR(ret);
diff --git a/cmds-subvolume.c b/cmds-subvolume.c
index 3508ce6..791ac3f 100644
--- a/cmds-subvolume.c
+++ b/cmds-subvolume.c
@@ -30,7 +30,7 @@
#include "commands.h"
/* btrfs-list.c */
-int list_subvols(int fd, int print_parent, int get_default);
+int list_subvols(int fd, int print_parent, int get_default, int list_ro);
int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
static const char * const subvolume_cmd_group_usage[] = {
@@ -219,10 +219,11 @@ static int cmd_subvol_delete(int argc, char **argv)
}
static const char * const cmd_subvol_list_usage[] = {
- "btrfs subvolume list [-p] <path>",
+ "btrfs subvolume list [-pr] <path>",
"List subvolumes (and snapshots)",
"",
"-p print parent ID",
+ "-r list read-only snapshots",
NULL
};
@@ -231,15 +232,19 @@ static int cmd_subvol_list(int argc, char **argv)
int fd;
int ret;
int print_parent = 0;
+ int list_ro = 0;
char *subvol;
optind = 1;
while(1) {
- int c = getopt(argc, argv, "p");
+ int c = getopt(argc, argv, "pr");
if (c < 0)
break;
switch(c) {
+ case 'r':
+ list_ro = 1;
+ break;
case 'p':
print_parent = 1;
break;
@@ -268,7 +273,7 @@ static int cmd_subvol_list(int argc, char **argv)
fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
return 12;
}
- ret = list_subvols(fd, print_parent, 0);
+ ret = list_subvols(fd, print_parent, 0, list_ro);
if (ret)
return 19;
return 0;
@@ -428,7 +433,7 @@ static int cmd_subvol_get_default(int argc, char **argv)
fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
return 12;
}
- ret = list_subvols(fd, 0, 1);
+ ret = list_subvols(fd, 0, 1, 0);
if (ret)
return 19;
return 0;
diff --git a/ctree.h b/ctree.h
index 71e387b..12da31a 100644
--- a/ctree.h
+++ b/ctree.h
@@ -138,6 +138,8 @@ static int btrfs_csum_sizes[] = { 4, 0 };
#define BTRFS_FT_XATTR 8
#define BTRFS_FT_MAX 9
+#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
+
/*
* the key defines the order in the tree, and so it also defines (optimal)
* block layout. objectid corresonds to the inode number. The flags
--
1.6.0.6
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] Btrfs-progs: enhance btrfs subvol list to show read-only snapshots
2012-08-02 10:13 [PATCH] Btrfs-progs: enhance btrfs subvol list to show read-only snapshots zhoubo
@ 2012-08-05 9:08 ` Goffredo Baroncelli
0 siblings, 0 replies; 2+ messages in thread
From: Goffredo Baroncelli @ 2012-08-05 9:08 UTC (permalink / raw)
To: zhoubo; +Cc: linux-btrfs
Hi Bo,
On 08/02/2012 12:13 PM, zhoubo wrote:
> From: Zhou Bo <zhoub-fnst@cn.fujitsu.com>
>
> This patch enhances btrfs subvol list to show read-only snapshots.
> You can use the -r option showing read-only snapshots, for example:
> btrfs subvolume list -r <path>
Please elaborate this sentence: if I read correctly your code, the
switch '-r' shows
*only* the read only subvolume. It is no clear from your description
>
> Signed-off-by: Zhou Bo <zhoub-fnst@cn.fujitsu.com>
> ---
> btrfs-list.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++------
> cmds-subvolume.c | 15 ++++++++----
> ctree.h | 2 +
> 3 files changed, 72 insertions(+), 13 deletions(-)
>
> diff --git a/btrfs-list.c b/btrfs-list.c
> index 693d241..9c10b9e 100644
> --- a/btrfs-list.c
> +++ b/btrfs-list.c
> @@ -608,7 +608,46 @@ out:
> return 0;
> }
>
> -static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
> +static int is_readonly_subvol(int fd, u64 objectid)
> +{
> + int ret;
> + struct btrfs_ioctl_search_args args;
> + struct btrfs_ioctl_search_key *sk = &args.key;
> + struct btrfs_ioctl_search_header *sh;
> + unsigned long off = 0;
> + int found = 0;
> + struct btrfs_root_item *item;
> +
> + memset(&args, 0, sizeof(args));
> +
> + /* search in the tree of tree roots */
> + sk->tree_id = BTRFS_ROOT_TREE_OBJECTID;
> + sk->min_objectid = objectid;
> + sk->max_objectid = objectid;
> + sk->max_type = BTRFS_ROOT_ITEM_KEY;
> + sk->min_type = BTRFS_ROOT_ITEM_KEY;
> + sk->max_offset = (u64)-1;
> + sk->max_transid = (u64)-1;
> + sk->nr_items = 1;
> + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
> + if (ret < 0)
> + return ret;
> + if (sk->nr_items == 0) {
> + errno = -ENOENT;
> + found = -1;
> + goto out;
> + }
> + sh = (struct btrfs_ioctl_search_header *)args.buf;
> + off += sizeof(*sh);
> + item = (struct btrfs_root_item *)(args.buf + off);
> + if (item->flags & cpu_to_le64(BTRFS_ROOT_SUBVOL_RDONLY))
> + found = 1;
> +out:
> + return found;
> +}
> +
> +static int __list_subvol_search(int fd, struct root_lookup *root_lookup,
