X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=fs%2Fext4%2Fmigrate.c;h=b9e077ba07e94b0c979ebea4530e1fc9471e6eee;hb=2a5f2e3e6cd1ce9fb3f8b186b6bc9aa1f1497a92;hp=8c6c685b9d22e1d399d34066e5e6a497150c81a9;hpb=0c0d61ca93d111c521182c0909e478fa709e05c6;p=linux-2.6

diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index 8c6c685b9d..b9e077ba07 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -13,8 +13,8 @@
  */
 
 #include <linux/module.h>
-#include <linux/ext4_jbd2.h>
-#include <linux/ext4_fs_extents.h>
+#include "ext4_jbd2.h"
+#include "ext4_extents.h"
 
 /*
  * The contiguous blocks details which can be
@@ -43,6 +43,7 @@ static int finish_range(handle_t *handle, struct inode *inode,
 
 	if (IS_ERR(path)) {
 		retval = PTR_ERR(path);
+		path = NULL;
 		goto err_out;
 	}
 
@@ -74,6 +75,10 @@ static int finish_range(handle_t *handle, struct inode *inode,
 	}
 	retval = ext4_ext_insert_extent(handle, inode, path, &newext);
 err_out:
+	if (path) {
+		ext4_ext_drop_refs(path);
+		kfree(path);
+	}
 	lb->first_pblock = 0;
 	return retval;
 }
@@ -322,7 +327,7 @@ static int free_ind_block(handle_t *handle, struct inode *inode, __le32 *i_data)
 }
 
 static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
-				struct inode *tmp_inode)
+						struct inode *tmp_inode)
 {
 	int retval;
 	__le32	i_data[3];
@@ -334,7 +339,7 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
 	 * i_data field of the original inode
 	 */
 	retval = ext4_journal_extend(handle, 1);
-	if (retval != 0) {
+	if (retval) {
 		retval = ext4_journal_restart(handle, 1);
 		if (retval)
 			goto err_out;
@@ -345,6 +350,18 @@ static int ext4_ext_swap_inode_data(handle_t *handle, struct inode *inode,
 	i_data[2] = ei->i_data[EXT4_TIND_BLOCK];
 
 	down_write(&EXT4_I(inode)->i_data_sem);
+	/*
+	 * if EXT4_EXT_MIGRATE is cleared a block allocation
+	 * happened after we started the migrate. We need to
+	 * fail the migrate
+	 */
+	if (!(EXT4_I(inode)->i_flags & EXT4_EXT_MIGRATE)) {
+		retval = -EAGAIN;
+		up_write(&EXT4_I(inode)->i_data_sem);
+		goto err_out;
+	} else
+		EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags &
+							~EXT4_EXT_MIGRATE;
 	/*
 	 * We have the extent map build with the tmp inode.
 	 * Now copy the i_data across
@@ -503,6 +520,17 @@ int ext4_ext_migrate(struct inode *inode, struct file *filp,
 	 * switch the inode format to prevent read.
 	 */
 	mutex_lock(&(inode->i_mutex));
+	/*
+	 * Even though we take i_mutex we can still cause block allocation
+	 * via mmap write to holes. If we have allocated new blocks we fail
+	 * migrate.  New block allocation will clear EXT4_EXT_MIGRATE flag.
+	 * The flag is updated with i_data_sem held to prevent racing with
+	 * block allocation.
+	 */
+	down_read((&EXT4_I(inode)->i_data_sem));
+	EXT4_I(inode)->i_flags = EXT4_I(inode)->i_flags | EXT4_EXT_MIGRATE;
+	up_read((&EXT4_I(inode)->i_data_sem));
+
 	handle = ext4_journal_start(inode, 1);
 
 	ei = EXT4_I(inode);
@@ -554,9 +582,15 @@ err_out:
 		 * tmp_inode
 		 */
 		free_ext_block(handle, tmp_inode);
-	else
-		retval = ext4_ext_swap_inode_data(handle, inode,
-							tmp_inode);
+	else {
+		retval = ext4_ext_swap_inode_data(handle, inode, tmp_inode);
+		if (retval)
+			/*
+			 * if we fail to swap inode data free the extent
+			 * details of the tmp inode
+			 */
+			free_ext_block(handle, tmp_inode);
+	}
 
 	/* We mark the tmp_inode dirty via ext4_ext_tree_init. */
 	if (ext4_journal_extend(handle, 1) != 0)