From 85c675d0d09a45a135bddd15d7b385f8758c32fb Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Sat, 18 May 2024 19:35:05 +0200 Subject: Adding upstream version 6.7.7. Signed-off-by: Daniel Baumann --- fs/tracefs/inode.c | 278 ++++++++++++++++++++++++----------------------------- 1 file changed, 126 insertions(+), 152 deletions(-) (limited to 'fs/tracefs/inode.c') diff --git a/fs/tracefs/inode.c b/fs/tracefs/inode.c index 0292c6a2b..d65ffad4c 100644 --- a/fs/tracefs/inode.c +++ b/fs/tracefs/inode.c @@ -38,8 +38,6 @@ static struct inode *tracefs_alloc_inode(struct super_block *sb) if (!ti) return NULL; - ti->flags = 0; - return &ti->vfs_inode; } @@ -91,6 +89,7 @@ static int tracefs_syscall_mkdir(struct mnt_idmap *idmap, struct inode *inode, struct dentry *dentry, umode_t mode) { + struct tracefs_inode *ti; char *name; int ret; @@ -98,6 +97,15 @@ static int tracefs_syscall_mkdir(struct mnt_idmap *idmap, if (!name) return -ENOMEM; + /* + * This is a new directory that does not take the default of + * the rootfs. It becomes the default permissions for all the + * files and directories underneath it. + */ + ti = get_tracefs(inode); + ti->flags |= TRACEFS_INSTANCE_INODE; + ti->private = inode; + /* * The mkdir call can call the generic functions that create * the files within the tracefs system. It is up to the individual @@ -141,10 +149,76 @@ static int tracefs_syscall_rmdir(struct inode *inode, struct dentry *dentry) return ret; } -static const struct inode_operations tracefs_dir_inode_operations = { +static void set_tracefs_inode_owner(struct inode *inode) +{ + struct tracefs_inode *ti = get_tracefs(inode); + struct inode *root_inode = ti->private; + + /* + * If this inode has never been referenced, then update + * the permissions to the superblock. + */ + if (!(ti->flags & TRACEFS_UID_PERM_SET)) + inode->i_uid = root_inode->i_uid; + + if (!(ti->flags & TRACEFS_GID_PERM_SET)) + inode->i_gid = root_inode->i_gid; +} + +static int tracefs_permission(struct mnt_idmap *idmap, + struct inode *inode, int mask) +{ + set_tracefs_inode_owner(inode); + return generic_permission(idmap, inode, mask); +} + +static int tracefs_getattr(struct mnt_idmap *idmap, + const struct path *path, struct kstat *stat, + u32 request_mask, unsigned int flags) +{ + struct inode *inode = d_backing_inode(path->dentry); + + set_tracefs_inode_owner(inode); + generic_fillattr(idmap, request_mask, inode, stat); + return 0; +} + +static int tracefs_setattr(struct mnt_idmap *idmap, struct dentry *dentry, + struct iattr *attr) +{ + unsigned int ia_valid = attr->ia_valid; + struct inode *inode = d_inode(dentry); + struct tracefs_inode *ti = get_tracefs(inode); + + if (ia_valid & ATTR_UID) + ti->flags |= TRACEFS_UID_PERM_SET; + + if (ia_valid & ATTR_GID) + ti->flags |= TRACEFS_GID_PERM_SET; + + return simple_setattr(idmap, dentry, attr); +} + +static const struct inode_operations tracefs_instance_dir_inode_operations = { .lookup = simple_lookup, .mkdir = tracefs_syscall_mkdir, .rmdir = tracefs_syscall_rmdir, + .permission = tracefs_permission, + .getattr = tracefs_getattr, + .setattr = tracefs_setattr, +}; + +static const struct inode_operations tracefs_dir_inode_operations = { + .lookup = simple_lookup, + .permission = tracefs_permission, + .getattr = tracefs_getattr, + .setattr = tracefs_setattr, +}; + +static const struct inode_operations tracefs_file_inode_operations = { + .permission = tracefs_permission, + .getattr = tracefs_getattr, + .setattr = tracefs_setattr, }; struct inode *tracefs_get_inode(struct super_block *sb) @@ -152,7 +226,7 @@ struct inode *tracefs_get_inode(struct super_block *sb) struct inode *inode = new_inode(sb); if (inode) { inode->i_ino = get_next_ino(); - inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode); + simple_inode_init_ts(inode); } return inode; } @@ -183,77 +257,6 @@ struct tracefs_fs_info { struct tracefs_mount_opts mount_opts; }; -static void change_gid(struct dentry *dentry, kgid_t gid) -{ - if (!dentry->d_inode) - return; - dentry->d_inode->i_gid = gid; -} - -/* - * Taken from d_walk, but without he need for handling renames. - * Nothing can be renamed while