Re: [PATCH V2] Btrfs-progs: add \btrfs subvolume get-default\ subcommand

2012-02-15 Thread Ilya Dryomov 
On Wed, Feb 15, 2012 at 01:43:02PM +0800, Anand Jain wrote:
 
 Hi Xin / Hugo,
  I am referring to
  git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs.git
 
  has miss match parameter list for list_subvols
  --
  # cd btrfs-progs
  # egrep list_subvols *
  btrfs_cmds.c:ret = list_subvols(fd, print_parent, 0);
  btrfs_cmds.c:ret = list_subvols(fd, 0, 1);
  btrfs_cmds.h:int list_subvols(int fd, int print_parent, int get_default);  
 -
  btrfs-list.c:int list_subvols(int fd, int print_parent)  -
  --
 
  --
  # egrep -A 3 list_subvols btrfs-list.c
  int list_subvols(int fd, int print_parent)
  {
   struct root_lookup root_lookup;
   struct rb_node *n;
  --
  Looks like the following patch was checked in partially.
http://www.mail-archive.com/linux-btrfs@vger.kernel.org/msg11103.html
 
  Could you pls take a look / comment.

I looked at this issue briefly when testing the new parser.  Looks like
Jan broke it with his split of list_subvols.  Jan's code was probably
based on the master branch of the old progs repo, whereas get-default
was based on one of the integration branches and the subsequent merge
missed it.  I'll fix it if nobody else steps up.

Thanks,

Ilya
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Re: [PATCH V2] Btrfs-progs: add btrfs subvolume get-default subcommand

2011-07-11 Thread Andreas Philipp 

-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
 
Would you mind rebasing your patch on Hugo Mills' integration-branch for
btrfs progs at
http://git.darksatanic.net/repo/btrfs-progs-unstable.git
integration-20110705
since it does not apply on top of all changes which are already there.
Additionally, I spotted one whitespace error in the patch and marked it
below.
 
Thanks,
Andreas Philipp
 
On 11.07.2011 10:56, Zhong, Xin wrote:
 Add subcommand to get the default subvolume of btrfs filesystem

 Reported-by: Yang, Yi yi.y.y...@intel.com
 Signed-off-by: Zhong, Xin xin.zh...@intel.com
 ---
 btrfs-list.c | 57
+++--
 btrfs.c | 3 +++
 btrfs_cmds.c | 31 ++-
 btrfs_cmds.h | 3 ++-
 4 files changed, 90 insertions(+), 4 deletions(-)

 diff --git a/btrfs-list.c b/btrfs-list.c
 index 93766a8..aa6a9b4 100644
 --- a/btrfs-list.c
 +++ b/btrfs-list.c
 @@ -536,7 +536,7 @@ build:
 return full;
 }

 -int list_subvols(int fd)
 +int list_subvols(int fd, int get_default)
 {
 struct root_lookup root_lookup;
 struct rb_node *n;
 @@ -545,10 +545,12 @@ int list_subvols(int fd)
 struct btrfs_ioctl_search_key *sk = args.key;
 struct btrfs_ioctl_search_header *sh;
 struct btrfs_root_ref *ref;
 + struct btrfs_dir_item *di;
 unsigned long off = 0;
 int name_len;
 char *name;
 u64 dir_id;
 + u64 subvol_id = 0;
 int i;

 root_lookup_init(root_lookup);
 @@ -642,6 +644,52 @@ int list_subvols(int fd)
 n = rb_next(n);
 }

