From 2b108260ea2c9ec07651aea4911d7e2e6ab560f7 Mon Sep 17 00:00:00 2001 From: Konstantin Komarov Date: Fri, 7 Oct 2022 19:53:30 +0300 Subject: fs/ntfs3: atomic_open implementation Added ntfs_atomic_open function. Relaxed locking in ntfs_create_inode. Signed-off-by: Konstantin Komarov --- fs/ntfs3/inode.c | 24 ++++++++++--- fs/ntfs3/namei.c | 100 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ 2 files changed, 120 insertions(+), 4 deletions(-) diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c index 45a4ddc0bcdc..7e369d69d3f2 100644 --- a/fs/ntfs3/inode.c +++ b/fs/ntfs3/inode.c @@ -1184,6 +1184,18 @@ out: return ERR_PTR(err); } +/* + * ntfs_create_inode + * + * Helper function for: + * - ntfs_create + * - ntfs_mknod + * - ntfs_symlink + * - ntfs_mkdir + * - ntfs_atomic_open + * + * NOTE: if fnd != NULL (ntfs_atomic_open) then @dir is locked + */ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns, struct inode *dir, struct dentry *dentry, const struct cpu_str *uni, umode_t mode, @@ -1213,7 +1225,8 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns, struct REPARSE_DATA_BUFFER *rp = NULL; bool rp_inserted = false; - ni_lock_dir(dir_ni); + if (!fnd) + ni_lock_dir(dir_ni); dir_root = indx_get_root(&dir_ni->dir, dir_ni, NULL, NULL); if (!dir_root) { @@ -1583,7 +1596,8 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns, goto out6; /* Unlock parent directory before ntfs_init_acl. */ - ni_unlock(dir_ni); + if (!fnd) + ni_unlock(dir_ni); inode->i_generation = le16_to_cpu(rec->seq); @@ -1643,7 +1657,8 @@ struct inode *ntfs_create_inode(struct user_namespace *mnt_userns, out7: /* Undo 'indx_insert_entry'. */ - ni_lock_dir(dir_ni); + if (!fnd) + ni_lock_dir(dir_ni); indx_delete_entry(&dir_ni->dir, dir_ni, new_de + 1, le16_to_cpu(new_de->key_size), sbi); /* ni_unlock(dir_ni); will be called later. */ @@ -1671,7 +1686,8 @@ out2: out1: if (err) { - ni_unlock(dir_ni); + if (!fnd) + ni_unlock(dir_ni); return ERR_PTR(err); } diff --git a/fs/ntfs3/namei.c b/fs/ntfs3/namei.c index ad6d16dec9f0..daff8d0cd63d 100644 --- a/fs/ntfs3/namei.c +++ b/fs/ntfs3/namei.c @@ -8,6 +8,7 @@ #include #include #include +#include #include "debug.h" #include "ntfs.h" @@ -334,6 +335,104 @@ out: return err; } +/* + * ntfs_atomic_open + * + * inode_operations::atomic_open + */ +static int ntfs_atomic_open(struct inode *dir, struct dentry *dentry, + struct file *file, u32 flags, umode_t mode) +{ + int err; + struct inode *inode; + struct ntfs_fnd *fnd = NULL; + struct ntfs_inode *ni = ntfs_i(dir); + struct dentry *d = NULL; + struct cpu_str *uni = __getname(); + bool locked = false; + + if (!uni) + return -ENOMEM; + + err = ntfs_nls_to_utf16(ni->mi.sbi, dentry->d_name.name, + dentry->d_name.len, uni, NTFS_NAME_LEN, + UTF16_HOST_ENDIAN); + if (err < 0) + goto out; + +#ifdef CONFIG_NTFS3_FS_POSIX_ACL + if (IS_POSIXACL(dir)) { + /* + * Load in cache current acl to avoid ni_lock(dir): + * ntfs_create_inode -> ntfs_init_acl -> posix_acl_create -> + * ntfs_get_acl -> ntfs_get_acl_ex -> ni_lock + */ + struct posix_acl *p = get_acl(dir, ACL_TYPE_DEFAULT); + + if (IS_ERR(p)) { + err = PTR_ERR(p); + goto out; + } + posix_acl_release(p); + } +#endif + + if (d_in_lookup(dentry)) { + ni_lock_dir(ni); + locked = true; + fnd = fnd_get(); + if (!fnd) { + err = -ENOMEM; + goto out1; + } + + d = d_splice_alias(dir_search_u(dir, uni, fnd), dentry); + if (IS_ERR(d)) { + err = PTR_ERR(d); + d = NULL; + goto out2; + } + + if (d) + dentry = d; + } + + if (!(flags & O_CREAT) || d_really_is_positive(dentry)) { + err = finish_no_open(file, d); + goto out2; + } + + file->f_mode |= FMODE_CREATED; + + /* + * fnd contains tree's path to insert to. + * If fnd is not NULL then dir is locked. + */ + + /* + * Unfortunately I don't know how to get here correct 'struct nameidata *nd' + * or 'struct user_namespace *mnt_userns'. + * See atomic_open in fs/namei.c. + * This is why xfstest/633 failed. + * Looks like ntfs_atomic_open must accept 'struct user_namespace *mnt_userns' as argument. + */ + + inode = ntfs_create_inode(&init_user_ns, dir, dentry, uni, mode, 0, + NULL, 0, fnd); + err = IS_ERR(inode) ? PTR_ERR(inode) + : finish_open(file, dentry, ntfs_file_open); + dput(d); + +out2: + fnd_put(fnd); +out1: + if (locked) + ni_unlock(ni); +out: + __putname(uni); + return err; +} + struct dentry *ntfs3_get_parent(struct dentry *child) { struct inode *inode = d_inode(child); @@ -500,6 +599,7 @@ const struct inode_operations ntfs_dir_inode_operations = { .setattr = ntfs3_setattr, .getattr = ntfs_getattr, .listxattr = ntfs_listxattr, + .atomic_open = ntfs_atomic_open, .fiemap = ntfs_fiemap, }; -- cgit v1.2.3