-A large part of this code is from the generic VFS code in fs/ioctl.c in the
-upstream kernel.
-
-Index: linux-2.6.9-67.0.22/fs/ext3/ioctl.c
-===================================================================
---- linux-2.6.9-67.0.22.orig/fs/ext3/ioctl.c
-+++ linux-2.6.9-67.0.22/fs/ext3/ioctl.c
-@@ -14,7 +14,159 @@
- #include <linux/time.h>
- #include <asm/uaccess.h>
- #include <linux/namei.h>
-+#include "fiemap.h"
-
-+/* So that the fiemap access checks can't overflow on 32 bit machines. */
-+#define FIEMAP_MAX_EXTENTS (UINT_MAX / sizeof(struct fiemap_extent))
-+
-+/**
-+ * fiemap_fill_next_extent - Fiemap helper function
-+ * @fieinfo: Fiemap context passed into ->fiemap
-+ * @logical: Extent logical start offset, in bytes
-+ * @phys: Extent physical start offset, in bytes
-+ * @len: Extent length, in bytes
-+ * @flags: FIEMAP_EXTENT flags that describe this extent
-+ * @lun: LUN on which this extent resides
-+ *
-+ * Called from file system ->fiemap callback. Will populate extent
-+ * info as passed in via arguments and copy to user memory. On
-+ * success, extent count on fieinfo is incremented.
-+ *
-+ * Returns 0 on success, -errno on error, 1 if this was the last
-+ * extent that will fit in user array.
-+ */
-+#define SET_UNKNOWN_FLAGS (FIEMAP_EXTENT_DELALLOC)
-+#define SET_NO_DIRECT_FLAGS (FIEMAP_EXTENT_DATA_COMPRESSED \
-+ |FIEMAP_EXTENT_DATA_ENCRYPTED \
-+ |FIEMAP_EXTENT_NET)
-+#define SET_NOT_ALIGNED_FLAGS (FIEMAP_EXTENT_DATA_TAIL|FIEMAP_EXTENT_DATA_INLINE)
-+int fiemap_fill_next_extent(struct fiemap_extent_info *fieinfo, u64 logical,
-+ u64 phys, u64 len, u32 flags, dev_t dev)
-+{
-+ struct fiemap_extent extent = { 0 };
-+ struct fiemap_extent *dest = fieinfo->fi_extents_start;
-+
-+ /* only count the extents */
-+ if (fieinfo->fi_extents_max == 0) {
-+ fieinfo->fi_extents_mapped++;
-+ return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
-+ }
-+
-+ if (fieinfo->fi_extents_mapped >= fieinfo->fi_extents_max)
-+ return 1;
-+
-+ if (flags & SET_UNKNOWN_FLAGS)
-+ flags |= FIEMAP_EXTENT_UNKNOWN;
-+ if (flags & SET_NO_DIRECT_FLAGS)
-+ flags |= FIEMAP_EXTENT_NO_DIRECT;
-+ if (flags & SET_NOT_ALIGNED_FLAGS)
-+ flags |= FIEMAP_EXTENT_NOT_ALIGNED;
-+
-+ extent.fe_logical = logical;
-+ extent.fe_physical = phys;
-+ extent.fe_length = len;
-+ extent.fe_flags = flags;
-+ extent.fe_device = new_encode_dev(dev);
-+
-+ dest += fieinfo->fi_extents_mapped;
-+ if (copy_to_user(dest, &extent, sizeof(extent)))
-+ return -EFAULT;
-+
-+ fieinfo->fi_extents_mapped++;
-+ if (fieinfo->fi_extents_mapped == fieinfo->fi_extents_max)
-+ return 1;
-+
-+ return (flags & FIEMAP_EXTENT_LAST) ? 1 : 0;
-+}
-+
-+static int fiemap_check_ranges(struct super_block *sb,
-+ u64 start, u64 len, u64 *new_len)
-+{
-+ *new_len = len;
-+
-+ if (len == 0)
-+ return -EINVAL;
-+
-+ if (start > sb->s_maxbytes)
-+ return -EFBIG;
-+
-+ /*
-+ * Shrink request scope to what the fs can actually handle.
