From: Beata Michalska Subject: [RFC 4/4] shmem: Add support for generic FS events Date: Wed, 15 Apr 2015 09:15:47 +0200 Message-ID: <1429082147-4151-5-git-send-email-b.michalska@samsung.com> References: <1429082147-4151-1-git-send-email-b.michalska@samsung.com> Cc: 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: linux-kernel@vger.kernel.org Return-path: In-reply-to: <1429082147-4151-1-git-send-email-b.michalska@samsung.com> Sender: owner-linux-mm@kvack.org List-Id: linux-ext4.vger.kernel.org Add support for the generic FS events interface covering threshold notifiactions and the ENOSPC warning. Signed-off-by: Beata Michalska --- mm/shmem.c | 39 ++++++++++++++++++++++++++++++++++++--- 1 file changed, 36 insertions(+), 3 deletions(-) diff --git a/mm/shmem.c b/mm/shmem.c index cf2d0ca..bb261ac 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -201,6 +201,7 @@ static int shmem_reserve_inode(struct super_block *sb) spin_lock(&sbinfo->stat_lock); if (!sbinfo->free_inodes) { spin_unlock(&sbinfo->stat_lock); + fs_event_notify(sb, FS_EVENT_WARN, FS_WARN_ENOSPC); return -ENOSPC; } sbinfo->free_inodes--; @@ -239,8 +240,10 @@ static void shmem_recalc_inode(struct inode *inode) freed = info->alloced - info->swapped - inode->i_mapping->nrpages; if (freed > 0) { struct shmem_sb_info *sbinfo = SHMEM_SB(inode->i_sb); - if (sbinfo->max_blocks) + if (sbinfo->max_blocks) { percpu_counter_add(&sbinfo->used_blocks, -freed); + fs_event_free_space(inode->i_sb, freed); + } info->alloced -= freed; inode->i_blocks -= freed * BLOCKS_PER_PAGE; shmem_unacct_blocks(info->flags, freed); @@ -1164,6 +1167,7 @@ repeat: goto unacct; } percpu_counter_inc(&sbinfo->used_blocks); + fs_event_alloc_space(inode->i_sb, 1); } page = shmem_alloc_page(gfp, info, index); @@ -1245,8 +1249,10 @@ trunc: spin_unlock(&info->lock); decused: sbinfo = SHMEM_SB(inode->i_sb); - if (sbinfo->max_blocks) + if (sbinfo->max_blocks) { percpu_counter_add(&sbinfo->used_blocks, -1); + fs_event_free_space(inode->i_sb, 1); + } unacct: shmem_unacct_blocks(info->flags, 1); failed: @@ -1258,12 +1264,17 @@ unlock: unlock_page(page); page_cache_release(page); } - if (error == -ENOSPC && !once++) { + if (error == -ENOSPC) { + if (!once++) { info = SHMEM_I(inode); spin_lock(&info->lock); shmem_recalc_inode(inode); spin_unlock(&info->lock); goto repeat; + } else { + fs_event_notify(inode->i_sb, FS_EVENT_WARN, + FS_WARN_ENOSPC); + } } if (error == -EEXIST) /* from above or from radix_tree_insert */ goto repeat; @@ -2729,12 +2740,33 @@ static int shmem_encode_fh(struct inode *inode, __u32 *fh, int *len, return 1; } +static int shmem_trace_query(struct super_block *sb, + struct fs_trace_sdata *data) +{ + struct shmem_sb_info *sbinfo = SHMEM_SB(sb); + + if (!sb || !data) + return -EINVAL; + + data->events_cap_mask = FS_EVENT_WARN; + if (sbinfo->max_blocks) { + data->available_blks = sbinfo->max_blocks - + percpu_counter_sum(&sbinfo->used_blocks); + data->events_cap_mask |= FS_EVENT_THRESH; + } + return 0; +} + static const struct export_operations shmem_export_ops = { .get_parent = shmem_get_parent, .encode_fh = shmem_encode_fh, .fh_to_dentry = shmem_fh_to_dentry, }; +static const struct fs_trace_operations shmem_trace_ops = { + .fs_trace_query = shmem_trace_query, +}; + static int shmem_parse_options(char *options, struct shmem_sb_info *sbinfo, bool remount) { @@ -3020,6 +3052,7 @@ int shmem_fill_super(struct super_block *sb, void *data, int silent) sb->s_flags |= MS_NOUSER; } sb->s_export_op = &shmem_export_ops; + sb->s_trace_ops = &shmem_trace_ops; sb->s_flags |= MS_NOSEC; #else sb->s_flags |= MS_NOUSER; -- 1.7.9.5 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org