| Message ID | 1480745978-24996-1-git-send-email-ce3g8jdj@umail.furryterror.org (mailing list archive) |
|---|---|
| State | Superseded |
| Headers | show |
On Sat, Dec 03, 2016 at 01:19:38AM -0500, Zygo Blaxell wrote: > I got tired of seeing "16.00EiB" whenever btrfs-progs encounters a > negative size value. > > e.g. during filesystem shrink we see: > > Unallocated: > /dev/mapper/testvol0 16.00EiB > > Interpreting this as a signed quantity is much more useful: > > Unallocated: > /dev/mapper/testvol0 -26.29GiB > > Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> > --- > utils.c | 13 ++++++++----- > 1 file changed, 8 insertions(+), 5 deletions(-) > > diff --git a/utils.c b/utils.c > index 69b580a..bd2b66e 100644 > --- a/utils.c > +++ b/utils.c > @@ -2594,20 +2594,23 @@ static const char* unit_suffix_binary[] = > static const char* unit_suffix_decimal[] = > { "B", "kB", "MB", "GB", "TB", "PB", "EB"}; > > -int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mode) > +int pretty_size_snprintf(u64 usize, char *str, size_t str_size, unsigned unit_mode) > { > int num_divs; > float fraction; > - u64 base = 0; > + s64 base = 0; > int mult = 0; > const char** suffix = NULL; > - u64 last_size; > + s64 last_size; > > if (str_size == 0) > return 0; > > + /* Negative numbers are more plausible than sizes over 8 EiB. */ > + s64 size = (s64)usize; Just make pretty_size_snprintf() take an s64 size so it's clear from the function signature that it's signed instead of hidden in the definition. > + > if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_RAW) { > - snprintf(str, str_size, "%llu", size); > + snprintf(str, str_size, "%lld", size); > return 0; > } > > @@ -2642,7 +2645,7 @@ int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mod > num_divs = 0; > break; > default: > - while (size >= mult) { > + while ((size < 0 ? -size : size) >= mult) { > last_size = size; > size /= mult; > num_divs++; > -- > 2.1.4 > > -- > 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 -- 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 Sat, Dec 03, 2016 at 10:25:17AM -0800, Omar Sandoval wrote: > On Sat, Dec 03, 2016 at 01:19:38AM -0500, Zygo Blaxell wrote: > > I got tired of seeing "16.00EiB" whenever btrfs-progs encounters a > > negative size value. > > > > e.g. during filesystem shrink we see: > > > > Unallocated: > > /dev/mapper/testvol0 16.00EiB > > > > Interpreting this as a signed quantity is much more useful: > > > > Unallocated: > > /dev/mapper/testvol0 -26.29GiB > > > > Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> > > --- > > utils.c | 13 ++++++++----- > > 1 file changed, 8 insertions(+), 5 deletions(-) > > > > diff --git a/utils.c b/utils.c > > index 69b580a..bd2b66e 100644 > > --- a/utils.c > > +++ b/utils.c > > @@ -2594,20 +2594,23 @@ static const char* unit_suffix_binary[] = > > static const char* unit_suffix_decimal[] = > > { "B", "kB", "MB", "GB", "TB", "PB", "EB"}; > > > > -int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mode) > > +int pretty_size_snprintf(u64 usize, char *str, size_t str_size, unsigned unit_mode) > > { > > int num_divs; > > float fraction; > > - u64 base = 0; > > + s64 base = 0; > > int mult = 0; > > const char** suffix = NULL; > > - u64 last_size; > > + s64 last_size; > > > > if (str_size == 0) > > return 0; > > > > + /* Negative numbers are more plausible than sizes over 8 EiB. */ > > + s64 size = (s64)usize; > > Just make pretty_size_snprintf() take an s64 size so it's clear from the > function signature that it's signed instead of hidden in the definition. I intentionally buried the unsigned -> signed conversion in the lowest level function so I wouldn't trigger signed/unsigned conversion warnings at all 46 call sites for pretty_size_mode. The btrfs code uses u64 endemically for all size data, and I wasn't about to try to change that. The word "pretty" in the function name should imply that what comes out is a possibly lossy transformation of what goes in. Since "16.00EiB" is much more lossy than "-29.96GiB", I believe I am merely reducing the lossiness quantitatively rather than qualitatively. On the other hand, the signed/unsigned warning isn't enabled by default in this project. I can certainly do it that way if you prefer. > > + > > if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_RAW) { > > - snprintf(str, str_size, "%llu", size); > > + snprintf(str, str_size, "%lld", size); > > return 0; > > } > > > > @@ -2642,7 +2645,7 @@ int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mod > > num_divs = 0; > > break; > > default: > > - while (size >= mult) { > > + while ((size < 0 ? -size : size) >= mult) { > > last_size = size; > > size /= mult; > > num_divs++; > > -- > > 2.1.4 > > > > -- > > 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/utils.c b/utils.c index 69b580a..bd2b66e 100644 --- a/utils.c +++ b/utils.c @@ -2594,20 +2594,23 @@ static const char* unit_suffix_binary[] = static const char* unit_suffix_decimal[] = { "B", "kB", "MB", "GB", "TB", "PB", "EB"}; -int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mode) +int pretty_size_snprintf(u64 usize, char *str, size_t str_size, unsigned unit_mode) { int num_divs; float fraction; - u64 base = 0; + s64 base = 0; int mult = 0; const char** suffix = NULL; - u64 last_size; + s64 last_size; if (str_size == 0) return 0; + /* Negative numbers are more plausible than sizes over 8 EiB. */ + s64 size = (s64)usize; + if ((unit_mode & ~UNITS_MODE_MASK) == UNITS_RAW) { - snprintf(str, str_size, "%llu", size); + snprintf(str, str_size, "%lld", size); return 0; } @@ -2642,7 +2645,7 @@ int pretty_size_snprintf(u64 size, char *str, size_t str_size, unsigned unit_mod num_divs = 0; break; default: - while (size >= mult) { + while ((size < 0 ? -size : size) >= mult) { last_size = size; size /= mult; num_divs++;
I got tired of seeing "16.00EiB" whenever btrfs-progs encounters a negative size value. e.g. during filesystem shrink we see: Unallocated: /dev/mapper/testvol0 16.00EiB Interpreting this as a signed quantity is much more useful: Unallocated: /dev/mapper/testvol0 -26.29GiB Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org> --- utils.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)