From: gaoyongliang <gaoyongli...@huawei.com> 1. create inode by insert_inode_locked, and return inode with I_NEW. 2. has writed the dnode successfully in the end of one block, then release the c->alloc_sem, but the dirent is not written yet. 3. the gc or jffs2_reserve_space which has got the c->alloc_sem may find the block which the dnode we just writed in, the dnode can't be gc because the dirent is not written and the state of inode is still I_NEW, we can only wait on inode without release c->alloc_sem. 4. we can't get the c->alloc_sem to write the dirent, so the inode state keep I_NEW forever. 5. this will cause deadlock, like ABBA deadlock.
lockf2.test D c02dead8 0 11666 1 0x00000001 locked: c90f9be8 &inode->i_mutex 0 [<c00bf158>] generic_file_aio_write+0x40/0xb0 c2c54c44 &c->alloc_sem 1 [<bf056f9c>] jffs2_garbage_collect_pass+0x1c/0xf08 [jffs2] [<c02dead8>] (__schedule+0x458/0x604) from [<c0114090>] (inode_wait+0x8/0x10) [<c0114090>] (inode_wait+0x8/0x10) from [<c02dd050>] (__wait_on_bit+0x54/0xa0) [<c02dd050>] (__wait_on_bit+0x54/0xa0) from [<c02dd114>] (out_of_line_wait_on_bit+0x78/0x84) [<c02dd114>] (out_of_line_wait_on_bit+0x78/0x84) from [<c01157a0>] (iget_locked+0x90/0x1b0) [<c01157a0>] (iget_locked+0x90/0x1b0) from [<bf059fe8>] (jffs2_iget+0xc/0x344 [jffs2]) [<bf059fe8>] (jffs2_iget+0xc/0x344 [jffs2]) from [<bf05a6fc>] (jffs2_gc_fetch_inode+0x104/0x158 [jffs2]) [<bf05a6fc>] (jffs2_gc_fetch_inode+0x104/0x158 [jffs2]) from [<bf0577f0>] (jffs2_garbage_collect_pass+0x870/0xf08 [jffs2]) [<bf0577f0>] (jffs2_garbage_collect_pass+0x870/0xf08 [jffs2]) from [<bf051248>] (jffs2_reserve_space+0x154/0x3b4 [jffs2]) [<bf051248>] (jffs2_reserve_space+0x154/0x3b4 [jffs2]) from [<bf053eac>] (jffs2_write_inode_range+0x58/0x3ac [jffs2]) [<bf053eac>] (jffs2_write_inode_range+0x58/0x3ac [jffs2]) from [<bf04ec20>] (jffs2_write_end+0x11c/0x224 [jffs2]) [<bf04ec20>] (jffs2_write_end+0x11c/0x224 [jffs2]) from [<c00bdfa4>] (generic_file_buffered_write+0x160/0x23c) [<c00bdfa4>] (generic_file_buffered_write+0x160/0x23c) from [<c00bf0ac>] (__generic_file_aio_write+0x328/0x394) [<c00bf0ac>] (__generic_file_aio_write+0x328/0x394) from [<c00bf16c>] (generic_file_aio_write+0x54/0xb0) [<c00bf16c>] (generic_file_aio_write+0x54/0xb0) from [<c00fdc24>] (do_sync_write+0x74/0x98) [<c00fdc24>] (do_sync_write+0x74/0x98) from [<c00fe550>] (vfs_write+0xcc/0x174) [<c00fe550>] (vfs_write+0xcc/0x174) from [<c00fe8a8>] (SyS_write+0x38/0x64) [<c00fe8a8>] (SyS_write+0x38/0x64) from [<c000f0c0>] (ret_fast_syscall+0x0/0x58) Fixes: e72e6497e74811e01d72b4c1b7537b3aea3ee857 Cc: <stable@vger.kernel.org> # 3.10.y+ Signed-off-by: gaoyongliang <gaoyongli...@huawei.com> --- fs/jffs2/dir.c | 25 +++++++++++++++++++++++++ fs/jffs2/fs.c | 1 + fs/jffs2/gc.c | 11 +++++++++++ fs/jffs2/jffs2_fs_sb.h | 1 + fs/jffs2/nodelist.h | 4 ++++ fs/jffs2/super.c | 1 + fs/jffs2/write.c | 1 + 7 files changed, 44 insertions(+), 0 deletions(-) diff --git a/fs/jffs2/dir.c b/fs/jffs2/dir.c index d211b8e..808ec17 100644 --- a/fs/jffs2/dir.c +++ b/fs/jffs2/dir.c @@ -195,7 +195,9 @@ static int jffs2_create(struct inode *dir_i, struct dentry *dentry, no chance of AB-BA deadlock involving its f->sem). */ mutex_unlock(&f->sem); + mutex_lock(&c->create_sem); ret = jffs2_do_create(c, dir_f, f, ri, &dentry->d_name); + mutex_unlock(&c->create_sem); if (ret) goto fail; @@ -208,12 +210,14 @@ static int jffs2_create(struct inode *dir_i, struct dentry *dentry, f->inocache->pino_nlink, inode->i_mapping->nrpages); unlock_new_inode(inode); + f->inocache->state_new = INO_STATE_N_NEW; d_instantiate(dentry, inode); return 0; fail: iget_failed(inode); jffs2_free_raw_inode(ri); + f->inocache->state_new = INO_STATE_N_NEW; return ret; } @@ -304,11 +308,13 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char * Just the node will do for now, though */ namelen = dentry->d_name.len; + mutex_lock(&c->create_sem); ret = jffs2_reserve_space(c, sizeof(*ri) + targetlen, &alloclen, ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); if (ret) { jffs2_free_raw_inode(ri); + mutex_unlock(&c->create_sem); return ret; } @@ -317,6 +323,7 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char if (IS_ERR(inode)) { jffs2_free_raw_inode(ri); jffs2_complete_reservation(c); + mutex_unlock(&c->create_sem); return PTR_ERR(inode); } @@ -429,11 +436,15 @@ static int jffs2_symlink (struct inode *dir_i, struct dentry *dentry, const char jffs2_complete_reservation(c); unlock_new_inode(inode); + f->inocache->state_new = INO_STATE_N_NEW; + mutex_unlock(&c->create_sem); d_instantiate(dentry, inode); return 0; fail: iget_failed(inode); + f->inocache->state_new = INO_STATE_N_NEW; + mutex_unlock(&c->create_sem); return ret; } @@ -463,11 +474,13 @@ static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode * Just the node will do for now, though */ namelen = dentry->d_name.len; + mutex_lock(&c->create_sem); ret = jffs2_reserve_space(c, sizeof(*ri), &alloclen, ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); if (ret) { jffs2_free_raw_inode(ri); + mutex_unlock(&c->create_sem); return ret; } @@ -476,6 +489,7 @@ static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode if (IS_ERR(inode)) { jffs2_free_raw_inode(ri); jffs2_complete_reservation(c); + mutex_unlock(&c->create_sem); return PTR_ERR(inode); } @@ -574,11 +588,15 @@ static int jffs2_mkdir (struct inode *dir_i, struct dentry *dentry, umode_t mode jffs2_complete_reservation(c); unlock_new_inode(inode); + f->inocache->state_new = INO_STATE_N_NEW; + mutex_unlock(&c->create_sem); d_instantiate(dentry, inode); return 0; fail: iget_failed(inode); + f->inocache->state_new = INO_STATE_N_NEW; + mutex_unlock(&c->create_sem); return ret; } @@ -634,11 +652,13 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode * Just the node will do for now, though */ namelen = dentry->d_name.len; + mutex_lock(&c->create_sem); ret = jffs2_reserve_space(c, sizeof(*ri) + devlen, &alloclen, ALLOC_NORMAL, JFFS2_SUMMARY_INODE_SIZE); if (ret) { jffs2_free_raw_inode(ri); + mutex_unlock(&c->create_sem); return ret; } @@ -647,6 +667,7 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode if (IS_ERR(inode)) { jffs2_free_raw_inode(ri); jffs2_complete_reservation(c); + mutex_unlock(&c->create_sem); return PTR_ERR(inode); } inode->i_op = &jffs2_file_inode_operations; @@ -746,11 +767,15 @@ static int jffs2_mknod (struct inode *dir_i, struct dentry *dentry, umode_t mode jffs2_complete_reservation(c); unlock_new_inode(inode); + f->inocache->state_new = INO_STATE_N_NEW; + mutex_unlock(&c->create_sem); d_instantiate(dentry, inode); return 0; fail: iget_failed(inode); + f->inocache->state_new = INO_STATE_N_NEW; + mutex_unlock(&c->create_sem); return ret; } diff --git a/fs/jffs2/fs.c