April 2022 - Linux-stable-mirror

FAILED: patch "[PATCH] ubifs: Fix 'ui->dirty' race between do_tmpfile() and" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 60eb3b9c9f11206996f57cb89521824304b305ad Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:37 +0800 Subject: [PATCH] ubifs: Fix 'ui->dirty' race between do_tmpfile() and writeback work 'ui->dirty' is not protected by 'ui_mutex' in function do_tmpfile() which may race with ubifs_write_inode[wb_workfn] to access/update 'ui->dirty', finally dirty space is released twice. open(O_TMPFILE) wb_workfn do_tmpfile ubifs_budget_space(ino_req = { .dirtied_ino = 1}) d_tmpfile // mark inode(tmpfile) dirty ubifs_jnl_update // without holding tmpfile's ui_mutex mark_inode_clean(ui) if (ui->dirty) ubifs_release_dirty_inode_budget(ui) // release first time ubifs_write_inode mutex_lock(&ui->ui_mutex) ubifs_release_dirty_inode_budget(ui) // release second time mutex_unlock(&ui->ui_mutex) ui->dirty = 0 Run generic/476 can reproduce following message easily (See reproducer in [Link]): UBIFS error (ubi0:0 pid 2578): ubifs_assert_failed [ubifs]: UBIFS assert failed: c->bi.dd_growth >= 0, in fs/ubifs/budget.c:554 UBIFS warning (ubi0:0 pid 2578): ubifs_ro_mode [ubifs]: switched to read-only mode, error -22 Workqueue: writeback wb_workfn (flush-ubifs_0_0) Call Trace: ubifs_ro_mode+0x54/0x60 [ubifs] ubifs_assert_failed+0x4b/0x80 [ubifs] ubifs_release_budget+0x468/0x5a0 [ubifs] ubifs_release_dirty_inode_budget+0x53/0x80 [ubifs] ubifs_write_inode+0x121/0x1f0 [ubifs] ... wb_workfn+0x283/0x7b0 Fix it by holding tmpfile ubifs inode lock during ubifs_jnl_update(). Similar problem exists in whiteout renaming, but previous fix("ubifs: Rename whiteout atomically") has solved the problem. Fixes: 474b93704f32163 ("ubifs: Implement O_TMPFILE") Link: https://bugzilla.kernel.org/show_bug.cgi?id=214765 Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index f2a6b45bfdae..faca567ef06b 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -397,6 +397,32 @@ static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry) return ERR_PTR(err); } +/** + * lock_2_inodes - a wrapper for locking two UBIFS inodes. + * @inode1: first inode + * @inode2: second inode + * + * We do not implement any tricks to guarantee strict lock ordering, because + * VFS has already done it for us on the @i_mutex. So this is just a simple + * wrapper function. + */ +static void lock_2_inodes(struct inode *inode1, struct inode *inode2) +{ + mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); + mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); +} + +/** + * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes. + * @inode1: first inode + * @inode2: second inode + */ +static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) +{ + mutex_unlock(&ubifs_inode(inode2)->ui_mutex); + mutex_unlock(&ubifs_inode(inode1)->ui_mutex); +} + static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, struct dentry *dentry, umode_t mode) { @@ -404,7 +430,7 @@ static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, struct ubifs_info *c = dir->i_sb->s_fs_info; struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1}; struct ubifs_budget_req ino_req = { .dirtied_ino = 1 }; - struct ubifs_inode *ui, *dir_ui = ubifs_inode(dir); + struct ubifs_inode *ui; int err, instantiated = 0; struct fscrypt_name nm; @@ -452,18 +478,18 @@ static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, instantiated = 1; mutex_unlock(&ui->ui_mutex); - mutex_lock(&dir_ui->ui_mutex); + lock_2_inodes(dir, inode); err = ubifs_jnl_update(c, dir, &nm, inode, 1, 0); if (err) goto out_cancel; - mutex_unlock(&dir_ui->ui_mutex); + unlock_2_inodes(dir, inode); ubifs_release_budget(c, &req); return 0; out_cancel: - mutex_unlock(&dir_ui->ui_mutex); + unlock_2_inodes(dir, inode); out_inode: make_bad_inode(inode); if (!instantiated) @@ -690,32 +716,6 @@ static int ubifs_dir_release(struct inode *dir, struct file *file) return 0; } -/** - * lock_2_inodes - a wrapper for locking two UBIFS inodes. - * @inode1: first inode - * @inode2: second inode - * - * We do not implement any tricks to guarantee strict lock ordering, because - * VFS has already done it for us on the @i_mutex. So this is just a simple - * wrapper function. - */ -static void lock_2_inodes(struct inode *inode1, struct inode *inode2) -{ - mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1); - mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2); -} - -/** - * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes. - * @inode1: first inode - * @inode2: second inode - */ -static void unlock_2_inodes(struct inode *inode1, struct inode *inode2) -{ - mutex_unlock(&ubifs_inode(inode2)->ui_mutex); - mutex_unlock(&ubifs_inode(inode1)->ui_mutex); -} - static int ubifs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) {