-+ */
-+ if ((len > sb->s_maxbytes) ||
-+ (sb->s_maxbytes - len) < start)
-+ *new_len = sb->s_maxbytes - start;
-+
-+ return 0;
-+}
-+
-+/*
-+ * fiemap_check_flags - check validity of requested flags for fiemap
-+ * @fieinfo: Fiemap context passed into ->fiemap
-+ * @fs_flags: Set of fiemap flags that the file system understands
-+ *
-+ * Called from file system ->fiemap callback. This will compute the
-+ * intersection of valid fiemap flags and those that the fs supports. That
-+ * value is then compared against the user supplied flags. In case of bad user
-+ * flags, the invalid values will be written into the fieinfo structure, and
-+ * -EBADR is returned, which tells ioctl_fiemap() to return those values to
-+ * userspace. For this reason, a return code of -EBADR should be preserved.
-+ *
-+ * Returns 0 on success, -EBADR on bad flags.
-+*/
-+int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags)
-+{
-+ u32 incompat_flags;
-+
-+ incompat_flags = fieinfo->fi_flags & ~(FIEMAP_FLAGS_COMPAT & fs_flags);
-+ if (incompat_flags) {
-+ fieinfo->fi_flags = incompat_flags;
-+ return -EBADR;
-+ }
-+
-+ return 0;
-+}
-+
-+int ioctl_fiemap(struct inode *inode, struct file *filp, unsigned long arg)
-+{
-+ struct fiemap fiemap;
-+ u64 len;
-+ struct fiemap_extent_info fieinfo = {0, };
-+ struct super_block *sb = inode->i_sb;
-+ int error = 0;
-+
-+ if (copy_from_user(&fiemap, (struct fiemap __user *) arg,
-+ sizeof(struct fiemap)))
-+ return -EFAULT;
-+
-+ if (fiemap.fm_extent_count > FIEMAP_MAX_EXTENTS)
-+ return -EINVAL;
-+
-+ error = fiemap_check_ranges(sb, fiemap.fm_start, fiemap.fm_length,
-+ &len);
-+ if (error)
-+ return error;
-+
-+ fieinfo.fi_flags = fiemap.fm_flags;
-+ fieinfo.fi_extents_max = fiemap.fm_extent_count;
-+ fieinfo.fi_extents_start = (struct fiemap_extent *)(arg + sizeof(fiemap));
-+
-+ if (fiemap.fm_extent_count != 0 &&
-+ !access_ok(VERIFY_WRITE, (void *)arg,
-+ offsetof(typeof(fiemap), fm_extents[fiemap.fm_extent_count])))
-+ return -EFAULT;
-+
-+ if (fieinfo.fi_flags & FIEMAP_FLAG_SYNC)
-+ ext3_sync_file(filp, filp->f_dentry, 1);
-+
-+ error = ext3_fiemap(inode, &fieinfo, fiemap.fm_start, len);
-+ fiemap.fm_flags = fieinfo.fi_flags;
-+ fiemap.fm_mapped_extents = fieinfo.fi_extents_mapped;
-+ if (copy_to_user((char *)arg, &fiemap, sizeof(fiemap)))
-+ error = -EFAULT;
-+
-+ return error;
-+}
-
- int ext3_ioctl (struct inode * inode, struct file * filp, unsigned int cmd,
- unsigned long arg)
-@@ -244,7 +396,9 @@ flags_err:
-
- return err;
- }
--
-+ case EXT3_IOC_FIEMAP: {
-+ return ioctl_fiemap(inode, filp, arg);
-+ }
-
- default:
- return -ENOTTY;
-Index: linux-2.6.9-67.0.22/include/linux/ext3_fs.h
-===================================================================
---- linux-2.6.9-67.0.22.orig/include/linux/ext3_fs.h
-+++ linux-2.6.9-67.0.22/include/linux/ext3_fs.h
-@@ -259,15 +259,19 @@ struct ext3_new_group_data {
- #define EXT3_IOC_SETFLAGS _IOW('f', 2, long)
- #define EXT3_IOC_GETVERSION _IOR('f', 3, long)
- #define EXT3_IOC_SETVERSION _IOW('f', 4, long)
-+#define EXT3_IOC_GETRSVSZ _IOR('f', 5, long)
-+#define EXT3_IOC_SETRSVSZ _IOW('f', 6, long)
- #define EXT3_IOC_GROUP_EXTEND _IOW('f', 7, unsigned long)
- #define EXT3_IOC_GROUP_ADD _IOW('f', 8,struct ext3_new_group_input)
-+#define EXT3_IOC_FIEMAP _IOWR('f', 10, struct fiemap)
- #define EXT3_IOC_GETVERSION_OLD _IOR('v', 1, long)
- #define EXT3_IOC_SETVERSION_OLD _IOW('v', 2, long)
- #ifdef CONFIG_JBD_DEBUG
- #define EXT3_IOC_WAIT_FOR_READONLY _IOR('f', 99, long)
- #endif
--#define EXT3_IOC_GETRSVSZ _IOR('f', 5, long)
--#define EXT3_IOC_SETRSVSZ _IOW('f', 6, long)
-+
-+/* FIEMAP flags supported by ext3 */
-+#define EXT3_FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC)
-
- /*
- * Structure of an inode on the disk
-@@ -969,6 +973,9 @@ extern void ext3_set_aops(struct inode *
- /* ioctl.c */
- extern int ext3_ioctl (struct inode *, struct file *, unsigned int,
- unsigned long);
-+struct fiemap_extent_info;
-+extern int ext3_fiemap(struct inode *, struct fiemap_extent_info *, __u64,
-+ __u64);
-
- /* namei.c */
- extern int ext3_orphan_add(handle_t *, struct inode *);
-Index: linux-2.6.9-67.0.22/include/linux/ext3_extents.h
-===================================================================
---- linux-2.6.9-67.0.22.orig/include/linux/ext3_extents.h
-+++ linux-2.6.9-67.0.22/include/linux/ext3_extents.h
-@@ -170,7 +170,10 @@ struct ext3_extents_helpers {
- */
- typedef int (*ext_prepare_callback)(struct ext3_extents_tree *,
- struct ext3_ext_path *,
-- struct ext3_ext_cache *);
-+ struct ext3_ext_cache *,
-+ struct ext3_extent *);
-+
-+#define HAVE_EXT_PREPARE_CB_EXTENT
-
- #define EXT_CONTINUE 0
- #define EXT_BREAK 1
-@@ -179,6 +182,25 @@ typedef int (*ext_prepare_callback)(stru
-
- #define EXT_MAX_BLOCK 0xffffffff
-
-+/*
-+ * EXT_INIT_MAX_LEN is the maximum number of blocks we can have in an
-+ * initialized extent. This is 2^15 and not (2^16 - 1), since we use the
-+ * MSB of ee_len field in the extent datastructure to signify if this
-+ * particular extent is an initialized extent or an uninitialized (i.e.
-+ * preallocated).
-+ * EXT_UNINIT_MAX_LEN is the maximum number of blocks we can have in an
-+ * uninitialized extent.
-+ * If ee_len is <= 0x8000, it is an initialized extent. Otherwise, it is an
-+ * uninitialized one. In other words, if MSB of ee_len is set, it is an
-+ * uninitialized extent with only one special scenario when ee_len = 0x8000.
-+ * In this case we can not have an uninitialized extent of zero length and
-+ * thus we make it as a special case of initialized extent with 0x8000 length.
-+ * This way we get better extent-to-group alignment for initialized extents.
-+ * Hence, the maximum number of blocks we can have in an *initialized*
-+ * extent is 2^15 (32768) and in an *uninitialized* extent is 2^15-1 (32767).
-+ */
-+#define EXT_INIT_MAX_LEN (1UL << 15)
-+#define EXT_UNINIT_MAX_LEN (EXT_INIT_MAX_LEN - 1)
-
- #define EXT_FIRST_EXTENT(__hdr__) \
- ((struct ext3_extent *) (((char *) (__hdr__)) + \
-@@ -244,6 +266,12 @@ struct ext3_extent_tree_stats {
- int leaf_num;
- };
-
-+static inline int ext3_ext_is_uninitialized(struct ext3_extent *ext)
-+{
-+ /* Extent with ee_len of 0x8000 is treated as an initialized extent */
-+ return (le16_to_cpu(ext->ee_len) > EXT_INIT_MAX_LEN);
-+}
-+
- extern int ext3_ext_search_left(struct ext3_extents_tree *, struct ext3_ext_path *, unsigned long *, unsigned long *);
- extern int ext3_ext_search_right(struct ext3_extents_tree *, struct ext3_ext_path *, unsigned long *, unsigned long *);
- extern void ext3_init_tree_desc(struct ext3_extents_tree *, struct inode *);
-Index: linux-2.6.9-67.0.22/fs/ext3/extents.c
-===================================================================
---- linux-2.6.9-67.0.22.orig/fs/ext3/extents.c
-+++ linux-2.6.9-67.0.22/fs/ext3/extents.c
-@@ -41,6 +41,7 @@
- #include <linux/string.h>
- #include <linux/slab.h>
- #include <linux/ext3_extents.h>
-+#include "fiemap.h"
- #include <asm/uaccess.h>
-
-
-@@ -1489,7 +1490,7 @@ int ext3_ext_walk_space(struct ext3_exte
-
- EXT_ASSERT(cbex.ec_len > 0);
- EXT_ASSERT(path[depth].p_hdr);
-- err = func(tree, path, &cbex);
-+ err = func(tree, path, &cbex, ex);
- ext3_ext_drop_refs(path);
-
- if (err < 0)
-@@ -2504,6 +2505,108 @@ int ext3_ext_calc_blockmap_metadata(stru
- return ext3_ext_calc_metadata_amount(&tree, blocks);
- }
-
-+/*
-+ * Callback function called for each extent to gather FIEMAP information.
-+ */
-+int ext3_ext_fiemap_cb(struct ext3_extents_tree *tree,
-+ struct ext3_ext_path *path, struct ext3_ext_cache *newex,
-+ struct ext3_extent *ex)
-+{
-+ struct fiemap_extent_info *fieinfo = (struct fiemap_extent_info *)tree->private;
-+ struct inode *inode = tree->inode;
-+ unsigned long blksize_bits = inode->i_sb->s_blocksize_bits;
-+ __u64 logical;
-+ __u64 physical;
-+ __u64 length;
-+ __u32 flags = 0;
-+ int error;
-+
-+ logical = (__u64)newex->ec_block << blksize_bits;
-+
-+ if (newex->ec_type == EXT3_EXT_CACHE_GAP) {
-+ pgoff_t offset;
-+ struct page *page;
-+ struct buffer_head *bh = NULL;
-+
-+ offset = logical >> PAGE_SHIFT;
-+ page = find_get_page(inode->i_mapping, offset);
-+ if (!page || !page_has_buffers(page))
-+ return EXT_CONTINUE;
-+
-+ bh = page_buffers(page);
-+
-+ if (!bh)
-+ return EXT_CONTINUE;
-+
-+ if (buffer_delay(bh)) {
-+ flags |= FIEMAP_EXTENT_DELALLOC;
-+ page_cache_release(page);
-+ } else {
-+ page_cache_release(page);
-+ return EXT_CONTINUE;
-+ }
-+ }
-+
-+ physical = (__u64)newex->ec_start << blksize_bits;
-+ length = (__u64)newex->ec_len << blksize_bits;
-+
-+ if (ex && ext3_ext_is_uninitialized(ex))
-+ flags |= FIEMAP_EXTENT_UNWRITTEN;
-+
-+ /*
-+ * If this extent reaches EXT_MAX_BLOCK, it must be last.
