This is a note to let you know that I've just added the patch titled f2fs: compress: don't redirty sparse cluster during {,de}compress to the 6.6-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: f2fs-compress-don-t-redirty-sparse-cluster-during-de.patch and it can be found in the queue-6.6 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit e75ff570134e3700b357c56dd7f8b6984bba8d51 Author: Yeongjin Gil <youngjin.gil@xxxxxxxxxxx> Date: Mon Aug 19 17:34:30 2024 +0900 f2fs: compress: don't redirty sparse cluster during {,de}compress [ Upstream commit f785cec298c95d00058560c0715233294a04b8f3 ] In f2fs_do_write_data_page, when the data block is NULL_ADDR, it skips writepage considering that it has been already truncated. This results in an infinite loop as the PAGECACHE_TAG_TOWRITE tag is not cleared during the writeback process for a compressed file including NULL_ADDR in compress_mode=user. This is the reproduction process: 1. dd if=/dev/zero bs=4096 count=1024 seek=1024 of=testfile 2. f2fs_io compress testfile 3. dd if=/dev/zero bs=4096 count=1 conv=notrunc of=testfile 4. f2fs_io decompress testfile To prevent the problem, let's check whether the cluster is fully allocated before redirty its pages. Fixes: 5fdb322ff2c2 ("f2fs: add F2FS_IOC_DECOMPRESS_FILE and F2FS_IOC_COMPRESS_FILE") Reviewed-by: Sungjong Seo <sj1557.seo@xxxxxxxxxxx> Reviewed-by: Sunmin Jeong <s_min.jeong@xxxxxxxxxxx> Tested-by: Jaewook Kim <jw5454.kim@xxxxxxxxxxx> Signed-off-by: Yeongjin Gil <youngjin.gil@xxxxxxxxxxx> Reviewed-by: Chao Yu <chao@xxxxxxxxxx> Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/fs/f2fs/compress.c b/fs/f2fs/compress.c index 995f6544cc300..f7ef69f44f3d8 100644 --- a/fs/f2fs/compress.c +++ b/fs/f2fs/compress.c @@ -945,7 +945,7 @@ static int __f2fs_get_cluster_blocks(struct inode *inode, unsigned int cluster_size = F2FS_I(inode)->i_cluster_size; int count, i; - for (i = 1, count = 1; i < cluster_size; i++) { + for (i = 0, count = 0; i < cluster_size; i++) { block_t blkaddr = data_blkaddr(dn->inode, dn->node_page, dn->ofs_in_node + i); @@ -956,8 +956,8 @@ static int __f2fs_get_cluster_blocks(struct inode *inode, return count; } -static int __f2fs_cluster_blocks(struct inode *inode, - unsigned int cluster_idx, bool compr_blks) +static int __f2fs_cluster_blocks(struct inode *inode, unsigned int cluster_idx, + enum cluster_check_type type) { struct dnode_of_data dn; unsigned int start_idx = cluster_idx << @@ -978,10 +978,12 @@ static int __f2fs_cluster_blocks(struct inode *inode, } if (dn.data_blkaddr == COMPRESS_ADDR) { - if (compr_blks) - ret = __f2fs_get_cluster_blocks(inode, &dn); - else + if (type == CLUSTER_COMPR_BLKS) + ret = 1 + __f2fs_get_cluster_blocks(inode, &dn); + else if (type == CLUSTER_IS_COMPR) ret = 1; + } else if (type == CLUSTER_RAW_BLKS) { + ret = __f2fs_get_cluster_blocks(inode, &dn); } fail: f2fs_put_dnode(&dn); @@ -991,7 +993,16 @@ static int __f2fs_cluster_blocks(struct inode *inode, /* return # of compressed blocks in compressed cluster */ static int f2fs_compressed_blocks(struct compress_ctx *cc) { - return __f2fs_cluster_blocks(cc->inode, cc->cluster_idx, true); + return __f2fs_cluster_blocks(cc->inode, cc->cluster_idx, + CLUSTER_COMPR_BLKS); +} + +/* return # of raw blocks in non-compressed cluster */ +static int f2fs_decompressed_blocks(struct inode *inode, + unsigned int cluster_idx) +{ + return __f2fs_cluster_blocks(inode, cluster_idx, + CLUSTER_RAW_BLKS); } /* return whether cluster is compressed one or not */ @@ -999,7 +1010,16 @@ int f2fs_is_compressed_cluster(struct inode *inode, pgoff_t index) { return __f2fs_cluster_blocks(inode, index >> F2FS_I(inode)->i_log_cluster_size, - false); + CLUSTER_IS_COMPR); +} + +/* return whether cluster contains non raw blocks or not */ +bool f2fs_is_sparse_cluster(struct inode *inode, pgoff_t index) +{ + unsigned int cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size; + + return f2fs_decompressed_blocks(inode, cluster_idx) != + F2FS_I(inode)->i_cluster_size; } static bool cluster_may_compress(struct compress_ctx *cc) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 6c9b1759f4e74..98a098cfcc3ca 