ref: fad2d51c6c20323408b13f5ff95c3794ace78376
parent: b4f36a128a7826b7343c8181b1ab34fe48ebfc18
author: gkostka <kostka.grzegorz@gmail.com>
date: Sun Jan 10 06:29:54 EST 2016
ext4: introduce ext4_trunc_inode to deal with ftruncate operation Truncate operations might consume a lot of blocks. New function will split one big transacion into a numerous of smaller ones. CONFIG_MAX_TRUNCATE_SIZE limits single inode truncate size.
--- a/lwext4/ext4.c
+++ b/lwext4/ext4.c
@@ -704,6 +704,56 @@
return false;
}
+static int ext4_trunc_inode(struct ext4_mountpoint *mp,
+ struct ext4_inode_ref *inode_ref, uint64_t new_size)
+{+ int r = EOK;
+ struct ext4_fs *const fs = &mp->fs;
+ uint64_t inode_size = ext4_inode_get_size(&fs->sb, inode_ref->inode);
+ uint32_t index = inode_ref->index;
+
+
+ while (inode_size > new_size + CONFIG_MAX_TRUNCATE_SIZE) {+
+ inode_size -= CONFIG_MAX_TRUNCATE_SIZE;
+ ext4_trans_start(mp);
+ r = ext4_fs_truncate_inode(inode_ref, inode_size);
+ if (r != EOK)
+ return r;
+
+ r = ext4_fs_put_inode_ref(inode_ref);
+ if (r != EOK)
+ ext4_trans_abort(mp);
+ else
+ ext4_trans_stop(mp);
+
+ r = ext4_fs_get_inode_ref(fs, index, inode_ref);
+ if (r != EOK)
+ return r;
+ }
+
+ if (inode_size > new_size) {+
+ inode_size = new_size;
+ ext4_trans_start(mp);
+ r = ext4_fs_truncate_inode(inode_ref, inode_size);
+ if (r != EOK)
+ return r;
+
+ r = ext4_fs_put_inode_ref(inode_ref);
+ if (r != EOK)
+ ext4_trans_abort(mp);
+ else
+ ext4_trans_stop(mp);
+
+ r = ext4_fs_get_inode_ref(fs, index, inode_ref);
+ if (r != EOK)
+ return r;
+ }
+
+ return r;
+}
+
/*
* NOTICE: if filetype is equal to EXT4_DIRENTRY_UNKNOWN,
* any filetype of the target dir entry will be accepted.
@@ -855,7 +905,7 @@
if (is_goal) { if ((f->flags & O_TRUNC) && (imode == EXT4_INODE_MODE_FILE)) {- r = ext4_fs_truncate_inode(&ref, 0);
+ r = ext4_trunc_inode(mp, &ref, 0);
if (r != EOK) {ext4_fs_put_inode_ref(&ref);
return r;
@@ -1237,7 +1287,7 @@
/*Turncate*/
ext4_block_cache_write_back(mp->fs.bdev, 1);
/*Truncate may be IO heavy. Do it writeback cache mode.*/
- r = ext4_fs_truncate_inode(&child, 0);
+ r = ext4_trunc_inode(mp, &child, 0);
ext4_block_cache_write_back(mp->fs.bdev, 0);
if (r != EOK)
@@ -1388,7 +1438,7 @@
if (r != EOK)
goto Finish;
- r = ext4_fs_truncate_inode(&ref, size);
+ r = ext4_trunc_inode(f->mp, &ref, size);
if (r != EOK)
goto Finish;
@@ -2511,7 +2561,7 @@
}
/* Truncate */
- r = ext4_fs_truncate_inode(&child, 0);
+ r = ext4_trunc_inode(mp, &child, 0);
if (r != EOK) {ext4_fs_put_inode_ref(&child);
goto End;
@@ -2604,7 +2654,7 @@
ext4_inode_set_links_cnt(act.inode, 0);
act.dirty = true;
/*Turncate*/
- r = ext4_fs_truncate_inode(&act, 0);
+ r = ext4_trunc_inode(mp, &act, 0);
if (r != EOK) {ext4_fs_put_inode_ref(&parent);
ext4_fs_put_inode_ref(&act);
--- a/lwext4/ext4_config.h
+++ b/lwext4/ext4_config.h
@@ -138,6 +138,12 @@
#define CONFIG_EXTENT_FULL 1
#endif
+/**@brief Maximum single truncate size. Transactions must be limited to reduce
+ * number of allocetions for single transaction*/
+#ifndef CONFIG_MAX_TRUNCATE_SIZE
+#define CONFIG_MAX_TRUNCATE_SIZE (16 * 1024 * 1024)
+#endif
+
#ifdef __cplusplus
}
#endif