From: "Darrick J. Wong" Subject: Re: [RFC 3/4] ext4: Add support for generic FS events Date: Wed, 15 Apr 2015 12:18:38 -0700 Message-ID: <20150415191838.GB11592@birch.djwong.org> References: <1429082147-4151-1-git-send-email-b.michalska@samsung.com> <1429082147-4151-4-git-send-email-b.michalska@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-kernel@vger.kernel.org, tytso@mit.edu, adilger.kernel@dilger.ca, hughd@google.com, lczerner@redhat.com, hch@infradead.org, linux-ext4@vger.kernel.org, linux-mm@kvack.org, kyungmin.park@samsung.com, kmpark@infradead.org To: Beata Michalska Return-path: Content-Disposition: inline In-Reply-To: <1429082147-4151-4-git-send-email-b.michalska@samsung.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org On Wed, Apr 15, 2015 at 09:15:46AM +0200, Beata Michalska 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 > --- > fs/ext4/balloc.c | 11 +++++++++-- > fs/ext4/ext4.h | 1 + > fs/ext4/inode.c | 2 +- > fs/ext4/mballoc.c | 6 +++++- > fs/ext4/resize.c | 1 + > fs/ext4/super.c | 43 +++++++++++++++++++++++++++++++++++++++++++ > 6 files changed, 60 insertions(+), 4 deletions(-) > > diff --git a/fs/ext4/balloc.c b/fs/ext4/balloc.c > index e95b27a..49d2ace 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; > @@ -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_EVENT_WARN, 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 +639,11 @@ 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_EVENT_WARN, > + FS_WANR_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)); While we're adding fs netlink notifications, could we add a message that means "This FS is corrupt, go run fsck"? A monitoring app could possibly figure this out by a sudden drop in free space accompanied by EIO errors hitting userland apps, but we might as well be explicit about the flaming death. :) --D > } > > /* > 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..e6cbbd6 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..52091da 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -398,6 +398,7 @@ static void ext4_handle_error(struct super_block *sb) > if (test_opt(sb, ERRORS_PANIC)) > panic("EXT4-fs (device %s): panic forced after error\n", > sb->s_id); > + fs_event_notify(sb, FS_EVENT_ERR, FS_ERR_UNKNOWN); > } > > #define ext4_error_ratelimit(sb) \ > @@ -585,6 +586,8 @@ 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_EVENT_ERR, FS_ERR_RO_REMOUT); > + > } > if (test_opt(sb, ERRORS_PANIC)) > panic("EXT4-fs panic from previous error\n"); > @@ -612,6 +615,8 @@ void __ext4_warning(struct super_block *sb, const char *function, > struct va_format vaf; > va_list args; > > + fs_event_notify(sb, FS_EVENT_WARN, FS_WARN_UNKNOWN); > + > if (!___ratelimit(&(EXT4_SB(sb)->s_warning_ratelimit_state), > "EXT4-fs warning")) > return; > @@ -1083,6 +1088,13 @@ static const struct quotactl_ops ext4_qctl_operations = { > }; > #endif > > +static int ext4_trace_query(struct super_block *sb, > + struct fs_trace_sdata *data); > + > +static const struct fs_trace_operations ext4_trace_ops = { > + .fs_trace_query = ext4_trace_query, > +}; > + > static const struct super_operations ext4_sops = { > .alloc_inode = ext4_alloc_inode, > .destroy_inode = ext4_destroy_inode, > @@ -3398,11 +3410,20 @@ 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 +3987,8 @@ 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_trace_ops = &ext4_trace_ops; > + > memcpy(sb->s_uuid, es->s_uuid, sizeof(es->s_uuid)); > > INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */ > @@ -5438,6 +5461,26 @@ out: > > #endif > > +static int ext4_trace_query(struct super_block *sb, struct fs_trace_sdata *data) > +{ > + struct ext4_sb_info *sbi = EXT4_SB(sb); > + struct ext4_super_block *es = sbi->s_es; > + ext4_fsblk_t rsv_blocks; > + > + data->available_blks = > + percpu_counter_sum_positive(&sbi->s_freeclusters_counter) - > + percpu_counter_sum_positive(&sbi->s_dirtyclusters_counter); > + data->available_blks = EXT4_C2B(sbi, data->available_blks); > + rsv_blocks = ext4_r_blocks_count(es) + > + EXT4_C2B(sbi, atomic64_read(&sbi->s_resv_clusters)); > + if (data->available_blks < rsv_blocks) > + data->available_blks = 0; > + else > + data->available_blks -= rsv_blocks; > + data->events_cap_mask = FS_EVENTS_ALL; > + return 0; > +} > + > static struct dentry *ext4_mount(struct file_system_type *fs_type, int flags, > const char *dev_name, void *data) > { > -- > 1.7.9.5 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. 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