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -4284,6 +4284,11 @@ static inline bool f2fs_meta_inode_gc_required(struct inode *inode) * compress.c */ #ifdef CONFIG_F2FS_FS_COMPRESSION +enum cluster_check_type { + CLUSTER_IS_COMPR, /* check only if compressed cluster */ + CLUSTER_COMPR_BLKS, /* return # of compressed blocks in a cluster */ + CLUSTER_RAW_BLKS /* return # of raw blocks in a cluster */ +}; bool f2fs_is_compressed_page(struct page *page); struct page *f2fs_compress_control_page(struct page *page); int f2fs_prepare_compress_overwrite(struct inode *inode, @@ -4310,6 +4315,7 @@ int f2fs_write_multi_pages(struct compress_ctx *cc, struct writeback_control *wbc, enum iostat_type io_type); int f2fs_is_compressed_cluster(struct inode *inode, pgoff_t index); +bool f2fs_is_sparse_cluster(struct inode *inode, pgoff_t index); void f2fs_update_read_extent_tree_range_compressed(struct inode *inode, pgoff_t fofs, block_t blkaddr, unsigned int llen, unsigned int c_len); @@ -4396,6 +4402,12 @@ static inline bool f2fs_load_compressed_page(struct f2fs_sb_info *sbi, static inline void f2fs_invalidate_compress_pages(struct f2fs_sb_info *sbi, nid_t ino) { } #define inc_compr_inode_stat(inode) do { } while (0) +static inline int f2fs_is_compressed_cluster( + struct inode *inode, + pgoff_t index) { return 0; } +static inline bool f2fs_is_sparse_cluster( + struct inode *inode, + pgoff_t index) { return true; } static inline void f2fs_update_read_extent_tree_range_compressed( struct inode *inode, pgoff_t fofs, block_t blkaddr, diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 0c279ba451205..f2969d8603421 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -4182,9 +4182,8 @@ static int f2fs_ioc_decompress_file(struct file *filp) struct inode *inode = file_inode(filp); struct f2fs_sb_info *sbi = F2FS_I_SB(inode); struct f2fs_inode_info *fi = F2FS_I(inode); - pgoff_t page_idx = 0, last_idx; - int cluster_size = fi->i_cluster_size; - int count, ret; + pgoff_t page_idx = 0, last_idx, cluster_idx; + int ret; if (!f2fs_sb_has_compression(sbi) || F2FS_OPTION(sbi).compress_mode != COMPR_MODE_USER) @@ -4217,10 +4216,15 @@ static int f2fs_ioc_decompress_file(struct file *filp) goto out; last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + last_idx >>= fi->i_log_cluster_size; + + for (cluster_idx = 0; cluster_idx < last_idx; cluster_idx++) { + page_idx = cluster_idx << fi->i_log_cluster_size; + + if (!f2fs_is_compressed_cluster(inode, page_idx)) + continue; - count = last_idx - page_idx; - while (count && count >= cluster_size) { - ret = redirty_blocks(inode, page_idx, cluster_size); + ret = redirty_blocks(inode, page_idx, fi->i_cluster_size); if (ret < 0) break; @@ -4230,9 +4234,6 @@ static int f2fs_ioc_decompress_file(struct file *filp) break; } - count -= cluster_size; - page_idx += cluster_size; - cond_resched(); if (fatal_signal_pending(current)) { ret = -EINTR; @@ -4258,9 +4259,9 @@ static int f2fs_ioc_compress_file(struct file *filp) { struct inode *inode = file_inode(filp); struct f2fs_sb_info *sbi = F2FS_I_SB(inode); - pgoff_t page_idx = 0, last_idx; - int cluster_size = F2FS_I(inode)->i_cluster_size; - int count, ret; + struct f2fs_inode_info *fi = F2FS_I(inode); + pgoff_t page_idx = 0, last_idx, cluster_idx; + int ret; if (!f2fs_sb_has_compression(sbi) || F2FS_OPTION(sbi).compress_mode != COMPR_MODE_USER) @@ -4292,10 +4293,15 @@ static int f2fs_ioc_compress_file(struct file *filp) set_inode_flag(inode, FI_ENABLE_COMPRESS); last_idx = DIV_ROUND_UP(i_size_read(inode), PAGE_SIZE); + last_idx >>= fi->i_log_cluster_size; - count = last_idx - page_idx; - while (count && count >= cluster_size) { - ret = redirty_blocks(inode, page_idx, cluster_size); + for (cluster_idx = 0; cluster_idx < last_idx; cluster_idx++) { + page_idx = cluster_idx << fi->i_log_cluster_size; + + if (f2fs_is_sparse_cluster(inode, page_idx)) + continue; + + ret = redirty_blocks(inode, page_idx, fi->i_cluster_size); if (ret < 0) break; @@ -4305,9 +4311,6 @@ static int f2fs_ioc_compress_file(struct file *filp) break; } - count -= cluster_size; - page_idx += cluster_size; - cond_resched(); if (fatal_signal_pending(current)) { ret = -EINTR;