walking the list, as tracefs - * does not support renames. This is only called when mounting - * or remounting the file system, to set all the files to - * the given gid. - */ -static void set_gid(struct dentry *parent, kgid_t gid) -{ - struct dentry *this_parent; - struct list_head *next; - - this_parent = parent; - spin_lock(&this_parent->d_lock); - - change_gid(this_parent, gid); -repeat: - next = this_parent->d_subdirs.next; -resume: - while (next != &this_parent->d_subdirs) { - struct list_head *tmp = next; - struct dentry *dentry = list_entry(tmp, struct dentry, d_child); - next = tmp->next; - - spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); - - change_gid(dentry, gid); - - if (!list_empty(&dentry->d_subdirs)) { - spin_unlock(&this_parent->d_lock); - spin_release(&dentry->d_lock.dep_map, _RET_IP_); - this_parent = dentry; - spin_acquire(&this_parent->d_lock.dep_map, 0, 1, _RET_IP_); - goto repeat; - } - spin_unlock(&dentry->d_lock); - } - /* - * All done at this level ... ascend and resume the search. - */ - rcu_read_lock(); -ascend: - if (this_parent != parent) { - struct dentry *child = this_parent; - this_parent = child->d_parent; - - spin_unlock(&child->d_lock); - spin_lock(&this_parent->d_lock); - - /* go into the first sibling still alive */ - do { - next = child->d_child.next; - if (next == &this_parent->d_subdirs) - goto ascend; - child = list_entry(next, struct dentry, d_child); - } while (unlikely(child->d_flags & DCACHE_DENTRY_KILLED)); - rcu_read_unlock(); - goto resume; - } - rcu_read_unlock(); - spin_unlock(&this_parent->d_lock); - return; -} - static int tracefs_parse_options(char *data, struct tracefs_mount_opts *opts) { substring_t args[MAX_OPT_ARGS]; @@ -326,10 +329,8 @@ static int tracefs_apply_options(struct super_block *sb, bool remount) if (!remount || opts->opts & BIT(Opt_uid)) inode->i_uid = opts->uid; - if (!remount || opts->opts & BIT(Opt_gid)) { - /* Set all the group ids to the mount option */ - set_gid(sb->s_root, opts->gid); - } + if (!remount || opts->opts & BIT(Opt_gid)) + inode->i_gid = opts->gid; return 0; } @@ -376,21 +377,30 @@ static const struct super_operations tracefs_super_operations = { .show_options = tracefs_show_options, }; -static void tracefs_dentry_iput(struct dentry *dentry, struct inode *inode) +/* + * It would be cleaner if eventfs had its own dentry ops. + * + * Note that d_revalidate is called potentially under RCU, + * so it can't take the eventfs mutex etc. It's fine - if + * we open a file just as it's marked dead, things will + * still work just fine, and just see the old stale case. + */ +static void tracefs_d_release(struct dentry *dentry) { - struct tracefs_inode *ti; + if (dentry->d_fsdata) + eventfs_d_release(dentry); +} - if (!dentry || !inode) - return; +static int tracefs_d_revalidate(struct dentry *dentry, unsigned int flags) +{ + struct eventfs_inode *ei = dentry->d_fsdata; - ti = get_tracefs(inode); - if (ti && ti->flags & TRACEFS_EVENT_INODE) - eventfs_set_ef_status_free(ti, dentry); - iput(inode); + return !(ei && ei->is_freed); } static const struct dentry_operations tracefs_dentry_operations = { - .d_iput = tracefs_dentry_iput, + .d_revalidate = tracefs_d_revalidate, + .d_release = tracefs_d_release, }; static int trace_fill_super(struct super_block *sb, void *data, int silent) @@ -494,73 +504,24 @@ struct dentry *tracefs_end_creating(struct dentry *dentry) return dentry; } -/** - * eventfs_start_creating - start the process of creating a dentry - * @name: Name of the file created for the dentry - * @parent: The parent dentry where this dentry will be created - * - * This is a simple helper function for the dynamically created eventfs - * files. When the directory of the eventfs files are accessed, their - * dentries are created on the fly. This function is used to start that - * process. - */ -struct dentry *eventfs_start_creating(const char *name, struct dentry *parent) +/* Find the inode that this will use for default */ +static struct inode *instance_inode(struct dentry *parent, struct inode *inode) { - struct dentry *dentry; - int error; - - /* Must always have a parent. */ - if (WARN_ON_ONCE(!parent)) - return ERR_PTR(-EINVAL); - - error = simple_pin_fs(&trace_fs_type, &tracefs_mount, - &tracefs_mount_count); - if (error) - return ERR_PTR(error); + struct tracefs_inode *ti; - if (unlikely(IS_DEADDIR(parent->d_inode))) - dentry = ERR_PTR(-ENOENT); - else - dentry = lookup_one_len(name, parent, strlen(name)); + /* If parent is NULL then use root inode */ + if (!parent) + return d_inode(inode->i_sb->s_root); - if (!IS_ERR(dentry) && dentry->d_inode) { - dput(dentry); - dentry = ERR_PTR(-EEXIST); + /* Find the inode that is flagged as an instance or the root inode */ + while (!IS_ROOT(parent)) { + ti = get_tracefs(d_inode(parent)); + if (ti->flags & TRACEFS_INSTANCE_INODE) + break; + parent = parent->d_parent; } - if (IS_ERR(dentry)) - simple_release_fs(&tracefs_mount, &tracefs_mount_count); - - return dentry; -} - -/** - * eventfs_failed_creating - clean up a failed eventfs dentry creation - * @dentry: The dentry to clean up - * - * If after calling eventfs_start_creating(), a failure is detected, the - * resources created by eventfs_start_creating() needs to be cleaned up. In - * that case, this function should be called to perform that clean up. - */ -struct dentry *eventfs_failed_creating(struct dentry *dentry) -{ - dput(dentry); - simple_release_fs(&tracefs_mount, &tracefs_mount_count); - return NULL; -} - -/** - * eventfs_end_creating - Finish the process of creating a eventfs dentry - * @dentry: The dentry that has successfully been created. - * - * This function is currently just a place holder to match - * eventfs_start_creating(). In case any synchronization needs to be added, - * this function will be used to implement that without having to modify - * the callers of eventfs_start_creating(). - */ -struct dentry *eventfs_end_creating(struct dentry *dentry) -{ - return dentry; + return d_inode(parent); } /** @@ -593,6 +554,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, struct dentry *parent, void *data, const struct file_operations *fops) { + struct tracefs_inode *ti; struct dentry *dentry; struct inode *inode; @@ -611,7 +573,11 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, if (unlikely(!inode)) return tracefs_failed_creating(dentry); + ti = get_tracefs(inode); + ti->private = instance_inode(parent, inode); + inode->i_mode = mode; + inode->i_op = &tracefs_file_inode_operations; inode->i_fop = fops ? fops : &tracefs_file_operations; inode->i_private = data; inode->i_uid = d_inode(dentry->d_parent)->i_uid; @@ -624,6 +590,7 @@ struct dentry *tracefs_create_file(const char *name, umode_t mode, static struct dentry *__create_dir(const char *name, struct dentry *parent, const struct inode_operations *ops) { + struct tracefs_inode *ti; struct dentry *dentry = tracefs_start_creating(name, parent); struct inode *inode; @@ -641,6 +608,9 @@ static struct dentry *__create_dir(const char *name, struct dentry *parent, inode->i_uid = d_inode(dentry->d_parent)->i_uid; inode->i_gid = d_inode(dentry->d_parent)->i_gid; + ti = get_tracefs(inode); + ti->private = instance_inode(parent, inode); + /* directory inodes start off with i_nlink == 2 (for "." entry) */ inc_nlink(inode); d_instantiate(dentry, inode); @@ -671,7 +641,7 @@ struct dentry *tracefs_create_dir(const char *name, struct dentry *parent) if (security_locked_down(LOCKDOWN_TRACEFS)) return NULL; - return __create_dir(name, parent, &simple_dir_inode_operations); + return __create_dir(name, parent, &tracefs_dir_inode_operations); } /** @@ -702,7 +672,7 @@ __init struct dentry *tracefs_create_instance_dir(const char *name, if (WARN_ON(tracefs_ops.mkdir || tracefs_ops.rmdir)) return NULL; - dentry = __create_dir(name, parent, &tracefs_dir_inode_operations); + dentry = __create_dir(name, parent, &tracefs_instance_dir_inode_operations); if (!dentry) return NULL; @@ -747,7 +717,11 @@ static void init_once(void *foo) { struct tracefs_inode *ti = (struct tracefs_inode *) foo; + /* inode_init_once() calls memset() on the vfs_inode portion */ inode_init_once(&ti->vfs_inode); + + /* Zero out the rest */ + memset_after(ti, 0, vfs_inode); } static int __init tracefs_init(void) -- cgit v1.2.3