Re: [PATCH 1/2] fs: add SEEK_HOLE and SEEK_DATA flags

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



On Thu, 21 Apr 2011 15:42:33 EDT, Josef Bacik said:

> -SEEK_HOLE: this moves the file pos to the nearest hole in the file from the
> given position. 

Do we want the semantic to be "the nearest" hole?  Or did we really want "the
next" hole?  Loops like a bullet loaded in the chamber and pointed at the
programmer's foot if they aren't allowing for the fact that this can go
*backwards* in the file if the closest hole is towards the beginning.  Good way
to end up in an infinite loop or other messy...

Consider the obvious implementation of "skip over a hole" - lseek(SEEK_HOLE),
lseek(SEEK_DATA).  and start reading data because we've skipped over the hole.
Wrong - the second seek may have gone backwards if the data was only 4K away
but the hole was 64K in size...

Attachment: pgpTrgsJ2Q5IX.pgp
Description: PGP signature


[Index of Archives]     [Linux Ext4 Filesystem]     [Union Filesystem]     [Filesystem Testing]     [Ceph Users]     [Ecryptfs]     [AutoFS]     [Kernel Newbies]     [Share Photos]     [Security]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux Cachefs]     [Reiser Filesystem]     [Linux RAID]     [Samba]     [Device Mapper]     [CEPH Development]
  Powered by Linux