Pull shmem_rename2() offset fixes from Chuck Lever:
The existing code in shmem_rename2() allocates a fresh directory offset value when renaming over an existing destination entry. User space does not expect this behavior. In particular, applications that rename while walking a directory can loop indefinitely because they never reach the end of the directory.
Chuck Lever (3): libfs: Fix simple_offset_rename_exchange() libfs: Add simple_offset_rename() API shmem: Fix shmem_rename2()
include/linux/fs.h | 2 ++ fs/libfs.c | 55 +++++++++++++++++++++++++++++++++++++++++----- mm/shmem.c | 3 +-- 3 files changed, 52 insertions(+), 8 deletions(-)
From: Chuck Lever chuck.lever@oracle.com
mainline inclusion from mainline-v6.10-rc1 commit 23cdd0eed3f1fff3af323092b0b88945a7950d8e bugzilla: https://gitee.com/src-openeuler/kernel/issues/IANSAC
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
--------------------------------
User space expects the replacement (old) directory entry to have the same directory offset after the rename.
Suggested-by: Christian Brauner brauner@kernel.org Fixes: a2e459555c5f ("shmem: stable directory offsets") Signed-off-by: Chuck Lever chuck.lever@oracle.com Link: https://lore.kernel.org/r/20240415152057.4605-2-cel@kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Conflicts: fs/libfs.c [Context differences] Signed-off-by: Yifan Qiao qiaoyifan4@huawei.com --- fs/libfs.c | 25 +++++++++++++++++++------ 1 file changed, 19 insertions(+), 6 deletions(-)
diff --git a/fs/libfs.c b/fs/libfs.c index dc0f7519045f..4e50155d317c 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -291,6 +291,18 @@ int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry) return 0; }
+static int simple_offset_replace(struct offset_ctx *octx, struct dentry *dentry, + long offset) +{ + int ret; + + ret = mtree_store(&octx->mt, offset, dentry, GFP_KERNEL); + if (ret) + return ret; + offset_set(dentry, offset); + return 0; +} + /** * simple_offset_remove - Remove an entry to a directory's offset map * @octx: directory offset ctx to be updated @@ -316,6 +328,9 @@ void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry) * @new_dir: destination parent * @new_dentry: destination dentry * + * This API preserves the directory offset values. Caller provides + * appropriate serialization. + * * Returns zero on success. Otherwise a negative errno is returned and the * rename is rolled back. */ @@ -333,11 +348,11 @@ int simple_offset_rename_exchange(struct inode *old_dir, simple_offset_remove(old_ctx, old_dentry); simple_offset_remove(new_ctx, new_dentry);
- ret = simple_offset_add(new_ctx, old_dentry); + ret = simple_offset_replace(new_ctx, old_dentry, new_index); if (ret) goto out_restore;
- ret = simple_offset_add(old_ctx, new_dentry); + ret = simple_offset_replace(old_ctx, new_dentry, old_index); if (ret) { simple_offset_remove(new_ctx, old_dentry); goto out_restore; @@ -352,10 +367,8 @@ int simple_offset_rename_exchange(struct inode *old_dir, return 0;
out_restore: - offset_set(old_dentry, old_index); - xa_store(&old_ctx->xa, old_index, old_dentry, GFP_KERNEL); - offset_set(new_dentry, new_index); - xa_store(&new_ctx->xa, new_index, new_dentry, GFP_KERNEL); + (void)simple_offset_replace(old_ctx, old_dentry, old_index); + (void)simple_offset_replace(new_ctx, new_dentry, new_index); return ret; }
From: Chuck Lever chuck.lever@oracle.com
mainline inclusion from mainline-v6.10-rc1 commit 5a1a25be995e1014abd01600479915683e356f5c bugzilla: https://gitee.com/src-openeuler/kernel/issues/IANSAC
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
--------------------------------
I'm about to fix a tmpfs rename bug that requires the use of internal simple_offset helpers that are not available in mm/shmem.c
Signed-off-by: Chuck Lever chuck.lever@oracle.com Link: https://lore.kernel.org/r/20240415152057.4605-3-cel@kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Conflicts: fs/libfs.c include/linux/fs.h [Context differences] Signed-off-by: Yifan Qiao qiaoyifan4@huawei.com --- include/linux/fs.h | 2 ++ fs/libfs.c | 21 +++++++++++++++++++++ mm/shmem.c | 3 +-- 3 files changed, 24 insertions(+), 2 deletions(-)
