From: Jiaying Zhang <jiayingz@xxxxxxxxxx>
fallocate() may potentially instantiate blocks past EOF, depending
on the flags used when it is called.
e2fsck currently has a test for blocks past i_size, and it
sometimes trips up - noticeably on xfstests 013 which runs fsstress.
This patch from Jiayang does fix it up - it (along with
e2fsprogs updates and other patches recently from Aneesh) has
survived many fsstress runs in a row.
(Eric Sandeen: removed ioctl interface and minor cleanups)
Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
---
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 874d169..1f6b936 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -284,6 +284,7 @@ struct flex_groups {
#define EXT4_TOPDIR_FL 0x00020000 /* Top of directory hierarchies*/
#define EXT4_HUGE_FILE_FL 0x00040000 /* Set to each huge file */
#define EXT4_EXTENTS_FL 0x00080000 /* Inode uses extents */
+#define EXT4_EOFBLOCKS_FL 0x00400000 /* Blocks allocated beyond EOF */
#define EXT4_RESERVED_FL 0x80000000 /* reserved for ext4 lib */
#define EXT4_FL_USER_VISIBLE 0x000BDFFF /* User visible flags */
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 765a482..95e94ae 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3185,7 +3185,7 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
{
struct ext4_ext_path *path = NULL;
struct ext4_extent_header *eh;
- struct ext4_extent newex, *ex;
+ struct ext4_extent newex, *ex, *last_ex;
ext4_fsblk_t newblock;
int err = 0, depth, ret, cache_type;
unsigned int allocated = 0;
@@ -3366,6 +3366,19 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode,
EXT4_STATE_DIO_UNWRITTEN;;
}
}
+
+ if (unlikely(EXT4_I(inode)->i_flags & EXT4_EOFBLOCKS_FL)) {
+ if (eh->eh_entries) {
+ last_ex = EXT_LAST_EXTENT(eh);
+ if (iblock + ar.len > le32_to_cpu(last_ex->ee_block)
+ + ext4_ext_get_actual_len(last_ex))
+ EXT4_I(inode)->i_flags &= ~EXT4_EOFBLOCKS_FL;
+ } else {
+ WARN_ON(eh->eh_entries == 0);
+ ext4_error(inode->i_sb, __func__,
+ "inode#%lu, eh->eh_entries = 0!", inode->i_ino);
+ }
+ }
err = ext4_ext_insert_extent(handle, inode, path, &newex, flags);
if (err) {
/* free data blocks we just allocated */
@@ -3499,6 +3512,13 @@ static void ext4_falloc_update_inode(struct inode *inode,
i_size_write(inode, new_size);
if (new_size > EXT4_I(inode)->i_disksize)
ext4_update_i_disksize(inode, new_size);
+ } else {
+ /*
+ * Mark that we allocate beyond EOF so the subsequent truncate
+ * can proceed even if the new size is the same as i_size.
+ */
+ if (new_size > i_size_read(inode))
+ EXT4_I(inode)->i_flags |= EXT4_EOFBLOCKS_FL;
}
}
diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index cbf56da..f5802e9 100644
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -4429,6 +4429,8 @@ void ext4_truncate(struct inode *inode)
if (!ext4_can_truncate(inode))
return;
+ EXT4_I(inode)->i_flags &= ~EXT4_EOFBLOCKS_FL;
+
if (inode->i_size == 0 && !test_opt(inode->i_sb, NO_AUTO_DA_ALLOC))
ei->i_state |= EXT4_STATE_DA_ALLOC_CLOSE;
@@ -5284,7 +5286,9 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
}
if (S_ISREG(inode->i_mode) &&
- attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
+ attr->ia_valid & ATTR_SIZE &&
+ (attr->ia_size < inode->i_size ||
+ (EXT4_I(inode)->i_flags & EXT4_EOFBLOCKS_FL))) {
handle_t *handle;
handle = ext4_journal_start(inode, 3);
@@ -5315,6 +5319,9 @@ int ext4_setattr(struct dentry *dentry, struct iattr *attr)
goto err_out;
}
}
+ /* ext4_truncate will clear the flag */
+ if ((EXT4_I(inode)->i_flags & EXT4_EOFBLOCKS_FL))
+ ext4_truncate(inode);
}
rc = inode_setattr(inode, attr);
--
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