diff options
Diffstat (limited to 'fs/libfs.c')
-rw-r--r-- | fs/libfs.c | 55 |
1 files changed, 49 insertions, 6 deletions
diff --git a/fs/libfs.c b/fs/libfs.c index 3a6f2cb364..b635ee5adb 100644 --- a/fs/libfs.c +++ b/fs/libfs.c @@ -295,6 +295,18 @@ 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 @@ -346,12 +358,45 @@ int simple_offset_empty(struct dentry *dentry) } /** + * 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. + * + * 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, + 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); + 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); +} + +/** * simple_offset_rename_exchange - exchange rename with directory offsets * @old_dir: parent of dentry being moved * @old_dentry: dentry being moved * @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. */ @@ -369,11 +414,11 @@ 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; @@ -388,10 +433,8 @@ int simple_offset_rename_exchange(struct inode *old_dir, return 0; out_restore: - offset_set(old_dentry, old_index); - mtree_store(&old_ctx->mt, old_index, old_dentry, GFP_KERNEL); - offset_set(new_dentry, new_index); - mtree_store(&new_ctx->mt, 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; } |