> Eric Sandeen wrote: > >Mingming Cao wrote: > > > >>ext4: delayed allocation i_blocks fix for stat(2) > >> > >>From: Mingming Cao <cmm@xxxxxxxxxx> > >> > >>Right now i_blocks is not getting updated until the disks are actually > >>allocaed on disk. This means with delayed allocation, right after files > >>are copied, "ls -sF" shoes the file as taking 0 blocks on disk. "du" > >>also shows the files taking zero space, which is highly confusing to the > >>user. > >> > >>Since current delayed allocation already keep track of per-inode total > >>number > >>of blocks that are subject to delayed allocation, this patch fix this by > >>using > >>that to adjust the value returned by stat(2). When real block allocation > >>is done, the i_blocks will get updated. Since the reserved blocks for > >>delayed > >>allocation will be decreased, this will be keep value returned by stat(2) > >>consistent. > >> > >>Signed-off-by: Mingming Cao <cmm@xxxxxxxxxx> > >> > > > >Thanks Mingming, looks like just the right approach. > > > >Something about the spinlock for every stat seems heavy-handed to me but > >I'll have to give that more thought. :) > > > > > > Since i_reserved_blocks is an unsigned long, it should be possible > to atomically fetch it on all of the supported architectures, > without the use of the spinlock. It seems to me that this spinlock > is not required here. Well, it's certainly not nice to rely on this. The clean solution would be to convert i_reserved_blocks to atomic_t or atomic64_t on archs that have it... Honza -- Jan Kara <jack@xxxxxxx> SuSE CR Labs -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
