[PATCH] filefrag: fix block size value
From: Rakesh Pandit <hidden>
Date: 2014-07-24 11:38:55
Subsystem:
the rest · Maintainer:
Linus Torvalds
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 returns back usage of FIGETBSZ to get block size. For file systems which don't support FIEMAP, this fixes the number of FIBMAP ioctl calls required. Signed-off-by: Rakesh Pandit <redacted> --- misc/filefrag.c | 24 ++++++++++++++---------- 1 file changed, 14 insertions(+), 10 deletions(-)
diff --git a/misc/filefrag.c b/misc/filefrag.c
index bb060b6..21de136 100644
--- a/misc/filefrag.c
+++ b/misc/filefrag.c@@ -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 +382,25 @@ 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) { + rc = -errno; + perror("FIGETBSZ"); + goto out_close; } 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 +409,13 @@ 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 +424,11 @@ 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 +436,7 @@ 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) {
--
1.9.3