e2fsprogs-fiemap.patch

Add support for ioctl(FIEMAP) to filefrag.  If the kernel supports FIEMAP
the filefrag program prefers this more efficient mechanism to get extent
information instead of repeated FIBMAP calls.

Signed-off-by: Kalpak Shah <kalpak@clusterfs.com>
Signed-off-by: Andreas Dilger <adilger@clusterfs.com>

diff --git a/misc/filefrag.c b/misc/filefrag.c
index 27675b198e7579ab5c5e28495cc883d625af1c6c..83d53db6268fc1f8604006a504dce1e9312ec5f7 100644 (file)
--- a/misc/filefrag.c
+++ b/misc/filefrag.c
@@ -38,11 +38,47 @@ extern int optind;
 #include <sys/vfs.h>
 #include <sys/ioctl.h>
 #include <linux/fd.h>
+#include <ext2fs/ext2_types.h>
 
 int verbose = 0;
 
-#define FIBMAP    _IO(0x00,1)  /* bmap access */
-#define FIGETBSZ   _IO(0x00,2) /* get the block size used for bmap */
+struct fiemap_extent {
+       __u64 fe_offset; /* offset in bytes for the start of the extent */
+       __u64 fe_length; /* length in bytes for the extent */
+       __u32 fe_flags;  /* returned FIEMAP_EXTENT_* flags for the extent */
+       __u32 fe_lun;    /* logical device number for extent (starting at 0) */
+};
+
+struct fiemap {
+       __u64 fm_start;         /* logical starting byte offset (in/out) */
+       __u64 fm_length;        /* logical length of map (in/out) */
+       __u32 fm_flags;         /* FIEMAP_FLAG_* flags for request (in/out) */
+       __u32 fm_extent_count;  /* number of extents in fm_extents (in/out) */
+       __u64 fm_unused;
+       struct fiemap_extent fm_extents[0];
+};
+
+#define FIEMAP_FLAG_SYNC       0x00000001 /* sync file data before map */
+#define FIEMAP_FLAG_HSM_READ    0x00000002 /* get data from HSM before map */
+#define FIEMAP_FLAG_NUM_EXTENTS 0x00000004 /* return only number of extents */
+#define FIEMAP_FLAG_INCOMPAT    0xff000000 /* error for unknown flags in here */
+
+#define FIEMAP_EXTENT_HOLE      0x00000001 /* has no data or space allocation */
+#define FIEMAP_EXTENT_UNWRITTEN 0x00000002 /* space allocated, but no data */
+#define FIEMAP_EXTENT_UNMAPPED  0x00000004 /* has data but no space allocation*/
+#define FIEMAP_EXTENT_ERROR     0x00000008 /* mapping error, errno in fe_start*/
+#define FIEMAP_EXTENT_NO_DIRECT 0x00000010 /* cannot access data directly */
+#define FIEMAP_EXTENT_LAST      0x00000020 /* last extent in the file */
+#define FIEMAP_EXTENT_DELALLOC  0x00000040 /* has data but not yet written,
+                                             must have EXTENT_UNKNOWN set */
+#define FIEMAP_EXTENT_SECONDARY 0x00000080 /* data (also) in secondary storage,
+                                             not in primary if EXTENT_UNKNOWN*/
+#define FIEMAP_EXTENT_EOF       0x00000100 /* if fm_start+fm_len is beyond EOF*/
+
+
+#define FIBMAP         _IO(0x00, 1)    /* bmap access */
+#define FIGETBSZ       _IO(0x00, 2)    /* get the block size used for bmap */
+#define EXT4_IOC_FIEMAP        _IOWR('f', 10, struct fiemap) /* get file  extent info*/
 
 #define EXT4_EXTENTS_FL                        0x00080000 /* Inode uses extents */
 #define        EXT3_IOC_GETFLAGS               _IOR('f', 1, long)
@@ -71,6 +107,62 @@ static unsigned long get_bmap(int fd, unsigned long block)
        return b;
 }
 
