| Message ID | 507FBB39.5090603@cn.fujitsu.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 10/18/2012 04:18 PM, Miao Xie wrote: > When we find a bitmap free space entry, we may check the previous extent > entry covers the offset or not. But if we find this entry is also a bitmap > entry, we will continue to check the previous entry of the current one by > a while loop. It is unnecessary because it is impossible that the extent > entry which is in front of a bitmap entry can cover the offset of the entry > after that bitmap entry. > Looks good to me. Reviewed-by: Liu Bo <bo.li.liu@oracle.com> > Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> > --- > Changelog v1 -> v2: > - fix the same problem in the other place > --- > fs/btrfs/free-space-cache.c | 30 ++++++++++-------------------- > 1 files changed, 10 insertions(+), 20 deletions(-) > > diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c > index 1027b85..557502c 100644 > --- a/fs/btrfs/free-space-cache.c > +++ b/fs/btrfs/free-space-cache.c > @@ -1250,18 +1250,13 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl, > * if previous extent entry covers the offset, > * we should return it instead of the bitmap entry > */ > - n = &entry->offset_index; > - while (1) { > - n = rb_prev(n); > - if (!n) > - break; > + n = rb_prev(&entry->offset_index); > + if (n) { > prev = rb_entry(n, struct btrfs_free_space, > offset_index); > - if (!prev->bitmap) { > - if (prev->offset + prev->bytes > offset) > - entry = prev; > - break; > - } > + if (!prev->bitmap && > + prev->offset + prev->bytes > offset) > + entry = prev; > } > } > return entry; > @@ -1287,18 +1282,13 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl, > } > > if (entry->bitmap) { > - n = &entry->offset_index; > - while (1) { > - n = rb_prev(n); > - if (!n) > - break; > + n = rb_prev(&entry->offset_index); > + if (n) { > prev = rb_entry(n, struct btrfs_free_space, > offset_index); > - if (!prev->bitmap) { > - if (prev->offset + prev->bytes > offset) > - return prev; > - break; > - } > + if (!prev->bitmap && > + prev->offset + prev->bytes > offset) > + return prev; > } > if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset) > return entry; > -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/btrfs/free-space-cache.c b/fs/btrfs/free-space-cache.c index 1027b85..557502c 100644 --- a/fs/btrfs/free-space-cache.c +++ b/fs/btrfs/free-space-cache.c @@ -1250,18 +1250,13 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl, * if previous extent entry covers the offset, * we should return it instead of the bitmap entry */ - n = &entry->offset_index; - while (1) { - n = rb_prev(n); - if (!n) - break; + n = rb_prev(&entry->offset_index); + if (n) { prev = rb_entry(n, struct btrfs_free_space, offset_index); - if (!prev->bitmap) { - if (prev->offset + prev->bytes > offset) - entry = prev; - break; - } + if (!prev->bitmap && + prev->offset + prev->bytes > offset) + entry = prev; } } return entry; @@ -1287,18 +1282,13 @@ tree_search_offset(struct btrfs_free_space_ctl *ctl, } if (entry->bitmap) { - n = &entry->offset_index; - while (1) { - n = rb_prev(n); - if (!n) - break; + n = rb_prev(&entry->offset_index); + if (n) { prev = rb_entry(n, struct btrfs_free_space, offset_index); - if (!prev->bitmap) { - if (prev->offset + prev->bytes > offset) - return prev; - break; - } + if (!prev->bitmap && + prev->offset + prev->bytes > offset) + return prev; } if (entry->offset + BITS_PER_BITMAP * ctl->unit > offset) return entry;
When we find a bitmap free space entry, we may check the previous extent entry covers the offset or not. But if we find this entry is also a bitmap entry, we will continue to check the previous entry of the current one by a while loop. It is unnecessary because it is impossible that the extent entry which is in front of a bitmap entry can cover the offset of the entry after that bitmap entry. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> --- Changelog v1 -> v2: - fix the same problem in the other place --- fs/btrfs/free-space-cache.c | 30 ++++++++++-------------------- 1 files changed, 10 insertions(+), 20 deletions(-)