2 years, 9 months

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FAILED: patch "[PATCH] ubifs: Rename whiteout atomically" failed to apply to 5.10-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 278d9a243635f26c05ad95dcf9c5a593b9e04dc6 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:36 +0800 Subject: [PATCH] ubifs: Rename whiteout atomically Currently, rename whiteout has 3 steps: 1. create tmpfile(which associates old dentry to tmpfile inode) for whiteout, and store tmpfile to disk 2. link whiteout, associate whiteout inode to old dentry agagin and store old dentry, old inode, new dentry on disk 3. writeback dirty whiteout inode to disk Suddenly power-cut or error occurring(eg. ENOSPC returned by budget, memory allocation failure) during above steps may cause kinds of problems: Problem 1: ENOSPC returned by whiteout space budget (before step 2), old dentry will disappear after rename syscall, whiteout file cannot be found either. ls dir // we get file, whiteout rename(dir/file, dir/whiteout, REANME_WHITEOUT) ENOSPC = ubifs_budget_space(&wht_req) // return ls dir // empty (no file, no whiteout) Problem 2: Power-cut happens before step 3, whiteout inode with 'nlink=1' is not stored on disk, whiteout dentry(old dentry) is written on disk, whiteout file is lost on next mount (We get "dead directory entry" after executing 'ls -l' on whiteout file). Now, we use following 3 steps to finish rename whiteout: 1. create an in-mem inode with 'nlink = 1' as whiteout 2. ubifs_jnl_rename (Write on disk to finish associating old dentry to whiteout inode, associating new dentry with old inode) 3. iput(whiteout) Rely writing in-mem inode on disk by ubifs_jnl_rename() to finish rename whiteout, which avoids middle disk state caused by suddenly power-cut and error occurring. Fixes: 9e0a1fff8db56ea ("ubifs: Implement RENAME_WHITEOUT") Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 745e6e3f246e..f2a6b45bfdae 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -349,8 +349,56 @@ static int ubifs_create(struct user_namespace *mnt_userns, struct inode *dir, return err; } -static int do_tmpfile(struct inode *dir, struct dentry *dentry, - umode_t mode, struct inode **whiteout) +static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry) +{ + int err; + umode_t mode = S_IFCHR | WHITEOUT_MODE; + struct inode *inode; + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct fscrypt_name nm; + + /* + * Create an inode('nlink = 1') for whiteout without updating journal, + * let ubifs_jnl_rename() store it on flash to complete rename whiteout + * atomically. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + if (err) + return ERR_PTR(err); + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_free; + } + + init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); + ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + /* The dir size is updated by do_rename. */ + insert_inode_hash(inode); + + return inode; + +out_inode: + make_bad_inode(inode); + iput(inode); +out_free: + fscrypt_free_filename(&nm); + ubifs_err(c, "cannot create whiteout file, error %d", err); + return ERR_PTR(err); +} + +static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode) { struct inode *inode; struct ubifs_info *c = dir->i_sb->s_fs_info; @@ -392,25 +440,13 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, } ui = ubifs_inode(inode); - if (whiteout) { - init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); - ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); - } - err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&ui->ui_mutex); insert_inode_hash(inode); - - if (whiteout) { - mark_inode_dirty(inode); - drop_nlink(inode); - *whiteout = inode; - } else { - d_tmpfile(dentry, inode); - } + d_tmpfile(dentry, inode); ubifs_assert(c, ui->dirty); instantiated = 1; @@ -432,8 +468,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, make_bad_inode(inode); if (!instantiated) iput(inode); - else if (whiteout) - iput(*whiteout); out_budg: ubifs_release_budget(c, &req); if (!instantiated) @@ -443,12 +477,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, return err; } -static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, - struct dentry *dentry, umode_t mode) -{ - return do_tmpfile(dir, dentry, mode, NULL); -} - /** * vfs_dent_type - get VFS directory entry type. * @type: UBIFS directory entry type @@ -1266,17 +1294,19 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, .dirtied_ino = 3 }; struct ubifs_budget_req ino_req = { .dirtied_ino = 1, .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; + struct ubifs_budget_req wht_req; struct timespec64 time; unsigned int saved_nlink; struct fscrypt_name old_nm, new_nm; /* - * Budget request settings: deletion direntry, new direntry, removing - * the old inode, and changing old and new parent directory inodes. + * Budget request settings: + * req: deletion direntry, new direntry, removing the old inode, + * and changing old and new parent directory inodes. * - * However, this operation also marks the target inode as dirty and - * does not write it, so we allocate budget for the target inode - * separately. + * wht_req: new whiteout inode for RENAME_WHITEOUT. + * + * ino_req: marks the target inode as dirty and does not write it. */ dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x", @@ -1326,7 +1356,6 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (flags & RENAME_WHITEOUT) { union ubifs_dev_desc *dev = NULL; - struct ubifs_budget_req wht_req; dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) { @@ -1334,24 +1363,26 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, goto out_release; } - err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout); - if (err) { + /* + * The whiteout inode without dentry is pinned in memory, + * umount won't happen during rename process because we + * got parent dentry. + */ + whiteout = create_whiteout(old_dir, old_dentry); + if (IS_ERR(whiteout)) { + err = PTR_ERR(whiteout); kfree(dev); goto out_release; } - spin_lock(&whiteout->i_lock); - whiteout->i_state |= I_LINKABLE; - spin_unlock(&whiteout->i_lock); - whiteout_ui = ubifs_inode(whiteout); whiteout_ui->data = dev; whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); ubifs_assert(c, !whiteout_ui->dirty); memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); - wht_req.dirtied_ino = 1; - wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); + wht_req.new_ino = 1; + wht_req.new_ino_d = ALIGN(whiteout_ui->data_len, 8); /* * To avoid deadlock between space budget (holds ui_mutex and * waits wb work) and writeback work(waits ui_mutex), do space @@ -1359,6 +1390,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, */ err = ubifs_budget_space(c, &wht_req); if (err) { + /* + * Whiteout inode can not be written on flash by + * ubifs_jnl_write_inode(), because it's neither + * dirty nor zero-nlink. + */ iput(whiteout); goto out_release; } @@ -1433,17 +1469,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); if (unlink && IS_SYNC(new_inode)) sync = 1; - } - - if (whiteout) { - inc_nlink(whiteout); - mark_inode_dirty(whiteout); - - spin_lock(&whiteout->i_lock); - whiteout->i_state &= ~I_LINKABLE; - spin_unlock(&whiteout->i_lock); - - iput(whiteout); + /* + * S_SYNC flag of whiteout inherits from the old_dir, and we + * have already checked the old dir inode. So there is no need + * to check whiteout. + */ } err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, @@ -1454,6 +1484,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); ubifs_release_budget(c, &req); + if (whiteout) { + ubifs_release_budget(c, &wht_req); + iput(whiteout); + } + mutex_lock(&old_inode_ui->ui_mutex); release = old_inode_ui->dirty; mark_inode_dirty_sync(old_inode); @@ -1462,11 +1497,16 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (release) ubifs_release_budget(c, &ino_req); if (IS_SYNC(old_inode)) - err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); + /* + * Rename finished here. Although old inode cannot be updated + * on flash, old ctime is not a big problem, don't return err + * code to userspace. + */ + old_inode->i_sb->s_op->write_inode(old_inode, NULL); fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); - return err; + return 0; out_cancel: if (unlink) { @@ -1487,11 +1527,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, inc_nlink(old_dir); } } + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); if (whiteout) { - drop_nlink(whiteout); + ubifs_release_budget(c, &wht_req); iput(whiteout); } - unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); out_release: ubifs_release_budget(c, &ino_req); ubifs_release_budget(c, &req); diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 8ea680dba61e..75dab0ae3939 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1207,9 +1207,9 @@ int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, * @sync: non-zero if the write-buffer has to be synchronized * * This function implements the re-name operation which may involve writing up - * to 4 inodes and 2 directory entries. It marks the written inodes as clean - * and returns zero on success. In case of failure, a negative error code is - * returned. + * to 4 inodes(new inode, whiteout inode, old and new parent directory inodes) + * and 2 directory entries. It marks the written inodes as clean and returns + * zero on success. In case of failure, a negative error code is returned. */ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, const struct inode *old_inode, @@ -1222,14 +1222,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, void *p; union ubifs_key key; struct ubifs_dent_node *dent, *dent2; - int err, dlen1, dlen2, ilen, lnum, offs, len, orphan_added = 0; + int err, dlen1, dlen2, ilen, wlen, lnum, offs, len, orphan_added = 0; int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ; int last_reference = !!(new_inode && new_inode->i_nlink == 0); int move = (old_dir != new_dir); - struct ubifs_inode *new_ui; + struct ubifs_inode *new_ui, *whiteout_ui; u8 hash_old_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_inode[UBIFS_HASH_ARR_SZ]; + u8 hash_whiteout_inode[UBIFS_HASH_ARR_SZ]; u8 hash_dent1[UBIFS_HASH_ARR_SZ]; u8 hash_dent2[UBIFS_HASH_ARR_SZ]; @@ -1249,9 +1250,20 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, } else ilen = 0; + if (whiteout) { + whiteout_ui = ubifs_inode(whiteout); + ubifs_assert(c, mutex_is_locked(&whiteout_ui->ui_mutex)); + ubifs_assert(c, whiteout->i_nlink == 1); + ubifs_assert(c, !whiteout_ui->dirty); + wlen = UBIFS_INO_NODE_SZ; + wlen += whiteout_ui->data_len; + } else + wlen = 0; + aligned_dlen1 = ALIGN(dlen1, 8); aligned_dlen2 = ALIGN(dlen2, 8); - len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8); + len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + + ALIGN(wlen, 8) + ALIGN(plen, 8); if (move) len += plen; @@ -1313,6 +1325,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, p += ALIGN(ilen, 8); } + if (whiteout) { + pack_inode(c, p, whiteout, 0); + err = ubifs_node_calc_hash(c, p, hash_whiteout_inode); + if (err) + goto out_release; + + p += ALIGN(wlen, 8); + } + if (!move) { pack_inode(c, p, old_dir, 1); err = ubifs_node_calc_hash(c, p, hash_old_dir); @@ -1352,6 +1373,9 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, if (new_inode) ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, new_inode->i_ino); + if (whiteout) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, + whiteout->i_ino); } release_head(c, BASEHD); @@ -1368,8 +1392,6 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, hash_dent2, old_nm); if (err) goto out_ro; - - ubifs_delete_orphan(c, whiteout->i_ino); } else { err = ubifs_add_dirt(c, lnum, dlen2); if (err) @@ -1390,6 +1412,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, offs += ALIGN(ilen, 8); } + if (whiteout) { + ino_key_init(c, &key, whiteout->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, wlen, + hash_whiteout_inode); + if (err) + goto out_ro; + offs += ALIGN(wlen, 8); + } + ino_key_init(c, &key, old_dir->i_ino); err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_old_dir); if (err) @@ -1410,6 +1441,11 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, new_ui->synced_i_size = new_ui->ui_size; spin_unlock(&new_ui->ui_lock); } + /* + * No need to mark whiteout inode clean. + * Whiteout doesn't have non-zero size, no need to update + * synced_i_size for whiteout_ui. + */ mark_inode_clean(c, ubifs_inode(old_dir)); if (move) mark_inode_clean(c, ubifs_inode(new_dir));

