On Fri, Aug 15, 2025 at 05:29:19PM +0800, Zhang Yi wrote: > Thank you for your review comments! > > On 2025/8/15 0:52, Darrick J. Wong wrote: > > On Wed, Aug 13, 2025 at 10:40:15AM +0800, Zhang Yi wrote: > >> From: Zhang Yi <yi.zh...@huawei.com> > >> > >> The Linux kernel (since version 6.17) supports FALLOC_FL_WRITE_ZEROES in > >> fallocate(2). Add support for FALLOC_FL_WRITE_ZEROES to the fallocate > >> utility by introducing a new option -w|--write-zeroes. > >> > >> Link: > >> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=278c7d9b5e0c > >> Signed-off-by: Zhang Yi <yi.zh...@huawei.com> > >> --- > >> v1->v2: > >> - Minor description modification to align with the kernel. > >> > >> sys-utils/fallocate.1.adoc | 11 +++++++++-- > >> sys-utils/fallocate.c | 20 ++++++++++++++++---- > >> 2 files changed, 25 insertions(+), 6 deletions(-) > >> > >> diff --git a/sys-utils/fallocate.1.adoc b/sys-utils/fallocate.1.adoc > >> index 44ee0ef4c..0ec9ff9a9 100644 > >> --- a/sys-utils/fallocate.1.adoc > >> +++ b/sys-utils/fallocate.1.adoc > >> @@ -12,7 +12,7 @@ fallocate - preallocate or deallocate space to a file > > > > <snip all the long lines> > > > >> +*-w*, *--write-zeroes*:: > >> +Zeroes space in the byte range starting at _offset_ and continuing > >> for _length_ bytes. Within the specified range, blocks are > >> preallocated for the regions that span the holes in the file. After a > >> successful call, subsequent reads from this range will return zeroes, > >> subsequent writes to that range do not require further changes to the > >> file mapping metadata. > > > > "...will return zeroes and subsequent writes to that range..." ? > > > > Yeah. > > >> ++ > >> +Zeroing is done within the filesystem by preferably submitting write > > > > I think we should say less about what the filesystem actually does to > > preserve some flexibility: > > > > "Zeroing is done within the filesystem. The filesystem may use a > > hardware accelerated zeroing command, or it may submit regular writes. > > The behavior depends on the filesystem design and available hardware." > > > > Sure. > > >> zeores commands, the alternative way is submitting actual zeroed data, > >> the specified range will be converted into written extents. The write > >> zeroes command is typically faster than write actual data if the > >> device supports unmap write zeroes, the specified range will not be > >> physically zeroed out on the device. > >> ++ > >> +Options *--keep-size* can not be specified for the write-zeroes > >> operation. > >> + > >> include::man-common/help-version.adoc[] > >> > >> == AUTHORS > [..] > >> @@ -429,6 +438,9 @@ int main(int argc, char **argv) > >> else if (mode & FALLOC_FL_ZERO_RANGE) > >> fprintf(stdout, _("%s: %s (%ju bytes) > >> zeroed.\n"), > >> filename, str, > >> length); > >> + else if (mode & FALLOC_FL_WRITE_ZEROES) > >> + fprintf(stdout, _("%s: %s (%ju bytes) write > >> zeroed.\n"), > > > > "write zeroed" is a little strange, but I don't have a better > > suggestion. :) > > > > Hmm... What about simply using "zeroed", the same to FALLOC_FL_ZERO_RANGE? > Users should be aware of the parameters they have passed to fallocate(), > so they should not use this print for further differentiation.
No thanks, different inputs should produce different outputs. :) --D > Thanks, > Yi. >
