ext4: call ext4_forget() from ext4_free_blocks()
Add the facility for ext4_forget() to be called from
ext4_free_blocks(). This simplifies the code in a large number of
places, and centralizes most of the work of calling ext4_forget() into
a single place.
Also fix a bug in the extents migration code; it wasn't calling
ext4_forget() when releasing the indirect blocks during the
conversion. As a result, if the system cashed during or shortly after
the extents migration, and the released indirect blocks get reused as
data blocks, the journal replay would corrupt the data blocks. With
this new patch, fixing this bug was as simple as adding the
EXT4_FREE_BLOCKS_FORGET flags to the call to ext4_free_blocks().
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 210e1b5..4cfc2f0 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -376,6 +376,12 @@
EXT4_GET_BLOCKS_DIO_CREATE_EXT)
/*
+ * Flags used by ext4_free_blocks
+ */
+#define EXT4_FREE_BLOCKS_METADATA 0x0001
+#define EXT4_FREE_BLOCKS_FORGET 0x0002
+
+/*
* ioctl commands
*/
#define EXT4_IOC_GETFLAGS FS_IOC_GETFLAGS
@@ -1384,8 +1390,8 @@
extern int __init init_ext4_mballoc(void);
extern void exit_ext4_mballoc(void);
extern void ext4_free_blocks(handle_t *handle, struct inode *inode,
- ext4_fsblk_t block, unsigned long count,
- int metadata);
+ struct buffer_head *bh, ext4_fsblk_t block,
+ unsigned long count, int flags);
extern int ext4_mb_add_groupinfo(struct super_block *sb,
ext4_group_t i, struct ext4_group_desc *desc);
extern int ext4_mb_get_buddy_cache_lock(struct super_block *, ext4_group_t);
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 74dcff8..2c4a932 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -1007,7 +1007,8 @@
for (i = 0; i < depth; i++) {
if (!ablocks[i])
continue;
- ext4_free_blocks(handle, inode, ablocks[i], 1, 1);
+ ext4_free_blocks(handle, inode, 0, ablocks[i], 1,
+ EXT4_FREE_BLOCKS_METADATA);
}
}
kfree(ablocks);
@@ -1957,7 +1958,6 @@
static int ext4_ext_rm_idx(handle_t *handle, struct inode *inode,
struct ext4_ext_path *path)
{
- struct buffer_head *bh;
int err;
ext4_fsblk_t leaf;
@@ -1973,9 +1973,8 @@
if (err)
return err;
ext_debug("index is empty, remove it, free block %llu\n", leaf);
- bh = sb_find_get_block(inode->i_sb, leaf);
- ext4_forget(handle, 1, inode, bh, leaf);
- ext4_free_blocks(handle, inode, leaf, 1, 1);
+ ext4_free_blocks(handle, inode, 0, leaf, 1,
+ EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
return err;
}
@@ -2042,12 +2041,11 @@
struct ext4_extent *ex,
ext4_lblk_t from, ext4_lblk_t to)
{
- struct buffer_head *bh;
unsigned short ee_len = ext4_ext_get_actual_len(ex);
- int i, metadata = 0;
+ int flags = EXT4_FREE_BLOCKS_FORGET;
if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
- metadata = 1;
+ flags |= EXT4_FREE_BLOCKS_METADATA;
#ifdef EXTENTS_STATS
{
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
@@ -2072,11 +2070,7 @@
num = le32_to_cpu(ex->ee_block) + ee_len - from;
start = ext_pblock(ex) + ee_len - num;
ext_debug("free last %u blocks starting %llu\n", num, start);
- for (i = 0; i < num; i++) {
- bh = sb_find_get_block(inode->i_sb, start + i);
- ext4_forget(handle, metadata, inode, bh, start + i);
- }
- ext4_free_blocks(handle, inode, start, num, metadata);
+ ext4_free_blocks(handle, inode, 0, start, num, flags);
} else if (from == le32_to_cpu(ex->ee_block)
&& to <= le32_to_cpu(ex->ee_block) + ee_len - 1) {
printk(KERN_INFO "strange request: removal %u-%u from %u:%u\n",
@@ -3319,8 +3313,8 @@
/* not a good idea to call discard here directly,
* but otherwise we'd need to call it every free() */
ext4_discard_preallocations(inode);
- ext4_free_blocks(handle, inode, ext_pblock(&newex),
- ext4_ext_get_actual_len(&newex), 0);
+ ext4_free_blocks(handle, inode, 0, ext_pblock(&newex),
+ ext4_ext_get_actual_len(&newex), 0);
goto out2;
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 72c6943..3b28e1f 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -669,7 +669,7 @@
return ret;
failed_out:
for (i = 0; i < index; i++)
- ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
+ ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
return ret;
}
@@ -765,20 +765,20 @@
return err;
failed:
/* Allocation failed, free what we already allocated */
+ ext4_free_blocks(handle, inode, 0, new_blocks[0], 1, 0);
for (i = 1; i <= n ; i++) {
- BUFFER_TRACE(branch[i].bh, "call jbd2_journal_forget");
/*
- * Note: is_metadata is 0 because branch[i].bh is
- * newly allocated, so there is no need to revoke the
- * block. If we do, it's harmless, but not necessary.
