filefrag: fix block size value
ioctl(FIGETBSZ) was used to get block size earlier but 2508eaa7
(filefrag: improvements to filefrag FIEMAP handling) moved to fstatfs
f_bsize which doesn't work well for many files systems.
Block size returned using fstatfs isn't block size but "optimal
transfer block size" as per man page. Even stat st_blksize is
"preferred I/O block size" and in may file systems it may even vary
from file to file (POSIX). This patch changes filefrag to use
FIGETBSZ preferentially over f_bsize.
[ Modified by tytso to add the fallback to f_bsize if FIGETBSZ fails
for some reason ]
Signed-off-by: Rakesh Pandit <rakesh@tuxera.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
1 file changed