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From: Alex Lyakas <alex@zadarastorage.com>
To: miaox@cn.fujitsu.com
Cc: linux-btrfs@vger.kernel.org
Subject: Re: [PATCH V4 5/7] Btrfs-progs: restructure list_subvolumes
Date: Wed, 10 Oct 2012 21:45:31 +0200	[thread overview]
Message-ID: <CAOcd+r115os7M+MFHoVzMBE4WhyBG+2=EFjwPqNPwPsvVBNOvg@mail.gmail.com> (raw)
In-Reply-To: <5074D9A3.2070405@cn.fujitsu.com>

Hi Miao,
you are absolutely right, it could have happened with the old code as well.

On Wed, Oct 10, 2012 at 4:12 AM, Miao Xie <miaox@cn.fujitsu.com> wrote:
> On Tue, 9 Oct 2012 18:05:51 +0200, Alex Lyakas wrote:
>> Hi Miao,
>> I have some trouble with this code.
>>
>> The problem that I see is after subvolume deletion. What happens is
>> that __list_subvol_search() is called at the point, at which ROOT_ITEM
>> still exists in the root tree, but ROOT_BACKREF does not exist
>> anymore. I think this is because btrfs_ioctl_snap_destroy() calls
>> btrfs_unlink_subvol(), which calls btrfs_del_root_ref(), which deletes
>> ROOT_BACKREF, but ROOT_ITEM still exists until transaction is
>> committed.
>>
>> So what happens is that we end up with struct root_info that has
>> ref_tree==0 (and dir_id==0).
>> So later, when __list_subvol_fill_paths() is called, it fails to
>> perform BTRFS_IOC_INO_LOOKUP because of ref_tree==0. As a result,
>> subvol_uuid_search_init fails and everything stops.
>>
>> Previously, before your change, root_info was not added until we see
>> ROOT_BACKREF in the tree.
>
> The old code still has the similar problem if we delete the subvolume completely
> between __list_subvol_search() and __list_subvol_fill_paths().
>
>> How do you think this should be fixed?
>
> Yes, I think it should be fixed. We can filter the deleted subvolume.

Something like this?

diff --git a/btrfs-list.c b/btrfs-list.c
index e5f0f96..5fd262c 100644
--- a/btrfs-list.c
+++ b/btrfs-list.c
@@ -1004,6 +1004,23 @@ out:
        return 0;
 }

+static void __drop_deleting_roots(struct root_lookup *root_lookup)
+{
+       struct rb_node *n;
+
+again:
+       n = rb_first(&root_lookup->root);
+       while (n) {
+               struct root_info *entry = rb_entry(n, struct
root_info, rb_node);
+               if (!entry->ref_tree) {
+                       rb_erase(n, &root_lookup->root);
+                       free(entry);
+                       goto again;
+               }
+               n = rb_next(n);
+       }
+}
+
 static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
 {
        int ret;
@@ -1123,6 +1140,8 @@ static int __list_subvol_search(int fd, struct
root_lookup *root_lookup)
                        break;
        }

+       __drop_deleting_roots(root_lookup);
+
        return 0;
 }








>
>>
>> Also, is there a way to issue a subvolume deletion and make sure that
>> it was deleted? I see that btrfs_ioctl_snap_destroy() calls
>
> no ROOT_BACKREF already tells us that the subvolume has been deleted, I think.
>
>> end_transaction() but not commit_transaction(). Moreover, there is no
>> way for the caller to know the transid, otherwise we could issue
>> BTRFS_IOC_WAIT_SYNC.
>
> we can get the transid by btrfs_ioctl_start_sync()
>
> Thanks
> Miao
>
>>
>> Thanks,
>> Alex.
>>
>>
>>
>> On Tue, Sep 18, 2012 at 1:06 PM, Miao Xie <miaox@cn.fujitsu.com> wrote:
>>> The current code of list_subvols() has very bad scalability, if we want to
>>> add new filter conditions or new sort methods, we have to modify lots of code.
>>>
>>> Beside that, the most code of list_snapshots() is similar to list_subvols(),
>>>
>>> So I restructure list_subvols(), and split the subvolume filter function,
>>> the subvolume sort function and the output function from list_subvols().
>>> In order to implement it, we defined some importtant structures:
>>> struct btrfs_list_filter {
>>>         btrfs_list_filter_func filter_func;
>>>         void *data;
>>> };
>>>
>>> struct btrfs_list_comparer {
>>>         btrfs_list_comp_func comp_func;
>>>         int is_descending;
>>> };
>>>
>>> struct {
>>>         char    *name;
>>>         char    *column_name;
>>>         int     need_print;
>>> } btrfs_list_columns[];
>>>
>>> If we want to add a new filter condition, we can choose a suitable filter
>>> function, or implement a new filter function[1], and add it into a set of
>>> the filters, and then pass the filter set into list_subvols(). We also can
>>> mix several filters (just add those filters into the set, and pass the set
>>> into list_subvols()) if the users specify two or more filter conditions.
>>>
>>> The subvolume sort function is similar to the subvolume filter function. The
>>> differentiation is the order of comparers in the array which is passed into
>>> list_subvols() show us the priority of the sort methods.
>>>
>>> The output function is different with the above two functions, we define a
>>> array to manage all the columns that can be outputed, and use a member variant
>>> (->need_print) to control the output of the relative column. Some columns are
>>> outputed by default. But we can change it according to the requirement of the
>>> users.
>>>
>>> After appling this patch, we needn't implement a independent list_snapshots()
>>> function, just pass a filter function which is used to identify the snapshot
>>> into list_subvols().
>>>
>>> [1]: If we implement new filter functions or compare functions, we must add
>>> them into the array all_filter_funcs or the array all_comp_funcs, and modify
>>> the relative enum variants(btrfs_list_filter_enum, btrfs_list_comp_enum).
>>>
>>> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
>>> ---
>>> Changelog v3 -> v4:
>>> - add the filter set and comparer set which are used to manage the filters and
>>>   comparers. And the memory space of these two set are allocated dynamically,
>>>   in this way, the users can specify lots of filters and comparers, not be limited
>>>   by the size of the array.
>>>
>>> Changelog v1 -> v3:
>>> - new patch.
>>> ---
>>>  btrfs-list.c     | 1004 ++++++++++++++++++++++++++++++++----------------------
>>>  btrfs-list.h     |   73 ++++-
>>>  cmds-inspect.c   |    2 +-
>>>  cmds-subvolume.c |   59 +++-
>>>  send-utils.c     |    3 +-
>>>  5 files changed, 712 insertions(+), 429 deletions(-)
>>>
>>> diff --git a/btrfs-list.c b/btrfs-list.c
>>> index ed28021..bace903 100644
>>> --- a/btrfs-list.c
>>> +++ b/btrfs-list.c
>>> @@ -37,6 +37,9 @@
>>>  #include <uuid/uuid.h>
>>>  #include "btrfs-list.h"
>>>
>>> +#define BTRFS_LIST_NFILTERS_INCREASE   (2 * BTRFS_LIST_FILTER_MAX)
>>> +#define BTRFS_LIST_NCOMPS_INCREASE     (2 * BTRFS_LIST_COMP_MAX)
>>> +
>>>  /* we store all the roots we find in an rbtree so that we can
>>>   * search for them later.
