Messages in this thread | | | Date | Mon, 24 Feb 2003 14:10:36 +0300 | From | Oleg Drokin <> | Subject | Re: [PATCH] comments on st_blksize and f_bsize for 2.5 |
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Hello!
On Mon, Feb 24, 2003 at 11:20:09AM +0100, Andries Brouwer wrote:
> The trivial part is st_blksize: all agree. > Quoting the man page: > The value st_blksize gives the "preferred" blocksize > for efficient file system I/O. (Writing to a file in > smaller chunks may cause an inefficient read-modify-rewrite.)
> The nontrivial part is f_bsize. As far as I can see > BSD and SYSV and SUS all differ. And there are the use > in struct statfs and the use in struct statvfs that are > nonequivalent. > Maybe BSD f_iosize, f_bsize in statfs corresponds to > SYSV f_bsize, f_frsize in statfs. Linux is again a > bit different.
Traditionally in Linux f_bsize in struct statfs is used as FS block size. (e.g. df calculates fs capacity by multiplying amount of blocks on fs by f_bsize). Actually, this is the only field in struct statfs that holds any data regarding fs blocksize. (well, some arches have f_frsize, but it is marked as unused).
Bye, Oleg - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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