From 9dec3c4d306b09b31331e475e895bb9674e16d81 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 8 May 2008 21:02:45 -0400 Subject: [PATCH] [PATCH] dup_fd() part 2 use alloc_fdtable() instead of expand_files(), get rid of pointless grabbing newf->file_lock, kill magic in copy_fdtable() that used to be there only to skip copying when called from dup_fd(). Signed-off-by: Al Viro --- fs/file.c | 24 ++++++++++++++++-------- 1 file changed, 16 insertions(+), 8 deletions(-) diff --git a/fs/file.c b/fs/file.c index 7dbadaaf00..6491b2b5bc 100644 --- a/fs/file.c +++ b/fs/file.c @@ -119,8 +119,6 @@ static void copy_fdtable(struct fdtable *nfdt, struct fdtable *ofdt) unsigned int cpy, set; BUG_ON(nfdt->max_fds < ofdt->max_fds); - if (ofdt->max_fds == 0) - return; cpy = ofdt->max_fds * sizeof(struct file *); set = (nfdt->max_fds - ofdt->max_fds) * sizeof(struct file *); @@ -327,14 +325,24 @@ struct files_struct *dup_fd(struct files_struct *oldf, int *errorp) * Note: we're not a clone task, so the open count won't change. */ if (open_files > new_fdt->max_fds) { - new_fdt->max_fds = 0; spin_unlock(&oldf->file_lock); - spin_lock(&newf->file_lock); - *errorp = expand_files(newf, open_files-1); - spin_unlock(&newf->file_lock); - if (*errorp < 0) + + new_fdt = alloc_fdtable(open_files - 1); + if (!new_fdt) { + *errorp = -ENOMEM; + goto out_release; + } + + /* beyond sysctl_nr_open; nothing to do */ + if (unlikely(new_fdt->max_fds < open_files)) { + free_fdarr(new_fdt); + free_fdset(new_fdt); + kfree(new_fdt); + *errorp = -EMFILE; goto out_release; - new_fdt = files_fdtable(newf); + } + rcu_assign_pointer(files->fdt, new_fdt); + /* * Reacquire the oldf lock and a pointer to its fd table * who knows it may have a new bigger fd table. We need -- 2.39.5