Re: [RFC v3 3/4] ext4: Add support for generic FS events

[Beata Michalska <b.michalska@samsung.com>]

On 06/17/2015 08:15 AM, Leon Romanovsky wrote:
> On Tue, Jun 16, 2015 at 4:09 PM, Beata Michalska
> <b.michalska@samsung.com> wrote:
>> Add support for generic FS events including threshold
>> notifications, ENOSPC and remount as read-only warnings,
>> along with generic internal warnings/errors.
>>
>> Signed-off-by: Beata Michalska <b.michalska@samsung.com>
>> ---
>>  fs/ext4/balloc.c  |   10 ++++++++--
>>  fs/ext4/ext4.h    |    1 +
>>  fs/ext4/inode.c   |    2 +-
>>  fs/ext4/mballoc.c |    6 +++++-
>>  fs/ext4/resize.c  |    1 +
>>  fs/ext4/super.c   |   39 +++++++++++++++++++++++++++++++++++++++
>>  6 files changed, 55 insertions(+), 4 deletions(-)
>>
>> diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c
>> index e95b27a..a48450f 100644
>> --- a/fs/ext4/balloc.c
>> +++ b/fs/ext4/balloc.c
>> @@ -569,6 +569,7 @@ int ext4_claim_free_clusters(struct ext4_sb_info *sbi,
>>  {
>>         if (ext4_has_free_clusters(sbi, nclusters, flags)) {
>>                 percpu_counter_add(&sbi->s_dirtyclusters_counter, nclusters);
>> +               fs_event_alloc_space(sbi->s_sb, EXT4_C2B(sbi, nclusters));
>>                 return 0;
>>         } else
>>                 return -ENOSPC;
> Do you need to add "fs_event_notify(sb, FS_WARN_ENOSPC);" here too?

Yeap, I've missed that one.

Thank You.

