| Message ID | c2fdfcbb1f4ac9a71633dfbe192ed1145b12b8ac.1489799604.git.calvinowens@fb.com (mailing list archive) |
|---|---|
| State | Rejected |
| Headers | show |
On Fri, Mar 17, 2017 at 06:26:09PM -0700, Calvin Owens wrote: > This allows testing FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE. Which is normally done through the "fpunch" command, which explains why nobody has noticed this. > Signed-off-by: Calvin Owens <calvinowens@fb.com> > --- > io/prealloc.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) > > diff --git a/io/prealloc.c b/io/prealloc.c > index a9d66cc..2a4bcdc 100644 > --- a/io/prealloc.c > +++ b/io/prealloc.c > @@ -201,19 +201,19 @@ fallocate_f( > while ((c = getopt(argc, argv, "cikpu")) != EOF) { > switch (c) { > case 'c': > - mode = FALLOC_FL_COLLAPSE_RANGE; > + mode |= FALLOC_FL_COLLAPSE_RANGE; > break; > case 'i': > - mode = FALLOC_FL_INSERT_RANGE; > + mode |= FALLOC_FL_INSERT_RANGE; > break; > case 'k': > - mode = FALLOC_FL_KEEP_SIZE; > + mode |= FALLOC_FL_KEEP_SIZE; > break; > case 'p': > - mode = FALLOC_FL_PUNCH_HOLE; > + mode |= FALLOC_FL_PUNCH_HOLE; > break; > case 'u': > - mode = FALLOC_FL_UNSHARE_RANGE; > + mode |= FALLOC_FL_UNSHARE_RANGE; > break; NACK. We should not allow users to set invalid combinations of commands such as 'falloc -cipu ...' - this would set the flags (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE | FALLOC_FL_PUNCH_HOLE | FALLOC_FL_UNSHARE_RANGE) and will always error out. The use of FALLOC_FL_KEEP_SIZE for the FALLOC_FL_PUNCH_HOLE command is essentially for documentation purposes - it does not do truncation, hence the FALLOC_FL_KEEP_SIZE flag was added to it to ensure developers understand that it does not truncate the file and change EOF. IOWs, the fix needed to make the 'falloc -p' command work is really just this: - mode = FALLOC_FL_PUNCH_HOLE; + mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; Cheers, Dave.
On 03/17/2017 11:55 PM, Dave Chinner wrote: > On Fri, Mar 17, 2017 at 06:26:09PM -0700, Calvin Owens wrote: >> This allows testing FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE. > > Which is normally done through the "fpunch" command, which explains > why nobody has noticed this. Ah okay, I was assuming parity with syscalls in the commands and picked the first one I saw ;) >> Signed-off-by: Calvin Owens <calvinowens@fb.com> >> --- >> io/prealloc.c | 10 +++++----- >> 1 file changed, 5 insertions(+), 5 deletions(-) >> >> diff --git a/io/prealloc.c b/io/prealloc.c >> index a9d66cc..2a4bcdc 100644 >> --- a/io/prealloc.c >> +++ b/io/prealloc.c >> @@ -201,19 +201,19 @@ fallocate_f( >> while ((c = getopt(argc, argv, "cikpu")) != EOF) { >> switch (c) { >> case 'c': >> - mode = FALLOC_FL_COLLAPSE_RANGE; >> + mode |= FALLOC_FL_COLLAPSE_RANGE; >> break; >> case 'i': >> - mode = FALLOC_FL_INSERT_RANGE; >> + mode |= FALLOC_FL_INSERT_RANGE; >> break; >> case 'k': >> - mode = FALLOC_FL_KEEP_SIZE; >> + mode |= FALLOC_FL_KEEP_SIZE; >> break; >> case 'p': >> - mode = FALLOC_FL_PUNCH_HOLE; >> + mode |= FALLOC_FL_PUNCH_HOLE; >> break; >> case 'u': >> - mode = FALLOC_FL_UNSHARE_RANGE; >> + mode |= FALLOC_FL_UNSHARE_RANGE; >> break; > > NACK. We should not allow users to set invalid combinations > of commands such as 'falloc -cipu ...' - this would set the flags > (FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE | > FALLOC_FL_PUNCH_HOLE | FALLOC_FL_UNSHARE_RANGE) and will always > error out. Isn't it potentially useful to test invalid behavior? > The use of FALLOC_FL_KEEP_SIZE for the FALLOC_FL_PUNCH_HOLE command > is essentially for documentation purposes - it does not do > truncation, hence the FALLOC_FL_KEEP_SIZE flag was added to it to > ensure developers understand that it does not truncate the file and > change EOF. > > IOWs, the fix needed to make the 'falloc -p' command work is really > just this: > > - mode = FALLOC_FL_PUNCH_HOLE; > + mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; My thinking was just "allow full exercising of the syscall", fpunch works for my testcase so if you'd prefer not to do that we can just drop this :) It might be worth cleaning up 'falloc' though: '-k' doesn't really make