 + memset(args, 0, sizeof(args));
 +
 + /* search in the tree of tree roots */
 + sk-tree_id = BTRFS_ROOT_TREE_OBJECTID;
 +
 + /* search dir item */
 + sk-max_type = BTRFS_DIR_ITEM_KEY;
 + sk-min_type = BTRFS_DIR_ITEM_KEY;
 +
 + sk-max_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
 + sk-min_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
 + sk-max_offset = (u64)-1;
 + sk-max_transid = (u64)-1;
 +
 + /* just a big number, doesn't matter much */
 + sk-nr_items = 4096;
 +
 + /* try to get the objectid of default subvolume */
 + if(get_default) {
 + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, args);
 + if (ret  0) {
 + fprintf(stderr, ERROR: can't perform the search\n);
 + return ret;
 + }
 +
 + off = 0;
 + /* go through each item to find dir item named default */
 + for (i = 0; i  sk-nr_items; i++) {
 + sh = (struct btrfs_ioctl_search_header *)(args.buf +
 + off);
 + off += sizeof(*sh);
 + if (sh-type == BTRFS_DIR_ITEM_KEY) {
 + di = (struct btrfs_dir_item *)(args.buf + off);
 + name_len = le16_to_cpu(di-name_len);
 + name = (char *)di + sizeof(struct btrfs_dir_item);
 + if (!strncmp(default, name, name_len)) {
 + subvol_id = btrfs_disk_key_objectid(
 + di-location);
 + break;
 + }
 + }
 +
 + off += sh-len;
 + }
 + }
 +
 /* now that we have all the subvol-relative paths filled in,
 * we have to string the subvols together so that we can get
 * a path all the way back to the FS root
 @@ -650,7 +698,12 @@ int list_subvols(int fd)
 while (n) {
 struct root_info *entry;
 entry = rb_entry(n, struct root_info, rb_node);
 - resolve_root(root_lookup, entry);
 + if(!get_default)
 + resolve_root(root_lookup, entry);
 + /* we only want the default subvolume */
 + else if(subvol_id == entry-root_id)
 + resolve_root(root_lookup, entry);
 +
This line adds a whitespace error.
 n = rb_prev(n);
 }

 diff --git a/btrfs.c b/btrfs.c
 index 46314cf..6b73f88 100644
 --- a/btrfs.c
 +++ b/btrfs.c
 @@ -73,6 +73,9 @@ static struct Command commands[] = {
 Set the subvolume of the filesystem path which will be mounted\n
 as default.
 },
 + { do_get_default_subvol, 1, subvolume get-default, path\n
 + Get the default subvolume of a filesystem.
 + },
 { do_fssync, 1,
 filesystem sync, path\n
 Force a sync on the filesystem path.
 diff --git a/btrfs_cmds.c b/btrfs_cmds.c
 index 8031c58..11c56f6 100644
 --- a/btrfs_cmds.c
 +++ b/btrfs_cmds.c
 @@ -301,7 +301,7 @@ int do_subvol_list(int argc, char **argv)
 fprintf(stderr, ERROR: can't access '%s'\n, subvol);
 return 12;
 }
 - ret = list_subvols(fd);
 + ret = list_subvols(fd, 0);
 if (ret)
 return 19;
 return 0;
 @@ -834,6 +834,35 @@ int do_set_default_subvol(int nargs, char **argv)
 return 0;
 }

 +int do_get_default_subvol(int nargs, char **argv)
 +{
 + int fd;
 + int ret;
 + char *subvol;
 +
 + subvol = argv[1];
 +
 + ret = test_issubvolume(subvol);
 + if (ret  0) {
 + fprintf(stderr, ERROR: error accessing '%s'\n, subvol);
 + return 12;
 + }
 + if (!ret) {
 + fprintf(stderr, ERROR: '%s' is not a subvolume\n, subvol);
 + return 13;
 + }
 +
 + fd = open_file_or_dir(subvol);
 + if (fd  0) {
 + fprintf(stderr, ERROR: can't access '%s'\n, subvol);
 + return 12;
 + }
 + ret = list_subvols(fd, 1);
 + if (ret)
 + return 19;
 + return 0;
 +}
 +
 int do_df_filesystem(int nargs, char **argv)
 {
 struct btrfs_ioctl_space_args *sargs;
 diff --git a/btrfs_cmds.h b/btrfs_cmds.h
 index 7bde191..9cf1ca1 100644
 --- a/btrfs_cmds.h
 +++ b/btrfs_cmds.h
 @@ -28,7 +28,8 @@ int do_scan(int nargs, char **argv);
 int do_resize(int nargs, char **argv);
 int