2 years, 9 months

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FAILED: patch "[PATCH] ubifs: Rename whiteout atomically" failed to apply to 5.4-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 278d9a243635f26c05ad95dcf9c5a593b9e04dc6 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:36 +0800 Subject: [PATCH] ubifs: Rename whiteout atomically Currently, rename whiteout has 3 steps: 1. create tmpfile(which associates old dentry to tmpfile inode) for whiteout, and store tmpfile to disk 2. link whiteout, associate whiteout inode to old dentry agagin and store old dentry, old inode, new dentry on disk 3. writeback dirty whiteout inode to disk Suddenly power-cut or error occurring(eg. ENOSPC returned by budget, memory allocation failure) during above steps may cause kinds of problems: Problem 1: ENOSPC returned by whiteout space budget (before step 2), old dentry will disappear after rename syscall, whiteout file cannot be found either. ls dir // we get file, whiteout rename(dir/file, dir/whiteout, REANME_WHITEOUT) ENOSPC = ubifs_budget_space(&wht_req) // return ls dir // empty (no file, no whiteout) Problem 2: Power-cut happens before step 3, whiteout inode with 'nlink=1' is not stored on disk, whiteout dentry(old dentry) is written on disk, whiteout file is lost on next mount (We get "dead directory entry" after executing 'ls -l' on whiteout file). Now, we use following 3 steps to finish rename whiteout: 1. create an in-mem inode with 'nlink = 1' as whiteout 2. ubifs_jnl_rename (Write on disk to finish associating old dentry to whiteout inode, associating new dentry with old inode) 3. iput(whiteout) Rely writing in-mem inode on disk by ubifs_jnl_rename() to finish rename whiteout, which avoids middle disk state caused by suddenly power-cut and error occurring. Fixes: 9e0a1fff8db56ea ("ubifs: Implement RENAME_WHITEOUT") Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 745e6e3f246e..f2a6b45bfdae 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -349,8 +349,56 @@ static int ubifs_create(struct user_namespace *mnt_userns, struct inode *dir, return err; } -static int do_tmpfile(struct inode *dir, struct dentry *dentry, - umode_t mode, struct inode **whiteout) +static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry) +{ + int err; + umode_t mode = S_IFCHR | WHITEOUT_MODE; + struct inode *inode; + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct fscrypt_name nm; + + /* + * Create an inode('nlink = 1') for whiteout without updating journal, + * let ubifs_jnl_rename() store it on flash to complete rename whiteout + * atomically. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + if (err) + return ERR_PTR(err); + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_free; + } + + init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); + ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + /* The dir size is updated by do_rename. */ + insert_inode_hash(inode); + + return inode; + +out_inode: + make_bad_inode(inode); + iput(inode); +out_free: + fscrypt_free_filename(&nm); + ubifs_err(c, "cannot create whiteout file, error %d", err); + return ERR_PTR(err); +} + +static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode) { struct inode *inode; struct ubifs_info *c = dir->i_sb->s_fs_info; @@ -392,25 +440,13 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, } ui = ubifs_inode(inode); - if (whiteout) { - init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); - ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); - } - err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&ui->ui_mutex); insert_inode_hash(inode); - - if (whiteout) { - mark_inode_dirty(inode); - drop_nlink(inode); - *whiteout = inode; - } else { - d_tmpfile(dentry, inode); - } + d_tmpfile(dentry, inode); ubifs_assert(c, ui->dirty); instantiated = 1; @@ -432,8 +468,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, make_bad_inode(inode); if (!instantiated) iput(inode); - else if (whiteout) - iput(*whiteout); out_budg: ubifs_release_budget(c, &req); if (!instantiated) @@ -443,12 +477,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, return err; } -static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, - struct dentry *dentry, umode_t mode) -{ - return do_tmpfile(dir, dentry, mode, NULL); -} - /** * vfs_dent_type - get VFS directory entry type. * @type: UBIFS directory entry type @@ -1266,17 +1294,19 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, .dirtied_ino = 3 }; struct ubifs_budget_req ino_req = { .dirtied_ino = 1, .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; + struct ubifs_budget_req wht_req; struct timespec64 time; unsigned int saved_nlink; struct fscrypt_name old_nm, new_nm; /* - * Budget request settings: deletion direntry, new direntry, removing - * the old inode, and changing old and new parent directory inodes. + * Budget request settings: + * req: deletion direntry, new direntry, removing the old inode, + * and changing old and new parent directory inodes. * - * However, this operation also marks the target inode as dirty and - * does not write it, so we allocate budget for the target inode - * separately. + * wht_req: new whiteout inode for RENAME_WHITEOUT. + * + * ino_req: marks the target inode as dirty and does not write it. */ dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x", @@ -1326,7 +1356,6 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (flags & RENAME_WHITEOUT) { union ubifs_dev_desc *dev = NULL; - struct ubifs_budget_req wht_req; dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) { @@ -1334,24 +1363,26 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, goto out_release; } - err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout); - if (err) { + /* + * The whiteout inode without dentry is pinned in memory, + * umount won't happen during rename process because we + * got parent dentry. + */ + whiteout = create_whiteout(old_dir, old_dentry); + if (IS_ERR(whiteout)) { + err = PTR_ERR(whiteout); kfree(dev); goto out_release; } - spin_lock(&whiteout->i_lock); - whiteout->i_state |= I_LINKABLE; - spin_unlock(&whiteout->i_lock); - whiteout_ui = ubifs_inode(whiteout); whiteout_ui->data = dev; whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); ubifs_assert(c, !whiteout_ui->dirty); memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); - wht_req.dirtied_ino = 1; - wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); + wht_req.new_ino = 1; + wht_req.new_ino_d = ALIGN(whiteout_ui->data_len, 8); /* * To avoid deadlock between space budget (holds ui_mutex and * waits wb work) and writeback work(waits ui_mutex), do space @@ -1359,6 +1390,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, */ err = ubifs_budget_space(c, &wht_req); if (err) { + /* + * Whiteout inode can not be written on flash by + * ubifs_jnl_write_inode(), because it's neither + * dirty nor zero-nlink. + */ iput(whiteout); goto out_release; } @@ -1433,17 +1469,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); if (unlink && IS_SYNC(new_inode)) sync = 1; - } - - if (whiteout) { - inc_nlink(whiteout); - mark_inode_dirty(whiteout); - - spin_lock(&whiteout->i_lock); - whiteout->i_state &= ~I_LINKABLE; - spin_unlock(&whiteout->i_lock); - - iput(whiteout); + /* + * S_SYNC flag of whiteout inherits from the old_dir, and we + * have already checked the old dir inode. So there is no need + * to check whiteout. + */ } err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, @@ -1454,6 +1484,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); ubifs_release_budget(c, &req); + if (whiteout) { + ubifs_release_budget(c, &wht_req); + iput(whiteout); + } + mutex_lock(&old_inode_ui->ui_mutex); release = old_inode_ui->dirty; mark_inode_dirty_sync(old_inode); @@ -1462,11 +1497,16 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (release) ubifs_release_budget(c, &ino_req); if (IS_SYNC(old_inode)) - err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); + /* + * Rename finished here. Although old inode cannot be updated + * on flash, old ctime is not a big problem, don't return err + * code to userspace. + */ + old_inode->i_sb->s_op->write_inode(old_inode, NULL); fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); - return err; + return 0; out_cancel: if (unlink) { @@ -1487,11 +1527,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, inc_nlink(old_dir); } } + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); if (whiteout) { - drop_nlink(whiteout); + ubifs_release_budget(c, &wht_req); iput(whiteout); } - unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); out_release: ubifs_release_budget(c, &ino_req); ubifs_release_budget(c, &req); diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 8ea680dba61e..75dab0ae3939 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1207,9 +1207,9 @@ int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, * @sync: non-zero if the write-buffer has to be synchronized * * This function implements the re-name operation which may involve writing up - * to 4 inodes and 2 directory entries. It marks the written inodes as clean - * and returns zero on success. In case of failure, a negative error code is - * returned. + * to 4 inodes(new inode, whiteout inode, old and new parent directory inodes) + * and 2 directory entries. It marks the written inodes as clean and returns + * zero on success. In case of failure, a negative error code is returned. */ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, const struct inode *old_inode, @@ -1222,14 +1222,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, void *p; union ubifs_key key; struct ubifs_dent_node *dent, *dent2; - int err, dlen1, dlen2, ilen, lnum, offs, len, orphan_added = 0; + int err, dlen1, dlen2, ilen, wlen, lnum, offs, len, orphan_added = 0; int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ; int last_reference = !!(new_inode && new_inode->i_nlink == 0); int move = (old_dir != new_dir); - struct ubifs_inode *new_ui; + struct ubifs_inode *new_ui, *whiteout_ui; u8 hash_old_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_inode[UBIFS_HASH_ARR_SZ]; + u8 hash_whiteout_inode[UBIFS_HASH_ARR_SZ]; u8 hash_dent1[UBIFS_HASH_ARR_SZ]; u8 hash_dent2[UBIFS_HASH_ARR_SZ]; @@ -1249,9 +1250,20 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, } else ilen = 0; + if (whiteout) { + whiteout_ui = ubifs_inode(whiteout); + ubifs_assert(c, mutex_is_locked(&whiteout_ui->ui_mutex)); + ubifs_assert(c, whiteout->i_nlink == 1); + ubifs_assert(c, !whiteout_ui->dirty); + wlen = UBIFS_INO_NODE_SZ; + wlen += whiteout_ui->data_len; + } else + wlen = 0; + aligned_dlen1 = ALIGN(dlen1, 8); aligned_dlen2 = ALIGN(dlen2, 8); - len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8); + len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + + ALIGN(wlen, 8) + ALIGN(plen, 8); if (move) len += plen; @@ -1313,6 +1325,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, p += ALIGN(ilen, 8); } + if (whiteout) { + pack_inode(c, p, whiteout, 0); + err = ubifs_node_calc_hash(c, p, hash_whiteout_inode); + if (err) + goto out_release; + + p += ALIGN(wlen, 8); + } + if (!move) { pack_inode(c, p, old_dir, 1); err = ubifs_node_calc_hash(c, p, hash_old_dir); @@ -1352,6 +1373,9 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, if (new_inode) ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, new_inode->i_ino); + if (whiteout) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, + whiteout->i_ino); } release_head(c, BASEHD); @@ -1368,8 +1392,6 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, hash_dent2, old_nm); if (err) goto out_ro; - - ubifs_delete_orphan(c, whiteout->i_ino); } else { err = ubifs_add_dirt(c, lnum, dlen2); if (err) @@ -1390,6 +1412,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, offs += ALIGN(ilen, 8); } + if (whiteout) { + ino_key_init(c, &key, whiteout->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, wlen, + hash_whiteout_inode); + if (err) + goto out_ro; + offs += ALIGN(wlen, 8); + } + ino_key_init(c, &key, old_dir->i_ino); err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_old_dir); if (err) @@ -1410,6 +1441,11 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, new_ui->synced_i_size = new_ui->ui_size; spin_unlock(&new_ui->ui_lock); } + /* + * No need to mark whiteout inode clean. + * Whiteout doesn't have non-zero size, no need to update + * synced_i_size for whiteout_ui. + */ mark_inode_clean(c, ubifs_inode(old_dir)); if (move) mark_inode_clean(c, ubifs_inode(new_dir));