+ * branch[i].bh is newly allocated, so there is no
+ * need to revoke the block, which is why we don't
+ * need to set EXT4_FREE_BLOCKS_METADATA.
*/
- ext4_forget(handle, 0, inode, branch[i].bh,
- branch[i].bh->b_blocknr);
+ ext4_free_blocks(handle, inode, 0, new_blocks[i], 1,
+ EXT4_FREE_BLOCKS_FORGET);
}
- for (i = 0; i < indirect_blks; i++)
- ext4_free_blocks(handle, inode, new_blocks[i], 1, 0);
+ for (i = n+1; i < indirect_blks; i++)
+ ext4_free_blocks(handle, inode, 0, new_blocks[i], 1, 0);
- ext4_free_blocks(handle, inode, new_blocks[i], num, 0);
+ ext4_free_blocks(handle, inode, 0, new_blocks[i], num, 0);
return err;
}
@@ -857,18 +857,16 @@
err_out:
for (i = 1; i <= num; i++) {
- BUFFER_TRACE(where[i].bh, "call jbd2_journal_forget");
/*
- * Note: is_metadata is 0 because branch[i].bh is
- * newly allocated, so there is no need to revoke the
- * block. If we do, it's harmless, but not necessary.
+ * branch[i].bh is newly allocated, so there is no
+ * need to revoke the block, which is why we don't
+ * need to set EXT4_FREE_BLOCKS_METADATA.
*/
- ext4_forget(handle, 0, inode, where[i].bh,
- where[i].bh->b_blocknr);
- ext4_free_blocks(handle, inode,
- le32_to_cpu(where[i-1].key), 1, 0);
+ ext4_free_blocks(handle, inode, where[i].bh, 0, 1,
+ EXT4_FREE_BLOCKS_FORGET);
}
- ext4_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks, 0);
+ ext4_free_blocks(handle, inode, 0, le32_to_cpu(where[num].key),
+ blks, 0);
return err;
}
@@ -4080,7 +4078,10 @@
__le32 *last)
{
__le32 *p;
- int is_metadata = S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode);
+ int flags = EXT4_FREE_BLOCKS_FORGET;
+
+ if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+ flags |= EXT4_FREE_BLOCKS_METADATA;
if (try_to_extend_transaction(handle, inode)) {
if (bh) {
@@ -4096,27 +4097,10 @@
}
}
- /*
- * Any buffers which are on the journal will be in memory. We
- * find them on the hash table so jbd2_journal_revoke() will
- * run jbd2_journal_forget() on them. We've already detached
- * each block from the file, so bforget() in
- * jbd2_journal_forget() should be safe.
- *
- * AKPM: turn on bforget in jbd2_journal_forget()!!!
- */
- for (p = first; p < last; p++) {
- u32 nr = le32_to_cpu(*p);
- if (nr) {
- struct buffer_head *tbh;
+ for (p = first; p < last; p++)
+ *p = 0;
- *p = 0;
- tbh = sb_find_get_block(inode->i_sb, nr);
- ext4_forget(handle, is_metadata, inode, tbh, nr);
- }
- }
-
- ext4_free_blocks(handle, inode, block_to_free, count, is_metadata);
+ ext4_free_blocks(handle, inode, 0, block_to_free, count, flags);
}
/**
@@ -4304,7 +4288,8 @@
blocks_for_truncate(inode));
}
- ext4_free_blocks(handle, inode, nr, 1, 1);
+ ext4_free_blocks(handle, inode, 0, nr, 1,
+ EXT4_FREE_BLOCKS_METADATA);
if (parent_bh) {
/*
diff --git a/fs/ext4/mballoc.c b/fs/ext4/mballoc.c
index 0dca90b..78de5d3 100644
--- a/fs/ext4/mballoc.c
+++ b/fs/ext4/mballoc.c
@@ -4436,8 +4436,8 @@
* @metadata: Are these metadata blocks
*/
void ext4_free_blocks(handle_t *handle, struct inode *inode,
- ext4_fsblk_t block, unsigned long count,
- int metadata)
+ struct buffer_head *bh, ext4_fsblk_t block,
+ unsigned long count, int flags)
{
struct buffer_head *bitmap_bh = NULL;
struct super_block *sb = inode->i_sb;
@@ -4454,15 +4454,12 @@
int err = 0;
int ret;
- /*
- * We need to make sure we don't reuse the freed block until
- * after the transaction is committed, which we can do by
- * treating the block as metadata, below. We make an
- * exception if the inode is to be written in writeback mode
- * since writeback mode has weak data consistency guarantees.