BR
Beata
> 
>> @@ -590,9 +591,10 @@ int ext4_should_retry_alloc(struct super_block *sb, int *retries)
>>  {
>>         if (!ext4_has_free_clusters(EXT4_SB(sb), 1, 0) ||
>>             (*retries)++ > 3 ||
>> -           !EXT4_SB(sb)->s_journal)
>> +           !EXT4_SB(sb)->s_journal) {
>> +               fs_event_notify(sb, FS_WARN_ENOSPC);
>>                 return 0;
>> -
>> +       }
>>         jbd_debug(1, "%s: retrying operation after ENOSPC\n", sb->s_id);
>>
>>         return jbd2_journal_force_commit_nested(EXT4_SB(sb)->s_journal);
>> @@ -637,6 +639,10 @@ ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
>>                 dquot_alloc_block_nofail(inode,
>>                                 EXT4_C2B(EXT4_SB(inode->i_sb), ar.len));
>>         }
>> +
>> +       if (*errp == -ENOSPC)
>> +               fs_event_notify(inode->i_sb, FS_WARN_ENOSPC_META);
>> +
>>         return ret;
>>  }
>>
>> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
>> index 163afe2..7d75ff9 100644
>> --- a/fs/ext4/ext4.h
>> +++ b/fs/ext4/ext4.h
>> @@ -2542,6 +2542,7 @@ void ext4_mark_group_corrupted(struct ext4_sb_info *sbi,
>>         if (!EXT4_MB_GRP_BBITMAP_CORRUPT(grp))
>>                 percpu_counter_sub(&sbi->s_freeclusters_counter, grp->bb_free);
>>         set_bit(EXT4_GROUP_INFO_BBITMAP_CORRUPT_BIT, &grp->bb_state);
>> +       fs_event_alloc_space(sbi->s_sb, EXT4_C2B(sbi, grp->bb_free));
>>  }
>>
>>  /*
>> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
>> index 5cb9a21..2a7af0f 100644
>> --- a/fs/ext4/inode.c
>> +++ b/fs/ext4/inode.c
>> @@ -1238,7 +1238,7 @@ static void ext4_da_release_space(struct inode *inode, int to_free)
>>         percpu_counter_sub(&sbi->s_dirtyclusters_counter, to_free);
>>
>>         spin_unlock(&EXT4_I(inode)->i_block_reservation_lock);
>> -
>> +       fs_event_free_space(sbi->s_sb, to_free);
>>         dquot_release_reservation_block(inode, EXT4_C2B(sbi, to_free));
>>  }
>>
>> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
>> index 24a4b6d..c2df6f0 100644
>> --- a/fs/ext4/mballoc.c
>> +++ b/fs/ext4/mballoc.c
>> @@ -4511,6 +4511,9 @@ out:
>>                 kmem_cache_free(ext4_ac_cachep, ac);
>>         if (inquota && ar->len < inquota)
>>                 dquot_free_block(ar->inode, EXT4_C2B(sbi, inquota - ar->len));
>> +       if (reserv_clstrs && ar->len < reserv_clstrs)
>> +               fs_event_free_space(sbi->s_sb,
>> +                       EXT4_C2B(sbi, reserv_clstrs - ar->len));
>>         if (!ar->len) {
>>                 if ((ar->flags & EXT4_MB_DELALLOC_RESERVED) == 0)
>>                         /* release all the reserved blocks if non delalloc */
>> @@ -4848,7 +4851,7 @@ do_more:
>>         if (!(flags & EXT4_FREE_BLOCKS_NO_QUOT_UPDATE))
>>                 dquot_free_block(inode, EXT4_C2B(sbi, count_clusters));
>>         percpu_counter_add(&sbi->s_freeclusters_counter, count_clusters);
>> -
>> +       fs_event_free_space(sb, EXT4_C2B(sbi, count_clusters));
>>         ext4_mb_unload_buddy(&e4b);
>>
>>         /* We dirtied the bitmap block */
>> @@ -4982,6 +4985,7 @@ int ext4_group_add_blocks(handle_t *handle, struct super_block *sb,
>>         ext4_unlock_group(sb, block_group);
>>         percpu_counter_add(&sbi->s_freeclusters_counter,
>>                            EXT4_NUM_B2C(sbi, blocks_freed));
>> +       fs_event_free_space(sb, blocks_freed);
>>
>>         if (sbi->s_log_groups_per_flex) {
>>                 ext4_group_t flex_group = ext4_flex_group(sbi, block_group);
>> diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c
>> index 8a8ec62..dbf08d6 100644
>> --- a/fs/ext4/resize.c
>> +++ b/fs/ext4/resize.c
>> @@ -1378,6 +1378,7 @@ static void ext4_update_super(struct super_block *sb,
>>                            EXT4_NUM_B2C(sbi, free_blocks));
>>         percpu_counter_add(&sbi->s_freeinodes_counter,
>>                            EXT4_INODES_PER_GROUP(sb) * flex_gd->count);
>> +       fs_event_free_space(sb, free_blocks - reserved_blocks);
>>
>>         ext4_debug("free blocks count %llu",
>>                    percpu_counter_read(&sbi->s_freeclusters_counter));
>> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
>> index e061e66..108b667 100644
>> --- a/fs/ext4/super.c
>> +++ b/fs/ext4/super.c
>> @@ -585,6 +585,8 @@ void __ext4_abort(struct super_block *sb, const char *function,
>>                 if (EXT4_SB(sb)->s_journal)
>>                         jbd2_journal_abort(EXT4_SB(sb)->s_journal, -EIO);
>>                 save_error_info(sb, function, line);
>> +               fs_event_notify(sb, FS_ERR_REMOUNT_RO);
>> +
>>         }
>>         if (test_opt(sb, ERRORS_PANIC))
>>                 panic("EXT4-fs panic from previous error\n");
>> @@ -1083,6 +1085,12 @@ static const struct quotactl_ops ext4_qctl_operations = {
>>  };
>>  #endif
>>
>> +static void ext4_trace_query(struct super_block *sb, u64 *ncount);
>> +
>> +static const struct fs_trace_operations ext4_trace_ops = {
>> +       .query  = ext4_trace_query,
>> +};
>> +
>>  static const struct super_operations ext4_sops = {
>>         .alloc_inode    = ext4_alloc_inode,
>>         .destroy_inode  = ext4_destroy_inode,
>> @@ -3398,11 +3406,20 @@ static int ext4_reserve_clusters(struct ext4_sb_info *sbi, ext4_fsblk_t count)
>>  {
>>         ext4_fsblk_t clusters = ext4_blocks_count(sbi->s_es) >>
>>                                 sbi->s_cluster_bits;
>> +       ext4_fsblk_t current_resv;
>>
>>         if (count >= clusters)
>>                 return -EINVAL;
>>
>> +       current_resv = atomic64_read(&sbi->s_resv_clusters);
>>         atomic64_set(&sbi->s_resv_clusters, count);
>> +
>> +       if (count > current_resv)
>> +               fs_event_alloc_space(sbi->s_sb,
>> +                       EXT4_C2B(sbi, count - current_resv));
>> +       else
>> +               fs_event_free_space(sbi->s_sb,
>> +                       EXT4_C2B(sbi, current_resv - count));
>>         return 0;
>>  }
>>
>> @@ -3966,6 +3983,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
>>                 sb->s_qcop = &ext4_qctl_operations;
>>         sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP;
>>  #endif
>> +       sb->s_etrace.ops = &ext4_trace_ops;
>> +       sb->s_etrace.events_cap_mask = FS_EVENTS_ALL;
>> +
>>         memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
>>
>>         INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
>> @@ -5438,6 +5458,25 @@ out:
>>
>>  #endif
>>
>> +static void ext4_trace_query(struct super_block *sb, u64 *ncount)
>> +{
>> +       struct ext4_sb_info *sbi = EXT4_SB(sb);
>> +       struct ext4_super_block *es = sbi->s_es;
>> +       ext4_fsblk_t rsv_blocks;
>> +       ext4_fsblk_t nblocks;
>> +
>> +       nblocks = percpu_counter_sum_positive(&sbi->s_freeclusters_counter) -
>> +               percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter);
>> +       nblocks = EXT4_C2B(sbi, nblocks);
>> +       rsv_blocks = ext4_r_blocks_count(es) +
>> +                    EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters));
>> +       if (nblocks < rsv_blocks)
>> +               nblocks = 0;
>> +       else
>> +               nblocks -= rsv_blocks;
>> +       *ncount = nblocks;
>> +}
>> +
>>  static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags,
>>                        const char *dev_name, void *data)
>>  {
>> --
>> 1.7.9.5
>>
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> 
> 
> 

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