RE: [PATCH V2] Btrfs-progs: add btrfs subvolume get-default subcommand

2011-07-11 Thread Zhong, Xin 


 -Original Message-
 From: Andreas Philipp [mailto:philipp.andr...@gmail.com]
 Sent: Monday, July 11, 2011 10:11 PM
 To: Zhong, Xin
 Cc: linux-btrfs@vger.kernel.org; Hugo Mills
 Subject: Re: [PATCH V2] Btrfs-progs: add btrfs subvolume get-default
 subcommand
 
 
 -BEGIN PGP SIGNED MESSAGE-
 Hash: SHA1
 
 Would you mind rebasing your patch on Hugo Mills' integration-branch
 for
 btrfs progs at
 http://git.darksatanic.net/repo/btrfs-progs-unstable.git
 integration-20110705
 since it does not apply on top of all changes which are already there.
 Additionally, I spotted one whitespace error in the patch and marked it
 below.

Ok. I will update my patch. Thanks!

 Thanks,
 Andreas Philipp
 
 On 11.07.2011 10:56, Zhong, Xin wrote:
  Add subcommand to get the default subvolume of btrfs filesystem
 
  Reported-by: Yang, Yi yi.y.y...@intel.com
  Signed-off-by: Zhong, Xin xin.zh...@intel.com
  ---
  btrfs-list.c | 57
 +++--
  btrfs.c | 3 +++
  btrfs_cmds.c | 31 ++-
  btrfs_cmds.h | 3 ++-
  4 files changed, 90 insertions(+), 4 deletions(-)
 
  diff --git a/btrfs-list.c b/btrfs-list.c
  index 93766a8..aa6a9b4 100644
  --- a/btrfs-list.c
  +++ b/btrfs-list.c
  @@ -536,7 +536,7 @@ build:
  return full;
  }
 
  -int list_subvols(int fd)
  +int list_subvols(int fd, int get_default)
  {
  struct root_lookup root_lookup;
  struct rb_node *n;
  @@ -545,10 +545,12 @@ int list_subvols(int fd)
  struct btrfs_ioctl_search_key *sk = args.key;
  struct btrfs_ioctl_search_header *sh;
  struct btrfs_root_ref *ref;
  + struct btrfs_dir_item *di;
  unsigned long off = 0;
  int name_len;
  char *name;
  u64 dir_id;
  + u64 subvol_id = 0;
  int i;
 
  root_lookup_init(root_lookup);
  @@ -642,6 +644,52 @@ int list_subvols(int fd)
  n = rb_next(n);
  }
 
  + memset(args, 0, sizeof(args));
  +
  + /* search in the tree of tree roots */
  + sk-tree_id = BTRFS_ROOT_TREE_OBJECTID;
  +
  + /* search dir item */
  + sk-max_type = BTRFS_DIR_ITEM_KEY;
  + sk-min_type = BTRFS_DIR_ITEM_KEY;
  +
  + sk-max_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
  + sk-min_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
  + sk-max_offset = (u64)-1;
  + sk-max_transid = (u64)-1;
  +
  + /* just a big number, doesn't matter much */
  + sk-nr_items = 4096;
  +
  + /* try to get the objectid of default subvolume */
  + if(get_default) {
  + ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, args);
  + if (ret  0) {
  + fprintf(stderr, ERROR: can't perform the search\n);
  + return ret;
  + }
  +
  + off = 0;
  + /* go through each item to find dir item named default */
  + for (i = 0; i  sk-nr_items; i++) {
  + sh = (struct btrfs_ioctl_search_header *)(args.buf +
  + off);
  + off += sizeof(*sh);
  + if (sh-type == BTRFS_DIR_ITEM_KEY) {
  + di = (struct btrfs_dir_item *)(args.buf + off);
  + name_len = le16_to_cpu(di-name_len);
  + name = (char *)di + sizeof(struct btrfs_dir_item);
  + if (!strncmp(default, name, name_len)) {
  + subvol_id = btrfs_disk_key_objectid(
  + di-location);
  + break;
  + }
  + }
  +
  + off += sh-len;
  + }
  + }
  +
  /* now that we have all the subvol-relative paths filled in,
  * we have to string the subvols together so that we can get
  * a path all the way back to the FS root
  @@ -650,7 +698,12 @@ int list_subvols(int fd)
  while (n) {
  struct root_info *entry;
  entry = rb_entry(n, struct root_info, rb_node);
  - resolve_root(root_lookup, entry);
  + if(!get_default)
  + resolve_root(root_lookup, entry);
  + /* we only want the default subvolume */
  + else if(subvol_id == entry-root_id)
  + resolve_root(root_lookup, entry);
  +
 This line adds a whitespace error.
  n = rb_prev(n);
  }
 