- */
- if (!ext4_should_writeback_data(inode))
- metadata = 1;
+ if (bh) {
+ if (block)
+ BUG_ON(block != bh->b_blocknr);
+ else
+ block = bh->b_blocknr;
+ }
sbi = EXT4_SB(sb);
es = EXT4_SB(sb)->s_es;
@@ -4476,7 +4473,32 @@
}
ext4_debug("freeing block %llu\n", block);
- trace_ext4_free_blocks(inode, block, count, metadata);
+ trace_ext4_free_blocks(inode, block, count, flags);
+
+ if (flags & EXT4_FREE_BLOCKS_FORGET) {
+ struct buffer_head *tbh = bh;
+ int i;
+
+ BUG_ON(bh && (count > 1));
+
+ for (i = 0; i < count; i++) {
+ if (!bh)
+ tbh = sb_find_get_block(inode->i_sb,
+ block + i);
+ ext4_forget(handle, flags & EXT4_FREE_BLOCKS_METADATA,
+ inode, tbh, block + i);
+ }
+ }
+
+ /*
+ * We need to make sure we don't reuse the freed block until
+ * after the transaction is committed, which we can do by
+ * treating the block as metadata, below. We make an
+ * exception if the inode is to be written in writeback mode
+ * since writeback mode has weak data consistency guarantees.
+ */
+ if (!ext4_should_writeback_data(inode))
+ flags |= EXT4_FREE_BLOCKS_METADATA;
ac = kmem_cache_alloc(ext4_ac_cachep, GFP_NOFS);
if (ac) {
@@ -4552,7 +4574,8 @@
err = ext4_mb_load_buddy(sb, block_group, &e4b);
if (err)
goto error_return;
- if (metadata && ext4_handle_valid(handle)) {
+
+ if ((flags & EXT4_FREE_BLOCKS_METADATA) && ext4_handle_valid(handle)) {
struct ext4_free_data *new_entry;
/*
* blocks being freed are metadata. these blocks shouldn't
diff --git a/fs/ext4/migrate.c b/fs/ext4/migrate.c
index a93d5b8..d641e13 100644
--- a/fs/ext4/migrate.c
+++ b/fs/ext4/migrate.c
@@ -262,13 +262,17 @@
for (i = 0; i < max_entries; i++) {
if (tmp_idata[i]) {
extend_credit_for_blkdel(handle, inode);
- ext4_free_blocks(handle, inode,
- le32_to_cpu(tmp_idata[i]), 1, 1);
+ ext4_free_blocks(handle, inode, 0,
+ le32_to_cpu(tmp_idata[i]), 1,
+ EXT4_FREE_BLOCKS_METADATA |
+ EXT4_FREE_BLOCKS_FORGET);
}
}
put_bh(bh);
extend_credit_for_blkdel(handle, inode);
- ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1);
+ ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
+ EXT4_FREE_BLOCKS_METADATA |
+ EXT4_FREE_BLOCKS_FORGET);
return 0;
}
@@ -297,7 +301,9 @@
}
put_bh(bh);
extend_credit_for_blkdel(handle, inode);
- ext4_free_blocks(handle, inode, le32_to_cpu(i_data), 1, 1);
+ ext4_free_blocks(handle, inode, 0, le32_to_cpu(i_data), 1,
+ EXT4_FREE_BLOCKS_METADATA |
+ EXT4_FREE_BLOCKS_FORGET);
return 0;
}
@@ -308,8 +314,10 @@
/* ei->i_data[EXT4_IND_BLOCK] */
if (i_data[0]) {
extend_credit_for_blkdel(handle, inode);
- ext4_free_blocks(handle, inode,
- le32_to_cpu(i_data[0]), 1, 1);
+ ext4_free_blocks(handle, inode, 0,
+ le32_to_cpu(i_data[0]), 1,
+ EXT4_FREE_BLOCKS_METADATA |
+ EXT4_FREE_BLOCKS_FORGET);
}
/* ei->i_data[EXT4_DIND_BLOCK] */
@@ -419,7 +427,8 @@
}
put_bh(bh);
extend_credit_for_blkdel(handle, inode);
- ext4_free_blocks(handle, inode, block, 1, 1);
+ ext4_free_blocks(handle, inode, 0, block, 1,
+ EXT4_FREE_BLOCKS_METADATA | EXT4_FREE_BLOCKS_FORGET);
return retval;
}
diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 0257019..910bf9a 100644
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -482,9 +482,10 @@
ea_bdebug(bh, "refcount now=0; freeing");
if (ce)
mb_cache_entry_free(ce);
- ext4_free_blocks(handle, inode, bh->b_blocknr, 1, 1);
get_bh(bh);
- ext4_forget(handle, 1, inode, bh, bh->b_blocknr);
+ ext4_free_blocks(handle, inode, bh, 0, 1,
+ EXT4_FREE_BLOCKS_METADATA |
+ EXT4_FREE_BLOCKS_FORGET);
} else {
le32_add_cpu(&BHDR(bh)->h_refcount, -1);
error = ext4_handle_dirty_metadata(handle, inode, bh);
@@ -832,7 +833,8 @@
new_bh = sb_getblk(sb, block);
if (!new_bh) {
getblk_failed:
- ext4_free_blocks(handle, inode, block, 1, 1);
+ ext4_free_blocks(handle, inode, 0, block, 1,
+ EXT4_FREE_BLOCKS_METADATA);
error = -EIO;
goto cleanup;
}