2 years, 9 months

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FAILED: patch "[PATCH] ubifs: Rename whiteout atomically" failed to apply to 4.19-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.19-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 278d9a243635f26c05ad95dcf9c5a593b9e04dc6 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:36 +0800 Subject: [PATCH] ubifs: Rename whiteout atomically Currently, rename whiteout has 3 steps: 1. create tmpfile(which associates old dentry to tmpfile inode) for whiteout, and store tmpfile to disk 2. link whiteout, associate whiteout inode to old dentry agagin and store old dentry, old inode, new dentry on disk 3. writeback dirty whiteout inode to disk Suddenly power-cut or error occurring(eg. ENOSPC returned by budget, memory allocation failure) during above steps may cause kinds of problems: Problem 1: ENOSPC returned by whiteout space budget (before step 2), old dentry will disappear after rename syscall, whiteout file cannot be found either. ls dir // we get file, whiteout rename(dir/file, dir/whiteout, REANME_WHITEOUT) ENOSPC = ubifs_budget_space(&wht_req) // return ls dir // empty (no file, no whiteout) Problem 2: Power-cut happens before step 3, whiteout inode with 'nlink=1' is not stored on disk, whiteout dentry(old dentry) is written on disk, whiteout file is lost on next mount (We get "dead directory entry" after executing 'ls -l' on whiteout file). Now, we use following 3 steps to finish rename whiteout: 1. create an in-mem inode with 'nlink = 1' as whiteout 2. ubifs_jnl_rename (Write on disk to finish associating old dentry to whiteout inode, associating new dentry with old inode) 3. iput(whiteout) Rely writing in-mem inode on disk by ubifs_jnl_rename() to finish rename whiteout, which avoids middle disk state caused by suddenly power-cut and error occurring. Fixes: 9e0a1fff8db56ea ("ubifs: Implement RENAME_WHITEOUT") Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 745e6e3f246e..f2a6b45bfdae 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -349,8 +349,56 @@ static int ubifs_create(struct user_namespace *mnt_userns, struct inode *dir, return err; } -static int do_tmpfile(struct inode *dir, struct dentry *dentry, - umode_t mode, struct inode **whiteout) +static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry) +{ + int err; + umode_t mode = S_IFCHR | WHITEOUT_MODE; + struct inode *inode; + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct fscrypt_name nm; + + /* + * Create an inode('nlink = 1') for whiteout without updating journal, + * let ubifs_jnl_rename() store it on flash to complete rename whiteout + * atomically. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + if (err) + return ERR_PTR(err); + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_free; + } + + init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); + ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + /* The dir size is updated by do_rename. */ + insert_inode_hash(inode); + + return inode; + +out_inode: + make_bad_inode(inode); + iput(inode); +out_free: + fscrypt_free_filename(&nm); + ubifs_err(c, "cannot create whiteout file, error %d", err); + return ERR_PTR(err); +} + +static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode) { struct inode *inode; struct ubifs_info *c = dir->i_sb->s_fs_info; @@ -392,25 +440,13 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, } ui = ubifs_inode(inode); - if (whiteout) { - init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); - ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); - } - err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&ui->ui_mutex); insert_inode_hash(inode); - - if (whiteout) { - mark_inode_dirty(inode); - drop_nlink(inode); - *whiteout = inode; - } else { - d_tmpfile(dentry, inode); - } + d_tmpfile(dentry, inode); ubifs_assert(c, ui->dirty); instantiated = 1; @@ -432,8 +468,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, make_bad_inode(inode); if (!instantiated) iput(inode); - else if (whiteout) - iput(*whiteout); out_budg: ubifs_release_budget(c, &req); if (!instantiated) @@ -443,12 +477,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, return err; } -static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, - struct dentry *dentry, umode_t mode) -{ - return do_tmpfile(dir, dentry, mode, NULL); -} - /** * vfs_dent_type - get VFS directory entry type. * @type: UBIFS directory entry type @@ -1266,17 +1294,19 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, .dirtied_ino = 3 }; struct ubifs_budget_req ino_req = { .dirtied_ino = 1, .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; + struct ubifs_budget_req wht_req; struct timespec64 time; unsigned int saved_nlink; struct fscrypt_name old_nm, new_nm; /* - * Budget request settings: deletion direntry, new direntry, removing - * the old inode, and changing old and new parent directory inodes. + * Budget request settings: + * req: deletion direntry, new direntry, removing the old inode, + * and changing old and new parent directory inodes. * - * However, this operation also marks the target inode as dirty and - * does not write it, so we allocate budget for the target inode - * separately. + * wht_req: new whiteout inode for RENAME_WHITEOUT. + * + * ino_req: marks the target inode as dirty and does not write it. */ dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x", @@ -1326,7 +1356,6 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (flags & RENAME_WHITEOUT) { union ubifs_dev_desc *dev = NULL; - struct ubifs_budget_req wht_req; dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) { @@ -1334,24 +1363,26 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, goto out_release; } - err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout); - if (err) { + /* + * The whiteout inode without dentry is pinned in memory, + * umount won't happen during rename process because we + * got parent dentry. + */ + whiteout = create_whiteout(old_dir, old_dentry); + if (IS_ERR(whiteout)) { + err = PTR_ERR(whiteout); kfree(dev); goto out_release; } - spin_lock(&whiteout->i_lock); - whiteout->i_state |= I_LINKABLE; - spin_unlock(&whiteout->i_lock); - whiteout_ui = ubifs_inode(whiteout); whiteout_ui->data = dev; whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); ubifs_assert(c, !whiteout_ui->dirty); memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); - wht_req.dirtied_ino = 1; - wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); + wht_req.new_ino = 1; + wht_req.new_ino_d = ALIGN(whiteout_ui->data_len, 8); /* * To avoid deadlock between space budget (holds ui_mutex and * waits wb work) and writeback work(waits ui_mutex), do space @@ -1359,6 +1390,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, */ err = ubifs_budget_space(c, &wht_req); if (err) { + /* + * Whiteout inode can not be written on flash by + * ubifs_jnl_write_inode(), because it's neither + * dirty nor zero-nlink. + */ iput(whiteout); goto out_release; } @@ -1433,17 +1469,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); if (unlink && IS_SYNC(new_inode)) sync = 1; - } - - if (whiteout) { - inc_nlink(whiteout); - mark_inode_dirty(whiteout); - - spin_lock(&whiteout->i_lock); - whiteout->i_state &= ~I_LINKABLE; - spin_unlock(&whiteout->i_lock); - - iput(whiteout); + /* + * S_SYNC flag of whiteout inherits from the old_dir, and we + * have already checked the old dir inode. So there is no need + * to check whiteout. + */ } err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, @@ -1454,6 +1484,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); ubifs_release_budget(c, &req); + if (whiteout) { + ubifs_release_budget(c, &wht_req); + iput(whiteout); + } + mutex_lock(&old_inode_ui->ui_mutex); release = old_inode_ui->dirty; mark_inode_dirty_sync(old_inode); @@ -1462,11 +1497,16 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (release) ubifs_release_budget(c, &ino_req); if (IS_SYNC(old_inode)) - err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); + /* + * Rename finished here. Although old inode cannot be updated + * on flash, old ctime is not a big problem, don't return err + * code to userspace. + */ + old_inode->i_sb->s_op->write_inode(old_inode, NULL); fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); - return err; + return 0; out_cancel: if (unlink) { @@ -1487,11 +1527,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, inc_nlink(old_dir); } } + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); if (whiteout) { - drop_nlink(whiteout); + ubifs_release_budget(c, &wht_req); iput(whiteout); } - unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); out_release: ubifs_release_budget(c, &ino_req); ubifs_release_budget(c, &req); diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 8ea680dba61e..75dab0ae3939 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1207,9 +1207,9 @@ int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, * @sync: non-zero if the write-buffer has to be synchronized * * This function implements the re-name operation which may involve writing up - * to 4 inodes and 2 directory entries. It marks the written inodes as clean - * and returns zero on success. In case of failure, a negative error code is - * returned. + * to 4 inodes(new inode, whiteout inode, old and new parent directory inodes) + * and 2 directory entries. It marks the written inodes as clean and returns + * zero on success. In case of failure, a negative error code is returned. */ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, const struct inode *old_inode, @@ -1222,14 +1222,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, void *p; union ubifs_key key; struct ubifs_dent_node *dent, *dent2; - int err, dlen1, dlen2, ilen, lnum, offs, len, orphan_added = 0; + int err, dlen1, dlen2, ilen, wlen, lnum, offs, len, orphan_added = 0; int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ; int last_reference = !!(new_inode && new_inode->i_nlink == 0); int move = (old_dir != new_dir); - struct ubifs_inode *new_ui; + struct ubifs_inode *new_ui, *whiteout_ui; u8 hash_old_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_inode[UBIFS_HASH_ARR_SZ]; + u8 hash_whiteout_inode[UBIFS_HASH_ARR_SZ]; u8 hash_dent1[UBIFS_HASH_ARR_SZ]; u8 hash_dent2[UBIFS_HASH_ARR_SZ]; @@ -1249,9 +1250,20 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, } else ilen = 0; + if (whiteout) { + whiteout_ui = ubifs_inode(whiteout); + ubifs_assert(c, mutex_is_locked(&whiteout_ui->ui_mutex)); + ubifs_assert(c, whiteout->i_nlink == 1); + ubifs_assert(c, !whiteout_ui->dirty); + wlen = UBIFS_INO_NODE_SZ; + wlen += whiteout_ui->data_len; + } else + wlen = 0; + aligned_dlen1 = ALIGN(dlen1, 8); aligned_dlen2 = ALIGN(dlen2, 8); - len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8); + len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + + ALIGN(wlen, 8) + ALIGN(plen, 8); if (move) len += plen; @@ -1313,6 +1325,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, p += ALIGN(ilen, 8); } + if (whiteout) { + pack_inode(c, p, whiteout, 0); + err = ubifs_node_calc_hash(c, p, hash_whiteout_inode); + if (err) + goto out_release; + + p += ALIGN(wlen, 8); + } + if (!move) { pack_inode(c, p, old_dir, 1); err = ubifs_node_calc_hash(c, p, hash_old_dir); @@ -1352,6 +1373,9 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, if (new_inode) ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, new_inode->i_ino); + if (whiteout) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, + whiteout->i_ino); } release_head(c, BASEHD); @@ -1368,8 +1392,6 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, hash_dent2, old_nm); if (err) goto out_ro; - - ubifs_delete_orphan(c, whiteout->i_ino); } else { err = ubifs_add_dirt(c, lnum, dlen2); if (err) @@ -1390,6 +1412,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, offs += ALIGN(ilen, 8); } + if (whiteout) { + ino_key_init(c, &key, whiteout->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, wlen, + hash_whiteout_inode); + if (err) + goto out_ro; + offs += ALIGN(wlen, 8); + } + ino_key_init(c, &key, old_dir->i_ino); err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_old_dir); if (err) @@ -1410,6 +1441,11 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, new_ui->synced_i_size = new_ui->ui_size; spin_unlock(&new_ui->ui_lock); } + /* + * No need to mark whiteout inode clean. + * Whiteout doesn't have non-zero size, no need to update + * synced_i_size for whiteout_ui. + */ mark_inode_clean(c, ubifs_inode(old_dir)); if (move) mark_inode_clean(c, ubifs_inode(new_dir));