-+ *
-+ * Or if ext3_ext_next_allocated_block is EXT_MAX_BLOCK,
-+ * this indicates no more allocated blocks.
-+ *
-+ * XXX this might miss a single-block extent at EXT_MAX_BLOCK
-+ */
-+ if (logical + length - 1 == EXT_MAX_BLOCK ||
-+ ext3_ext_next_allocated_block(path) == EXT_MAX_BLOCK)
-+ flags |= FIEMAP_EXTENT_LAST;
-+
-+ error = fiemap_fill_next_extent(fieinfo, logical, physical,
-+ length, flags, inode->i_sb->s_dev);
-+ if (error < 0)
-+ return error;
-+ if (error == 1)
-+ return EXT_BREAK;
-+
-+ return EXT_CONTINUE;
-+}
-+
-+int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
-+ __u64 start, __u64 len)
-+{
-+ struct ext3_extents_tree tree;
-+ unsigned long start_blk;
-+ unsigned long len_blks;
-+ int error = 0;
-+
-+ if (!(EXT3_I(inode)->i_flags & EXT3_EXTENTS_FL))
-+ return -EOPNOTSUPP;
-+
-+ if (fiemap_check_flags(fieinfo, EXT3_FIEMAP_FLAGS_COMPAT))
-+ return -EBADR;
-+
-+ start_blk = start >> inode->i_sb->s_blocksize_bits;
-+ len_blks = (len + inode->i_sb->s_blocksize - 1) >> inode->i_sb->s_blocksize_bits;
-+
-+ ext3_init_tree_desc(&tree, inode);
-+ tree.private = fieinfo;
-+
-+ /*
-+ * Walk the extent tree gathering extent information.
-+ * ext3_ext_fiemap_cb will push extents back to user.
-+ */
-+ down(&EXT3_I(inode)->truncate_sem);
-+ error = ext3_ext_walk_space(&tree, start_blk, len_blks,
-+ ext3_ext_fiemap_cb);
-+ up(&EXT3_I(inode)->truncate_sem);
-+
-+ return error;
-+}
-+
- EXPORT_SYMBOL(ext3_init_tree_desc);
- EXPORT_SYMBOL(ext3_mark_inode_dirty);
- EXPORT_SYMBOL(ext3_ext_invalidate_cache);
-Index: linux-2.6.9-67.0.22/fs/ext3/fiemap.h
-===================================================================
---- /dev/null
-+++ linux-2.6.9-67.0.22/fs/ext3/fiemap.h
-@@ -0,0 +1,84 @@
-+/*
-+ * FIEMAP ioctl infrastructure.
-+ *
-+ * Copyright 2008 Sun Microsystems, Inc.
-+ *
-+ * Author: Kalpak Shah <kalpak.shah@sun.com>
-+ * Andreas Dilger <adilger@sun.com>
-+ */
-+
-+#ifndef _LINUX_EXT3_FIEMAP_H
-+#define _LINUX_EXT3_FIEMAP_H
-+
-+struct fiemap_extent {
-+ __u64 fe_logical; /* logical offset in bytes for the start of
-+ * the extent from the beginning of the file */
-+ __u64 fe_physical; /* physical offset in bytes for the start
-+ * of the extent from the beginning of the disk */
-+ __u64 fe_length; /* length in bytes for this extent */
-+ __u32 fe_flags; /* FIEMAP_EXTENT_* flags for this extent */
-+ __u32 fe_device; /* device number for this extent */
-+};
-+
-+struct fiemap {
-+ __u64 fm_start; /* logical offset (inclusive) at
-+ * which to start mapping (in) */
-+ __u64 fm_length; /* logical length of mapping which
-+ * userspace wants (in) */
-+ __u32 fm_flags; /* FIEMAP_FLAG_* flags for request (in/out) */
-+ __u32 fm_mapped_extents;/* number of extents that were mapped (out) */
-+ __u32 fm_extent_count; /* size of fm_extents array (in) */
-+ __u32 fm_reserved;
-+ struct fiemap_extent fm_extents[0]; /* array of mapped extents (out) */
-+};
-+
-+/*
-+ * FIEMAP helper definition.
