On Tue, Feb 25, 2020 at 08:43:53AM +0200, Amir Goldstein wrote: > On Tue, Feb 25, 2020 at 8:26 AM Dave Chinner <david@xxxxxxxxxxxxx> wrote: > > > > On Sun, Feb 23, 2020 at 02:20:32PM +0200, Amir Goldstein wrote: > > > On Sun, Feb 23, 2020 at 4:07 AM Allison Collins > > > <allison.henderson@xxxxxxxxxx> wrote: > > > > > > > > From: Allison Henderson <allison.henderson@xxxxxxxxxx> > > > > > > > > This patch adds a new functions to check for the existence of an attribute. > > > > Subroutines are also added to handle the cases of leaf blocks, nodes or shortform. > > > > Common code that appears in existing attr add and remove functions have been > > > > factored out to help reduce the appearance of duplicated code. We will need these > > > > routines later for delayed attributes since delayed operations cannot return error > > > > codes. > > > > > > > > Signed-off-by: Allison Collins <allison.henderson@xxxxxxxxxx> > > > > --- > > > > fs/xfs/libxfs/xfs_attr.c | 171 ++++++++++++++++++++++++++++-------------- > > > > fs/xfs/libxfs/xfs_attr.h | 1 + > > > > fs/xfs/libxfs/xfs_attr_leaf.c | 111 +++++++++++++++++---------- > > > > fs/xfs/libxfs/xfs_attr_leaf.h | 3 + > > > > 4 files changed, 188 insertions(+), 98 deletions(-) > > > > > > > > diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c > > > > index 9acdb23..2255060 100644 > > > > --- a/fs/xfs/libxfs/xfs_attr.c > > > > +++ b/fs/xfs/libxfs/xfs_attr.c > > > > @@ -46,6 +46,7 @@ STATIC int xfs_attr_shortform_addname(xfs_da_args_t *args); > > > > STATIC int xfs_attr_leaf_get(xfs_da_args_t *args); > > > > STATIC int xfs_attr_leaf_addname(xfs_da_args_t *args); > > > > STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args); > > > > +STATIC int xfs_attr_leaf_hasname(struct xfs_da_args *args, struct xfs_buf **bp); > > > > > > > > /* > > > > * Internal routines when attribute list is more than one block. > > > > @@ -53,6 +54,8 @@ STATIC int xfs_attr_leaf_removename(xfs_da_args_t *args); > > > > STATIC int xfs_attr_node_get(xfs_da_args_t *args); > > > > STATIC int xfs_attr_node_addname(xfs_da_args_t *args); > > > > STATIC int xfs_attr_node_removename(xfs_da_args_t *args); > > > > +STATIC int xfs_attr_node_hasname(xfs_da_args_t *args, > > > > + struct xfs_da_state **state); > > > > STATIC int xfs_attr_fillstate(xfs_da_state_t *state); > > > > STATIC int xfs_attr_refillstate(xfs_da_state_t *state); > > > > > > > > @@ -310,6 +313,37 @@ xfs_attr_set_args( > > > > } > > > > > > > > /* > > > > + * Return EEXIST if attr is found, or ENOATTR if not > > > > > > This is a very silly return value for a function named has_attr in my taste. > > > I realize you inherited this interface from xfs_attr3_leaf_lookup_int(), but > > > IMO this change looks like a very good opportunity to change that internal > > > API: > > > > tl;dr Cleaning up this API is work for another patchset. > > > > > > > > xfs_has_attr? > > > > > > 0: NO > > > 1: YES (or stay with the syscall standard of -ENOATTR) > > > <0: error > > > > While I agree with your sentiment, Amir, the API you suggest is an > > anti-pattern. We've been removing ternary return value APIs like > > this from XFS and replacing them with an explicit error return value > > and an operational return parameter like so: > > > > error = xfs_has_attr(&exists) > > if (error) > > return error; > > > > That would be neat and tidy. > > One of the outcomes of new reviewers is comments on code unrelated > to the changes... I have no problem of keeping API as is for Allison's > change, but I did want to point out that the API became worse to read > due to the helper name change from _lookup_attr to _has_attr, which > really asks for a yes or no answer. No argument from me on that. :P But we really need to make progress on the new attribute features rather than get bogged down in completely rewriting the attribute code because it's a bit gross and smelly. The smell can be removed later... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx
