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authorSteven Rostedt (Google) <rostedt@goodmis.org>2024-01-05 00:57:14 +0300
committerSteven Rostedt (Google) <rostedt@goodmis.org>2024-01-05 01:11:58 +0300
commit704f960dbee2f1634f4b4e16f208cb16eaf41c1e (patch)
tree46c0ff0987ba4d65f80a2fdadbf56d6930643bdb /fs/tracefs
parent1e4624eb5a0ecaae0d2c4e3019bece119725bb98 (diff)
downloadlinux-704f960dbee2f1634f4b4e16f208cb16eaf41c1e.tar.xz
eventfs: Read ei->entries before ei->children in eventfs_iterate()
In order to apply a shortcut to skip over the current ctx->pos immediately, by using the ei->entries array, the reading of that array should be first. Moving the array reading before the linked list reading will make the shortcut change diff nicer to read. Link: https://lore.kernel.org/all/CAHk-=wiKwDUDv3+jCsv-uacDcHDVTYsXtBR9=6sGM5mqX+DhOg@mail.gmail.com/ Link: https://lore.kernel.org/linux-trace-kernel/20240104220048.333115095@goodmis.org Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Christian Brauner <brauner@kernel.org> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Diffstat (limited to 'fs/tracefs')
-rw-r--r--fs/tracefs/event_inode.c46
1 files changed, 23 insertions, 23 deletions
diff --git a/fs/tracefs/event_inode.c b/fs/tracefs/event_inode.c
index c73fb1f7ddbc..a1934e0eea3b 100644
--- a/fs/tracefs/event_inode.c
+++ b/fs/tracefs/event_inode.c
@@ -752,8 +752,8 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx)
* Need to create the dentries and inodes to have a consistent
* inode number.
*/
- list_for_each_entry_srcu(ei_child, &ei->children, list,
- srcu_read_lock_held(&eventfs_srcu)) {
+ for (i = 0; i < ei->nr_entries; i++) {
+ void *cdata = ei->data;
if (c > 0) {
c--;
@@ -762,23 +762,32 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx)
ctx->pos++;
- if (ei_child->is_freed)
- continue;
+ entry = &ei->entries[i];
+ name = entry->name;
- name = ei_child->name;
+ mutex_lock(&eventfs_mutex);
+ /* If ei->is_freed then just bail here, nothing more to do */
+ if (ei->is_freed) {
+ mutex_unlock(&eventfs_mutex);
+ goto out_dec;
+ }
+ r = entry->callback(name, &mode, &cdata, &fops);
+ mutex_unlock(&eventfs_mutex);
+ if (r <= 0)
+ continue;
- dentry = create_dir_dentry(ei, ei_child, ei_dentry);
+ dentry = create_file_dentry(ei, i, ei_dentry, name, mode, cdata, fops);
if (!dentry)
goto out_dec;
ino = dentry->d_inode->i_ino;
dput(dentry);
- if (!dir_emit(ctx, name, strlen(name), ino, DT_DIR))
+ if (!dir_emit(ctx, name, strlen(name), ino, DT_REG))
goto out_dec;
}
- for (i = 0; i < ei->nr_entries; i++) {
- void *cdata = ei->data;
+ list_for_each_entry_srcu(ei_child, &ei->children, list,
+ srcu_read_lock_held(&eventfs_srcu)) {
if (c > 0) {
c--;
@@ -787,27 +796,18 @@ static int eventfs_iterate(struct file *file, struct dir_context *ctx)
ctx->pos++;
- entry = &ei->entries[i];
- name = entry->name;
-
- mutex_lock(&eventfs_mutex);
- /* If ei->is_freed then just bail here, nothing more to do */
- if (ei->is_freed) {
- mutex_unlock(&eventfs_mutex);
- goto out_dec;
- }
- r = entry->callback(name, &mode, &cdata, &fops);
- mutex_unlock(&eventfs_mutex);
- if (r <= 0)
+ if (ei_child->is_freed)
continue;
- dentry = create_file_dentry(ei, i, ei_dentry, name, mode, cdata, fops);
+ name = ei_child->name;
+
+ dentry = create_dir_dentry(ei, ei_child, ei_dentry);
if (!dentry)
goto out_dec;
ino = dentry->d_inode->i_ino;
dput(dentry);
- if (!dir_emit(ctx, name, strlen(name), ino, DT_REG))
+ if (!dir_emit(ctx, name, strlen(name), ino, DT_DIR))
goto out_dec;
}
ret = 1;