-+ */
-+struct fiemap_extent_info {
-+ unsigned int fi_flags; /* Flags as passed from user */
-+ unsigned int fi_extents_mapped; /* Number of mapped extents */
-+ unsigned int fi_extents_max; /* Size of fiemap_extent array*/
-+ struct fiemap_extent *fi_extents_start; /* Start of fiemap_extent array */
-+};
-+
-+int fiemap_check_flags(struct fiemap_extent_info *fieinfo, u32 fs_flags);
-+int fiemap_fill_next_extent(struct fiemap_extent_info *info, u64 logical,
-+ u64 phys, u64 len, u32 flags, u32 lun);
-+
-+#define FIEMAP_MAX_OFFSET (~0ULL)
-+
-+#define FIEMAP_FLAG_SYNC 0x00000001 /* sync file data before map */
-+#define FIEMAP_FLAG_XATTR 0x00000002 /* map extended attribute tree */
-+
-+/* ldiskfs only supports FLAG_SYNC flag currently */
-+#define FIEMAP_FLAGS_COMPAT (FIEMAP_FLAG_SYNC | FIEMAP_FLAG_XATTR)
-+
-+
-+#define FIEMAP_EXTENT_LAST 0x00000001 /* Last extent in file. */
-+#define FIEMAP_EXTENT_UNKNOWN 0x00000002 /* Data location unknown. */
-+#define FIEMAP_EXTENT_DELALLOC 0x00000004 /* Location still pending.
-+ * Sets EXTENT_UNKNOWN. */
-+#define FIEMAP_EXTENT_NO_DIRECT 0x00000008 /* Data mapping undefined */
-+#define FIEMAP_EXTENT_SECONDARY 0x00000010 /* Data copied offline. May
-+ * set EXTENT_NO_DIRECT. */
-+#define FIEMAP_EXTENT_NET 0x00000020 /* Data stored remotely.
-+ * Sets EXTENT_NO_DIRECT. */
-+#define FIEMAP_EXTENT_DATA_COMPRESSED 0x00000040 /* Data is compressed by fs.
-+ * Sets EXTENT_NO_DIRECT. */
-+#define FIEMAP_EXTENT_DATA_ENCRYPTED 0x00000080 /* Data is encrypted by fs.
-+ * Sets EXTENT_NO_DIRECT. */
-+#define FIEMAP_EXTENT_NOT_ALIGNED 0x00000100 /* Extent offsets may not be
-+ * block aligned. */
-+#define FIEMAP_EXTENT_DATA_INLINE 0x00000200 /* Data mixed with metadata.
-+ * Sets EXTENT_NOT_ALIGNED.*/
-+#define FIEMAP_EXTENT_DATA_TAIL 0x00000400 /* Multiple files in block.
-+ * Sets EXTENT_NOT_ALIGNED.*/
-+#define FIEMAP_EXTENT_UNWRITTEN 0x00000800 /* Space allocated, but
-+ * no data (i.e. zero). */
-+#define FIEMAP_EXTENT_MERGED 0x00001000 /* File does not natively
-+ * support extents. Result
-+ * merged for efficiency. */
-+
-+#endif /* _LINUX_EXT3_FIEMAP_H */
-+