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[PATCH] dup_fd() part 2

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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 <viro@zeniv.linux.org.uk>
This commit is contained in:
Al Viro 2008-05-08 21:02:45 -04:00
parent 02afc6267f
commit 9dec3c4d30
1 changed files with 16 additions and 8 deletions
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24
fs/file.c
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@ -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;
new_fdt = files_fdtable(newf);
}
/* 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;
}
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