sense on its own right? Maybe remove "-k" and make "-p" OR in KEEP_SIZE like you suggest? Thanks, Calvin > Cheers, > > Dave. > -- To unsubscribe from this list: send the line "unsubscribe linux-xfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Sun, Mar 19, 2017 at 09:33:50PM -0700, Calvin Owens wrote: > On 03/17/2017 11:55 PM, Dave Chinner wrote: > >On Fri, Mar 17, 2017 at 06:26:09PM -0700, Calvin Owens wrote: > >>This allows testing FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE. > > > >Which is normally done through the "fpunch" command, which explains > >why nobody has noticed this. > > Ah okay, I was assuming parity with syscalls in the commands and picked > the first one I saw ;) > > >>Signed-off-by: Calvin Owens <calvinowens@fb.com> > >>--- > >> io/prealloc.c | 10 +++++----- > >> 1 file changed, 5 insertions(+), 5 deletions(-) > >> > >>diff --git a/io/prealloc.c b/io/prealloc.c > >>index a9d66cc..2a4bcdc 100644 > >>--- a/io/prealloc.c > >>+++ b/io/prealloc.c > >>@@ -201,19 +201,19 @@ fallocate_f( > >> while ((c = getopt(argc, argv, "cikpu")) != EOF) { > >> switch (c) { > >> case 'c': > >>- mode = FALLOC_FL_COLLAPSE_RANGE; > >>+ mode |= FALLOC_FL_COLLAPSE_RANGE; > >> break; > >> case 'i': > >>- mode = FALLOC_FL_INSERT_RANGE; > >>+ mode |= FALLOC_FL_INSERT_RANGE; > >> break; > >> case 'k': > >>- mode = FALLOC_FL_KEEP_SIZE; > >>+ mode |= FALLOC_FL_KEEP_SIZE; > >> break; > >> case 'p': > >>- mode = FALLOC_FL_PUNCH_HOLE; > >>+ mode |= FALLOC_FL_PUNCH_HOLE; > >> break; > >> case 'u': > >>- mode = FALLOC_FL_UNSHARE_RANGE; > >>+ mode |= FALLOC_FL_UNSHARE_RANGE; > >> break; > > > >NACK. We should not allow users to set invalid combinations > >of commands such as 'falloc -cipu ...' - this would set the flags > >(FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_INSERT_RANGE | > >FALLOC_FL_PUNCH_HOLE | FALLOC_FL_UNSHARE_RANGE) and will always > >error out. > > Isn't it potentially useful to test invalid behavior? Yes, but exhaustive testing of syscall option validity is not what xfs_io is for - xfs_io is for giving test scripts access to the syscall functionality, and so if someone passes an invalid combination of options it should fail. > >The use of FALLOC_FL_KEEP_SIZE for the FALLOC_FL_PUNCH_HOLE command > >is essentially for documentation purposes - it does not do > >truncation, hence the FALLOC_FL_KEEP_SIZE flag was added to it to > >ensure developers understand that it does not truncate the file and > >change EOF. > > > >IOWs, the fix needed to make the 'falloc -p' command work is really > >just this: > > > >- mode = FALLOC_FL_PUNCH_HOLE; > >+ mode = FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE; > > My thinking was just "allow full exercising of the syscall", fpunch works > for my testcase so if you'd prefer not to do that we can just drop this :) If you want to go test invalid combinations, write a syscall test for ltp. > It might be worth cleaning up 'falloc' though: '-k' doesn't really make > sense on its own right? As I said in my last response: "falloc -k" is a valid usage for preallocation because it means "allow preallocation beyond EOF". i.e. future writes that extend the file will not need to allocate blocks.... > Maybe remove "-k" and make "-p" OR in KEEP_SIZE > like you suggest? See above, and the answer is obvious. Cheers, Dave.
diff --git a/io/prealloc.c b/io/prealloc.c index a9d66cc..2a4bcdc 100644 --- a/io/prealloc.c +++ b/io/prealloc.c @@ -201,19 +201,19 @@ fallocate_f( while ((c = getopt(argc, argv, "cikpu")) != EOF) { switch (c) { case 'c': - mode = FALLOC_FL_COLLAPSE_RANGE; + mode |= FALLOC_FL_COLLAPSE_RANGE; break; case 'i': - mode = FALLOC_FL_INSERT_RANGE; + mode |= FALLOC_FL_INSERT_RANGE; break; case 'k': - mode = FALLOC_FL_KEEP_SIZE; + mode |= FALLOC_FL_KEEP_SIZE; break; case 'p': - mode = FALLOC_FL_PUNCH_HOLE; + mode |= FALLOC_FL_PUNCH_HOLE; break; case 'u': - mode = FALLOC_FL_UNSHARE_RANGE; + mode |= FALLOC_FL_UNSHARE_RANGE; break; default: command_usage(&falloc_cmd);
This allows testing FALLOC_FL_PUNCH_HOLE|FALLOC_FL_KEEP_SIZE. Signed-off-by: Calvin Owens <calvinowens@fb.com> --- io/prealloc.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)