| Message ID | 20181015062538.30784-1-lufq.fnst@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | btrfs: delayed-ref: extract find_first_ref_head from find_ref_head | expand |
On 15.10.2018 09:25, Lu Fengqi wrote: > The find_ref_head shouldn't return the first entry even if no exact match > is found. So move the hidden behavior to higher level. > > Besides, remove the useless local variables in the btrfs_select_ref_head. > > Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Reviewed-by: Nikolay Borisov <nborisov@suse.com> > --- > fs/btrfs/delayed-ref.c | 45 +++++++++++++++++++++++------------------- > 1 file changed, 25 insertions(+), 20 deletions(-) > > diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c > index 6e8be384398e..a92f104cf06f 100644 > --- a/fs/btrfs/delayed-ref.c > +++ b/fs/btrfs/delayed-ref.c > @@ -164,14 +164,28 @@ static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root, > return NULL; > } > > +static struct btrfs_delayed_ref_head *find_first_ref_head( > + struct btrfs_delayed_ref_root *dr) > +{ > + struct rb_node *n; > + struct btrfs_delayed_ref_head *entry; > + > + n = rb_first_cached(&dr->href_root); > + if (!n) > + return NULL; > + > + entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node); > + > + return entry; > +} > + > /* > * find an head entry based on bytenr. This returns the delayed ref > * head if it was able to find one, or NULL if nothing was in that spot. > * If return_bigger is given, the next bigger entry is returned if no exact > - * match is found. But if no bigger one is found then the first node of the > - * ref head tree will be returned. > + * match is found. > */ > -static struct btrfs_delayed_ref_head* find_ref_head( > +static struct btrfs_delayed_ref_head *find_ref_head( > struct btrfs_delayed_ref_root *dr, u64 bytenr, > bool return_bigger) > { > @@ -195,10 +209,9 @@ static struct btrfs_delayed_ref_head* find_ref_head( > if (bytenr > entry->bytenr) { > n = rb_next(&entry->href_node); > if (!n) > - n = rb_first_cached(&dr->href_root); > + return NULL; > entry = rb_entry(n, struct btrfs_delayed_ref_head, > href_node); > - return entry; > } > return entry; > } > @@ -358,33 +371,25 @@ struct btrfs_delayed_ref_head *btrfs_select_ref_head( > struct btrfs_delayed_ref_root *delayed_refs) > { > struct btrfs_delayed_ref_head *head; > - u64 start; > - bool loop = false; > > again: > - start = delayed_refs->run_delayed_start; > - head = find_ref_head(delayed_refs, start, true); > - if (!head && !loop) { > + head = find_ref_head(delayed_refs, delayed_refs->run_delayed_start, > + true); > + if (!head && delayed_refs->run_delayed_start != 0) { > delayed_refs->run_delayed_start = 0; > - start = 0; > - loop = true; > - head = find_ref_head(delayed_refs, start, true); > - if (!head) > - return NULL; > - } else if (!head && loop) { > - return NULL; > + head = find_first_ref_head(delayed_refs); > } > + if (!head) > + return NULL; > > while (head->processing) { > struct rb_node *node; > > node = rb_next(&head->href_node); > if (!node) { > - if (loop) > + if (delayed_refs->run_delayed_start == 0) > return NULL; > delayed_refs->run_delayed_start = 0; > - start = 0; > - loop = true; > goto again; > } > head = rb_entry(node, struct btrfs_delayed_ref_head, >
On Mon, Oct 15, 2018 at 02:25:38PM +0800, Lu Fengqi wrote: > The find_ref_head shouldn't return the first entry even if no exact match > is found. So move the hidden behavior to higher level. > > Besides, remove the useless local variables in the btrfs_select_ref_head. > > Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> Added to misc-next, thanks.
diff --git a/fs/btrfs/delayed-ref.c b/fs/btrfs/delayed-ref.c index 6e8be384398e..a92f104cf06f 100644 --- a/fs/btrfs/delayed-ref.c +++ b/fs/btrfs/delayed-ref.c @@ -164,14 +164,28 @@ static struct btrfs_delayed_ref_node* tree_insert(struct rb_root_cached *root, return NULL; } +static struct btrfs_delayed_ref_head *find_first_ref_head( + struct btrfs_delayed_ref_root *dr) +{ + struct rb_node *n; + struct btrfs_delayed_ref_head *entry; + + n = rb_first_cached(&dr->href_root); + if (!n) + return NULL; + + entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node); + + return entry; +} + /* * find an head entry based on bytenr. This returns the delayed ref * head if it was able to find one, or NULL if nothing was in that spot. * If return_bigger is given, the next bigger entry is returned if no exact - * match is found. But if no bigger one is found then the first node of the - * ref head tree will be returned. + * match is found. */ -static struct btrfs_delayed_ref_head* find_ref_head( +static struct btrfs_delayed_ref_head *find_ref_head( struct btrfs_delayed_ref_root *dr, u64 bytenr, bool return_bigger) { @@ -195,10 +209,9 @@ static struct btrfs_delayed_ref_head* find_ref_head( if (bytenr > entry->bytenr) { n = rb_next(&entry->href_node); if (!n) - n = rb_first_cached(&dr->href_root); + return NULL; entry = rb_entry(n, struct btrfs_delayed_ref_head, href_node); - return entry; } return entry; } @@ -358,33 +371,25 @@ struct btrfs_delayed_ref_head *btrfs_select_ref_head( struct btrfs_delayed_ref_root *delayed_refs) { struct btrfs_delayed_ref_head *head; - u64 start; - bool loop = false; again: - start = delayed_refs->run_delayed_start; - head = find_ref_head(delayed_refs, start, true); - if (!head && !loop) { + head = find_ref_head(delayed_refs, delayed_refs->run_delayed_start, + true); + if (!head && delayed_refs->run_delayed_start != 0) { delayed_refs->run_delayed_start = 0; - start = 0; - loop = true; - head = find_ref_head(delayed_refs, start, true); - if (!head) - return NULL; - } else if (!head && loop) { - return NULL; + head = find_first_ref_head(delayed_refs); } + if (!head) + return NULL; while (head->processing) { struct rb_node *node; node = rb_next(&head->href_node); if (!node) { - if (loop) + if (delayed_refs->run_delayed_start == 0) return NULL; delayed_refs->run_delayed_start = 0; - start = 0; - loop = true; goto again; } head = rb_entry(node, struct btrfs_delayed_ref_head,
The find_ref_head shouldn't return the first entry even if no exact match is found. So move the hidden behavior to higher level. Besides, remove the useless local variables in the btrfs_select_ref_head. Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com> --- fs/btrfs/delayed-ref.c | 45 +++++++++++++++++++++++------------------- 1 file changed, 25 insertions(+), 20 deletions(-)