Re: [PATCH v2 8/9] ext4: remove unnecessary parameter "needed" in ext4_discard_preallocations

From: Jan Kara
Date: Wed Jan 03 2024 - 04:15:22 EST


On Wed 03-01-24 18:28:20, Kemeng Shi wrote:
> The "needed" controls the number of ext4_prealloc_space to discard in
> ext4_discard_preallocations. Function ext4_discard_preallocations is
> supposed to discard all non-used preallocated blocks when "needed"
> is 0 and now ext4_discard_preallocations is always called with "needed"
> = 0. Remove unnecessary parameter "needed" and remove all non-used
> preallocated spaces in ext4_discard_preallocations to simplify the
> code.
>
> Note: If count of non-used preallocated spaces could be more than
> UINT_MAX, there was a memory leak as some non-used preallocated
> spaces are left ununsed and this commit will fix it. Otherwise,
> there is no behavior change.
>
> Signed-off-by: Kemeng Shi <shikemeng@xxxxxxxxxxxxxxx>

Looks good. Feel free to add:

Reviewed-by: Jan Kara <jack@xxxxxxx>

Honza

> ---
> fs/ext4/ext4.h | 2 +-
> fs/ext4/extents.c | 10 +++++-----
> fs/ext4/file.c | 2 +-
> fs/ext4/indirect.c | 2 +-
> fs/ext4/inode.c | 6 +++---
> fs/ext4/ioctl.c | 2 +-
> fs/ext4/mballoc.c | 10 +++-------
> fs/ext4/move_extent.c | 4 ++--
> fs/ext4/super.c | 2 +-
> 9 files changed, 18 insertions(+), 22 deletions(-)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index fb35cae16..2fd444034 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -2905,7 +2905,7 @@ extern int ext4_mb_init(struct super_block *);
> extern void ext4_mb_release(struct super_block *);
> extern ext4_fsblk_t ext4_mb_new_blocks(handle_t *,
> struct ext4_allocation_request *, int *);
> -extern void ext4_discard_preallocations(struct inode *, unsigned int);
> +extern void ext4_discard_preallocations(struct inode *);
> extern int __init ext4_init_mballoc(void);
> extern void ext4_exit_mballoc(void);
> extern ext4_group_t ext4_mb_prefetch(struct super_block *sb,
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 880f383df..fd350889a 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -100,7 +100,7 @@ static int ext4_ext_trunc_restart_fn(struct inode *inode, int *dropped)
> * i_rwsem. So we can safely drop the i_data_sem here.
> */
> BUG_ON(EXT4_JOURNAL(inode) == NULL);
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
> up_write(&EXT4_I(inode)->i_data_sem);
> *dropped = 1;
> return 0;
> @@ -4313,7 +4313,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
> * not a good idea to call discard here directly,
> * but otherwise we'd need to call it every free().
> */
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
> if (flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE)
> fb_flags = EXT4_FREE_BLOCKS_NO_QUOT_UPDATE;
> ext4_free_blocks(handle, inode, NULL, newblock,
> @@ -5354,7 +5354,7 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
> ext4_fc_mark_ineligible(sb, EXT4_FC_REASON_FALLOC_RANGE, handle);
>
> down_write(&EXT4_I(inode)->i_data_sem);
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
> ext4_es_remove_extent(inode, punch_start, EXT_MAX_BLOCKS - punch_start);
>
> ret = ext4_ext_remove_space(inode, punch_start, punch_stop - 1);
> @@ -5362,7 +5362,7 @@ static int ext4_collapse_range(struct file *file, loff_t offset, loff_t len)
> up_write(&EXT4_I(inode)->i_data_sem);
> goto out_stop;
> }
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
>
> ret = ext4_ext_shift_extents(inode, handle, punch_stop,
> punch_stop - punch_start, SHIFT_LEFT);
> @@ -5494,7 +5494,7 @@ static int ext4_insert_range(struct file *file, loff_t offset, loff_t len)
> goto out_stop;
>
> down_write(&EXT4_I(inode)->i_data_sem);
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
>
> path = ext4_find_extent(inode, offset_lblk, NULL, 0);
> if (IS_ERR(path)) {
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 0166bb9ca..89cb28da8 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -174,7 +174,7 @@ static int ext4_release_file(struct inode *inode, struct file *filp)
> (atomic_read(&inode->i_writecount) == 1) &&
> !EXT4_I(inode)->i_reserved_data_blocks) {
> down_write(&EXT4_I(inode)->i_data_sem);
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
> up_write(&EXT4_I(inode)->i_data_sem);
> }
> if (is_dx(inode) && filp->private_data)
> diff --git a/fs/ext4/indirect.c b/fs/ext4/indirect.c
