From b292dcab068e141d8a820b77cbcc88d98c610eb4 Mon Sep 17 00:00:00 2001 From: Jaegeuk Kim Date: Wed, 22 May 2013 08:02:02 +0900 Subject: [PATCH] f2fs: reuse the locked dnode page and its inode This patch fixes the following deadlock bug during the recovery. INFO: task mount:1322 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. mount D ffffffff81125870 0 1322 1266 0x00000000 ffff8801207e39d8 0000000000000046 ffff88012ab1dee0 0000000000000046 ffff8801207e3a08 ffff880115903f40 ffff8801207e3fd8 ffff8801207e3fd8 ffff8801207e3fd8 ffff880115903f40 ffff8801207e39d8 ffff88012fc94520 Call Trace: [] ? __lock_page+0x70/0x70 [] schedule+0x29/0x70 [] io_schedule+0x8f/0xd0 [] sleep_on_page+0xe/0x20 [] __wait_on_bit_lock+0x5a/0xc0 [] __lock_page+0x67/0x70 [] ? autoremove_wake_function+0x40/0x40 [] find_lock_page+0x67/0x80 [] find_or_create_page+0x3f/0xb0 [] ? sync_inode_page+0xa8/0xd0 [f2fs] [] get_node_page+0x67/0x180 [f2fs] [] recover_fsync_data+0xacb/0xff0 [f2fs] [] ? _raw_spin_unlock+0x3e/0x40 [] f2fs_fill_super+0x7d4/0x850 [f2fs] [] mount_bdev+0x1c9/0x210 [] ? validate_superblock+0x180/0x180 [f2fs] [] f2fs_mount+0x15/0x20 [f2fs] [] mount_fs+0x43/0x1b0 [] ? __alloc_percpu+0x10/0x20 [] vfs_kern_mount+0x76/0x120 [] do_mount+0x237/0xa10 [] ? strndup_user+0x5b/0x80 [] SyS_mount+0x90/0xe0 [] system_call_fastpath+0x16/0x1b The bug is triggered when check_index_in_prev_nodes tries to get the direct node page by calling get_node_page. At this point, if the direct node page is already locked by get_dnode_of_data, its caller, we got a deadlock condition. This patch adds additional condition check for the reuse of locked direct node pages prior to the get_node_page call. Signed-off-by: Jaegeuk Kim --- fs/f2fs/f2fs.h | 1 + fs/f2fs/file.c | 2 +- fs/f2fs/recovery.c | 26 +++++++++++++++++++++----- 3 files changed, 23 insertions(+), 6 deletions(-) diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h index 6594ce15a7bb..7b050298d6c9 100644 --- a/fs/f2fs/f2fs.h +++ b/fs/f2fs/f2fs.h @@ -900,6 +900,7 @@ void truncate_data_blocks(struct dnode_of_data *); void f2fs_truncate(struct inode *); int f2fs_setattr(struct dentry *, struct iattr *); int truncate_hole(struct inode *, pgoff_t, pgoff_t); +int truncate_data_blocks_range(struct dnode_of_data *, int); long f2fs_ioctl(struct file *, unsigned int, unsigned long); long f2fs_compat_ioctl(struct file *, unsigned int, unsigned long); diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c index 316bcfe80448..deefd258b847 100644 --- a/fs/f2fs/file.c +++ b/fs/f2fs/file.c @@ -168,7 +168,7 @@ static int f2fs_file_mmap(struct file *file, struct vm_area_struct *vma) return 0; } -static int truncate_data_blocks_range(struct dnode_of_data *dn, int count) +int truncate_data_blocks_range(struct dnode_of_data *dn, int count) { int nr_free = 0, ofs = dn->ofs_in_node; struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb); diff --git a/fs/f2fs/recovery.c b/fs/f2fs/recovery.c index 5148d90049b0..eceb6652532d 100644 --- a/fs/f2fs/recovery.c +++ b/fs/f2fs/recovery.c @@ -189,14 +189,14 @@ static void destroy_fsync_dnodes(struct f2fs_sb_info *sbi, } static void check_index_in_prev_nodes(struct f2fs_sb_info *sbi, - block_t blkaddr) + block_t blkaddr, struct dnode_of_data *dn) { struct seg_entry *sentry; unsigned int segno = GET_SEGNO(sbi, blkaddr); unsigned short blkoff = GET_SEGOFF_FROM_SEG0(sbi, blkaddr) & (sbi->blocks_per_seg - 1); struct f2fs_summary sum; - nid_t ino; + nid_t ino, nid; void *kaddr; struct inode *inode; struct page *node_page; @@ -224,10 +224,26 @@ static void check_index_in_prev_nodes(struct f2fs_sb_info *sbi, f2fs_put_page(sum_page, 1); } + /* Use the locked dnode page and inode */ + nid = le32_to_cpu(sum.nid); + if (dn->inode->i_ino == nid) { + struct dnode_of_data tdn = *dn; + tdn.nid = nid; + tdn.node_page = dn->inode_page; + tdn.ofs_in_node = sum.ofs_in_node; + truncate_data_blocks_range(&tdn, 1); + return; + } else if (dn->nid == nid) { + struct dnode_of_data tdn = *dn; + tdn.ofs_in_node = sum.ofs_in_node; + truncate_data_blocks_range(&tdn, 1); + return; + } + /* Get the node page */ - node_page = get_node_page(sbi, le32_to_cpu(sum.nid)); + node_page = get_node_page(sbi, nid); bidx = start_bidx_of_node(ofs_of_node(node_page)) + - le16_to_cpu(sum.ofs_in_node); + le16_to_cpu(sum.ofs_in_node); ino = ino_of_node(node_page); f2fs_put_page(node_page, 1); @@ -285,7 +301,7 @@ static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode, } /* Check the previous node page having this index */ - check_index_in_prev_nodes(sbi, dest); + check_index_in_prev_nodes(sbi, dest, &dn); set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); -- 2.39.5