- Get all extents information of specified inode number to calculate
the combination of extents which should be moved to other block group.
Signed-off-by: Takashi Sato <[email protected]>
Signed-off-by: Akira Fujita <[email protected]>
---
diff -X Online-Defrag_linux-2.6.19-rc6-git/Documentation/dontdiff -upNr Online-Defrag_linux-2.6.19-rc6-git-EXTENTS_INFO/fs/ext4/extents.c Online-Defrag_linux-2.6.19-rc6-git-MOVE_VICTIM/fs/ext4/extents.c
--- Online-Defrag_linux-2.6.19-rc6-git-EXTENTS_INFO/fs/ext4/extents.c 2007-06-20 08:50:57.000000000 +0900
+++ Online-Defrag_linux-2.6.19-rc6-git-MOVE_VICTIM/fs/ext4/extents.c 2007-06-20 08:27:44.000000000 +0900
@@ -43,6 +43,12 @@
#include <linux/ext4_fs_extents.h>
#include <asm/uaccess.h>
+#define DIO_CREDITS (EXT4_RESERVE_TRANS_BLOCKS + 32)
+#define EXT_SET_EXTENT_DATA(src, dest) do {\
+ dest.block = le32_to_cpu(src->ee_block);\
+ dest.start = ext_pblock(src);\
+ dest.len = le16_to_cpu(src->ee_len);\
+ } while (0)
/*
* ext_pblock:
* combine low and high parts of physical block number into ext4_fsblk_t
@@ -2479,6 +2485,121 @@ ext4_ext_next_extent(struct inode *inode
}
/**
+ * ext4_ext_extents_info() - get extents information
+ *
+ * @ext_info: pointer to ext4_extents_info
+ * @ext_info->ino describe an inode which is used to get extent
+ * information
+ * @ext_info->max_entries: defined by DEFRAG_MAX_ENT
+ * @ext_info->entries: amount of extents (output)
+ * @ext_info->ext[]: array of extent (output)
+ * @ext_info->offset: starting block offset of targeted extent
+ * (file relative)
+ *
+ * @sb: for iget()
+ *
+ * This function returns 0 if next extent(s) exists,
+ * or returns 1 if next extent doesn't exist, otherwise returns error value.
+ * Called under truncate_mutex lock.
+ */
+static int ext4_ext_extents_info(struct ext4_extents_info *ext_info,
+ struct super_block *sb)
+{
+ struct ext4_ext_path *path = NULL;
+ struct ext4_extent *ext = NULL;
+ struct inode *inode = NULL;
+ unsigned long offset = ext_info->offset;
+ int max = ext_info->max_entries;
+ int is_last_extent = 0;
+ int depth = 0;
+ int entries = 0;
+ int err = 0;
+
+ inode = iget(sb, ext_info->ino);
+ if (!inode)
+ return -EACCES;
+
+ mutex_lock(&EXT4_I(inode)->truncate_mutex);
+
+ /* if a file doesn't exist*/
+ if ((!inode->i_nlink) || (inode->i_ino < 12) ||
+ !S_ISREG(inode->i_mode)) {
+ ext_info->entries = 0;
+ err = -ENOENT;
+ goto out;
+ }
+
+ path = ext4_ext_find_extent(inode, offset, NULL);
+ if (IS_ERR(path)) {
+ err = PTR_ERR(path);
+ path = NULL;
+ goto out;
+ }
+ depth = ext_depth(inode);
+ ext = path[depth].p_ext;
+ EXT_SET_EXTENT_DATA(ext, ext_info->ext[entries]);
+ entries = 1;
+
+ /*
+ * The ioctl can return 'max' ext4_extent_data per a call,
+ * so if @inode has > 'max' extents, we must get away here.
+ */
+ while (entries < max) {
+ is_last_extent = ext4_ext_next_extent(inode, path, &ext);
+ /* found next extent (not the last one)*/
+ if (is_last_extent == 0) {
+ EXT_SET_EXTENT_DATA(ext, ext_info->ext[entries]);
+ entries++;
+
+ /*
+ * If @inode has > 'max' extents,
+ * this function should be called again,
+ * (per a call, it can resolve only 'max' extents)
+ * next time we have to start from 'max*n+1'th extent.
+ */
+ if (entries == max) {
+ ext_info->offset =
+ le32_to_cpu(ext->ee_block) +
+ le32_to_cpu(ext->ee_len);
+ /* check the extent is the last one or not*/
+ is_last_extent =
+ ext4_ext_next_extent(inode, path, &ext);
+ if (is_last_extent) {
+ is_last_extent = 1;
+ err = is_last_extent;
+ } else if (is_last_extent < 0) {
+ /*ERR*/
+ err = is_last_extent;
+ goto out;
+ }
+ break;
+ }
+
+ /* the extent is the last one */
+ } else if (is_last_extent == 1) {
+ ext_info->offset = 0;
+ err = is_last_extent;
+ break;
+ } else {
+ /* ERR */
+ err = is_last_extent;
+ goto out;
+ }
+ }
+
+ ext_info->entries = entries;
+
+out:
+ if (path) {
+ ext4_ext_drop_refs(path);
+ kfree(path);
+ }
+ mutex_unlock(&EXT4_I(inode)->truncate_mutex);
+ iput(inode);
+ return err;
+}
+
+/**
* ext4_ext_fblocks_distribution - Search free block distribution
* @filp target file
* @ex_info ext4_extents_info
@@ -2653,6 +2774,20 @@ int ext4_ext_ioctl(struct inode *inode,
if (!err)
err = copy_to_user((struct ext4_extents_info*)arg,
&ext_info, sizeof(ext_info));
+ } else if (cmd == EXT4_IOC_EXTENTS_INFO) {
+ struct ext4_extents_info ext_info;
+
+ if (copy_from_user(&ext_info,
+ (struct ext4_extents_info __user *)arg,
+ sizeof(ext_info)))
+ return -EFAULT;
+
+ err = ext4_ext_extents_info(&ext_info, inode->i_sb);
+ if (err >= 0) {
+ if (copy_to_user((struct ext4_extents_info __user *)arg,
+ &ext_info, sizeof(ext_info)))
+ return -EFAULT;
+ }
} else if (cmd == EXT4_IOC_DEFRAG) {
struct ext4_ext_defrag_data defrag;