[PATCH 4.4 098/124] ext4: fix inline data updates with checksums enabled

From: Greg Kroah-Hartman
Date: Sat Aug 04 2018 - 05:11:27 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Theodore Ts'o <tytso@xxxxxxx>

commit 362eca70b53389bddf3143fe20f53dcce2cfdf61 upstream.

The inline data code was updating the raw inode directly; this is
problematic since if metadata checksums are enabled,
ext4_mark_inode_dirty() must be called to update the inode's checksum.
In addition, the jbd2 layer requires that get_write_access() be called
before the metadata buffer is modified. Fix both of these problems.

https://bugzilla.kernel.org/show_bug.cgi?id=200443

Signed-off-by: Theodore Ts'o <tytso@xxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
fs/ext4/inline.c | 19 +++++++++++--------
fs/ext4/inode.c | 16 +++++++---------
2 files changed, 18 insertions(+), 17 deletions(-)

--- a/fs/ext4/inline.c
+++ b/fs/ext4/inline.c
@@ -678,6 +678,10 @@ int ext4_try_to_write_inline_data(struct
goto convert;
}

+ ret = ext4_journal_get_write_access(handle, iloc.bh);
+ if (ret)
+ goto out;
+
flags |= AOP_FLAG_NOFS;

page = grab_cache_page_write_begin(mapping, 0, flags);
@@ -706,7 +710,7 @@ int ext4_try_to_write_inline_data(struct
out_up_read:
up_read(&EXT4_I(inode)->xattr_sem);
out:
- if (handle)
+ if (handle && (ret != 1))
ext4_journal_stop(handle);
brelse(iloc.bh);
return ret;
@@ -748,6 +752,7 @@ int ext4_write_inline_data_end(struct in

ext4_write_unlock_xattr(inode, &no_expand);
brelse(iloc.bh);
+ mark_inode_dirty(inode);
out:
return copied;
}
@@ -894,7 +899,6 @@ retry_journal:
goto out;
}

-
page = grab_cache_page_write_begin(mapping, 0, flags);
if (!page) {
ret = -ENOMEM;
@@ -912,6 +916,9 @@ retry_journal:
if (ret < 0)
goto out_release_page;
}
+ ret = ext4_journal_get_write_access(handle, iloc.bh);
+ if (ret)
+ goto out_release_page;

up_read(&EXT4_I(inode)->xattr_sem);
*pagep = page;
@@ -932,7 +939,6 @@ int ext4_da_write_inline_data_end(struct
unsigned len, unsigned copied,
struct page *page)
{
- int i_size_changed = 0;
int ret;

ret = ext4_write_inline_data_end(inode, pos, len, copied, page);
@@ -950,10 +956,8 @@ int ext4_da_write_inline_data_end(struct
* But it's important to update i_size while still holding page lock:
* page writeout could otherwise come in and zero beyond i_size.
*/
- if (pos+copied > inode->i_size) {
+ if (pos+copied > inode->i_size)
i_size_write(inode, pos+copied);
- i_size_changed = 1;
- }
unlock_page(page);
page_cache_release(page);

@@ -963,8 +967,7 @@ int ext4_da_write_inline_data_end(struct
* ordering of page lock and transaction start for journaling
* filesystems.
*/
- if (i_size_changed)
- mark_inode_dirty(inode);
+ mark_inode_dirty(inode);

return copied;
}
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1164,9 +1164,10 @@ static int ext4_write_end(struct file *f
loff_t old_size = inode->i_size;
int ret = 0, ret2;
int i_size_changed = 0;
+ int inline_data = ext4_has_inline_data(inode);

trace_ext4_write_end(inode, pos, len, copied);
- if (ext4_has_inline_data(inode)) {
+ if (inline_data) {
ret = ext4_write_inline_data_end(inode, pos, len,
copied, page);
if (ret < 0) {
@@ -1194,7 +1195,7 @@ static int ext4_write_end(struct file *f
* ordering of page lock and transaction start for journaling
* filesystems.
*/
- if (i_size_changed)
+ if (i_size_changed || inline_data)
ext4_mark_inode_dirty(handle, inode);

if (pos + len > inode->i_size && ext4_can_truncate(inode))
@@ -1268,6 +1269,7 @@ static int ext4_journalled_write_end(str
int partial = 0;
unsigned from, to;
int size_changed = 0;
+ int inline_data = ext4_has_inline_data(inode);

trace_ext4_journalled_write_end(inode, pos, len, copied);
from = pos & (PAGE_CACHE_SIZE - 1);
@@ -1275,7 +1277,7 @@ static int ext4_journalled_write_end(str

BUG_ON(!ext4_handle_valid(handle));

- if (ext4_has_inline_data(inode)) {
+ if (inline_data) {
ret = ext4_write_inline_data_end(inode, pos, len,
copied, page);
if (ret < 0) {
@@ -1306,7 +1308,7 @@ static int ext4_journalled_write_end(str
if (old_size < pos)
pagecache_isize_extended(inode, old_size, pos);

- if (size_changed) {
+ if (size_changed || inline_data) {
ret2 = ext4_mark_inode_dirty(handle, inode);
if (!ret)
ret = ret2;
@@ -1804,11 +1806,7 @@ static int __ext4_journalled_writepage(s
}

if (inline_data) {
- BUFFER_TRACE(inode_bh, "get write access");
- ret = ext4_journal_get_write_access(handle, inode_bh);
-
- err = ext4_handle_dirty_metadata(handle, inode, inode_bh);
-
+ ret = ext4_mark_inode_dirty(handle, inode);
} else {
ret = ext4_walk_page_buffers(handle, page_bufs, 0, len, NULL,
do_journal_get_write_access);