diff options
Diffstat (limited to 'ext4-fix-races-of-writeback-with-punch-hole-and-zero.patch')
| -rw-r--r-- | ext4-fix-races-of-writeback-with-punch-hole-and-zero.patch | 110 |
1 files changed, 0 insertions, 110 deletions
diff --git a/ext4-fix-races-of-writeback-with-punch-hole-and-zero.patch b/ext4-fix-races-of-writeback-with-punch-hole-and-zero.patch deleted file mode 100644 index 9ff9e2761..000000000 --- a/ext4-fix-races-of-writeback-with-punch-hole-and-zero.patch +++ /dev/null @@ -1,110 +0,0 @@ -From 011278485ecc3cd2a3954b5d4c73101d919bf1fa Mon Sep 17 00:00:00 2001 -From: Jan Kara <jack@suse.com> -Date: Mon, 7 Dec 2015 14:34:49 -0500 -Subject: [PATCH 4/4] ext4: fix races of writeback with punch hole and zero - range - -When doing delayed allocation, update of on-disk inode size is postponed -until IO submission time. However hole punch or zero range fallocate -calls can end up discarding the tail page cache page and thus on-disk -inode size would never be properly updated. - -Make sure the on-disk inode size is updated before truncating page -cache. - -Signed-off-by: Jan Kara <jack@suse.com> -Signed-off-by: Theodore Ts'o <tytso@mit.edu> ---- - fs/ext4/ext4.h | 3 +++ - fs/ext4/extents.c | 5 +++++ - fs/ext4/inode.c | 35 ++++++++++++++++++++++++++++++++++- - 3 files changed, 42 insertions(+), 1 deletion(-) - -diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h -index 348a5ff4a0e2..80f76f092079 100644 ---- a/fs/ext4/ext4.h -+++ b/fs/ext4/ext4.h -@@ -2858,6 +2858,9 @@ static inline int ext4_update_inode_size(struct inode *inode, loff_t newsize) - return changed; - } - -+int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset, -+ loff_t len); -+ - struct ext4_group_info { - unsigned long bb_state; - struct rb_root bb_free_root; -diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c -index 4b105c96df08..3578b25fccfd 100644 ---- a/fs/ext4/extents.c -+++ b/fs/ext4/extents.c -@@ -4847,6 +4847,11 @@ static long ext4_zero_range(struct file *file, loff_t offset, - * released from page cache. - */ - down_write(&EXT4_I(inode)->i_mmap_sem); -+ ret = ext4_update_disksize_before_punch(inode, offset, len); -+ if (ret) { -+ up_write(&EXT4_I(inode)->i_mmap_sem); -+ goto out_dio; -+ } - /* Now release the pages and zero block aligned part of pages */ - truncate_pagecache_range(inode, start, end - 1); - inode->i_mtime = inode->i_ctime = ext4_current_time(inode); -diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c -index d1207d03c961..472e608da13d 100644 ---- a/fs/ext4/inode.c -+++ b/fs/ext4/inode.c -@@ -3559,6 +3559,35 @@ int ext4_can_truncate(struct inode *inode) - } - - /* -+ * We have to make sure i_disksize gets properly updated before we truncate -+ * page cache due to hole punching or zero range. Otherwise i_disksize update -+ * can get lost as it may have been postponed to submission of writeback but -+ * that will never happen after we truncate page cache. -+ */ -+int ext4_update_disksize_before_punch(struct inode *inode, loff_t offset, -+ loff_t len) -+{ -+ handle_t *handle; -+ loff_t size = i_size_read(inode); -+ -+ WARN_ON(!mutex_is_locked(&inode->i_mutex)); -+ if (offset > size || offset + len < size) -+ return 0; -+ -+ if (EXT4_I(inode)->i_disksize >= size) -+ return 0; -+ -+ handle = ext4_journal_start(inode, EXT4_HT_MISC, 1); -+ if (IS_ERR(handle)) -+ return PTR_ERR(handle); -+ ext4_update_i_disksize(inode, size); -+ ext4_mark_inode_dirty(handle, inode); -+ ext4_journal_stop(handle); -+ -+ return 0; -+} -+ -+/* - * ext4_punch_hole: punches a hole in a file by releaseing the blocks - * associated with the given offset and length - * -@@ -3636,9 +3665,13 @@ int ext4_punch_hole(struct inode *inode, loff_t offset, loff_t length) - last_block_offset = round_down((offset + length), sb->s_blocksize) - 1; - - /* Now release the pages and zero block aligned part of pages*/ -- if (last_block_offset > first_block_offset) -+ if (last_block_offset > first_block_offset) { -+ ret = ext4_update_disksize_before_punch(inode, offset, length); -+ if (ret) -+ goto out_dio; - truncate_pagecache_range(inode, first_block_offset, - last_block_offset); -+ } - - if (ext4_test_inode_flag(inode, EXT4_INODE_EXTENTS)) - credits = ext4_writepage_trans_blocks(inode); --- -2.5.5 - |