2 years, 9 months

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FAILED: patch "[PATCH] ubifs: Rename whiteout atomically" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 278d9a243635f26c05ad95dcf9c5a593b9e04dc6 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:36 +0800 Subject: [PATCH] ubifs: Rename whiteout atomically Currently, rename whiteout has 3 steps: 1. create tmpfile(which associates old dentry to tmpfile inode) for whiteout, and store tmpfile to disk 2. link whiteout, associate whiteout inode to old dentry agagin and store old dentry, old inode, new dentry on disk 3. writeback dirty whiteout inode to disk Suddenly power-cut or error occurring(eg. ENOSPC returned by budget, memory allocation failure) during above steps may cause kinds of problems: Problem 1: ENOSPC returned by whiteout space budget (before step 2), old dentry will disappear after rename syscall, whiteout file cannot be found either. ls dir // we get file, whiteout rename(dir/file, dir/whiteout, REANME_WHITEOUT) ENOSPC = ubifs_budget_space(&wht_req) // return ls dir // empty (no file, no whiteout) Problem 2: Power-cut happens before step 3, whiteout inode with 'nlink=1' is not stored on disk, whiteout dentry(old dentry) is written on disk, whiteout file is lost on next mount (We get "dead directory entry" after executing 'ls -l' on whiteout file). Now, we use following 3 steps to finish rename whiteout: 1. create an in-mem inode with 'nlink = 1' as whiteout 2. ubifs_jnl_rename (Write on disk to finish associating old dentry to whiteout inode, associating new dentry with old inode) 3. iput(whiteout) Rely writing in-mem inode on disk by ubifs_jnl_rename() to finish rename whiteout, which avoids middle disk state caused by suddenly power-cut and error occurring. Fixes: 9e0a1fff8db56ea ("ubifs: Implement RENAME_WHITEOUT") Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 745e6e3f246e..f2a6b45bfdae 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -349,8 +349,56 @@ static int ubifs_create(struct user_namespace *mnt_userns, struct inode *dir, return err; } -static int do_tmpfile(struct inode *dir, struct dentry *dentry, - umode_t mode, struct inode **whiteout) +static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry) +{ + int err; + umode_t mode = S_IFCHR | WHITEOUT_MODE; + struct inode *inode; + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct fscrypt_name nm; + + /* + * Create an inode('nlink = 1') for whiteout without updating journal, + * let ubifs_jnl_rename() store it on flash to complete rename whiteout + * atomically. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + if (err) + return ERR_PTR(err); + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_free; + } + + init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); + ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + /* The dir size is updated by do_rename. */ + insert_inode_hash(inode); + + return inode; + +out_inode: + make_bad_inode(inode); + iput(inode); +out_free: + fscrypt_free_filename(&nm); + ubifs_err(c, "cannot create whiteout file, error %d", err); + return ERR_PTR(err); +} + +static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode) { struct inode *inode; struct ubifs_info *c = dir->i_sb->s_fs_info; @@ -392,25 +440,13 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, } ui = ubifs_inode(inode); - if (whiteout) { - init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); - ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); - } - err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&ui->ui_mutex); insert_inode_hash(inode); - - if (whiteout) { - mark_inode_dirty(inode); - drop_nlink(inode); - *whiteout = inode; - } else { - d_tmpfile(dentry, inode); - } + d_tmpfile(dentry, inode); ubifs_assert(c, ui->dirty); instantiated = 1; @@ -432,8 +468,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, make_bad_inode(inode); if (!instantiated) iput(inode); - else if (whiteout) - iput(*whiteout); out_budg: ubifs_release_budget(c, &req); if (!instantiated) @@ -443,12 +477,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, return err; } -static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, - struct dentry *dentry, umode_t mode) -{ - return do_tmpfile(dir, dentry, mode, NULL); -} - /** * vfs_dent_type - get VFS directory entry type. * @type: UBIFS directory entry type @@ -1266,17 +1294,19 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, .dirtied_ino = 3 }; struct ubifs_budget_req ino_req = { .dirtied_ino = 1, .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; + struct ubifs_budget_req wht_req; struct timespec64 time; unsigned int saved_nlink; struct fscrypt_name old_nm, new_nm; /* - * Budget request settings: deletion direntry, new direntry, removing - * the old inode, and changing old and new parent directory inodes. + * Budget request settings: + * req: deletion direntry, new direntry, removing the old inode, + * and changing old and new parent directory inodes. * - * However, this operation also marks the target inode as dirty and - * does not write it, so we allocate budget for the target inode - * separately. + * wht_req: new whiteout inode for RENAME_WHITEOUT. + * + * ino_req: marks the target inode as dirty and does not write it. */ dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x", @@ -1326,7 +1356,6 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (flags & RENAME_WHITEOUT) { union ubifs_dev_desc *dev = NULL; - struct ubifs_budget_req wht_req; dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) { @@ -1334,24 +1363,26 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, goto out_release; } - err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout); - if (err) { + /* + * The whiteout inode without dentry is pinned in memory, + * umount won't happen during rename process because we + * got parent dentry. + */ + whiteout = create_whiteout(old_dir, old_dentry); + if (IS_ERR(whiteout)) { + err = PTR_ERR(whiteout); kfree(dev); goto out_release; } - spin_lock(&whiteout->i_lock); - whiteout->i_state |= I_LINKABLE; - spin_unlock(&whiteout->i_lock); - whiteout_ui = ubifs_inode(whiteout); whiteout_ui->data = dev; whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); ubifs_assert(c, !whiteout_ui->dirty); memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); - wht_req.dirtied_ino = 1; - wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); + wht_req.new_ino = 1; + wht_req.new_ino_d = ALIGN(whiteout_ui->data_len, 8); /* * To avoid deadlock between space budget (holds ui_mutex and * waits wb work) and writeback work(waits ui_mutex), do space @@ -1359,6 +1390,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, */ err = ubifs_budget_space(c, &wht_req); if (err) { + /* + * Whiteout inode can not be written on flash by + * ubifs_jnl_write_inode(), because it's neither + * dirty nor zero-nlink. + */ iput(whiteout); goto out_release; } @@ -1433,17 +1469,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); if (unlink && IS_SYNC(new_inode)) sync = 1; - } - - if (whiteout) { - inc_nlink(whiteout); - mark_inode_dirty(whiteout); - - spin_lock(&whiteout->i_lock); - whiteout->i_state &= ~I_LINKABLE; - spin_unlock(&whiteout->i_lock); - - iput(whiteout); + /* + * S_SYNC flag of whiteout inherits from the old_dir, and we + * have already checked the old dir inode. So there is no need + * to check whiteout. + */ } err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, @@ -1454,6 +1484,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); ubifs_release_budget(c, &req); + if (whiteout) { + ubifs_release_budget(c, &wht_req); + iput(whiteout); + } + mutex_lock(&old_inode_ui->ui_mutex); release = old_inode_ui->dirty; mark_inode_dirty_sync(old_inode); @@ -1462,11 +1497,16 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (release) ubifs_release_budget(c, &ino_req); if (IS_SYNC(old_inode)) - err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); + /* + * Rename finished here. Although old inode cannot be updated + * on flash, old ctime is not a big problem, don't return err + * code to userspace. + */ + old_inode->i_sb->s_op->write_inode(old_inode, NULL); fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); - return err; + return 0; out_cancel: if (unlink) { @@ -1487,11 +1527,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, inc_nlink(old_dir); } } + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); if (whiteout) { - drop_nlink(whiteout); + ubifs_release_budget(c, &wht_req); iput(whiteout); } - unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); out_release: ubifs_release_budget(c, &ino_req); ubifs_release_budget(c, &req); diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 8ea680dba61e..75dab0ae3939 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1207,9 +1207,9 @@ int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, * @sync: non-zero if the write-buffer has to be synchronized * * This function implements the re-name operation which may involve writing up - * to 4 inodes and 2 directory entries. It marks the written inodes as clean - * and returns zero on success. In case of failure, a negative error code is - * returned. + * to 4 inodes(new inode, whiteout inode, old and new parent directory inodes) + * and 2 directory entries. It marks the written inodes as clean and returns + * zero on success. In case of failure, a negative error code is returned. */ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, const struct inode *old_inode, @@ -1222,14 +1222,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, void *p; union ubifs_key key; struct ubifs_dent_node *dent, *dent2; - int err, dlen1, dlen2, ilen, lnum, offs, len, orphan_added = 0; + int err, dlen1, dlen2, ilen, wlen, lnum, offs, len, orphan_added = 0; int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ; int last_reference = !!(new_inode && new_inode->i_nlink == 0); int move = (old_dir != new_dir); - struct ubifs_inode *new_ui; + struct ubifs_inode *new_ui, *whiteout_ui; u8 hash_old_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_inode[UBIFS_HASH_ARR_SZ]; + u8 hash_whiteout_inode[UBIFS_HASH_ARR_SZ]; u8 hash_dent1[UBIFS_HASH_ARR_SZ]; u8 hash_dent2[UBIFS_HASH_ARR_SZ]; @@ -1249,9 +1250,20 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, } else ilen = 0; + if (whiteout) { + whiteout_ui = ubifs_inode(whiteout); + ubifs_assert(c, mutex_is_locked(&whiteout_ui->ui_mutex)); + ubifs_assert(c, whiteout->i_nlink == 1); + ubifs_assert(c, !whiteout_ui->dirty); + wlen = UBIFS_INO_NODE_SZ; + wlen += whiteout_ui->data_len; + } else + wlen = 0; + aligned_dlen1 = ALIGN(dlen1, 8); aligned_dlen2 = ALIGN(dlen2, 8); - len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8); + len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + + ALIGN(wlen, 8) + ALIGN(plen, 8); if (move) len += plen; @@ -1313,6 +1325,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, p += ALIGN(ilen, 8); } + if (whiteout) { + pack_inode(c, p, whiteout, 0); + err = ubifs_node_calc_hash(c, p, hash_whiteout_inode); + if (err) + goto out_release; + + p += ALIGN(wlen, 8); + } + if (!move) { pack_inode(c, p, old_dir, 1); err = ubifs_node_calc_hash(c, p, hash_old_dir); @@ -1352,6 +1373,9 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, if (new_inode) ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, new_inode->i_ino); + if (whiteout) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, + whiteout->i_ino); } release_head(c, BASEHD); @@ -1368,8 +1392,6 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, hash_dent2, old_nm); if (err) goto out_ro; - - ubifs_delete_orphan(c, whiteout->i_ino); } else { err = ubifs_add_dirt(c, lnum, dlen2); if (err) @@ -1390,6 +1412,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, offs += ALIGN(ilen, 8); } + if (whiteout) { + ino_key_init(c, &key, whiteout->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, wlen, + hash_whiteout_inode); + if (err) + goto out_ro; + offs += ALIGN(wlen, 8); + } + ino_key_init(c, &key, old_dir->i_ino); err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_old_dir); if (err) @@ -1410,6 +1441,11 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, new_ui->synced_i_size = new_ui->ui_size; spin_unlock(&new_ui->ui_lock); } + /* + * No need to mark whiteout inode clean. + * Whiteout doesn't have non-zero size, no need to update + * synced_i_size for whiteout_ui. + */ mark_inode_clean(c, ubifs_inode(old_dir)); if (move) mark_inode_clean(c, ubifs_inode(new_dir));