>>>   */
>>> @@ -49,19 +52,28 @@ struct root_lookup {
>>>   */
>>>  struct root_info {
>>>         struct rb_node rb_node;
>>> +       struct rb_node sort_node;
>>>
>>>         /* this root's id */
>>>         u64 root_id;
>>>
>>> +       /* equal the offset of the root's key */
>>> +       u64 root_offset;
>>> +
>>>         /* the id of the root that references this one */
>>>         u64 ref_tree;
>>>
>>>         /* the dir id we're in from ref_tree */
>>>         u64 dir_id;
>>>
>>> +       u64 top_id;
>>> +
>>>         /* generation when the root is created or last updated */
>>>         u64 gen;
>>>
>>> +       /* creation generation of this root in sec*/
>>> +       u64 ogen;
>>> +
>>>         /* creation time of this root in sec*/
>>>         time_t otime;
>>>
>>> @@ -73,35 +85,254 @@ struct root_info {
>>>         char *path;
>>>
>>>         /* the name of this root in the directory it lives in */
>>> -       char name[];
>>> +       char *name;
>>> +
>>> +       char *full_path;
>>>  };
>>>
>>> +struct {
>>> +       char    *name;
>>> +       char    *column_name;
>>> +       int     need_print;
>>> +} btrfs_list_columns[] = {
>>> +       {
>>> +               .name           = "ID",
>>> +               .column_name    = "ID",
>>> +               .need_print     = 1,
>>> +       },
>>> +       {
>>> +               .name           = "gen",
>>> +               .column_name    = "Gen",
>>> +               .need_print     = 1,
>>> +       },
>>> +       {
>>> +               .name           = "cgen",
>>> +               .column_name    = "CGen",
>>> +               .need_print     = 0,
>>> +       },
>>> +       {
>>> +               .name           = "parent",
>>> +               .column_name    = "Parent",
>>> +               .need_print     = 0,
>>> +       },
>>> +       {
>>> +               .name           = "top level",
>>> +               .column_name    = "Top Level",
>>> +               .need_print     = 1,
>>> +       },
>>> +       {
>>> +               .name           = "otime",
>>> +               .column_name    = "OTime",
>>> +               .need_print     = 0,
>>> +       },
>>> +       {
>>> +               .name           = "uuid",
>>> +               .column_name    = "UUID",
>>> +               .need_print     = 0,
>>> +       },
>>> +       {
>>> +               .name           = "path",
>>> +               .column_name    = "Path",
>>> +               .need_print     = 1,
>>> +       },
>>> +       {
>>> +               .name           = NULL,
>>> +               .column_name    = NULL,
>>> +               .need_print     = 0,
>>> +       },
>>> +};
>>> +
>>> +static btrfs_list_filter_func all_filter_funcs[];
>>> +static btrfs_list_comp_func all_comp_funcs[];
>>> +
>>> +void btrfs_list_setup_print_column(enum btrfs_list_column_enum column)
>>> +{
>>> +       int i;
>>> +
>>> +       BUG_ON(column < 0 || column > BTRFS_LIST_ALL);
>>> +
>>> +       if (column < BTRFS_LIST_ALL) {
>>> +               btrfs_list_columns[column].need_print = 1;
>>> +               return;
>>> +       }
>>> +
>>> +       for (i = 0; i < BTRFS_LIST_ALL; i++)
>>> +               btrfs_list_columns[i].need_print = 1;
>>> +}
>>> +
>>>  static void root_lookup_init(struct root_lookup *tree)
>>>  {
>>>         tree->root.rb_node = NULL;
>>>  }
>>>
>>> -static int comp_entry(struct root_info *entry, u64 root_id, u64 ref_tree)
>>> +static int comp_entry_with_rootid(struct root_info *entry1,
>>> +                                 struct root_info *entry2,
>>> +                                 int is_descending)
>>>  {
>>> -       if (entry->root_id > root_id)
>>> -               return 1;
>>> -       if (entry->root_id < root_id)
>>> -               return -1;
>>> -       if (entry->ref_tree > ref_tree)
>>> -               return 1;
>>> -       if (entry->ref_tree < ref_tree)
>>> -               return -1;
>>> +       int ret;
>>> +
>>> +       if (entry1->root_id > entry2->root_id)
>>> +               ret = 1;
>>> +       else if (entry1->root_id < entry2->root_id)
>>> +               ret = -1;
>>> +       else
>>> +               ret = 0;
>>> +
>>> +       return is_descending ? -ret : ret;
>>> +}
>>> +
>>> +static int comp_entry_with_gen(struct root_info *entry1,
>>> +                              struct root_info *entry2,
>>> +                              int is_descending)
>>> +{
>>> +       int ret;
>>> +
>>> +       if (entry1->gen > entry2->gen)
>>> +               ret = 1;
>>> +       else if (entry1->gen < entry2->gen)
>>> +               ret = -1;
>>> +       else
>>> +               ret = 0;
>>> +
>>> +       return is_descending ? -ret : ret;
>>> +}
>>> +
>>> +static int comp_entry_with_ogen(struct root_info *entry1,
>>> +                               struct root_info *entry2,
>>> +                               int is_descending)
>>> +{
>>> +       int ret;
>>> +
>>> +       if (entry1->ogen > entry2->ogen)
>>> +               ret = 1;
>>> +       else if (entry1->ogen < entry2->ogen)
>>> +               ret = -1;
>>> +       else
>>> +               ret = 0;
>>> +
>>> +       return is_descending ? -ret : ret;
>>> +}
>>> +
>>> +static btrfs_list_comp_func all_comp_funcs[] = {
>>> +       [BTRFS_LIST_COMP_ROOTID]        = comp_entry_with_rootid,
>>> +       [BTRFS_LIST_COMP_OGEN]          = comp_entry_with_ogen,
>>> +       [BTRFS_LIST_COMP_GEN]           = comp_entry_with_gen,
>>> +};
>>> +
>>> +struct btrfs_list_comparer_set *btrfs_list_alloc_comparer_set(void)
>>> +{
>>> +       struct btrfs_list_comparer_set *set;
>>> +       int size;
>>> +
>>> +       size = sizeof(struct btrfs_list_comparer_set) +
>>> +              BTRFS_LIST_NCOMPS_INCREASE * sizeof(struct btrfs_list_comparer);
>>> +       set = malloc(size);
>>> +       if (!set) {
>>> +               fprintf(stderr, "memory allocation failed\n");
>>> +               exit(1);
>>> +       }
>>> +
>>> +       memset(set, 0, size);
>>> +       set->total = BTRFS_LIST_NCOMPS_INCREASE;
>>> +
>>> +       return set;
>>> +}
>>> +
>>> +void btrfs_list_free_comparer_set(struct btrfs_list_comparer_set *comp_set)
>>> +{
>>> +       free(comp_set);
>>> +}
>>> +
>>> +int btrfs_list_setup_comparer(struct btrfs_list_comparer_set  **comp_set,
>>> +                             enum btrfs_list_comp_enum comparer,
>>> +                             int is_descending)
>>> +{
>>> +       struct btrfs_list_comparer_set *set = *comp_set;
>>> +       int size;
>>> +
>>> +       BUG_ON(!set);
>>> +       BUG_ON(comparer >= BTRFS_LIST_COMP_MAX);
>>> +       BUG_ON(set->ncomps > set->total);
>>> +
>>> +       if (set->ncomps == set->total) {
>>> +               size = set->total + BTRFS_LIST_NCOMPS_INCREASE;
>>> +               size = sizeof(*set) + size * sizeof(struct btrfs_list_comparer);
>>> +               set = realloc(set, size);
>>> +               if (!set) {
>>> +                       fprintf(stderr, "memory allocation failed\n");
>>> +                       exit(1);
>>> +               }
>>> +
>>> +               memset(&set->comps[set->total], 0,
>>> +                      BTRFS_LIST_NCOMPS_INCREASE *
>>> +                      sizeof(struct btrfs_list_comparer));
>>> +               set->total += BTRFS_LIST_NCOMPS_INCREASE;
>>> +               *comp_set = set;
>>> +       }
>>> +
>>> +       BUG_ON(set->comps[set->ncomps].comp_func);
>>> +
>>> +       set->comps[set->ncomps].comp_func = all_comp_funcs[comparer];
>>> +       set->comps[set->ncomps].is_descending = is_descending;
>>> +       set->ncomps++;
>>>         return 0;
>>>  }
>>>
>>> -static int comp_entry_with_gen(struct root_info *entry, u64 root_id,
>>> -                              u64 ref_tree, u64 gen)
>>> +static int sort_comp(struct root_info *entry1, struct root_info *entry2,
>>> +                    struct btrfs_list_comparer_set *set)
>>>  {
>>> -       if (entry->gen < gen)
>>> -               return 1;
>>> -       if (entry->gen > gen)
>>> -               return -1;
>>> -       return comp_entry(entry, root_id, ref_tree);
>>> +       int rootid_compared = 0;
>>> +       int i, ret = 0;
>>> +
>>> +       if (!set || !set->ncomps)
>>> +               goto comp_rootid;
>>> +
>>> +       for (i = 0; i < set->ncomps; i++) {
>>> +               if (!set->comps[i].comp_func)
>>> +                       break;
>>> +
>>> +               ret = set->comps[i].comp_func(entry1, entry2,
>>> +                                             set->comps[i].is_descending);
>>> +               if (ret)
>>> +                       return ret;
>>> +
>>> +               if (set->comps[i].comp_func == comp_entry_with_rootid)
>>> +                       rootid_compared = 1;
>>> +       }
>>> +
>>> +       if (!rootid_compared) {
>>> +comp_rootid:
>>> +               ret = comp_entry_with_rootid(entry1, entry2, 0);
>>> +       }
>>> +
>>> +       return ret;
>>> +}
>>> +
