ext4: add flag to ext4_has_free_blocks

This patch adds an allocation request flag to the ext4_has_free_blocks
function which enables the use of reserved blocks.  This will allow a
punch hole to proceed even if the disk is full.  Punching a hole may
require additional blocks to first split the extents.

Because ext4_has_free_blocks is a low level function, the flag needs
to be passed down through several functions listed below:

ext4_ext_insert_extent
ext4_ext_create_new_leaf
ext4_ext_grow_indepth
ext4_ext_split
ext4_ext_new_meta_block
ext4_mb_new_blocks
ext4_claim_free_blocks
ext4_has_free_blocks

[ext4 punch hole patch series 1/5 v7]

Signed-off-by: Allison Henderson <achender@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Mingming Cao <cmm@us.ibm.com>

1 files changed, 10 insertions, 3 deletions

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 2bc4c21f1d26..2f310d1839ed 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -108,7 +108,8 @@ typedef unsigned int ext4_group_t;
 #define EXT4_MB_DELALLOC_RESERVED       0x0400
 /* We are doing stream allocation */
 #define EXT4_MB_STREAM_ALLOC            0x0800
-
+/* Use reserved root blocks if needed */
+#define EXT4_MB_USE_ROOT_BLOCKS         0x1000
 
 struct ext4_allocation_request {
         /* target inode for block we're allocating */
@@ -514,6 +515,8 @@ struct ext4_new_group_data {
         /* Convert extent to initialized after IO complete */
 #define EXT4_GET_BLOCKS_IO_CONVERT_EXT          (EXT4_GET_BLOCKS_CONVERT|\
                                          EXT4_GET_BLOCKS_CREATE_UNINIT_EXT)
+        /* Punch out blocks of an extent */
+#define EXT4_GET_BLOCKS_PUNCH_OUT_EXT           0x0020
 
 /*
  * Flags used by ext4_free_blocks
@@ -1718,8 +1721,12 @@ extern int ext4_bg_has_super(struct super_block *sb, ext4_group_t group);
 extern unsigned long ext4_bg_num_gdb(struct super_block *sb,
                         ext4_group_t group);
 extern ext4_fsblk_t ext4_new_meta_blocks(handle_t *handle, struct inode *inode,
-                        ext4_fsblk_t goal, unsigned long *count, int *errp);
-extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi, s64 nblocks);
+                                         ext4_fsblk_t goal,
+                                         unsigned int flags,
+                                         unsigned long *count,
+                                         int *errp);
+extern int ext4_claim_free_blocks(struct ext4_sb_info *sbi,
+                                  s64 nblocks, unsigned int flags);
 extern ext4_fsblk_t ext4_count_free_blocks(struct super_block *);
 extern void ext4_check_blocks_bitmap(struct super_block *);
 extern struct ext4_group_desc * ext4_get_group_desc(struct super_block * sb,