2 years, 9 months

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FAILED: patch "[PATCH] ubifs: Rename whiteout atomically" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 278d9a243635f26c05ad95dcf9c5a593b9e04dc6 Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:36 +0800 Subject: [PATCH] ubifs: Rename whiteout atomically Currently, rename whiteout has 3 steps: 1. create tmpfile(which associates old dentry to tmpfile inode) for whiteout, and store tmpfile to disk 2. link whiteout, associate whiteout inode to old dentry agagin and store old dentry, old inode, new dentry on disk 3. writeback dirty whiteout inode to disk Suddenly power-cut or error occurring(eg. ENOSPC returned by budget, memory allocation failure) during above steps may cause kinds of problems: Problem 1: ENOSPC returned by whiteout space budget (before step 2), old dentry will disappear after rename syscall, whiteout file cannot be found either. ls dir // we get file, whiteout rename(dir/file, dir/whiteout, REANME_WHITEOUT) ENOSPC = ubifs_budget_space(&wht_req) // return ls dir // empty (no file, no whiteout) Problem 2: Power-cut happens before step 3, whiteout inode with 'nlink=1' is not stored on disk, whiteout dentry(old dentry) is written on disk, whiteout file is lost on next mount (We get "dead directory entry" after executing 'ls -l' on whiteout file). Now, we use following 3 steps to finish rename whiteout: 1. create an in-mem inode with 'nlink = 1' as whiteout 2. ubifs_jnl_rename (Write on disk to finish associating old dentry to whiteout inode, associating new dentry with old inode) 3. iput(whiteout) Rely writing in-mem inode on disk by ubifs_jnl_rename() to finish rename whiteout, which avoids middle disk state caused by suddenly power-cut and error occurring. Fixes: 9e0a1fff8db56ea ("ubifs: Implement RENAME_WHITEOUT") Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index 745e6e3f246e..f2a6b45bfdae 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -349,8 +349,56 @@ static int ubifs_create(struct user_namespace *mnt_userns, struct inode *dir, return err; } -static int do_tmpfile(struct inode *dir, struct dentry *dentry, - umode_t mode, struct inode **whiteout) +static struct inode *create_whiteout(struct inode *dir, struct dentry *dentry) +{ + int err; + umode_t mode = S_IFCHR | WHITEOUT_MODE; + struct inode *inode; + struct ubifs_info *c = dir->i_sb->s_fs_info; + struct fscrypt_name nm; + + /* + * Create an inode('nlink = 1') for whiteout without updating journal, + * let ubifs_jnl_rename() store it on flash to complete rename whiteout + * atomically. + */ + + dbg_gen("dent '%pd', mode %#hx in dir ino %lu", + dentry, mode, dir->i_ino); + + err = fscrypt_setup_filename(dir, &dentry->d_name, 0, &nm); + if (err) + return ERR_PTR(err); + + inode = ubifs_new_inode(c, dir, mode); + if (IS_ERR(inode)) { + err = PTR_ERR(inode); + goto out_free; + } + + init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); + ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); + + err = ubifs_init_security(dir, inode, &dentry->d_name); + if (err) + goto out_inode; + + /* The dir size is updated by do_rename. */ + insert_inode_hash(inode); + + return inode; + +out_inode: + make_bad_inode(inode); + iput(inode); +out_free: + fscrypt_free_filename(&nm); + ubifs_err(c, "cannot create whiteout file, error %d", err); + return ERR_PTR(err); +} + +static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, + struct dentry *dentry, umode_t mode) { struct inode *inode; struct ubifs_info *c = dir->i_sb->s_fs_info; @@ -392,25 +440,13 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, } ui = ubifs_inode(inode); - if (whiteout) { - init_special_inode(inode, inode->i_mode, WHITEOUT_DEV); - ubifs_assert(c, inode->i_op == &ubifs_file_inode_operations); - } - err = ubifs_init_security(dir, inode, &dentry->d_name); if (err) goto out_inode; mutex_lock(&ui->ui_mutex); insert_inode_hash(inode); - - if (whiteout) { - mark_inode_dirty(inode); - drop_nlink(inode); - *whiteout = inode; - } else { - d_tmpfile(dentry, inode); - } + d_tmpfile(dentry, inode); ubifs_assert(c, ui->dirty); instantiated = 1; @@ -432,8 +468,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, make_bad_inode(inode); if (!instantiated) iput(inode); - else if (whiteout) - iput(*whiteout); out_budg: ubifs_release_budget(c, &req); if (!instantiated) @@ -443,12 +477,6 @@ static int do_tmpfile(struct inode *dir, struct dentry *dentry, return err; } -static int ubifs_tmpfile(struct user_namespace *mnt_userns, struct inode *dir, - struct dentry *dentry, umode_t mode) -{ - return do_tmpfile(dir, dentry, mode, NULL); -} - /** * vfs_dent_type - get VFS directory entry type. * @type: UBIFS directory entry type @@ -1266,17 +1294,19 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, .dirtied_ino = 3 }; struct ubifs_budget_req ino_req = { .dirtied_ino = 1, .dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) }; + struct ubifs_budget_req wht_req; struct timespec64 time; unsigned int saved_nlink; struct fscrypt_name old_nm, new_nm; /* - * Budget request settings: deletion direntry, new direntry, removing - * the old inode, and changing old and new parent directory inodes. + * Budget request settings: + * req: deletion direntry, new direntry, removing the old inode, + * and changing old and new parent directory inodes. * - * However, this operation also marks the target inode as dirty and - * does not write it, so we allocate budget for the target inode - * separately. + * wht_req: new whiteout inode for RENAME_WHITEOUT. + * + * ino_req: marks the target inode as dirty and does not write it. */ dbg_gen("dent '%pd' ino %lu in dir ino %lu to dent '%pd' in dir ino %lu flags 0x%x", @@ -1326,7 +1356,6 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (flags & RENAME_WHITEOUT) { union ubifs_dev_desc *dev = NULL; - struct ubifs_budget_req wht_req; dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) { @@ -1334,24 +1363,26 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, goto out_release; } - err = do_tmpfile(old_dir, old_dentry, S_IFCHR | WHITEOUT_MODE, &whiteout); - if (err) { + /* + * The whiteout inode without dentry is pinned in memory, + * umount won't happen during rename process because we + * got parent dentry. + */ + whiteout = create_whiteout(old_dir, old_dentry); + if (IS_ERR(whiteout)) { + err = PTR_ERR(whiteout); kfree(dev); goto out_release; } - spin_lock(&whiteout->i_lock); - whiteout->i_state |= I_LINKABLE; - spin_unlock(&whiteout->i_lock); - whiteout_ui = ubifs_inode(whiteout); whiteout_ui->data = dev; whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); ubifs_assert(c, !whiteout_ui->dirty); memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); - wht_req.dirtied_ino = 1; - wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); + wht_req.new_ino = 1; + wht_req.new_ino_d = ALIGN(whiteout_ui->data_len, 8); /* * To avoid deadlock between space budget (holds ui_mutex and * waits wb work) and writeback work(waits ui_mutex), do space @@ -1359,6 +1390,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, */ err = ubifs_budget_space(c, &wht_req); if (err) { + /* + * Whiteout inode can not be written on flash by + * ubifs_jnl_write_inode(), because it's neither + * dirty nor zero-nlink. + */ iput(whiteout); goto out_release; } @@ -1433,17 +1469,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir); if (unlink && IS_SYNC(new_inode)) sync = 1; - } - - if (whiteout) { - inc_nlink(whiteout); - mark_inode_dirty(whiteout); - - spin_lock(&whiteout->i_lock); - whiteout->i_state &= ~I_LINKABLE; - spin_unlock(&whiteout->i_lock); - - iput(whiteout); + /* + * S_SYNC flag of whiteout inherits from the old_dir, and we + * have already checked the old dir inode. So there is no need + * to check whiteout. + */ } err = ubifs_jnl_rename(c, old_dir, old_inode, &old_nm, new_dir, @@ -1454,6 +1484,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); ubifs_release_budget(c, &req); + if (whiteout) { + ubifs_release_budget(c, &wht_req); + iput(whiteout); + } + mutex_lock(&old_inode_ui->ui_mutex); release = old_inode_ui->dirty; mark_inode_dirty_sync(old_inode); @@ -1462,11 +1497,16 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (release) ubifs_release_budget(c, &ino_req); if (IS_SYNC(old_inode)) - err = old_inode->i_sb->s_op->write_inode(old_inode, NULL); + /* + * Rename