>>> +static int sort_tree_insert(struct root_lookup *sort_tree,
>>> +                           struct root_info *ins,
>>> +                           struct btrfs_list_comparer_set *comp_set)
>>> +{
>>> +       struct rb_node **p = &sort_tree->root.rb_node;
>>> +       struct rb_node *parent = NULL;
>>> +       struct root_info *curr;
>>> +       int ret;
>>> +
>>> +       while (*p) {
>>> +               parent = *p;
>>> +               curr = rb_entry(parent, struct root_info, sort_node);
>>> +
>>> +               ret = sort_comp(ins, curr, comp_set);
>>> +               if (ret < 0)
>>> +                       p = &(*p)->rb_left;
>>> +               else if (ret > 0)
>>> +                       p = &(*p)->rb_right;
>>> +               else
>>> +                       return -EEXIST;
>>> +       }
>>> +
>>> +       rb_link_node(&ins->sort_node, parent, p);
>>> +       rb_insert_color(&ins->sort_node, &sort_tree->root);
>>> +       return 0;
>>>  }
>>>
>>>  /*
>>> @@ -109,118 +340,165 @@ static int comp_entry_with_gen(struct root_info *entry, u64 root_id,
>>>   * if one is already there.  Both root_id and ref_tree are used
>>>   * as the key
>>>   */
>>> -static struct rb_node *tree_insert(struct rb_root *root, u64 root_id,
>>> -                                  u64 ref_tree, u64 *gen, struct rb_node *node)
>>> +static int root_tree_insert(struct root_lookup *root_tree,
>>> +                           struct root_info *ins)
>>>  {
>>> -       struct rb_node ** p = &root->rb_node;
>>> +       struct rb_node **p = &root_tree->root.rb_node;
>>>         struct rb_node * parent = NULL;
>>> -       struct root_info *entry;
>>> -       int comp;
>>> +       struct root_info *curr;
>>> +       int ret;
>>>
>>>         while(*p) {
>>>                 parent = *p;
>>> -               entry = rb_entry(parent, struct root_info, rb_node);
>>> +               curr = rb_entry(parent, struct root_info, rb_node);
>>>
>>> -               if (!gen)
>>> -                       comp = comp_entry(entry, root_id, ref_tree);
>>> -               else
>>> -                       comp = comp_entry_with_gen(entry, root_id, ref_tree,
>>> -                                                  *gen);
>>> -
>>> -               if (comp < 0)
>>> +               ret = comp_entry_with_rootid(ins, curr, 0);
>>> +               if (ret < 0)
>>>                         p = &(*p)->rb_left;
>>> -               else if (comp > 0)
>>> +               else if (ret > 0)
>>>                         p = &(*p)->rb_right;
>>>                 else
>>> -                       return parent;
>>> +                       return -EEXIST;
>>>         }
>>>
>>> -       entry = rb_entry(parent, struct root_info, rb_node);
>>> -       rb_link_node(node, parent, p);
>>> -       rb_insert_color(node, root);
>>> -       return NULL;
>>> +       rb_link_node(&ins->rb_node, parent, p);
>>> +       rb_insert_color(&ins->rb_node, &root_tree->root);
>>> +       return 0;
>>>  }
>>>
>>>  /*
>>>   * find a given root id in the tree.  We return the smallest one,
>>>   * rb_next can be used to move forward looking for more if required
>>>   */
>>> -static struct root_info *tree_search(struct rb_root *root, u64 root_id)
>>> +static struct root_info *root_tree_search(struct root_lookup *root_tree,
>>> +                                         u64 root_id)
>>>  {
>>> -       struct rb_node * n = root->rb_node;
>>> +       struct rb_node *n = root_tree->root.rb_node;
>>>         struct root_info *entry;
>>> +       struct root_info tmp;
>>> +       int ret;
>>> +
>>> +       tmp.root_id = root_id;
>>>
>>>         while(n) {
>>>                 entry = rb_entry(n, struct root_info, rb_node);
>>>
>>> -               if (entry->root_id < root_id)
>>> +               ret = comp_entry_with_rootid(&tmp, entry, 0);
>>> +               if (ret < 0)
>>>                         n = n->rb_left;
>>> -               else if (entry->root_id > root_id)
>>> +               else if (ret > 0)
>>>                         n = n->rb_right;
>>> -               else {
>>> -                       struct root_info *prev;
>>> -                       struct rb_node *prev_n;
>>> -                       while (1) {
>>> -                               prev_n = rb_prev(n);
>>> -                               if (!prev_n)
>>> -                                       break;
>>> -                               prev = rb_entry(prev_n, struct root_info,
>>> -                                                     rb_node);
>>> -                               if (prev->root_id != root_id)
>>> -                                       break;
>>> -                               entry = prev;
>>> -                               n = prev_n;
>>> -                       }
>>> +               else
>>>                         return entry;
>>> -               }
>>>         }
>>>         return NULL;
>>>  }
>>>
>>> +static int update_root(struct root_lookup *root_lookup,
>>> +                      u64 root_id, u64 ref_tree, u64 root_offset, u64 dir_id,
>>> +                      char *name, int name_len, u64 ogen, u64 gen, time_t ot,
>>> +                      void *uuid)
>>> +{
>>> +       struct root_info *ri;
>>> +
>>> +       ri = root_tree_search(root_lookup, root_id);
>>> +       if (!ri || ri->root_id != root_id)
>>> +               return -ENOENT;
>>> +       if (name && name_len > 0) {
>>> +               if (ri->name)
>>> +                       free(ri->name);
>>> +
>>> +               ri->name = malloc(name_len + 1);
>>> +               if (!ri->name) {
>>> +                       fprintf(stderr, "memory allocation failed\n");
>>> +                       exit(1);
>>> +               }
>>> +               strncpy(ri->name, name, name_len);
>>> +               ri->name[name_len] = 0;
>>> +       }
>>> +       if (ref_tree)
>>> +               ri->ref_tree = ref_tree;
>>> +       if (root_offset)
>>> +               ri->root_offset = root_offset;
>>> +       if (dir_id)
>>> +               ri->dir_id = dir_id;
>>> +       if (gen)
>>> +               ri->gen = gen;
>>> +       if (ogen)
>>> +               ri->ogen = ogen;
>>> +       if (!ri->ogen && root_offset)
>>> +               ri->ogen = root_offset;
>>> +       if (ot)
>>> +               ri->otime = ot;
>>> +       if (uuid)
>>> +               memcpy(&ri->uuid, uuid, BTRFS_UUID_SIZE);
>>> +
>>> +       return 0;
>>> +}
>>> +
>>>  /*
>>> - * this allocates a new root in the lookup tree.
>>> - *
>>> - * root_id should be the object id of the root
>>> - *
>>> - * ref_tree is the objectid of the referring root.
>>> - *
>>> - * dir_id is the directory in ref_tree where this root_id can be found.
>>> - *
>>> - * name is the name of root_id in that directory
>>> - *
>>> - * name_len is the length of name
>>> + * add_root - update the existed root, or allocate a new root and insert it
>>> + *           into the lookup tree.
>>> + * root_id: object id of the root
>>> + * ref_tree: object id of the referring root.
>>> + * root_offset: offset value of the root'key
>>> + * dir_id: inode id of the directory in ref_tree where this root can be found.
>>> + * name: the name of root_id in that directory
>>> + * name_len: the length of name
>>> + * ogen: the original generation of the root
>>> + * gen: the current generation of the root
>>> + * ot: the original time(create time) of the root
>>> + * uuid: uuid of the root
>>>   */
>>>  static int add_root(struct root_lookup *root_lookup,
>>> -                   u64 root_id, u64 ref_tree, u64 dir_id, char *name,
>>> -                   int name_len, u64 *gen, time_t ot, void *uuid)
>>> +                   u64 root_id, u64 ref_tree, u64 root_offset, u64 dir_id,
>>> +                   char *name, int name_len, u64 ogen, u64 gen, time_t ot,
>>> +                   void *uuid)
>>>  {
>>>         struct root_info *ri;
>>> -       struct rb_node *ret;
>>> -       ri = malloc(sizeof(*ri) + name_len + 1);
>>> +       int ret;
>>> +
>>> +       ret = update_root(root_lookup, root_id, ref_tree, root_offset, dir_id,
>>> +                         name, name_len, ogen, gen, ot, uuid);
>>> +       if (!ret)
>>> +               return 0;
>>> +
>>> +       ri = malloc(sizeof(*ri));
>>>         if (!ri) {
>>>                 printf("memory allocation failed\n");
>>>                 exit(1);
>>>         }
>>> -       memset(ri, 0, sizeof(*ri) + name_len + 1);
>>> -       ri->path = NULL;
>>> -       ri->dir_id = dir_id;
>>> +       memset(ri, 0, sizeof(*ri));
>>>         ri->root_id = root_id;
>>> -       ri->ref_tree = ref_tree;
>>> -       if (name)
>>> +
>>> +       if (name && name_len > 0) {
>>> +               ri->name = malloc(name_len + 1);
>>> +               if (!ri->name) {
>>> +                       fprintf(stderr, "memory allocation failed\n");
>>> +                       exit(1);
>>> +               }
>>>                 strncpy(ri->name, name, name_len);