  diff --git a/btrfs.c b/btrfs.c
  index 46314cf..6b73f88 100644
  --- a/btrfs.c
  +++ b/btrfs.c
  @@ -73,6 +73,9 @@ static struct Command commands[] = {
  Set the subvolume of the filesystem path which will be mounted\n
  as default.
  },
  + { do_get_default_subvol, 1, subvolume get-default, path\n
  + Get the default subvolume of a filesystem.
  + },
  { do_fssync, 1,
  filesystem sync, path\n
  Force a sync on the filesystem path.
  diff --git a/btrfs_cmds.c b/btrfs_cmds.c
  index 8031c58..11c56f6 100644
  --- a/btrfs_cmds.c
  +++ b/btrfs_cmds.c
  @@ -301,7 +301,7 @@ int do_subvol_list(int argc, char **argv)
  fprintf(stderr, ERROR: can't access '%s'\n, subvol);
  return 12;
  }
  - ret = list_subvols(fd);
  + ret = list_subvols(fd, 0);
  if (ret)
  return 19;
  return 0;
  @@ -834,6 +834,35 @@ int do_set_default_subvol(int nargs, char **argv)
  return 0;
  }
 
  +int do_get_default_subvol(int nargs, char **argv)
  +{
  + int fd;
  + int ret;
  + char *subvol;
  +
  + subvol = argv[1];
  +
  + ret = test_issubvolume(subvol);
  + if (ret  0) {
  + fprintf(stderr, ERROR: error accessing '%s'\n, subvol);
  + return 12;
  + }
  + if (!ret) {
  + fprintf(stderr, ERROR: '%s' is not a subvolume\n, subvol);
  + return 13;
  + }
  +
  + fd = open_file_or_dir(subvol

RE: [PATCH V2] Btrfs-progs: add btrfs subvolume get-default subcommand

2011-07-11 Thread Zhong, Xin 
 -Original Message-
 From: Goffredo Baroncelli kreij...@libero.it
 [mailto:kreij...@libero.it]
 Sent: Monday, July 11, 2011 8:03 PM
 To: Zhong, Xin
 Cc: linux-btrfs@vger.kernel.org
 Subject: R: [PATCH V2] Btrfs-progs: add btrfs subvolume get-default
 subcommand
 
 Messaggio originale
 Da: xin.zh...@intel.com
 Data: 11/07/2011 10.56
 A: linux-btrfs@vger.kernel.org
 Cc: xin.zh...@intel.com
 Ogg: [PATCH V2] Btrfs-progs: add quot;btrfs subvolume get-
 defaultquot;
 subcommand
 
 Add subcommand to get the default subvolume of btrfs filesystem
 
 Reported-by: Yang, Yi yi.y.y...@intel.com
 Signed-off-by: Zhong, Xin xin.zh...@intel.com
 ---
  btrfs-list.c |   57
 +++--
  btrfs.c  |3 +++
  btrfs_cmds.c |   31 ++-
  btrfs_cmds.h |3 ++-
  4 files changed, 90 insertions(+), 4 deletions(-)
 
 please update the man page too.
 