> + int list_ro)
> {
> int ret;
> struct btrfs_ioctl_search_args args;
> @@ -668,9 +707,23 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
> name_len = btrfs_stack_root_ref_name_len(ref);
> name = (char *)(ref + 1);
> dir_id = btrfs_stack_root_ref_dirid(ref);
> -
> - add_root(root_lookup, sh->objectid, sh->offset,
> - dir_id, name, name_len);
> + if (list_ro) {
> + int subvol_readonly =
> + is_readonly_subvol(fd,
> + sh->objectid);
> + if (subvol_readonly < 0) {
> + return subvol_readonly;
> + } else if (subvol_readonly) {
> + add_root(root_lookup,
> + sh->objectid,
> + sh->offset, dir_id,
> + name, name_len);
> + }
> + } else {
> + add_root(root_lookup, sh->objectid,
> + sh->offset, dir_id,
> + name, name_len);
> + }
> }
>
> off += sh->len;
> @@ -719,7 +772,7 @@ static int __list_subvol_fill_paths(int fd, struct root_lookup *root_lookup)
> return 0;
> }
>
> -int list_subvols(int fd, int print_parent, int get_default)
> +int list_subvols(int fd, int print_parent, int get_default, int list_ro)
> {
> struct root_lookup root_lookup;
> struct rb_node *n;
> @@ -745,7 +798,7 @@ int list_subvols(int fd, int print_parent, int get_default)
> }
> }
>
> - ret = __list_subvol_search(fd, &root_lookup);
> + ret = __list_subvol_search(fd, &root_lookup, list_ro);
> if (ret) {
> fprintf(stderr, "ERROR: can't perform the search - %s\n",
> strerror(errno));
> @@ -788,7 +841,6 @@ int list_subvols(int fd, int print_parent, int get_default)
> (unsigned long long)entry->root_id,
> (unsigned long long)level, path);
> }
> -
> free(path);
> n = rb_prev(n);
> }
> @@ -983,7 +1035,7 @@ char *path_for_root(int fd, u64 root)
> char *ret_path = NULL;
> int ret;
>
> - ret = __list_subvol_search(fd, &root_lookup);
> + ret = __list_subvol_search(fd, &root_lookup, 0);
> if (ret < 0)
> return ERR_PTR(ret);
>
> diff --git a/cmds-subvolume.c b/cmds-subvolume.c
> index 3508ce6..791ac3f 100644
> --- a/cmds-subvolume.c
> +++ b/cmds-subvolume.c
> @@ -30,7 +30,7 @@
> #include "commands.h"
>
> /* btrfs-list.c */
> -int list_subvols(int fd, int print_parent, int get_default);
> +int list_subvols(int fd, int print_parent, int get_default, int list_ro);
> int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
Does make sense to put these declaration in an header file ?
>
> static const char * const subvolume_cmd_group_usage[] = {
> @@ -219,10 +219,11 @@ static int cmd_subvol_delete(int argc, char **argv)
> }
>
> static const char * const cmd_subvol_list_usage[] = {
> - "btrfs subvolume list [-p] <path>",
> + "btrfs subvolume list [-pr] <path>",
> "List subvolumes (and snapshots)",
> "",
> "-p print parent ID",
> + "-r list read-only snapshots",
Please, if you change the btrfs command update the man page too
> NULL
> };
>
> @@ -231,15 +232,19 @@ static int cmd_subvol_list(int argc, char **argv)
> int fd;
> int ret;
> int print_parent = 0;
> + int list_ro = 0;
> char *subvol;
>
> optind = 1;
> while(1) {
> - int c = getopt(argc, argv, "p");
> + int c = getopt(argc, argv, "pr");
> if (c < 0)
> break;
>
> switch(c) {
> + case 'r':
> + list_ro = 1;
> + break;
> case 'p':
> print_parent = 1;
> break;
> @@ -268,7 +273,7 @@ static int cmd_subvol_list(int argc, char **argv)
> fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
> return 12;
> }
> - ret = list_subvols(fd, print_parent, 0);
> + ret = list_subvols(fd, print_parent, 0, list_ro);
> if (ret)
> return 19;
> return 0;
> @@ -428,7 +433,7 @@ static int cmd_subvol_get_default(int argc, char **argv)
> fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
> return 12;
> }
> - ret = list_subvols(fd, 0, 1);
> + ret = list_subvols(fd, 0, 1, 0);
> if (ret)
> return 19;
> return 0;
> diff --git a/ctree.h b/ctree.h
> index 71e387b..12da31a 100644
> --- a/ctree.h
> +++ b/ctree.h
> @@ -138,6 +138,8 @@ static int btrfs_csum_sizes[] = { 4, 0 };
> #define BTRFS_FT_XATTR 8
> #define BTRFS_FT_MAX 9
>
> +#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
> +
> /*
> * the key defines the order in the tree, and so it also defines (optimal)
> * block layout. objectid corresonds to the inode number. The flags
^ permalink raw reply [flat|nested] 2+ messages in thread
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2012-08-02 10:13 [PATCH] Btrfs-progs: enhance btrfs subvol list to show read-only snapshots zhoubo
2012-08-05 9:08 ` Goffredo Baroncelli
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