| From 3e5e479a39ce9ed60cd63f7565cc1d9da77c2a4e Mon Sep 17 00:00:00 2001 |
| From: Chao Yu <chao@kernel.org> |
| Date: Fri, 27 Dec 2019 18:44:56 +0800 |
| Subject: f2fs: fix to add swap extent correctly |
| |
| From: Chao Yu <yuchao0@huawei.com> |
| |
| commit 3e5e479a39ce9ed60cd63f7565cc1d9da77c2a4e upstream. |
| |
| As Youling reported in mailing list: |
| |
| https://www.linuxquestions.org/questions/linux-newbie-8/the-file-system-f2fs-is-broken-4175666043/ |
| |
| https://www.linux.org/threads/the-file-system-f2fs-is-broken.26490/ |
| |
| There is a test case can corrupt f2fs image: |
| - dd if=/dev/zero of=/swapfile bs=1M count=4096 |
| - chmod 600 /swapfile |
| - mkswap /swapfile |
| - swapon --discard /swapfile |
| |
| The root cause is f2fs_swap_activate() intends to return zero value |
| to setup_swap_extents() to enable SWP_FS mode (swap file goes through |
| fs), in this flow, setup_swap_extents() setups swap extent with wrong |
| block address range, result in discard_swap() erasing incorrect address. |
| |
| Because f2fs_swap_activate() has pinned swapfile, its data block |
| address will not change, it's safe to let swap to handle IO through |
| raw device, so we can get rid of SWAP_FS mode and initial swap extents |
| inside f2fs_swap_activate(), by this way, later discard_swap() can trim |
| in right address range. |
| |
| Fixes: 4969c06a0d83 ("f2fs: support swap file w/ DIO") |
| Signed-off-by: Chao Yu <yuchao0@huawei.com> |
| Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| |
| --- |
| fs/f2fs/data.c | 32 +++++++++++++++++++++++++------- |
| 1 file changed, 25 insertions(+), 7 deletions(-) |
| |
| --- a/fs/f2fs/data.c |
| +++ b/fs/f2fs/data.c |
| @@ -3132,7 +3132,8 @@ int f2fs_migrate_page(struct address_spa |
| |
| #ifdef CONFIG_SWAP |
| /* Copied from generic_swapfile_activate() to check any holes */ |
| -static int check_swap_activate(struct file *swap_file, unsigned int max) |
| +static int check_swap_activate(struct swap_info_struct *sis, |
| + struct file *swap_file, sector_t *span) |
| { |
| struct address_space *mapping = swap_file->f_mapping; |
| struct inode *inode = mapping->host; |
| @@ -3143,6 +3144,8 @@ static int check_swap_activate(struct fi |
| sector_t last_block; |
| sector_t lowest_block = -1; |
| sector_t highest_block = 0; |
| + int nr_extents = 0; |
| + int ret; |
| |
| blkbits = inode->i_blkbits; |
| blocks_per_page = PAGE_SIZE >> blkbits; |
| @@ -3154,7 +3157,8 @@ static int check_swap_activate(struct fi |
| probe_block = 0; |
| page_no = 0; |
| last_block = i_size_read(inode) >> blkbits; |
| - while ((probe_block + blocks_per_page) <= last_block && page_no < max) { |
| + while ((probe_block + blocks_per_page) <= last_block && |
| + page_no < sis->max) { |
| unsigned block_in_page; |
| sector_t first_block; |
| |
| @@ -3194,13 +3198,27 @@ static int check_swap_activate(struct fi |
| highest_block = first_block; |
| } |
| |
| + /* |
| + * We found a PAGE_SIZE-length, PAGE_SIZE-aligned run of blocks |
| + */ |
| + ret = add_swap_extent(sis, page_no, 1, first_block); |
| + if (ret < 0) |
| + goto out; |
| + nr_extents += ret; |
| page_no++; |
| probe_block += blocks_per_page; |
| reprobe: |
| continue; |
| } |
| - return 0; |
| - |
| + ret = nr_extents; |
| + *span = 1 + highest_block - lowest_block; |
| + if (page_no == 0) |
| + page_no = 1; /* force Empty message */ |
| + sis->max = page_no; |
| + sis->pages = page_no - 1; |
| + sis->highest_bit = page_no - 1; |
| +out: |
| + return ret; |
| bad_bmap: |
| pr_err("swapon: swapfile has holes\n"); |
| return -EINVAL; |
| @@ -3222,14 +3240,14 @@ static int f2fs_swap_activate(struct swa |
| if (ret) |
| return ret; |
| |
| - ret = check_swap_activate(file, sis->max); |
| - if (ret) |
| + ret = check_swap_activate(sis, file, span); |
| + if (ret < 0) |
| return ret; |
| |
| set_inode_flag(inode, FI_PIN_FILE); |
| f2fs_precache_extents(inode); |
| f2fs_update_time(F2FS_I_SB(inode), REQ_TIME); |
| - return 0; |
| + return ret; |
| } |
| |
| static void f2fs_swap_deactivate(struct file *file) |