>>> -       if (name_len > 0)
>>>                 ri->name[name_len] = 0;
>>> +       }
>>> +       if (ref_tree)
>>> +               ri->ref_tree = ref_tree;
>>> +       if (dir_id)
>>> +               ri->dir_id = dir_id;
>>> +       if (root_offset)
>>> +               ri->root_offset = root_offset;
>>>         if (gen)
>>> -               ri->gen = *gen;
>>> -       ri->otime = ot;
>>> +               ri->gen = gen;
>>> +       if (ogen)
>>> +               ri->ogen = ogen;
>>> +       if (!ri->ogen && root_offset)
>>> +               ri->ogen = root_offset;
>>> +       if (ot)
>>> +               ri->otime = ot;
>>>
>>>         if (uuid)
>>>                 memcpy(&ri->uuid, uuid, BTRFS_UUID_SIZE);
>>> -       else
>>> -               memset(&ri->uuid, 0, BTRFS_UUID_SIZE);
>>>
>>> -       ret = tree_insert(&root_lookup->root, root_id, ref_tree, gen,
>>> -                         &ri->rb_node);
>>> +       ret = root_tree_insert(root_lookup, ri);
>>>         if (ret) {
>>>                 printf("failed to insert tree %llu\n", (unsigned long long)root_id);
>>>                 exit(1);
>>> @@ -228,24 +506,33 @@ static int add_root(struct root_lookup *root_lookup,
>>>         return 0;
>>>  }
>>>
>>> -static int update_root(struct root_lookup *root_lookup, u64 root_id, u64 gen,
>>> -                       time_t ot, void *uuid)
>>> +void __free_root_info(struct root_info *ri)
>>>  {
>>> -       struct root_info *ri;
>>> +       if (ri->name)
>>> +               free(ri->name);
>>>
>>> -       ri = tree_search(&root_lookup->root, root_id);
>>> -       if (!ri || ri->root_id != root_id) {
>>> -               fprintf(stderr, "could not find subvol %llu\n", root_id);
>>> -               return -ENOENT;
>>> -       }
>>> -       ri->gen = gen;
>>> -       ri->otime = ot;
>>> -       if (uuid)
>>> -               memcpy(&ri->uuid, uuid, BTRFS_UUID_SIZE);
>>> -       else
>>> -               memset(&ri->uuid, 0, BTRFS_UUID_SIZE);
>>> +       if (ri->path)
>>> +               free(ri->path);
>>>
>>> -       return 0;
>>> +       if (ri->full_path)
>>> +               free(ri->full_path);
>>> +
>>> +       free(ri);
>>> +}
>>> +
>>> +void __free_all_subvolumn(struct root_lookup *root_tree)
>>> +{
>>> +       struct root_info *entry;
>>> +       struct rb_node *n;
>>> +
>>> +       n = rb_first(&root_tree->root);
>>> +       while (n) {
>>> +               entry = rb_entry(n, struct root_info, rb_node);
>>> +               rb_erase(n, &root_tree->root);
>>> +               __free_root_info(entry);
>>> +
>>> +               n = rb_first(&root_tree->root);
>>> +       }
>>>  }
>>>
>>>  /*
>>> @@ -255,8 +542,7 @@ static int update_root(struct root_lookup *root_lookup, u64 root_id, u64 gen,
>>>   * This can't be called until all the root_info->path fields are filled
>>>   * in by lookup_ino_path
>>>   */
>>> -static int resolve_root(struct root_lookup *rl, struct root_info *ri,
>>> -                       u64 *parent_id, u64 *top_id, char **path)
>>> +static int resolve_root(struct root_lookup *rl, struct root_info *ri)
>>>  {
>>>         char *full_path = NULL;
>>>         int len = 0;
>>> @@ -266,7 +552,6 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri,
>>>          * we go backwards from the root_info object and add pathnames
>>>          * from parent directories as we go.
>>>          */
>>> -       *parent_id = 0;
>>>         found = ri;
>>>         while (1) {
>>>                 char *tmp;
>>> @@ -275,6 +560,10 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri,
>>>
>>>                 /* room for / and for null */
>>>                 tmp = malloc(add_len + 2 + len);
>>> +               if (!tmp) {
>>> +                       perror("malloc failed");
>>> +                       exit(1);
>>> +               }
>>>                 if (full_path) {
>>>                         memcpy(tmp + add_len + 1, full_path, len);
>>>                         tmp[add_len] = '/';
>>> @@ -289,13 +578,10 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri,
>>>                 }
>>>
>>>                 next = found->ref_tree;
>>> -               /* record the first parent */
>>> -               if (*parent_id == 0)
>>> -                       *parent_id = next;
>>>
>>>                 /* if the ref_tree refers to ourselves, we're at the top */
>>>                 if (next == found->root_id) {
>>> -                       *top_id = next;
>>> +                       ri->top_id = next;
>>>                         break;
>>>                 }
>>>
>>> @@ -303,14 +589,14 @@ static int resolve_root(struct root_lookup *rl, struct root_info *ri,
>>>                  * if the ref_tree wasn't in our tree of roots, we're
>>>                  * at the top
>>>                  */
>>> -               found = tree_search(&rl->root, next);
>>> +               found = root_tree_search(rl, next);
>>>                 if (!found) {
>>> -                       *top_id = next;
>>> +                       ri->top_id = next;
>>>                         break;
>>>                 }
>>>         }
>>>
>>> -       *path = full_path;
>>> +       ri->full_path = full_path;
>>>
>>>         return 0;
>>>  }
>>> @@ -608,7 +894,7 @@ build:
>>>         return full;
>>>  }
>>>
>>> -static int get_default_subvolid(int fd, u64 *default_id)
>>> +int btrfs_list_get_default_subvolume(int fd, u64 *default_id)
>>>  {
>>>         struct btrfs_ioctl_search_args args;
>>>         struct btrfs_ioctl_search_key *sk = &args.key;
>>> @@ -674,10 +960,9 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
>>>         int name_len;
>>>         char *name;
>>>         u64 dir_id;
>>> -       u8 type;
>>>         u64 gen = 0;
>>> +       u64 ogen;
>>>         int i;
>>> -       int get_gen = 0;
>>>         time_t t;
>>>         u8 uuid[BTRFS_UUID_SIZE];
>>>
>>> @@ -692,7 +977,7 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
>>>          * only send back this type of key now.
>>>          */
>>>         sk->max_type = BTRFS_ROOT_BACKREF_KEY;
>>> -       sk->min_type = BTRFS_ROOT_BACKREF_KEY;
>>> +       sk->min_type = BTRFS_ROOT_ITEM_KEY;
>>>
>>>         sk->min_objectid = BTRFS_FIRST_FREE_OBJECTID;
>>>
>>> @@ -704,7 +989,6 @@ static int __list_subvol_search(int fd, struct root_lookup *root_lookup)
>>>         sk->max_offset = (u64)-1;
>>>         sk->max_transid = (u64)-1;
>>>
>>> -again:
>>>         /* just a big number, doesn't matter much */
>>>         sk->nr_items = 4096;
>>>
>>> @@ -726,28 +1010,32 @@ again:
>>>                         sh = (struct btrfs_ioctl_search_header *)(args.buf +
>>>                                                                   off);
>>>                         off += sizeof(*sh);
>>> -                       if (!get_gen && sh->type == BTRFS_ROOT_BACKREF_KEY) {
>>> +                       if (sh->type == BTRFS_ROOT_BACKREF_KEY) {
>>>                                 ref = (struct btrfs_root_ref *)(args.buf + off);
>>>                                 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, NULL, 0, NULL);
>>> -                       } else if (get_gen && sh->type == BTRFS_ROOT_ITEM_KEY) {
>>> +                                        0, dir_id, name, name_len, 0, 0, 0,
>>> +                                        NULL);
>>> +                       } else if (sh->type == BTRFS_ROOT_ITEM_KEY) {
>>>                                 ri = (struct btrfs_root_item *)(args.buf + off);
>>>                                 gen = btrfs_root_generation(ri);
>>>                                 if(sh->len >
>>>                                    sizeof(struct btrfs_root_item_v0)) {
>>>                                         t = ri->otime.sec;
>>> +                                       ogen = btrfs_root_otransid(ri);
>>>                                         memcpy(uuid, ri->uuid, BTRFS_UUID_SIZE);
>>>                                 } else {
>>>                                         t = 0;
>>> +                                       ogen = 0;
>>>                                         memset(uuid, 0, BTRFS_UUID_SIZE);
>>>                                 }
>>>
>>> -                               update_root(root_lookup, sh->objectid, gen, t,
>>> -                                       uuid);
>>> +                               add_root(root_lookup, sh->objectid, 0,
>>> +                                        sh->offset, 0, NULL, 0, ogen, gen, t,
>>> +                                        uuid);
>>>                         }
>>>
>>>                         off += sh->len;
>>> @@ -761,129 +1049,139 @@ again:
>>>                         sk->min_offset = sh->offset;
>>>                 }
>>>                 sk->nr_items = 4096;
>>> -               /* this iteration is done, step forward one root for the next
>>> -                * ioctl
>>> -                */
>>> -               if (get_gen)