finished here. Although old inode cannot be updated + * on flash, old ctime is not a big problem, don't return err + * code to userspace. + */ + old_inode->i_sb->s_op->write_inode(old_inode, NULL); fscrypt_free_filename(&old_nm); fscrypt_free_filename(&new_nm); - return err; + return 0; out_cancel: if (unlink) { @@ -1487,11 +1527,11 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, inc_nlink(old_dir); } } + unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); if (whiteout) { - drop_nlink(whiteout); + ubifs_release_budget(c, &wht_req); iput(whiteout); } - unlock_4_inodes(old_dir, new_dir, new_inode, whiteout); out_release: ubifs_release_budget(c, &ino_req); ubifs_release_budget(c, &req); diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c index 8ea680dba61e..75dab0ae3939 100644 --- a/fs/ubifs/journal.c +++ b/fs/ubifs/journal.c @@ -1207,9 +1207,9 @@ int ubifs_jnl_xrename(struct ubifs_info *c, const struct inode *fst_dir, * @sync: non-zero if the write-buffer has to be synchronized * * This function implements the re-name operation which may involve writing up - * to 4 inodes and 2 directory entries. It marks the written inodes as clean - * and returns zero on success. In case of failure, a negative error code is - * returned. + * to 4 inodes(new inode, whiteout inode, old and new parent directory inodes) + * and 2 directory entries. It marks the written inodes as clean and returns + * zero on success. In case of failure, a negative error code is returned. */ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, const struct inode *old_inode, @@ -1222,14 +1222,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, void *p; union ubifs_key key; struct ubifs_dent_node *dent, *dent2; - int err, dlen1, dlen2, ilen, lnum, offs, len, orphan_added = 0; + int err, dlen1, dlen2, ilen, wlen, lnum, offs, len, orphan_added = 0; int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ; int last_reference = !!(new_inode && new_inode->i_nlink == 0); int move = (old_dir != new_dir); - struct ubifs_inode *new_ui; + struct ubifs_inode *new_ui, *whiteout_ui; u8 hash_old_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_dir[UBIFS_HASH_ARR_SZ]; u8 hash_new_inode[UBIFS_HASH_ARR_SZ]; + u8 hash_whiteout_inode[UBIFS_HASH_ARR_SZ]; u8 hash_dent1[UBIFS_HASH_ARR_SZ]; u8 hash_dent2[UBIFS_HASH_ARR_SZ]; @@ -1249,9 +1250,20 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, } else ilen = 0; + if (whiteout) { + whiteout_ui = ubifs_inode(whiteout); + ubifs_assert(c, mutex_is_locked(&whiteout_ui->ui_mutex)); + ubifs_assert(c, whiteout->i_nlink == 1); + ubifs_assert(c, !whiteout_ui->dirty); + wlen = UBIFS_INO_NODE_SZ; + wlen += whiteout_ui->data_len; + } else + wlen = 0; + aligned_dlen1 = ALIGN(dlen1, 8); aligned_dlen2 = ALIGN(dlen2, 8); - len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8); + len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + + ALIGN(wlen, 8) + ALIGN(plen, 8); if (move) len += plen; @@ -1313,6 +1325,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, p += ALIGN(ilen, 8); } + if (whiteout) { + pack_inode(c, p, whiteout, 0); + err = ubifs_node_calc_hash(c, p, hash_whiteout_inode); + if (err) + goto out_release; + + p += ALIGN(wlen, 8); + } + if (!move) { pack_inode(c, p, old_dir, 1); err = ubifs_node_calc_hash(c, p, hash_old_dir); @@ -1352,6 +1373,9 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, if (new_inode) ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, new_inode->i_ino); + if (whiteout) + ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, + whiteout->i_ino); } release_head(c, BASEHD); @@ -1368,8 +1392,6 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen2, hash_dent2, old_nm); if (err) goto out_ro; - - ubifs_delete_orphan(c, whiteout->i_ino); } else { err = ubifs_add_dirt(c, lnum, dlen2); if (err) @@ -1390,6 +1412,15 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, offs += ALIGN(ilen, 8); } + if (whiteout) { + ino_key_init(c, &key, whiteout->i_ino); + err = ubifs_tnc_add(c, &key, lnum, offs, wlen, + hash_whiteout_inode); + if (err) + goto out_ro; + offs += ALIGN(wlen, 8); + } + ino_key_init(c, &key, old_dir->i_ino); err = ubifs_tnc_add(c, &key, lnum, offs, plen, hash_old_dir); if (err) @@ -1410,6 +1441,11 @@ int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir, new_ui->synced_i_size = new_ui->ui_size; spin_unlock(&new_ui->ui_lock); } + /* + * No need to mark whiteout inode clean. + * Whiteout doesn't have non-zero size, no need to update + * synced_i_size for whiteout_ui. + */ mark_inode_clean(c, ubifs_inode(old_dir)); if (move) mark_inode_clean(c, ubifs_inode(new_dir));

2 years, 9 months

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FAILED: patch "[PATCH] ubifs: Fix deadlock in concurrent rename whiteout and inode" failed to apply to 4.14-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.14-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From afd427048047e8efdedab30e8888044e2be5aa9c Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:33 +0800 Subject: [PATCH] ubifs: Fix deadlock in concurrent rename whiteout and inode writeback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Following hung tasks: [ 77.028764] task:kworker/u8:4 state:D stack: 0 pid: 132 [ 77.028820] Call Trace: [ 77.029027] schedule+0x8c/0x1b0 [ 77.029067] mutex_lock+0x50/0x60 [ 77.029074] ubifs_write_inode+0x68/0x1f0 [ubifs] [ 77.029117] __writeback_single_inode+0x43c/0x570 [ 77.029128] writeback_sb_inodes+0x259/0x740 [ 77.029148] wb_writeback+0x107/0x4d0 [ 77.029163] wb_workfn+0x162/0x7b0 [ 92.390442] task:aa state:D stack: 0 pid: 1506 [ 92.390448] Call Trace: [ 92.390458] schedule+0x8c/0x1b0 [ 92.390461] wb_wait_for_completion+0x82/0xd0 [ 92.390469] __writeback_inodes_sb_nr+0xb2/0x110 [ 92.390472] writeback_inodes_sb_nr+0x14/0x20 [ 92.390476] ubifs_budget_space+0x705/0xdd0 [ubifs] [ 92.390503] do_rename.cold+0x7f/0x187 [ubifs] [ 92.390549] ubifs_rename+0x8b/0x180 [ubifs] [ 92.390571] vfs_rename+0xdb2/0x1170 [ 92.390580] do_renameat2+0x554/0x770 , are caused by concurrent rename whiteout and inode writeback processes: rename_whiteout(Thread 1) wb_workfn(Thread2) ubifs_rename do_rename lock_4_inodes (Hold ui_mutex) ubifs_budget_space make_free_space shrink_liability __writeback_inodes_sb_nr bdi_split_work_to_wbs (Queue new wb work) wb_do_writeback(wb work) __writeback_single_inode ubifs_write_inode LOCK(ui_mutex) ↑ wb_wait_for_completion (Wait wb work) <-- deadlock! Reproducer (Detail program in [Link]): 1. SYS_renameat2("/mp/dir/file", "/mp/dir/whiteout", RENAME_WHITEOUT) 2. Consume out of space before kernel(mdelay) doing budget for whiteout Fix it by doing whiteout space budget before locking ubifs inodes. BTW, it also fixes wrong goto tag 'out_release' in whiteout budget error handling path(It should at least recover dir i_size and unlock 4 ubifs inodes). Fixes: 9e0a1fff8db56ea ("ubifs: Implement RENAME_WHITEOUT") Link: https://bugzilla.kernel.org/show_bug.cgi?id=214733 Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index d3ed93d94930..f4783e1ae775 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -1324,6 +1324,7 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (flags & RENAME_WHITEOUT) { union ubifs_dev_desc *dev = NULL; + struct ubifs_budget_req wht_req; dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) { @@ -1345,6 +1346,20 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, whiteout_ui->data = dev; whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); ubifs_assert(c, !whiteout_ui->dirty); + + memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); + wht_req.dirtied_ino = 1; + wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); + /* + * To avoid deadlock between space budget (holds ui_mutex and + * waits wb work) and writeback work(waits ui_mutex), do space + * budget before ubifs inodes locked. + */ + err = ubifs_budget_space(c, &wht_req); + if (err) { + iput(whiteout); + goto out_release; + } } lock_4_inodes(old_dir, new_dir, new_inode, whiteout); @@ -1419,16 +1434,6 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, } if (whiteout) { - struct ubifs_budget_req wht_req = { .dirtied_ino = 1, - .dirtied_ino_d = \ - ALIGN(ubifs_inode(whiteout)->data_len, 8) }; - - err = ubifs_budget_space(c, &wht_req); - if (err) { - iput(whiteout); - goto out_release; - } - inc_nlink(whiteout); mark_inode_dirty(whiteout);

