misc: handle very large files with filefrag

Avoid overflowing the column-width calc printing files over 4B blocks.

Document the [KMG] suffixes for the "-b <blocksize>" option.

The blocksize is limited to at most 1GiB blocksize to avoid shifting
all extents down to zero GB in size.  Even the use of 1GB blocksize
is unlikely, but non-ext4 filesystems may use multi-GB extents.

Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Lustre-bug-id: https://jira.whamcloud.com/browse/LU-13197
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

diff --git a/misc/filefrag.8.in b/misc/filefrag.8.in
index 5292672f88dc0eb39642f3af712cea4dec53cec0..4b89e72be26549ab74690194a8a7e3af6ae3054a 100644 (file)
--- a/misc/filefrag.8.in
+++ b/misc/filefrag.8.in
@@ -33,8 +33,8 @@ testing purposes.
 .BI \-b blocksize
 Use
 .I blocksize
-in bytes for output instead of the filesystem blocksize.
-For compatibility with earlier versions of
+in bytes, or with [KMG] suffix, up to 1GB for output instead of the
+filesystem blocksize.  For compatibility with earlier versions of
 .BR filefrag ,
 if
 .I blocksize

diff --git a/misc/filefrag.c b/misc/filefrag.c
index 1eec146d8b364151eb5191ab3cf91cb278b9d6e7..032535f3834028ea53f675ab9038a546e8fb84e7 100644 (file)
--- a/misc/filefrag.c
+++ b/misc/filefrag.c
@@ -53,7 +53,7 @@ extern int optind;
 #include <ext2fs/fiemap.h>
 
 int verbose = 0;
-int blocksize;         /* Use specified blocksize (default 1kB) */
+unsigned int blocksize;        /* Use specified blocksize (default 1kB) */
 int sync_file = 0;     /* fsync file before getting the mapping */
 int xattr_map = 0;     /* get xattr mapping */
 int force_bmap;        /* force use of FIBMAP instead of FIEMAP */
@@ -73,7 +73,7 @@ const char *hex_fmt = "%4d: %*llx..%*llx: %*llx..%*llx: %6llx: %s\n";
 #define        EXT4_EXTENTS_FL                 0x00080000 /* Inode uses extents */
 #define        EXT3_IOC_GETFLAGS               _IOR('f', 1, long)
 
-static int int_log2(int arg)
+static int ulong_log2(unsigned long arg)
 {
        int     l = 0;
 
@@ -85,7 +85,7 @@ static int int_log2(int arg)
        return l;
 }
 
-static int int_log10(unsigned long long arg)
+static int ulong_log10(unsigned long long arg)
 {
        int     l = 0;
 
@@ -452,17 +452,17 @@ static int frag_report(const char *filename)
        }
        last_device = st.st_dev;
 
-       width = int_log10(fsinfo.f_blocks);
+       width = ulong_log10(fsinfo.f_blocks);
        if (width > physical_width)
                physical_width = width;
 
        numblocks = (st.st_size + blksize - 1) / blksize;
        if (blocksize != 0)
-               blk_shift = int_log2(blocksize);
+               blk_shift = ulong_log2(blocksize);
        else
-               blk_shift = int_log2(blksize);
+               blk_shift = ulong_log2(blksize);
 
-       width = int_log10(numblocks);
+       width = ulong_log10(numblocks);
        if (width > logical_width)
                logical_width = width;
        if (verbose)
@@ -517,7 +517,7 @@ out_close:
 
 static void usage(const char *progname)
 {
-       fprintf(stderr, "Usage: %s [-b{blocksize}] [-BeksvxX] file ...\n",
+       fprintf(stderr, "Usage: %s [-b{blocksize}[KMG]] [-BeksvxX] file ...\n",
                progname);
        exit(1);
 }
@@ -535,7 +535,9 @@ int main(int argc, char**argv)
                case 'b':
                        if (optarg) {
                                char *end;
-                               blocksize = strtoul(optarg, &end, 0);
+                               unsigned long val;
+
+                               val = strtoul(optarg, &end, 0);
                                if (end) {
 #if __GNUC_PREREQ (7, 0)
 #pragma GCC diagnostic push
@@ -544,15 +546,15 @@ int main(int argc, char**argv)
                                        switch (end[0]) {
                                        case 'g':
                                        case 'G':
-                                               blocksize *= 1024;
+                                               val *= 1024;
                                                /* fall through */
                                        case 'm':
                                        case 'M':
-                                               blocksize *= 1024;
+                                               val *= 1024;
                                                /* fall through */
                                        case 'k':
                                        case 'K':
-                                               blocksize *= 1024;
+                                               val *= 1024;
                                                break;
                                        default:
                                                break;
@@ -561,6 +563,16 @@ int main(int argc, char**argv)
 #pragma GCC diagnostic pop
 #endif
                                }
+                               /* Specifying too large a blocksize will just
+                                * shift all extents down to zero length. Even
+                                * 1GB is questionable, but caveat emptor. */
+                               if (val > 1024 * 1024 * 1024) {
+                                       fprintf(stderr,
+                                               "%s: blocksize %lu over 1GB\n",
+                                               argv[0], val);
+                                       usage(argv[0]);
+                               }
+                               blocksize = val;
                        } else { /* Allow -b without argument for compat. Remove
                                  * this eventually so "-b {blocksize}" works */
                                fprintf(stderr, "%s: -b needs a blocksize "