>>> -                       type = BTRFS_ROOT_ITEM_KEY;
>>> +               sk->min_offset++;
>>> +               if (!sk->min_offset)    /* overflow */
>>> +                       sk->min_type++;
>>>                 else
>>> -                       type = BTRFS_ROOT_BACKREF_KEY;
>>> +                       continue;
>>>
>>> -               if (sk->min_type < type) {
>>> -                       sk->min_type = type;
>>> -                       sk->min_offset = 0;
>>> -               } else  if (sk->min_objectid < BTRFS_LAST_FREE_OBJECTID) {
>>> +               if (sk->min_type > BTRFS_ROOT_BACKREF_KEY) {
>>> +                       sk->min_type = BTRFS_ROOT_ITEM_KEY;
>>>                         sk->min_objectid++;
>>> -                       sk->min_type = type;
>>> -                       sk->min_offset = 0;
>>>                 } else
>>> +                       continue;
>>> +
>>> +               if (sk->min_objectid > sk->max_objectid)
>>>                         break;
>>>         }
>>>
>>> -       if (!get_gen) {
>>> -               memset(&args, 0, sizeof(args));
>>> +       return 0;
>>> +}
>>>
>>> -               sk->tree_id = 1;
>>> -               sk->max_type = BTRFS_ROOT_ITEM_KEY;
>>> -               sk->min_type = BTRFS_ROOT_ITEM_KEY;
>>> +static int filter_by_rootid(struct root_info *ri, void *arg)
>>> +{
>>> +       u64 default_root_id = *((u64 *)arg);
>>>
>>> -               sk->min_objectid = BTRFS_FIRST_FREE_OBJECTID;
>>> +       return ri->root_id == default_root_id;
>>> +}
>>>
>>> -               sk->max_objectid = BTRFS_LAST_FREE_OBJECTID;
>>> -               sk->max_offset = (u64)-1;
>>> -               sk->max_transid = (u64)-1;
>>> +static int filter_snapshot(struct root_info *ri, void *arg)
>>> +{
>>> +       return !!ri->root_offset;
>>> +}
>>> +
>>> +static btrfs_list_filter_func all_filter_funcs[] = {
>>> +       [BTRFS_LIST_FILTER_ROOTID]              = filter_by_rootid,
>>> +       [BTRFS_LIST_FILTER_SNAPSHOT_ONLY]       = filter_snapshot,
>>> +};
>>>
>>> -               get_gen = 1;
>>> -               goto again;
>>> +struct btrfs_list_filter_set *btrfs_list_alloc_filter_set(void)
>>> +{
>>> +       struct btrfs_list_filter_set *set;
>>> +       int size;
>>> +
>>> +       size = sizeof(struct btrfs_list_filter_set) +
>>> +              BTRFS_LIST_NFILTERS_INCREASE * sizeof(struct btrfs_list_filter);
>>> +       set = malloc(size);
>>> +       if (!set) {
>>> +               fprintf(stderr, "memory allocation failed\n");
>>> +               exit(1);
>>>         }
>>> -       return 0;
>>> +
>>> +       memset(set, 0, size);
>>> +       set->total = BTRFS_LIST_NFILTERS_INCREASE;
>>> +
>>> +       return set;
>>>  }
>>>
>>> -static int __list_snapshot_search(int fd, struct root_lookup *root_lookup)
>>> +void btrfs_list_free_filter_set(struct btrfs_list_filter_set *filter_set)
>>>  {
>>> -       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;
>>> -       u64 gen = 0;
>>> -       int i;
>>> -
>>> -       root_lookup_init(root_lookup);
>>> -       memset(&args, 0, sizeof(args));
>>> +       free(filter_set);
>>> +}
>>>
>>> -       sk->tree_id = 1;
>>> -       sk->max_type = BTRFS_ROOT_ITEM_KEY;
>>> -       sk->min_type = BTRFS_ROOT_ITEM_KEY;
>>> -       sk->min_objectid = BTRFS_FIRST_FREE_OBJECTID;
>>> -       sk->max_objectid = BTRFS_LAST_FREE_OBJECTID;
>>> -       sk->max_offset = (u64)-1;
>>> -       sk->max_transid = (u64)-1;
>>> -       sk->nr_items = 4096;
>>> +int btrfs_list_setup_filter(struct btrfs_list_filter_set **filter_set,
>>> +                           enum btrfs_list_filter_enum filter, void *data)
>>> +{
>>> +       struct btrfs_list_filter_set *set = *filter_set;
>>> +       int size;
>>> +
>>> +       BUG_ON(!set);
>>> +       BUG_ON(filter >= BTRFS_LIST_FILTER_MAX);
>>> +       BUG_ON(set->nfilters > set->total);
>>> +
>>> +       if (set->nfilters == set->total) {
>>> +               size = set->total + BTRFS_LIST_NFILTERS_INCREASE;
>>> +               size = sizeof(*set) + size * sizeof(struct btrfs_list_filter);
>>> +               set = realloc(set, size);
>>> +               if (!set) {
>>> +                       fprintf(stderr, "memory allocation failed\n");
>>> +                       exit(1);
>>> +               }
>>>
>>> -       while (1) {
>>> -               ret = ioctl(fd, BTRFS_IOC_TREE_SEARCH, &args);
>>> -               if (ret < 0)
>>> -                       return ret;
>>> -               /* the ioctl returns the number of item it found in nr_items */
>>> -               if (sk->nr_items == 0)
>>> -                       break;
>>> +               memset(&set->filters[set->total], 0,
>>> +                      BTRFS_LIST_NFILTERS_INCREASE *
>>> +                      sizeof(struct btrfs_list_filter));
>>> +               set->total += BTRFS_LIST_NFILTERS_INCREASE;
>>> +               *filter_set = set;
>>> +       }
>>>
>>> -               off = 0;
>>> +       BUG_ON(set->filters[set->nfilters].filter_func);
>>>
>>> -               /*
>>> -                * for each item, pull the key out of the header and then
>>> -                * read the root_ref item it contains
>>> -                */
>>> -               for (i = 0; i < sk->nr_items; i++) {
>>> -                       struct btrfs_root_item *item;
>>> -                       time_t  t;
>>> -                       u8 uuid[BTRFS_UUID_SIZE];
>>> +       set->filters[set->nfilters].filter_func = all_filter_funcs[filter];
>>> +       set->filters[set->nfilters].data = data;
>>> +       set->nfilters++;
>>> +       return 0;
>>> +}
>>>
>>> -                       sh = (struct btrfs_ioctl_search_header *)(args.buf +
>>> -                                                                 off);
>>> -                       off += sizeof(*sh);
>>> -                       if (sh->type == BTRFS_ROOT_ITEM_KEY && sh->offset) {
>>> -                               item = (struct btrfs_root_item *)(args.buf + off);
>>> -                               if(sh->len >
>>> -                                  sizeof(struct btrfs_root_item_v0)) {
>>> -                                       t = item->otime.sec;
>>> -                                       memcpy(uuid, item->uuid,
>>> -                                              BTRFS_UUID_SIZE);
>>> -                               } else {
>>> -                                       t = 0;
>>> -                                       memset(uuid, 0, BTRFS_UUID_SIZE);
>>> -                               }
>>> -                               gen = sh->offset;
>>> +static int filter_root(struct root_info *ri,
>>> +                      struct btrfs_list_filter_set *set)
>>> +{
>>> +       int i, ret;
>>>
>>> -                               add_root(root_lookup, sh->objectid, 0,
>>> -                                        0, NULL, 0, &gen, t, uuid);
>>> -                       }
>>> -                       off += sh->len;
>>> +       if (!set || !set->nfilters)
>>> +               return 1;
>>>
>>> -                       /*
>>> -                        * record the mins in sk so we can make sure the
>>> -                        * next search doesn't repeat this root
>>> -                        */
>>> -                       sk->min_objectid = sh->objectid;
>>> -                       sk->min_type = sh->type;
>>> -                       sk->min_offset = sh->offset;
>>> -               }
>>> -               sk->nr_items = 4096;
>>> -               /* this iteration is done, step forward one root for the next
>>> -                * ioctl
>>> -                */
>>> -               if (sk->min_type < BTRFS_ROOT_ITEM_KEY) {
>>> -                       sk->min_type = BTRFS_ROOT_ITEM_KEY;
>>> -                       sk->min_offset = 0;
>>> -               } else  if (sk->min_objectid < BTRFS_LAST_FREE_OBJECTID) {
>>> -                       sk->min_objectid++;
>>> -                       sk->min_type = BTRFS_ROOT_ITEM_KEY;
>>> -                       sk->min_offset = 0;
>>> -               } else
>>> +       for (i = 0; i < set->nfilters; i++) {
>>> +               if (!set->filters[i].filter_func)
>>>                         break;
>>> +               ret = set->filters[i].filter_func(ri, set->filters[i].data);
>>> +               if (!ret)
>>> +                       return 0;
>>> +       }
>>> +       return 1;
>>> +}
>>> +
>>> +static void __filter_and_sort_subvol(struct root_lookup *all_subvols,
>>> +                                   struct root_lookup *sort_tree,
>>> +                                   struct btrfs_list_filter_set *filter_set,
>>> +                                   struct btrfs_list_comparer_set *comp_set)
>>> +{
>>> +       struct rb_node *n;
>>> +       struct root_info *entry;
>>> +       int ret;
>>> +
>>> +       root_lookup_init(sort_tree);
>>> +
>>> +       n = rb_last(&all_subvols->root);
>>> +       while (n) {
>>> +               entry = rb_entry(n, struct root_info, rb_node);
>>> +
>>> +               resolve_root(all_subvols, entry);
>>> +               ret = filter_root(entry, filter_set);
>>> +               if (ret)
>>> +                       sort_tree_insert(sort_tree, entry, comp_set);
>>> +               n = rb_prev(n);
>>>         }
>>> -       return 0;
>>>  }
>>>
>>>  static int __list_subvol_fill_paths(int fd, struct root_lookup *root_lookup)
>>> @@ -904,128 +1202,91 @@ 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 print_uuid)
>>> +static void print_subvolume_column(struct root_info *subv,
>>> +                                  enum btrfs_list_column_enum column)
>>>  {
>>> -       struct root_lookup root_lookup;
>>> -       struct rb_node *n;
>>> -       u64 default_id;
>>> -       int ret;
>>> +       char tstr[256];
>>>         char uuidparse[37];
>>>
>>> -       if (get_default) {
>>> -               ret = get_default_subvolid(fd, &default_id);
>>> -               if (ret) {
>>> -                       fprintf(stderr, "ERROR: can't perform the search - %s\n",
>>> -                               strerror(errno));
>>> -                       return ret;
>>> -               }
>>> -               if (default_id == 0) {
>>> -                       fprintf(stderr, "ERROR: 'default' dir item not found\n");
>>> -                       return ret;
>>> -               }
>>> -
>>> -               /* no need to resolve roots if FS_TREE is default */
>>> -               if (default_id == BTRFS_FS_TREE_OBJECTID) {
>>> -                       printf("ID 5 (FS_TREE)\n");
>>> -                       return ret;
>>> -               }
>>> -       }
>>> -
>>> -       ret = __list_subvol_search(fd, &root_lookup);
>>> -       if (ret) {
>>> -               fprintf(stderr, "ERROR: can't perform the search - %s\n",
>>> -                               strerror(errno));
>>> -               return ret;
>>> +       BUG_ON(column >= BTRFS_LIST_ALL || column < 0);
>>> +
>>> +       switch (column) {
>>> +       case BTRFS_LIST_OBJECTID:
>>> +               printf("%llu", subv->root_id);
>>> +               break;
>>> +       case BTRFS_LIST_GENERATION:
>>> +               printf("%llu", subv->gen);
>>> +               break;
>>> +       case BTRFS_LIST_OGENERATION:
>>> +               printf("%llu", subv->ogen);
>>> +               break;
>>> +       case BTRFS_LIST_PARENT:
>>> +               printf("%llu", subv->ref_tree);
>>> +               break;
>>> +       case BTRFS_LIST_TOP_LEVEL:
>>> +               printf("%llu", subv->top_id);
>>> +               break;
>>> +       case BTRFS_LIST_OTIME:
>>> +               if (subv->otime)
>>> +                       strftime(tstr, 256, "%Y-%m-%d %X",
>>> +                                localtime(&subv->otime));
>>> +               else
>>> +                       strcpy(tstr, "-");
>>> +               printf("%s", tstr);
>>> +               break;
>>> +       case BTRFS_LIST_UUID:
>>> +               if (uuid_is_null(subv->uuid))
>>> +                       strcpy(uuidparse, "-");
>>> +               else
>>> +                       uuid_unparse(subv->uuid, uuidparse);
>>> +               printf("%s", uuidparse);
>>> +               break;
>>> +       case BTRFS_LIST_PATH:
>>> +               BUG_ON(!subv->full_path);
>>> +               printf("%s", subv->full_path);
>>> +               break;
>>> +       default:
>>> +               break;
>>>         }
>>> +}
>>>
>>> -       /*
>>> -        * now we have an rbtree full of root_info objects, but we need to fill
>>> -        * in their path names within the subvol that is referencing each one.
>>> -        */
>>> -       ret = __list_subvol_fill_paths(fd, &root_lookup);
>>> -       if (ret < 0)
>>> -               return ret;
>>> -
>>> -       /* 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
>>> -        */
>>> -       n = rb_last(&root_lookup.root);
>>> -       while (n) {
>>> -               struct root_info *entry;
>>> -               u64 level;
>>> -               u64 parent_id;
>>> -               char *path;
>>> +static void print_single_volume_info_default(struct root_info *subv)
>>> +{
>>> +       int i;
>>>
>>> -               entry = rb_entry(n, struct root_info, rb_node);
>>> -               if (get_default && entry->root_id != default_id) {
>>> -                       n = rb_prev(n);
>>> +       for (i = 0; i < BTRFS_LIST_ALL; i++) {
>>> +               if (!btrfs_list_columns[i].need_print)
>>>                         continue;
>>> -               }
>>>
>>> -               resolve_root(&root_lookup, entry, &parent_id, &level, &path);
>>> -               if (print_parent) {
>>> -                       if (print_uuid) {
>>> -                               if (uuid_is_null(entry->uuid))
>>> -                                       strcpy(uuidparse, "-");
>>> -                               else
>>> -                                       uuid_unparse(entry->uuid, uuidparse);
>>> -                               printf("ID %llu gen %llu parent %llu top level %llu"
>>> -                                       " uuid %s path %s\n",
>>> -                                       (unsigned long long)entry->root_id,
>>> -                                       (unsigned long long)entry->gen,
>>> -                                       (unsigned long long)parent_id,
>>> -                                       (unsigned long long)level,
>>> -                                       uuidparse, path);
>>> -                       } else {
>>> -                               printf("ID %llu gen %llu parent %llu top level"
>>> -                                       " %llu path %s\n",
>>> -                                       (unsigned long long)entry->root_id,
>>> -                                       (unsigned long long)entry->gen,
>>> -                                       (unsigned long long)parent_id,
>>> -                                       (unsigned long long)level, path);
>>> -                       }
>>> -               } else {
>>> -                       if (print_uuid) {
>>> -                               if (uuid_is_null(entry->uuid))
>>> -                                       strcpy(uuidparse, "-");
>>> -                               else
>>> -                                       uuid_unparse(entry->uuid, uuidparse);
>>> -                               printf("ID %llu gen %llu top level %llu"
>>> -                                       " uuid %s path %s\n",
>>> -                                       (unsigned long long)entry->root_id,
>>> -                                       (unsigned long long)entry->gen,
>>> -                                       (unsigned long long)level,
>>> -                                       uuidparse, path);
>>> -                       } else {
>>> -                               printf("ID %llu gen %llu top level %llu path %s\n",
>>> -                                       (unsigned long long)entry->root_id,
>>> -                                       (unsigned long long)entry->gen,
>>> -                                       (unsigned long long)level, path);
>>> -                       }
>>> -               }
>>> +               printf("%s ", btrfs_list_columns[i].name);
>>> +               print_subvolume_column(subv, i);
>>>
>>> -               free(path);
>>> -               n = rb_prev(n);
>>> +               if (i != BTRFS_LIST_PATH)
>>> +                       printf(" ");
>>>         }
>>> +       printf("\n");
>>> +}
>>>
>>> -       return ret;
>>> +static void print_all_volume_info_default(struct root_lookup *sorted_tree)
>>> +{
>>> +       struct rb_node *n;
>>> +       struct root_info *entry;
>>> +
>>> +       n = rb_first(&sorted_tree->root);
>>> +       while (n) {
>>> +               entry = rb_entry(n, struct root_info, sort_node);
>>> +               print_single_volume_info_default(entry);
>>> +               n = rb_next(n);
>>> +       }
>>>  }
>>>
>>> -int list_snapshots(int fd, int print_parent, int order, int print_uuid)
>>> +int btrfs_list_subvols(int fd, struct btrfs_list_filter_set *filter_set,
>>> +                      struct btrfs_list_comparer_set *comp_set)
>>>  {
>>>         struct root_lookup root_lookup;
>>> -       struct root_lookup root_lookup_snap;
>>> -       struct rb_node *n;
>>> +       struct root_lookup root_sort;
>>>         int ret;
>>>
>>> -       ret = __list_snapshot_search(fd, &root_lookup_snap);
>>> -       if (ret) {
>>> -               fprintf(stderr, "ERROR: can't perform the search - %s\n",
>>> -                               strerror(errno));
>>> -               return ret;
>>> -       }
>>> -
>>>         ret = __list_subvol_search(fd, &root_lookup);
>>>         if (ret) {
>>>                 fprintf(stderr, "ERROR: can't perform the search - %s\n",
>>> @@ -1041,86 +1302,11 @@ int list_snapshots(int fd, int print_parent, int order, int print_uuid)