b/fs/jffs2/fs.c index 2caf168..c98fd3c 100644 --- a/fs/jffs2/fs.c +++ b/fs/jffs2/fs.c @@ -482,6 +482,7 @@ struct inode *jffs2_new_inode (struct inode *dir_i, umode_t mode, struct jffs2_r mutex_unlock(&f->sem); make_bad_inode(inode); iput(inode); + f->inocache->state_new = INO_STATE_N_NEW; return ERR_PTR(-EINVAL); } diff --git a/fs/jffs2/gc.c b/fs/jffs2/gc.c index 5a2dec2..51f2a4b 100644 --- a/fs/jffs2/gc.c +++ b/fs/jffs2/gc.c @@ -333,6 +333,17 @@ int jffs2_garbage_collect_pass(struct jffs2_sb_info *c) __func__, jeb->offset, ref_offset(raw), ref_flags(raw), ic->ino); + /* create but not finished so find next block */ + if (ic->state_new == INO_STATE_I_NEW) { + jffs2_dbg(1, "%s(): ino #%u in state new so find next block\n", + __func__, ic->ino); + c->gcblock = NULL; + list_add_tail(&jeb->list, &c->dirty_list); + mutex_unlock(&c->alloc_sem); + spin_unlock(&c->inocache_lock); + return 0; + } + /* Three possibilities: 1. Inode is already in-core. We must iget it and do proper updating to its fragtree, etc. diff --git a/fs/jffs2/jffs2_fs_sb.h b/fs/jffs2/jffs2_fs_sb.h index 046fee8..32193b7 100644 --- a/fs/jffs2/jffs2_fs_sb.h +++ b/fs/jffs2/jffs2_fs_sb.h @@ -57,6 +57,7 @@ struct jffs2_sb_info { struct completion gc_thread_start; /* GC thread start completion */ struct completion gc_thread_exit; /* GC thread exit completion port */ + struct mutex create_sem; /* Used to protect write dnode and dirent in order */ struct mutex alloc_sem; /* Used to protect all the following fields, and also to protect against out-of-order writing of nodes. And GC. */ diff --git a/fs/jffs2/nodelist.h b/fs/jffs2/nodelist.h index fa35ff7..ec377e0 100644 --- a/fs/jffs2/nodelist.h +++ b/fs/jffs2/nodelist.h @@ -180,6 +180,7 @@ struct jffs2_inode_cache { here; other inodes store nlink. Zero always means that it's completely unlinked. */ + uint32_t state_new; /* create flag */ }; /* Inode states for 'state' above. We need the 'GC' state to prevent @@ -193,6 +194,9 @@ struct jffs2_inode_cache { #define INO_STATE_READING 5 /* In read_inode() */ #define INO_STATE_CLEARING 6 /* In clear_inode() */ +#define INO_STATE_N_NEW 0 /* Finish to create */ +#define INO_STATE_I_NEW 1 /* Just create but not finish */ + #define INO_FLAGS_XATTR_CHECKED 0x01 /* has no duplicate xattr_ref */ #define RAWNODE_CLASS_INODE_CACHE 0 diff --git a/fs/jffs2/super.c b/fs/jffs2/super.c index d86c5e3..99c5715 100644 --- a/fs/jffs2/super.c +++ b/fs/jffs2/super.c @@ -292,6 +292,7 @@ static int jffs2_fill_super(struct super_block *sb, void *data, int silent) /* Initialize JFFS2 superblock locks, the further initialization will * be done later */ + mutex_init(&c->create_sem); mutex_init(&c->alloc_sem); mutex_init(&c->erase_free_sem); init_waitqueue_head(&c->erase_wait); diff --git a/fs/jffs2/write.c b/fs/jffs2/write.c index b634de4..dc8242d 100644 --- a/fs/jffs2/write.c +++ b/fs/jffs2/write.c @@ -36,6 +36,7 @@ int jffs2_do_new_inode(struct jffs2_sb_info *c, struct jffs2_inode_info *f, f->inocache->pino_nlink = 1; /* Will be overwritten shortly for directories */ f->inocache->nodes = (struct jffs2_raw_node_ref *)f->inocache; f->inocache->state = INO_STATE_PRESENT; + f->inocache->state_new = INO_STATE_I_NEW; jffs2_add_ino_cache(c, f->inocache); jffs2_dbg(1, "%s(): Assigned ino# %d\n", __func__, f->inocache->ino); -- 1.7.6 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html