From 25b229dff4ffffd0fad2dd409faf1e2ae4d94866 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 26 Apr 2019 13:37:25 -0400 Subject: [PATCH] fsnotify(): switch to passing const struct qstr * for file_name Note that in fnsotify_move() and fsnotify_link() we are guaranteed that dentry->d_name won't change during the fsnotify() evaluation (by having the parent directory locked exclusive), so we don't need to fetch dentry->d_name.name in the callers. In fsnotify_dirent() the same stability of dentry->d_name is also true, but it's a bit more convoluted - there is one callchain (devpts_pty_new() -> fsnotify_create() -> fsnotify_dirent()) where the parent is _not_ locked, but on devpts ->d_name of everything is unchanging; it has neither explicit nor implicit renames. Signed-off-by: Al Viro --- fs/kernfs/file.c | 6 ++++-- fs/notify/fsnotify.c | 8 ++++---- include/linux/fsnotify.h | 10 +++++----- include/linux/fsnotify_backend.h | 4 ++-- 4 files changed, 15 insertions(+), 13 deletions(-) diff --git a/fs/kernfs/file.c b/fs/kernfs/file.c index ae948aaa4c53..553ce0a92b05 100644 --- a/fs/kernfs/file.c +++ b/fs/kernfs/file.c @@ -885,6 +885,7 @@ repeat: list_for_each_entry(info, &kernfs_root(kn)->supers, node) { struct kernfs_node *parent; struct inode *inode; + struct qstr name; /* * We want fsnotify_modify() on @kn but as the @@ -896,6 +897,7 @@ repeat: if (!inode) continue; + name = (struct qstr)QSTR_INIT(kn->name, strlen(kn->name)); parent = kernfs_get_parent(kn); if (parent) { struct inode *p_inode; @@ -903,7 +905,7 @@ repeat: p_inode = ilookup(info->sb, parent->id.ino); if (p_inode) { fsnotify(p_inode, FS_MODIFY | FS_EVENT_ON_CHILD, - inode, FSNOTIFY_EVENT_INODE, kn->name, 0); + inode, FSNOTIFY_EVENT_INODE, &name, 0); iput(p_inode); } @@ -911,7 +913,7 @@ repeat: } fsnotify(inode, FS_MODIFY, inode, FSNOTIFY_EVENT_INODE, - kn->name, 0); + &name, 0); iput(inode); } diff --git a/fs/notify/fsnotify.c b/fs/notify/fsnotify.c index fb22f76329ae..9cbb5ae11d2f 100644 --- a/fs/notify/fsnotify.c +++ b/fs/notify/fsnotify.c @@ -179,10 +179,10 @@ int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask take_dentry_name_snapshot(&name, dentry); if (path) ret = fsnotify(p_inode, mask, path, FSNOTIFY_EVENT_PATH, - name.name.name, 0); + &name.name, 0); else ret = fsnotify(p_inode, mask, dentry->d_inode, FSNOTIFY_EVENT_INODE, - name.name.name, 0); + &name.name, 0); release_dentry_name_snapshot(&name); } @@ -325,7 +325,7 @@ static void fsnotify_iter_next(struct fsnotify_iter_info *iter_info) * notification event in whatever means they feel necessary. */ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, - const unsigned char *file_name, u32 cookie) + const struct qstr *file_name, u32 cookie) { struct fsnotify_iter_info iter_info = {}; struct super_block *sb = to_tell->i_sb; @@ -379,7 +379,7 @@ int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, */ while (fsnotify_iter_select_report_types(&iter_info)) { ret = send_to_group(to_tell, mask, data, data_is, cookie, - file_name, &iter_info); + file_name->name, &iter_info); if (ret && (mask & ALL_FSNOTIFY_PERM_EVENTS)) goto out; diff --git a/include/linux/fsnotify.h b/include/linux/fsnotify.h index f816bd29b82c..0c0ef3078a22 100644 --- a/include/linux/fsnotify.h +++ b/include/linux/fsnotify.h @@ -27,7 +27,7 @@ static inline int fsnotify_dirent(struct inode *dir, struct dentry *dentry, __u32 mask) { return fsnotify(dir, mask, d_inode(dentry), FSNOTIFY_EVENT_INODE, - dentry->d_name.name, 0); + &dentry->d_name, 0); } /* Notify this dentry's parent about a child's events. */ @@ -111,7 +111,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, __u32 old_dir_mask = FS_MOVED_FROM; __u32 new_dir_mask = FS_MOVED_TO; __u32 mask = FS_MOVE_SELF; - const unsigned char *new_name = moved->d_name.name; + const struct qstr *new_name = &moved->d_name; if (old_dir == new_dir) old_dir_mask |= FS_DN_RENAME; @@ -122,7 +122,7 @@ static inline void fsnotify_move(struct inode *old_dir, struct inode *new_dir, mask |= FS_ISDIR; } - fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name->name, + fsnotify(old_dir, old_dir_mask, source, FSNOTIFY_EVENT_INODE, old_name, fs_cookie); fsnotify(new_dir, new_dir_mask, source, FSNOTIFY_EVENT_INODE, new_name, fs_cookie); @@ -178,7 +178,7 @@ static inline void fsnotify_nameremove(struct dentry *dentry, int isdir) take_dentry_name_snapshot(&name, dentry); fsnotify(d_inode(parent), mask, d_inode(dentry), FSNOTIFY_EVENT_INODE, - name.name.name, 0); + &name.name, 0); release_dentry_name_snapshot(&name); dput(parent); @@ -218,7 +218,7 @@ static inline void fsnotify_link(struct inode *dir, struct inode *inode, struct fsnotify_link_count(inode); audit_inode_child(dir, new_dentry, AUDIT_TYPE_CHILD_CREATE); - fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, new_dentry->d_name.name, 0); + fsnotify(dir, FS_CREATE, inode, FSNOTIFY_EVENT_INODE, &new_dentry->d_name, 0); } /* diff --git a/include/linux/fsnotify_backend.h b/include/linux/fsnotify_backend.h index dfc28fcb4de8..7eb7821766d5 100644 --- a/include/linux/fsnotify_backend.h +++ b/include/linux/fsnotify_backend.h @@ -350,7 +350,7 @@ struct fsnotify_mark { /* main fsnotify call to send events */ extern int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, - const unsigned char *name, u32 cookie); + const struct qstr *name, u32 cookie); extern int __fsnotify_parent(const struct path *path, struct dentry *dentry, __u32 mask); extern void __fsnotify_inode_delete(struct inode *inode); extern void __fsnotify_vfsmount_delete(struct vfsmount *mnt); @@ -505,7 +505,7 @@ static inline void fsnotify_init_event(struct fsnotify_event *event, #else static inline int fsnotify(struct inode *to_tell, __u32 mask, const void *data, int data_is, - const unsigned char *name, u32 cookie) + const struct qstr *name, u32 cookie) { return 0; }