 
 diff --git a/btrfs-list.c b/btrfs-list.c
 index 93766a8..aa6a9b4 100644
 --- a/btrfs-list.c
 +++ b/btrfs-list.c
 @@ -536,7 +536,7 @@ build:
  return full;
 [...]
 +/* search dir item */
 +sk-max_type = BTRFS_DIR_ITEM_KEY;
 +sk-min_type = BTRFS_DIR_ITEM_KEY;
 +
 +sk-max_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
 +sk-min_objectid = BTRFS_ROOT_TREE_DIR_OBJECTID;
 +sk-max_offset = (u64)-1;
 +sk-max_transid = (u64)-1;
 +
 [...]
 +/* go through each item to find dir item named default */
 +for (i = 0; i  sk-nr_items; i++) {
 +sh = (struct btrfs_ioctl_search_header *)(args.buf +
 +  off);
 +off += sizeof(*sh);
 +if (sh-type == BTRFS_DIR_ITEM_KEY) {
 +di = (struct btrfs_dir_item *)(args.buf + off);
 +name_len = le16_to_cpu(di-name_len);
 +name = (char *)di + sizeof(struct
 btrfs_dir_item);
 +if (!strncmp(default, name, name_len)) {
 +subvol_id = btrfs_disk_key_objectid(
 +di-location);
 +break;
 +}
 +}
 +
 +off += sh-len;
 +}
 
 I am not familiar with the default subvolume key, but are you sure
 that the
 key is always in the first set of returned keys ?


It seems there's not too much dir item in the root tree. In fact, I only see it 
used for for default subvolume in the root tree.
So it should be enough. 

 +}
 +
  /* now that we have all the subvol-relative paths filled in,
   * we have to string the subvols together so that we can get
   * a path all the way back to the FS root
 @@ -650,7 +698,12 @@ int list_subvols(int fd)
  while (n) {
  struct root_info *entry;
  entry = rb_entry(n, struct root_info, rb_node);
 -resolve_root(root_lookup, entry);
 +if(!get_default)
 +resolve_root(root_lookup, entry);
 +/* we only want the default subvolume */
 +else if(subvol_id == entry-root_id)
 +resolve_root(root_lookup, entry);
 +
 
 What happens if there no is a default subvolume (for example a very old
 btrfs
 filesystem, and/or after removing the default subvolume) ?
 I suggest to handle this case printing something like No default
 subvolume
 found

If there's no default subvolume, the output is empty. Just the same as when you 
use btrfs subvolume list and there's no subvolume at all.
Thanks for all the review!
 
 BR
 G.Baroncelli
 
  n = rb_prev(n);
  }
 
 diff --git a/btrfs.c b/btrfs.c
 index 46314cf..6b73f88 100644
 --- a/btrfs.c
 +++ b/btrfs.c
 @@ -73,6 +73,9 @@ static struct Command commands[] = {
  Set the subvolume of the filesystem path which will be
 mounted\n
  as default.
  },
 +{ do_get_default_subvol, 1, subvolume get-default, path\n
 +Get the default subvolume of a filesystem.
 +},
  { do_fssync, 1,
filesystem sync, path\n
  Force a sync on the filesystem path.
 diff --git a/btrfs_cmds.c b/btrfs_cmds.c
 index 8031c58..11c56f6 100644
 --- a/btrfs_cmds.c
 +++ b/btrfs_cmds.c
 @@ -301,7 +301,7 @@ int do_subvol_list(int argc, char **argv)
  fprintf(stderr, ERROR: can't access '%s'\n, subvol);
  return 12;
  }
 -ret = list_subvols(fd);
 +ret = list_subvols(fd, 0);
  if (ret)
  return 19;
  return 0;
 @@ -834,6 +834,35 @@ int do_set_default_subvol(int nargs, char **argv)
  return 0;
  }
 
 +int do_get_default_subvol(int nargs, char **argv)
 +{
 +int fd;
 +int ret;
 +char *subvol;
 +
 +subvol = argv[1];
 +
 +ret = test_issubvolume(subvol);
 +if (ret  0) {
 +fprintf(stderr, ERROR: error accessing '%s'\n,