diff --git a/include/linux/fs.h b/include/linux/fs.h index e4ea5c34b90c..60541d17d038 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -3255,6 +3255,8 @@ struct offset_ctx { void simple_offset_init(struct offset_ctx *octx); int simple_offset_add(struct offset_ctx *octx, struct dentry *dentry); void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry); +int simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry); int simple_offset_rename_exchange(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, diff --git a/fs/libfs.c b/fs/libfs.c index 4e50155d317c..8dd6e0e37e9c 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -321,6 +321,27 @@ void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry) offset_set(dentry, 0); }
+/** + * simple_offset_rename - handle directory offsets for rename + * @old_dir: parent directory of source entry + * @old_dentry: dentry of source entry + * @new_dir: parent_directory of destination entry + * @new_dentry: dentry of destination + * + * Caller provides appropriate serialization. + * + * Returns zero on success, a negative errno value on failure. + */ +int simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, + struct inode *new_dir, struct dentry *new_dentry) +{ + struct offset_ctx *old_ctx = old_dir->i_op->get_offset_ctx(old_dir); + struct offset_ctx *new_ctx = new_dir->i_op->get_offset_ctx(new_dir); + + simple_offset_remove(old_ctx, old_dentry); + return simple_offset_add(new_ctx, old_dentry); +} + /** * simple_offset_rename_exchange - exchange rename with directory offsets * @old_dir: parent of dentry being moved diff --git a/mm/shmem.c b/mm/shmem.c index 0b82806727cf..f259850950fb 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -3448,8 +3448,7 @@ static int shmem_rename2(struct mnt_idmap *idmap, return error; }
- simple_offset_remove(shmem_get_offset_ctx(old_dir), old_dentry); - error = simple_offset_add(shmem_get_offset_ctx(new_dir), old_dentry); + error = simple_offset_rename(old_dir, old_dentry, new_dir, new_dentry); if (error) return error;
From: Chuck Lever chuck.lever@oracle.com
mainline inclusion from mainline-v6.10-rc1 commit ad191eb6d6942bb835a0b20b647f7c53c1d99ca4 bugzilla: https://gitee.com/src-openeuler/kernel/issues/IANSAC
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i...
--------------------------------
When renaming onto an existing directory entry, user space expects the replacement entry to have the same directory offset as the original one.
Link: https://gitlab.alpinelinux.org/alpine/aports/-/issues/15966 Fixes: a2e459555c5f ("shmem: stable directory offsets") Signed-off-by: Chuck Lever chuck.lever@oracle.com Link: https://lore.kernel.org/r/20240415152057.4605-4-cel@kernel.org Signed-off-by: Christian Brauner brauner@kernel.org Signed-off-by: Yifan Qiao qiaoyifan4@huawei.com --- fs/libfs.c | 9 +++++++++ 1 file changed, 9 insertions(+)
diff --git a/fs/libfs.c b/fs/libfs.c index 8dd6e0e37e9c..3dea681302a8 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -330,6 +330,9 @@ void simple_offset_remove(struct offset_ctx *octx, struct dentry *dentry) * * Caller provides appropriate serialization. * + * User space expects the directory offset value of the replaced + * (new) directory entry to be unchanged after a rename. + * * Returns zero on success, a negative errno value on failure. */ int simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, @@ -337,8 +340,14 @@ int simple_offset_rename(struct inode *old_dir, struct dentry *old_dentry, { struct offset_ctx *old_ctx = old_dir->i_op->get_offset_ctx(old_dir); struct offset_ctx *new_ctx = new_dir->i_op->get_offset_ctx(new_dir); + long new_offset = dentry2offset(new_dentry);
simple_offset_remove(old_ctx, old_dentry); + + if (new_offset) { + offset_set(new_dentry, 0); + return simple_offset_replace(new_ctx, old_dentry, new_offset); + } return simple_offset_add(new_ctx, old_dentry); }
反馈： 您发送到kernel@openeuler.org的补丁/补丁集，已成功转换为PR！ PR链接地址： https://gitee.com/openeuler/kernel/pulls/11294 邮件列表地址：https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/T...
FeedBack: The patch(es) which you have sent to kernel@openeuler.org mailing list has been converted to a pull request successfully! Pull request link: https://gitee.com/openeuler/kernel/pulls/11294 Mailing list address: https://mailweb.openeuler.org/hyperkitty/list/kernel@openeuler.org/message/T...
-
patchwork bot -
Yifan Qiao