>>>         if (ret < 0)
>>>                 return ret;
>>>
>>> -       /* 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
>>> -        */
>>> -       if (!order)
>>> -               n = rb_last(&root_lookup_snap.root);
>>> -       else
>>> -               n = rb_first(&root_lookup_snap.root);
>>> -       while (n) {
>>> -               struct root_info *entry_snap;
>>> -               struct root_info *entry;
>>> -               u64 level;
>>> -               u64 parent_id;
>>> -               char *path;
>>> -               time_t t;
>>> -               char tstr[256];
>>> -               char uuidparse[37];
>>> -
>>> -               entry_snap = rb_entry(n, struct root_info, rb_node);
>>> -               entry = tree_search(&root_lookup.root, entry_snap->root_id);
>>> -
>>> -               resolve_root(&root_lookup, entry, &parent_id, &level, &path);
>>> -               t = entry->otime;
>>> -               if(t)
>>> -                       strftime(tstr,256,"%Y-%m-%d %X",localtime(&t));
>>> -               else
>>> -                       strcpy(tstr,"-");
>>> -               if (print_parent) {
>>> -                       if (print_uuid) {
>>> -                               if (uuid_is_null(entry->uuid))
>>> -                                       strcpy(uuidparse, "-");
>>> -                               else
>>> -                                       uuid_unparse(entry->uuid, uuidparse);
>>> -                               printf("ID %llu gen %llu cgen %llu parent %llu"
>>> -                                       " top level %llu otime %s uuid %s path %s\n",
>>> -                                       (unsigned long long)entry->root_id,
>>> -                                       (unsigned long long)entry->gen,
>>> -                                       (unsigned long long)entry_snap->gen,
>>> -                                       (unsigned long long)parent_id,
>>> -                                       (unsigned long long)level,
>>> -                                       tstr, uuidparse, path);
>>> -                       } else {
>>> -                               printf("ID %llu gen %llu cgen %llu parent %llu"
>>> -                                       " top level %llu otime %s path %s\n",
>>> -                                       (unsigned long long)entry->root_id,
>>> -                                       (unsigned long long)entry->gen,
>>> -                                       (unsigned long long)entry_snap->gen,
>>> -                                       (unsigned long long)parent_id,
>>> -                                       (unsigned long long)level, tstr, path);
>>> -                       }
>>> -               } else {
>>> -                       if (print_uuid) {
>>> -                               if (uuid_is_null(entry->uuid))
>>> -                                       strcpy(uuidparse, "-");
>>> -                               else
>>> -                                       uuid_unparse(entry->uuid, uuidparse);
>>> -                               printf("ID %llu gen %llu cgen %llu top level %llu "
>>> -                                       "otime %s uuid %s path %s\n",
>>> -                                       (unsigned long long)entry->root_id,
>>> -                                       (unsigned long long)entry->gen,
>>> -                                       (unsigned long long)entry_snap->gen,
>>> -                                       (unsigned long long)level,
>>> -                                       tstr, uuidparse, path);
>>> -                       } else {
>>> -                               printf("ID %llu gen %llu cgen %llu top level %llu "
>>> -                                       "otime %s path %s\n",
>>> -                                       (unsigned long long)entry->root_id,
>>> -                                       (unsigned long long)entry->gen,
>>> -                                       (unsigned long long)entry_snap->gen,
>>> -                                       (unsigned long long)level, tstr, path);
>>> -                       }
>>> -               }
>>> -
>>> -               free(path);
>>> -               if (!order)
>>> -                       n = rb_prev(n);
>>> -               else
>>> -                       n = rb_next(n);
>>> -       }
>>> +       __filter_and_sort_subvol(&root_lookup, &root_sort, filter_set,
>>> +                                comp_set);
>>>
>>> +       print_all_volume_info_default(&root_sort);
>>> +       __free_all_subvolumn(&root_lookup);
>>>         return ret;
>>>  }
>>>
>>> @@ -1203,7 +1389,7 @@ static int print_one_extent(int fd, struct btrfs_ioctl_search_header *sh,
>>>         return 0;
>>>  }
>>>
>>> -int find_updated_files(int fd, u64 root_id, u64 oldest_gen)
>>> +int btrfs_list_find_updated_files(int fd, u64 root_id, u64 oldest_gen)
>>>  {
>>>         int ret;
>>>         struct btrfs_ioctl_search_args args;
>>> @@ -1304,7 +1490,7 @@ int find_updated_files(int fd, u64 root_id, u64 oldest_gen)
>>>         return ret;
>>>  }
>>>
>>> -char *path_for_root(int fd, u64 root)
>>> +char *btrfs_list_path_for_root(int fd, u64 root)
>>>  {
>>>         struct root_lookup root_lookup;
>>>         struct rb_node *n;
>>> @@ -1322,19 +1508,17 @@ char *path_for_root(int fd, u64 root)
>>>         n = rb_last(&root_lookup.root);
>>>         while (n) {
>>>                 struct root_info *entry;
>>> -               u64 parent_id;
>>> -               u64 level;
>>> -               char *path;
>>>
>>>                 entry = rb_entry(n, struct root_info, rb_node);
>>> -               resolve_root(&root_lookup, entry, &parent_id, &level, &path);
>>> -               if (entry->root_id == root)
>>> -                       ret_path = path;
>>> -               else
>>> -                       free(path);
>>> +               resolve_root(&root_lookup, entry);
>>> +               if (entry->root_id == root) {
>>> +                       ret_path = entry->full_path;
>>> +                       entry->full_path = NULL;
>>> +               }
>>>
>>>                 n = rb_prev(n);
>>>         }
>>> +       __free_all_subvolumn(&root_lookup);
>>>
>>>         return ret_path;
>>>  }
>>> diff --git a/btrfs-list.h b/btrfs-list.h
>>> index b4a7f30..ca3eb7b 100644
>>> --- a/btrfs-list.h
>>> +++ b/btrfs-list.h
>>> @@ -16,7 +16,72 @@
>>>   * Boston, MA 021110-1307, USA.
>>>   */
>>>
>>> -int list_subvols(int fd, int print_parent, int get_default, int print_uuid);
>>> -int list_snapshots(int fd, int print_parent, int order, int print_uuid);
>>> -int find_updated_files(int fd, u64 root_id, u64 oldest_gen);
>>> -char *path_for_root(int fd, u64 root);
>>> +struct root_info;
>>> +
>>> +typedef int (*btrfs_list_filter_func)(struct root_info *, void *);
>>> +typedef int (*btrfs_list_comp_func)(struct root_info *, struct root_info *,
>>> +                                   int);
>>> +
>>> +struct btrfs_list_filter {
>>> +       btrfs_list_filter_func filter_func;
>>> +       void *data;
>>> +};
>>> +
>>> +struct btrfs_list_comparer {
>>> +       btrfs_list_comp_func comp_func;
>>> +       int is_descending;
>>> +};
>>> +
>>> +struct btrfs_list_filter_set {
>>> +       int total;
>>> +       int nfilters;
>>> +       struct btrfs_list_filter filters[0];
>>> +};
>>> +
>>> +struct btrfs_list_comparer_set {
>>> +       int total;
>>> +       int ncomps;
>>> +       struct btrfs_list_comparer comps[0];
>>> +};
>>> +
>>> +enum btrfs_list_column_enum {
>>> +       BTRFS_LIST_OBJECTID,
>>> +       BTRFS_LIST_GENERATION,
>>> +       BTRFS_LIST_OGENERATION,
>>> +       BTRFS_LIST_PARENT,
>>> +       BTRFS_LIST_TOP_LEVEL,
>>> +       BTRFS_LIST_OTIME,
>>> +       BTRFS_LIST_UUID,
>>> +       BTRFS_LIST_PATH,
>>> +       BTRFS_LIST_ALL,
>>> +};
>>> +
>>> +enum btrfs_list_filter_enum {
>>> +       BTRFS_LIST_FILTER_ROOTID,
>>> +       BTRFS_LIST_FILTER_SNAPSHOT_ONLY,
>>> +       BTRFS_LIST_FILTER_MAX,
>>> +};
>>> +
>>> +enum btrfs_list_comp_enum {
>>> +       BTRFS_LIST_COMP_ROOTID,
>>> +       BTRFS_LIST_COMP_OGEN,
>>> +       BTRFS_LIST_COMP_GEN,
>>> +       BTRFS_LIST_COMP_MAX,
>>> +};
>>> +
>>> +void btrfs_list_setup_print_column(enum btrfs_list_column_enum column);
>>> +struct btrfs_list_filter_set *btrfs_list_alloc_filter_set(void);
>>> +void btrfs_list_free_filter_set(struct btrfs_list_filter_set *filter_set);
>>> +int btrfs_list_setup_filter(struct btrfs_list_filter_set **filter_set,
>>> +                           enum btrfs_list_filter_enum filter, void *data);
>>> +struct btrfs_list_comparer_set *btrfs_list_alloc_comparer_set(void);
>>> +void btrfs_list_free_comparer_set(struct btrfs_list_comparer_set *comp_set);
>>> +int btrfs_list_setup_comparer(struct btrfs_list_comparer_set **comp_set,
>>> +                             enum btrfs_list_comp_enum comparer,
>>> +                             int is_descending);