+int filefrag_fiemap(int fd, int bs, int *num_extents)
+{
+       char buf[4096] = "";
+       struct fiemap *fiemap = (struct fiemap *)buf;
+       int count = (sizeof(buf) - sizeof(*fiemap)) /
+                       sizeof(struct fiemap_extent);
+       __u64 logical_blk = 0, last_blk = 0;
+       unsigned long flags;
+       int tot_extents = 0;
+       int eof = 0;
+       int i;
+       int rc;
+
+       memset(fiemap, 0, sizeof(struct fiemap));
+       fiemap->fm_extent_count = count;
+       fiemap->fm_length = ~0ULL;
+       if (!verbose)
+               flags |= FIEMAP_FLAG_NUM_EXTENTS;
+
+       do {
+               fiemap->fm_length = ~0ULL;
+               fiemap->fm_flags = flags;
+               fiemap->fm_extent_count = count;
+               rc = ioctl (fd, EXT4_IOC_FIEMAP, (unsigned long) fiemap);
+               if (rc)
+                       return rc;
+
+               if (!verbose) {
+                       *num_extents = fiemap->fm_extent_count;
+                       goto out;
+               }
+
+               for (i = 0; i < fiemap->fm_extent_count; i++) {
+                       __u64 phy_blk;
+                       unsigned long ext_len;
+
+                       phy_blk = fiemap->fm_extents[i].fe_offset / bs;
+                       ext_len = fiemap->fm_extents[i].fe_length / bs;
+                       if (logical_blk && (phy_blk != last_blk+1))
+                               printf("Discontinuity: Block %llu is at %llu "
+                                      "(was %llu)\n", logical_blk, phy_blk,
+                                      last_blk);
+                       logical_blk += ext_len;
+                       last_blk = phy_blk + ext_len - 1;
+                       if (fiemap->fm_extents[i].fe_flags & FIEMAP_EXTENT_EOF)
+                               eof = 1;
+               }
+               fiemap->fm_start += fiemap->fm_length;
+               tot_extents += fiemap->fm_extent_count;
+       } while (0);
+
+       *num_extents = tot_extents;
+out:
+       return 0;
+}
+
 #define EXT2_DIRECT    12
 
 static void frag_report(const char *filename)
@@ -86,7 +178,7 @@ static void frag_report(const char *filename)
        unsigned long   block, last_block = 0, numblocks, i;
        long            bpib;   /* Blocks per indirect block */
        long            cylgroups;
-       int             discont = 0, expected;
+       int             num_extents = 0, expected;
        int             is_ext2 = 0;
        unsigned int    flags;
 
@@ -135,7 +227,8 @@ static void frag_report(const char *filename)
        if (ioctl(fd, EXT3_IOC_GETFLAGS, &flags) < 0)
                flags = 0;
        if (flags & EXT4_EXTENTS_FL) {
-               printf("File is stored in extents format\n");
+               if (verbose)
+                       printf("File is stored in extents format\n");
                is_ext2 = 0;
        }
        if (verbose)
@@ -148,32 +241,36 @@ static void frag_report(const char *filename)
                printf("First block: %lu\nLast block: %lu\n",
                       get_bmap(fd, 0), get_bmap(fd, numblocks - 1));
        }
-       for (i=0; i < numblocks; i++) {
-               if (is_ext2 && last_block) {
-                       if (((i-EXT2_DIRECT) % bpib) == 0)
-                               last_block++;
-                       if (((i-EXT2_DIRECT-bpib) % (bpib*bpib)) == 0)
-                               last_block++;
-                       if (((i-EXT2_DIRECT-bpib-bpib*bpib) % (bpib*bpib*bpib)) == 0)
-                               last_block++;
-               }
-               block = get_bmap(fd, i);
-               if (block == 0)
-                       continue;
-               if (last_block && (block != last_block +1) ) {
-                       if (verbose)
-                               printf("Discontinuity: Block %ld is at %lu (was %lu)\n",
-                                      i, block, last_block);
-                       discont++;
+       if (is_ext2 || (filefrag_fiemap(fd, bs, &num_extents) != 0)) {
+               for (i = 0; i < numblocks; i++) {
+                       if (is_ext2 && last_block) {
+                               if (((i-EXT2_DIRECT) % bpib) == 0)
+                                       last_block++;
+                               if (((i-EXT2_DIRECT-bpib) % (bpib*bpib)) == 0)
+                                       last_block++;
+                               if (((i-EXT2_DIRECT-bpib-bpib*bpib) %
+                                                       (bpib*bpib*bpib)) == 0)
+                                       last_block++;
+                       }
+                       block = get_bmap(fd, i);
+                       if (block == 0)
+                               continue;
+                       if (last_block && (block != last_block+1) ) {
+                               if (verbose)
+                                       printf("Discontinuity: Block %ld is at "
+                                              "%lu (was %lu)\n",
+                                              i, block, last_block+1);
+                               num_extents++;
+                       }
+                       last_block = block;
                }
-               last_block = block;
        }
-       if (discont==0)
+       if (num_extents == 1)
                printf("%s: 1 extent found", filename);
        else
-               printf("%s: %d extents found", filename, discont+1);
+               printf("%s: %d extents found", filename, num_extents);
        expected = (numblocks/((bs*8)-(fsinfo.f_files/8/cylgroups)-3))+1;
-       if (is_ext2 && expected != discont+1)
+       if (is_ext2 && expected != num_extents)
                printf(", perfection would be %d extent%s\n", expected,
                        (expected>1) ? "s" : "");
        else