| Message ID | 20170913182521.31304-1-bo.li.liu@oracle.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 2017年09月14日 02:25, Liu Bo wrote: > It doens't make sense to backup tree roots when doing fsync, since > during fsync those tree roots have not been consistent on disk. > > Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com> With a pit can be improved. > --- > fs/btrfs/disk-io.c | 9 ++++++++- > 1 file changed, 8 insertions(+), 1 deletion(-) > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > index 79ac228..a145a88 100644 > --- a/fs/btrfs/disk-io.c > +++ b/fs/btrfs/disk-io.c > @@ -3668,7 +3668,14 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) > u64 flags; > > do_barriers = !btrfs_test_opt(fs_info, NOBARRIER); > - backup_super_roots(fs_info); > + > + /* > + * max_mirrors == 0 indicates we're from commit_transaction, > + * not from fsync where the tree roots in fs_info have not > + * been consistent on disk. > + */ > + if (max_mirrors == 0) > + backup_super_roots(fs_info); BTW, the @max_mirrors naming here is really confusing. Normally I would expect max_mirrors == 0 means we don't need to backup super roots... And since there are only two callers it won't be a big thing to change. Thanks, Qu > > sb = fs_info->super_for_commit; > dev_item = &sb->dev_item; > -- 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
On Thu, Sep 14, 2017 at 09:55:48AM +0800, Qu Wenruo wrote: > > > On 2017年09月14日 02:25, Liu Bo wrote: > > It doens't make sense to backup tree roots when doing fsync, since > > during fsync those tree roots have not been consistent on disk. > > > > Signed-off-by: Liu Bo <bo.li.liu@oracle.com> > > Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com> > > With a pit can be improved. > > --- > > fs/btrfs/disk-io.c | 9 ++++++++- > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > > index 79ac228..a145a88 100644 > > --- a/fs/btrfs/disk-io.c > > +++ b/fs/btrfs/disk-io.c > > @@ -3668,7 +3668,14 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) > > u64 flags; > > > > do_barriers = !btrfs_test_opt(fs_info, NOBARRIER); > > - backup_super_roots(fs_info); > > + > > + /* > > + * max_mirrors == 0 indicates we're from commit_transaction, > > + * not from fsync where the tree roots in fs_info have not > > + * been consistent on disk. > > + */ > > + if (max_mirrors == 0) > > + backup_super_roots(fs_info); > > BTW, the @max_mirrors naming here is really confusing. > Normally I would expect max_mirrors == 0 means we don't need to backup > super roots... Agreed it's confusing, could be something like "bool write_backups" (in a separate patch). -- 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
On Thu, Sep 14, 2017 at 02:49:03PM +0200, David Sterba wrote: > On Thu, Sep 14, 2017 at 09:55:48AM +0800, Qu Wenruo wrote: > > > > > > On 2017年09月14日 02:25, Liu Bo wrote: > > > It doens't make sense to backup tree roots when doing fsync, since > > > during fsync those tree roots have not been consistent on disk. > > > > > > Signed-off-by: Liu Bo <bo.li.liu@oracle.com> > > > > Reviewed-by: Qu Wenruo <quwenruo.btrfs@gmx.com> > > > > With a pit can be improved. > > > --- > > > fs/btrfs/disk-io.c | 9 ++++++++- > > > 1 file changed, 8 insertions(+), 1 deletion(-) > > > > > > diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c > > > index 79ac228..a145a88 100644 > > > --- a/fs/btrfs/disk-io.c > > > +++ b/fs/btrfs/disk-io.c > > > @@ -3668,7 +3668,14 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) > > > u64 flags; > > > > > > do_barriers = !btrfs_test_opt(fs_info, NOBARRIER); > > > - backup_super_roots(fs_info); > > > + > > > + /* > > > + * max_mirrors == 0 indicates we're from commit_transaction, > > > + * not from fsync where the tree roots in fs_info have not > > > + * been consistent on disk. > > > + */ > > > + if (max_mirrors == 0) > > > + backup_super_roots(fs_info); > > > > BTW, the @max_mirrors naming here is really confusing. > > Normally I would expect max_mirrors == 0 means we don't need to backup > > super roots... > > Agreed it's confusing, could be something like "bool write_backups" (in a > separate patch). Good point, will do in a separate one, thanks to both for the comments. Thanks, -liubo -- 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/disk-io.c b/fs/btrfs/disk-io.c index 79ac228..a145a88 100644 --- a/fs/btrfs/disk-io.c +++ b/fs/btrfs/disk-io.c @@ -3668,7 +3668,14 @@ int write_all_supers(struct btrfs_fs_info *fs_info, int max_mirrors) u64 flags; do_barriers = !btrfs_test_opt(fs_info, NOBARRIER); - backup_super_roots(fs_info); + + /* + * max_mirrors == 0 indicates we're from commit_transaction, + * not from fsync where the tree roots in fs_info have not + * been consistent on disk. + */ + if (max_mirrors == 0) + backup_super_roots(fs_info); sb = fs_info->super_for_commit; dev_item = &sb->dev_item;
It doens't make sense to backup tree roots when doing fsync, since during fsync those tree roots have not been consistent on disk. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> --- fs/btrfs/disk-io.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-)