>>> +
>>> +int btrfs_list_subvols(int fd, struct btrfs_list_filter_set *filter_set,
>>> +                      struct btrfs_list_comparer_set *comp_set);
>>> +int btrfs_list_find_updated_files(int fd, u64 root_id, u64 oldest_gen);
>>> +int btrfs_list_get_default_subvolume(int fd, u64 *default_id);
>>> +char *btrfs_list_path_for_root(int fd, u64 root);
>>> diff --git a/cmds-inspect.c b/cmds-inspect.c
>>> index f943ed9..376fab2 100644
>>> --- a/cmds-inspect.c
>>> +++ b/cmds-inspect.c
>>> @@ -194,7 +194,7 @@ static int cmd_logical_resolve(int argc, char **argv)
>>>                 char *name;
>>>
>>>                 if (getpath) {
>>> -                       name = path_for_root(fd, root);
>>> +                       name = btrfs_list_path_for_root(fd, root);
>>>                         if (IS_ERR(name))
>>>                                 return PTR_ERR(name);
>>>                         if (!name) {
>>> diff --git a/cmds-subvolume.c b/cmds-subvolume.c
>>> index cd4b5a7..b1cf2bd 100644
>>> --- a/cmds-subvolume.c
>>> +++ b/cmds-subvolume.c
>>> @@ -28,6 +28,7 @@
>>>  #include "ioctl.h"
>>>  #include "qgroup.h"
>>>
>>> +#include "ctree.h"
>>>  #include "commands.h"
>>>  #include "btrfs-list.h"
>>>
>>> @@ -270,13 +271,15 @@ static const char * const cmd_subvol_list_usage[] = {
>>>
>>>  static int cmd_subvol_list(int argc, char **argv)
>>>  {
>>> +       struct btrfs_list_filter_set *filter_set;
>>> +       struct btrfs_list_comparer_set *comparer_set;
>>>         int fd;
>>>         int ret;
>>> -       int print_parent = 0;
>>> -       int print_snap_only = 0;
>>> -       int order = 0;
>>> +       int order;
>>>         char *subvol;
>>> -       int print_uuid = 0;
>>> +
>>> +       filter_set = btrfs_list_alloc_filter_set();
>>> +       comparer_set = btrfs_list_alloc_comparer_set();
>>>
>>>         optind = 1;
>>>         while(1) {
>>> @@ -286,14 +289,21 @@ static int cmd_subvol_list(int argc, char **argv)
>>>
>>>                 switch(c) {
>>>                 case 'p':
>>> -                       print_parent = 1;
>>> +                       btrfs_list_setup_print_column(BTRFS_LIST_PARENT);
>>>                         break;
>>>                 case 's':
>>> -                       print_snap_only = 1;
>>>                         order = atoi(optarg);
>>> +                       btrfs_list_setup_filter(&filter_set,
>>> +                                               BTRFS_LIST_FILTER_SNAPSHOT_ONLY,
>>> +                                               NULL);
>>> +                       btrfs_list_setup_comparer(&comparer_set,
>>> +                                                 BTRFS_LIST_COMP_OGEN,
>>> +                                                 !order);
>>> +                       btrfs_list_setup_print_column(BTRFS_LIST_OGENERATION);
>>> +                       btrfs_list_setup_print_column(BTRFS_LIST_OTIME);
>>>                         break;
>>>                 case 'u':
>>> -                       print_uuid =1;
>>> +                       btrfs_list_setup_print_column(BTRFS_LIST_UUID);
>>>                         break;
>>>                 default:
>>>                         usage(cmd_subvol_list_usage);
>>> @@ -320,10 +330,8 @@ static int cmd_subvol_list(int argc, char **argv)
>>>                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
>>>                 return 12;
>>>         }
>>> -       if (!print_snap_only)
>>> -               ret = list_subvols(fd, print_parent, 0, print_uuid);
>>> -       else
>>> -               ret = list_snapshots(fd, print_parent, order, print_uuid);
>>> +
>>> +       ret = btrfs_list_subvols(fd, filter_set, comparer_set);
>>>         if (ret)
>>>                 return 19;
>>>         return 0;
>>> @@ -483,6 +491,8 @@ static int cmd_subvol_get_default(int argc, char **argv)
>>>         int fd;
>>>         int ret;
>>>         char *subvol;
>>> +       struct btrfs_list_filter_set *filter_set;
>>> +       u64 default_id;
>>>
>>>         if (check_argc_exact(argc, 2))
>>>                 usage(cmd_subvol_get_default_usage);
>>> @@ -504,7 +514,30 @@ 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, 0);
>>> +
>>> +       ret = btrfs_list_get_default_subvolume(fd, &default_id);
>>> +       if (ret) {
>>> +               fprintf(stderr, "ERROR: can't perform the search - %s\n",
>>> +                       strerror(errno));
>>> +               return ret;
>>> +       }
>>> +
>>> +       if (default_id == 0) {
>>> +               fprintf(stderr, "ERROR: 'default' dir item not found\n");
>>> +               return ret;
>>> +       }
>>> +
>>> +       /* no need to resolve roots if FS_TREE is default */
>>> +       if (default_id == BTRFS_FS_TREE_OBJECTID) {
>>> +               printf("ID 5 (FS_TREE)\n");
>>> +               return ret;
>>> +       }
>>> +
>>> +       filter_set = btrfs_list_alloc_filter_set();
>>> +       btrfs_list_setup_filter(&filter_set, BTRFS_LIST_FILTER_ROOTID,
>>> +                               (void *)&default_id);
>>> +
>>> +       ret = btrfs_list_subvols(fd, filter_set, NULL);
>>>         if (ret)
>>>                 return 19;
>>>         return 0;
>>> @@ -585,7 +618,7 @@ static int cmd_find_new(int argc, char **argv)
>>>                 fprintf(stderr, "ERROR: can't access '%s'\n", subvol);
>>>                 return 12;
>>>         }
>>> -       ret = find_updated_files(fd, 0, last_gen);
>>> +       ret = btrfs_list_find_updated_files(fd, 0, last_gen);
>>>         if (ret)
>>>                 return 19;
>>>         return 0;
>>> diff --git a/send-utils.c b/send-utils.c
>>> index 096fa02..fcde5c2 100644
>>> --- a/send-utils.c
>>> +++ b/send-utils.c
>>> @@ -244,7 +244,8 @@ int subvol_uuid_search_init(int mnt_fd, struct subvol_uuid_search *s)
>>>                                 if (!root_item_valid)
>>>                                         goto skip;
>>>
>>> -                               path = path_for_root(mnt_fd, sh->objectid);
>>> +                               path = btrfs_list_path_for_root(mnt_fd,
>>> +                                                               sh->objectid);
>>>                                 if (!path)
>>>                                         path = strdup("");
>>>                                 if (IS_ERR(path)) {
>>> --
>>> 1.7.6.5
>>>
>>> --
>>> To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in
>>> the body of a message to majordomo@vger.kernel.org
>>> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>>
>
>

Alex.

  reply	other threads:[~2012-10-10 19:45 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-09-18 10:35 [PATCH V4 0/7 ] Btrfs-progs: enhance btrfs subvol list only to show read-only snapshots Miao Xie
2012-09-18 10:50 ` [PATCH V4 1/7] Btrfs-progs: move the function declarations to a new head file Miao Xie
2012-09-18 10:52 ` [PATCH V4 2/7] Btrfs-progs: fix compile warning of implicit declaration of "list_snapshots" Miao Xie
2012-09-18 10:55 ` [PATCH V4 3/7] Btrfs-progs: fix wrong usage of btrfs subvolume list command Miao Xie
2012-09-18 10:59 ` [PATCH V4 4/7] Btrfs-progs: fix wrong way to check if the root item contains otime and uuid Miao Xie
2012-09-19  1:55   ` Anand Jain
2012-09-19  2:58     ` Miao Xie
2012-09-18 11:06 ` [PATCH V4 5/7] Btrfs-progs: restructure list_subvolumes Miao Xie
2012-09-20 12:09   ` David Sterba
2012-10-09 16:05   ` Alex Lyakas
2012-10-10  2:12     ` Miao Xie
2012-10-10 19:45       ` Alex Lyakas [this message]
2012-10-15  4:06         ` Miao Xie
2012-09-18 11:09 ` [PATCH V4 6/7] Btrfs-progs: enhance btrfs subvol list only to show read-only snapshots Miao Xie
2012-09-18 15:11   ` Martin Steigerwald
2012-09-18 11:12 ` [PATCH V4 7/7] Btrfs-progs: update the manpage entries for the btrfs subvolume list Miao Xie
2012-09-28 12:55 ` [PATCH] Btrfs-progs: make btrfs_list_setup_filter to modify a set filter Anand jain
2012-10-03  0:03 ` [PATCH V4 0/7 ] Btrfs-progs: enhance btrfs subvol list only to show read-only snapshots Chris Mason
2012-10-09  6:01   ` Miao Xie
2012-10-09 15:57     ` David Sterba
2012-10-04 10:12 ` [PATCH] Btrfs-progs: add parent uuid for snapshots Anand jain
2012-10-04 12:00   ` Dong Robin
2012-10-05  2:27     ` Anand Jain
2012-10-05  2:25 ` [PATCH] Btrfs-progs: Corrections and additions to the btrfs man page Anand jain
2012-10-05  2:25   ` [PATCH] Btrfs-progs: Update btrfs man page for -P option Anand jain
2012-10-05  2:25   ` [PATCH V2] Btrfs-progs: add parent uuid for snapshots Anand jain
2012-10-09 15:44     ` David Sterba
2012-10-16  7:00       ` [PATCH V3] " Anand jain
2012-10-16  7:00         ` [PATCH] Btrfs-progs: make use of column_name Anand jain
2012-10-16  7:00         ` [PATCH] Btrfs-progs: update man page for -u and -q option in subvol list Anand jain
2012-10-16  7:03       ` [PATCH V2] Btrfs-progs: add parent uuid for snapshots Anand Jain

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