> index a9f371611..d8ca7f64f 100644
> --- a/fs/ext4/indirect.c
> +++ b/fs/ext4/indirect.c
> @@ -714,7 +714,7 @@ static int ext4_ind_trunc_restart_fn(handle_t *handle, struct inode *inode,
> * i_rwsem. So we can safely drop the i_data_sem here.
> */
> BUG_ON(EXT4_JOURNAL(inode) == NULL);
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
> up_write(&EXT4_I(inode)->i_data_sem);
> *dropped = 1;
> return 0;
> diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
> index d77323204..53ed4a0ad 100644
> --- a/fs/ext4/inode.c
> +++ b/fs/ext4/inode.c
> @@ -371,7 +371,7 @@ void ext4_da_update_reserve_space(struct inode *inode,
> */
> if ((ei->i_reserved_data_blocks == 0) &&
> !inode_is_open_for_write(inode))
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
> }
>
> static int __check_block_validity(struct inode *inode, const char *func,
> @@ -4014,7 +4014,7 @@ int ext4_punch_hole(struct file *file, loff_t offset, loff_t length)
> if (stop_block > first_block) {
>
> down_write(&EXT4_I(inode)->i_data_sem);
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
>
> ext4_es_remove_extent(inode, first_block,
> stop_block - first_block);
> @@ -4167,7 +4167,7 @@ int ext4_truncate(struct inode *inode)
>
> down_write(&EXT4_I(inode)->i_data_sem);
>
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
>
> if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS))
> err = ext4_ext_truncate(handle, inode);
> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
> index 0bfe2ce58..2e2bcd22b 100644
> --- a/fs/ext4/ioctl.c
> +++ b/fs/ext4/ioctl.c
> @@ -458,7 +458,7 @@ static long swap_inode_boot_loader(struct super_block *sb,
> ext4_reset_inode_seed(inode);
> ext4_reset_inode_seed(inode_bl);
>
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
>
> err = ext4_mark_inode_dirty(handle, inode);
> if (err < 0) {
> diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
> index e6561a09d..0e6beb3b4 100644
> --- a/fs/ext4/mballoc.c
> +++ b/fs/ext4/mballoc.c
> @@ -5469,7 +5469,7 @@ ext4_mb_discard_group_preallocations(struct super_block *sb,
> *
> * FIXME!! Make sure it is valid at all the call sites
> */
> -void ext4_discard_preallocations(struct inode *inode, unsigned int needed)
> +void ext4_discard_preallocations(struct inode *inode)
> {
> struct ext4_inode_info *ei = EXT4_I(inode);
> struct super_block *sb = inode->i_sb;
> @@ -5491,15 +5491,12 @@ void ext4_discard_preallocations(struct inode *inode, unsigned int needed)
> mb_debug(sb, "discard preallocation for inode %lu\n",
> inode->i_ino);
> trace_ext4_discard_preallocations(inode,
> - atomic_read(&ei->i_prealloc_active), needed);
> -
> - if (needed == 0)
> - needed = UINT_MAX;
> + atomic_read(&ei->i_prealloc_active), 0);
>
> repeat:
> /* first, collect all pa's in the inode */
> write_lock(&ei->i_prealloc_lock);
> - for (iter = rb_first(&ei->i_prealloc_node); iter && needed;
> + for (iter = rb_first(&ei->i_prealloc_node); iter;
> iter = rb_next(iter)) {
> pa = rb_entry(iter, struct ext4_prealloc_space,
> pa_node.inode_node);
> @@ -5523,7 +5520,6 @@ void ext4_discard_preallocations(struct inode *inode, unsigned int needed)
> spin_unlock(&pa->pa_lock);
> rb_erase(&pa->pa_node.inode_node, &ei->i_prealloc_node);
> list_add(&pa->u.pa_tmp_list, &list);
> - needed--;
> continue;
> }
>
> diff --git a/fs/ext4/move_extent.c b/fs/ext4/move_extent.c
> index 18a9e7c47..0abfc104a 100644
> --- a/fs/ext4/move_extent.c
> +++ b/fs/ext4/move_extent.c
> @@ -689,8 +689,8 @@ ext4_move_extents(struct file *o_filp, struct file *d_filp, __u64 orig_blk,
>
> out:
> if (*moved_len) {
> - ext4_discard_preallocations(orig_inode, 0);
> - ext4_discard_preallocations(donor_inode, 0);
> + ext4_discard_preallocations(orig_inode);
> + ext4_discard_preallocations(donor_inode);
> }
>
> ext4_free_ext_path(path);
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index d062383ea..c0cfc3e46 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1518,7 +1518,7 @@ void ext4_clear_inode(struct inode *inode)
> ext4_fc_del(inode);
> invalidate_inode_buffers(inode);
> clear_inode(inode);
> - ext4_discard_preallocations(inode, 0);
> + ext4_discard_preallocations(inode);
> ext4_es_remove_extent(inode, 0, EXT_MAX_BLOCKS);
> dquot_drop(inode);
> if (EXT4_I(inode)->jinode) {
> --
> 2.30.0
>
--
Jan Kara <jack@xxxxxxxx>
SUSE Labs, CR