| Message ID | 1403440209-13370-1-git-send-email-geert@linux-m68k.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Headers | show |
On Sun, 22 Jun 2014 14:30:09 +0200, Geert Uytterhoeven wrote: > fs/btrfs/extent-tree.c: In function ‘btrfs_lock_cluster’: > fs/btrfs/extent-tree.c:6399: warning: ‘used_bg’ may be used uninitialized in this function > > - Replace "again: ... goto again;" by standard C "while (1) { ... }", > - Move block not processed during the first iteration of the loop to the > end of the loop, which allows to kill the "locked" variable, > > Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Looks good to me. Reviewed-and-Tested-by: Miao Xie <miaox@cn.fujitsu.com> > --- > Please review, compile tested only. > --- > fs/btrfs/extent-tree.c | 42 ++++++++++++++++++++---------------------- > 1 file changed, 20 insertions(+), 22 deletions(-) > > diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c > index 99c253918208..e151c4a73d7b 100644 > --- a/fs/btrfs/extent-tree.c > +++ b/fs/btrfs/extent-tree.c > @@ -6397,36 +6397,34 @@ btrfs_lock_cluster(struct btrfs_block_group_cache *block_group, > int delalloc) > { > struct btrfs_block_group_cache *used_bg; > - bool locked = false; > -again: > + > spin_lock(&cluster->refill_lock); > - if (locked) { > - if (used_bg == cluster->block_group) > - return used_bg; > + while (1) { > + used_bg = cluster->block_group; > + if (!used_bg) > + return NULL; > > - up_read(&used_bg->data_rwsem); > - btrfs_put_block_group(used_bg); > - } > + if (used_bg == block_group) > + return used_bg; > > - used_bg = cluster->block_group; > - if (!used_bg) > - return NULL; > + btrfs_get_block_group(used_bg); > > - if (used_bg == block_group) > - return used_bg; > + if (!delalloc) > + return used_bg; > > - btrfs_get_block_group(used_bg); > + if (down_read_trylock(&used_bg->data_rwsem)) > + return used_bg; > > - if (!delalloc) > - return used_bg; > + spin_unlock(&cluster->refill_lock); > + down_read(&used_bg->data_rwsem); > > - if (down_read_trylock(&used_bg->data_rwsem)) > - return used_bg; > + spin_lock(&cluster->refill_lock); > + if (used_bg == cluster->block_group) > + return used_bg; > > - spin_unlock(&cluster->refill_lock); > - down_read(&used_bg->data_rwsem); > - locked = true; > - goto again; > + up_read(&used_bg->data_rwsem); > + btrfs_put_block_group(used_bg); > + } > } > > static inline void > -- 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/extent-tree.c b/fs/btrfs/extent-tree.c index 99c253918208..e151c4a73d7b 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -6397,36 +6397,34 @@ btrfs_lock_cluster(struct btrfs_block_group_cache *block_group, int delalloc) { struct btrfs_block_group_cache *used_bg; - bool locked = false; -again: + spin_lock(&cluster->refill_lock); - if (locked) { - if (used_bg == cluster->block_group) - return used_bg; + while (1) { + used_bg = cluster->block_group; + if (!used_bg) + return NULL; - up_read(&used_bg->data_rwsem); - btrfs_put_block_group(used_bg); - } + if (used_bg == block_group) + return used_bg; - used_bg = cluster->block_group; - if (!used_bg) - return NULL; + btrfs_get_block_group(used_bg); - if (used_bg == block_group) - return used_bg; + if (!delalloc) + return used_bg; - btrfs_get_block_group(used_bg); + if (down_read_trylock(&used_bg->data_rwsem)) + return used_bg; - if (!delalloc) - return used_bg; + spin_unlock(&cluster->refill_lock); + down_read(&used_bg->data_rwsem); - if (down_read_trylock(&used_bg->data_rwsem)) - return used_bg; + spin_lock(&cluster->refill_lock); + if (used_bg == cluster->block_group) + return used_bg; - spin_unlock(&cluster->refill_lock); - down_read(&used_bg->data_rwsem); - locked = true; - goto again; + up_read(&used_bg->data_rwsem); + btrfs_put_block_group(used_bg); + } } static inline void
fs/btrfs/extent-tree.c: In function ‘btrfs_lock_cluster’: fs/btrfs/extent-tree.c:6399: warning: ‘used_bg’ may be used uninitialized in this function - Replace "again: ... goto again;" by standard C "while (1) { ... }", - Move block not processed during the first iteration of the loop to the end of the loop, which allows to kill the "locked" variable, Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> --- Please review, compile tested only. --- fs/btrfs/extent-tree.c | 42 ++++++++++++++++++++---------------------- 1 file changed, 20 insertions(+), 22 deletions(-)