2 years, 9 months

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FAILED: patch "[PATCH] ubifs: Fix deadlock in concurrent rename whiteout and inode" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From afd427048047e8efdedab30e8888044e2be5aa9c Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:33 +0800 Subject: [PATCH] ubifs: Fix deadlock in concurrent rename whiteout and inode writeback MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Following hung tasks: [ 77.028764] task:kworker/u8:4 state:D stack: 0 pid: 132 [ 77.028820] Call Trace: [ 77.029027] schedule+0x8c/0x1b0 [ 77.029067] mutex_lock+0x50/0x60 [ 77.029074] ubifs_write_inode+0x68/0x1f0 [ubifs] [ 77.029117] __writeback_single_inode+0x43c/0x570 [ 77.029128] writeback_sb_inodes+0x259/0x740 [ 77.029148] wb_writeback+0x107/0x4d0 [ 77.029163] wb_workfn+0x162/0x7b0 [ 92.390442] task:aa state:D stack: 0 pid: 1506 [ 92.390448] Call Trace: [ 92.390458] schedule+0x8c/0x1b0 [ 92.390461] wb_wait_for_completion+0x82/0xd0 [ 92.390469] __writeback_inodes_sb_nr+0xb2/0x110 [ 92.390472] writeback_inodes_sb_nr+0x14/0x20 [ 92.390476] ubifs_budget_space+0x705/0xdd0 [ubifs] [ 92.390503] do_rename.cold+0x7f/0x187 [ubifs] [ 92.390549] ubifs_rename+0x8b/0x180 [ubifs] [ 92.390571] vfs_rename+0xdb2/0x1170 [ 92.390580] do_renameat2+0x554/0x770 , are caused by concurrent rename whiteout and inode writeback processes: rename_whiteout(Thread 1) wb_workfn(Thread2) ubifs_rename do_rename lock_4_inodes (Hold ui_mutex) ubifs_budget_space make_free_space shrink_liability __writeback_inodes_sb_nr bdi_split_work_to_wbs (Queue new wb work) wb_do_writeback(wb work) __writeback_single_inode ubifs_write_inode LOCK(ui_mutex) ↑ wb_wait_for_completion (Wait wb work) <-- deadlock! Reproducer (Detail program in [Link]): 1. SYS_renameat2("/mp/dir/file", "/mp/dir/whiteout", RENAME_WHITEOUT) 2. Consume out of space before kernel(mdelay) doing budget for whiteout Fix it by doing whiteout space budget before locking ubifs inodes. BTW, it also fixes wrong goto tag 'out_release' in whiteout budget error handling path(It should at least recover dir i_size and unlock 4 ubifs inodes). Fixes: 9e0a1fff8db56ea ("ubifs: Implement RENAME_WHITEOUT") Link: https://bugzilla.kernel.org/show_bug.cgi?id=214733 Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index d3ed93d94930..f4783e1ae775 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -1324,6 +1324,7 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, if (flags & RENAME_WHITEOUT) { union ubifs_dev_desc *dev = NULL; + struct ubifs_budget_req wht_req; dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS); if (!dev) { @@ -1345,6 +1346,20 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, whiteout_ui->data = dev; whiteout_ui->data_len = ubifs_encode_dev(dev, MKDEV(0, 0)); ubifs_assert(c, !whiteout_ui->dirty); + + memset(&wht_req, 0, sizeof(struct ubifs_budget_req)); + wht_req.dirtied_ino = 1; + wht_req.dirtied_ino_d = ALIGN(whiteout_ui->data_len, 8); + /* + * To avoid deadlock between space budget (holds ui_mutex and + * waits wb work) and writeback work(waits ui_mutex), do space + * budget before ubifs inodes locked. + */ + err = ubifs_budget_space(c, &wht_req); + if (err) { + iput(whiteout); + goto out_release; + } } lock_4_inodes(old_dir, new_dir, new_inode, whiteout); @@ -1419,16 +1434,6 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, } if (whiteout) { - struct ubifs_budget_req wht_req = { .dirtied_ino = 1, - .dirtied_ino_d = \ - ALIGN(ubifs_inode(whiteout)->data_len, 8) }; - - err = ubifs_budget_space(c, &wht_req); - if (err) { - iput(whiteout); - goto out_release; - } - inc_nlink(whiteout); mark_inode_dirty(whiteout);

2 years, 9 months

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FAILED: patch "[PATCH] ubifs: rename_whiteout: Fix double free for whiteout_ui->data" failed to apply to 4.9-stable tree

by gregkh＠linuxfoundation.org

The patch below does not apply to the 4.9-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <stable(a)vger.kernel.org>. thanks, greg k-h ------------------ original commit in Linus's tree ------------------ From 40a8f0d5e7b3999f096570edab71c345da812e3e Mon Sep 17 00:00:00 2001 From: Zhihao Cheng <chengzhihao1(a)huawei.com> Date: Mon, 27 Dec 2021 11:22:32 +0800 Subject: [PATCH] ubifs: rename_whiteout: Fix double free for whiteout_ui->data 'whiteout_ui->data' will be freed twice if space budget fail for rename whiteout operation as following process: rename_whiteout dev = kmalloc whiteout_ui->data = dev kfree(whiteout_ui->data) // Free first time iput(whiteout) ubifs_free_inode kfree(ui->data) // Double free! KASAN reports: ================================================================== BUG: KASAN: double-free or invalid-free in ubifs_free_inode+0x4f/0x70 Call Trace: kfree+0x117/0x490 ubifs_free_inode+0x4f/0x70 [ubifs] i_callback+0x30/0x60 rcu_do_batch+0x366/0xac0 __do_softirq+0x133/0x57f Allocated by task 1506: kmem_cache_alloc_trace+0x3c2/0x7a0 do_rename+0x9b7/0x1150 [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 Freed by task 1506: kfree+0x117/0x490 do_rename.cold+0x53/0x8a [ubifs] ubifs_rename+0x106/0x1f0 [ubifs] do_syscall_64+0x35/0x80 The buggy address belongs to the object at ffff88810238bed8 which belongs to the cache kmalloc-8 of size 8 ================================================================== Let ubifs_free_inode() free 'whiteout_ui->data'. BTW, delete unused assignment 'whiteout_ui->data_len = 0', process 'ubifs_evict_inode() -> ubifs_jnl_delete_inode() -> ubifs_jnl_write_inode()' doesn't need it (because 'inc_nlink(whiteout)' won't be excuted by 'goto out_release', and the nlink of whiteout inode is 0). Fixes: 9e0a1fff8db56ea ("ubifs: Implement RENAME_WHITEOUT") Signed-off-by: Zhihao Cheng <chengzhihao1(a)huawei.com> Signed-off-by: Richard Weinberger <richard(a)nod.at> diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c index dbe72f664abf..d3ed93d94930 100644 --- a/fs/ubifs/dir.c +++ b/fs/ubifs/dir.c @@ -1425,8 +1425,6 @@ static int do_rename(struct inode *old_dir, struct dentry *old_dentry, err = ubifs_budget_space(c, &wht_req); if (err) { - kfree(whiteout_ui->data); - whiteout_ui->data_len = 0; iput(whiteout); goto out_release; }

2 years, 9 months

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[PATCH for-stable] ASoC: SOF: Intel: Fix NULL ptr dereference when ENOMEM

by Ammar Faizi

Hello Greg, commit b7fb0ae09009d076964afe4c1a2bde1ee2bd88a9 upstream. Please take these two backport patches: 1. For Linux 5.4 LTS. 2. For Linux 5.10 LTS. Both will be sent as a reply to this email. Thank you! ===== 5.4 failed report: https://lore.kernel.org/stable/164889915082249@kroah.com/ 5.10 failed report: https://lore.kernel.org/stable/164889914960214@kroah.com/ -- Ammar Faizi

2 years, 9 months

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