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>
test-maint
Rakesh Pandit 2014-07-27 20:04:48 -04:00 committed by Theodore Ts'o
parent abc4697d5a
commit 01824c9bbc
1 changed files with 11 additions and 10 deletions

View File

@ -351,6 +351,7 @@ static int filefrag_fibmap(int fd, int blk_shift, int *num_extents,
static int frag_report(const char *filename)
{
static struct statfs fsinfo;
static unsigned int blksize;
ext2fs_struct_stat st;
int blk_shift;
long fd;
@ -381,22 +382,22 @@ static int frag_report(const char *filename)
#endif
rc = -errno;
perror("stat");
close(fd);
return rc;
goto out_close;
}
if (last_device != st.st_dev) {
if (fstatfs(fd, &fsinfo) < 0) {
rc = -errno;
perror("fstatfs");
close(fd);
return rc;
goto out_close;
}
if (ioctl(fd, FIGETBSZ, &blksize) < 0)
blksize = fsinfo.f_bsize;
if (verbose)
printf("Filesystem type is: %lx\n",
(unsigned long)fsinfo.f_type);
}
st.st_blksize = fsinfo.f_bsize;
st.st_blksize = blksize;
if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
flags = 0;
if (!(flags & EXT4_EXTENTS_FL) &&
@ -405,13 +406,13 @@ static int frag_report(const char *filename)
is_ext2++;
if (is_ext2) {
long cylgroups = div_ceil(fsinfo.f_blocks, fsinfo.f_bsize * 8);
long cylgroups = div_ceil(fsinfo.f_blocks, blksize * 8);
if (verbose && last_device != st.st_dev)
printf("Filesystem cylinder groups approximately %ld\n",
cylgroups);
data_blocks_per_cyl = fsinfo.f_bsize * 8 -
data_blocks_per_cyl = blksize * 8 -
(fsinfo.f_files / 8 / cylgroups) - 3;
}
last_device = st.st_dev;
@ -420,11 +421,11 @@ static int frag_report(const char *filename)
if (width > physical_width)
physical_width = width;
numblocks = (st.st_size + fsinfo.f_bsize - 1) / fsinfo.f_bsize;
numblocks = (st.st_size + blksize - 1) / blksize;
if (blocksize != 0)
blk_shift = int_log2(blocksize);
else
blk_shift = int_log2(fsinfo.f_bsize);
blk_shift = int_log2(blksize);
width = int_log10(numblocks);
if (width > logical_width)
@ -432,7 +433,7 @@ static int frag_report(const char *filename)
if (verbose)
printf("File size of %s is %llu (%llu block%s of %d bytes)\n",
filename, (unsigned long long)st.st_size,
numblocks * fsinfo.f_bsize >> blk_shift,
numblocks * blksize >> blk_shift,
numblocks == 1 ? "" : "s", 1 << blk_shift);
if (!force_bmap) {