diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2014-03-14 10:56:20 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2014-04-01 23:19:11 -0400 |
| commit | dd20908a8a06b22c171f6c3fcdbdbd65bed07505 (patch) | |
| tree | 447e2df881b2f056608098d3b24ab6d9734ce992 | |
| parent | 44ba8406d0005400e56c6b6a279a669eb761d1b8 (diff) | |
| download | linux-dd20908a8a06b22c171f6c3fcdbdbd65bed07505.tar.bz2 | |
don't bother with {get,put}_write_access() on non-regular files
it's pointless and actually leads to wrong behaviour in at least one
moderately convoluted case (pipe(), close one end, try to get to
another via /proc/*/fd and run into ETXTBUSY).
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| -rw-r--r-- | fs/file_table.c | 4 | ||||
| -rw-r--r-- | fs/open.c | 26 |
2 files changed, 9 insertions, 21 deletions
diff --git a/fs/file_table.c b/fs/file_table.c index 5b24008ea4f6..79ecae62209a 100644 --- a/fs/file_table.c +++ b/fs/file_table.c @@ -209,10 +209,10 @@ static void drop_file_write_access(struct file *file) struct dentry *dentry = file->f_path.dentry; struct inode *inode = dentry->d_inode; - put_write_access(inode); - if (special_file(inode->i_mode)) return; + + put_write_access(inode); if (file_check_writeable(file) != 0) return; __mnt_drop_write(mnt); diff --git a/fs/open.c b/fs/open.c index b9ed8b25c108..2ed7325f713e 100644 --- a/fs/open.c +++ b/fs/open.c @@ -641,23 +641,12 @@ out: static inline int __get_file_write_access(struct inode *inode, struct vfsmount *mnt) { - int error; - error = get_write_access(inode); + int error = get_write_access(inode); if (error) return error; - /* - * Do not take mount writer counts on - * special files since no writes to - * the mount itself will occur. - */ - if (!special_file(inode->i_mode)) { - /* - * Balanced in __fput() - */ - error = __mnt_want_write(mnt); - if (error) - put_write_access(inode); - } + error = __mnt_want_write(mnt); + if (error) + put_write_access(inode); return error; } @@ -690,12 +679,11 @@ static int do_dentry_open(struct file *f, path_get(&f->f_path); inode = f->f_inode = f->f_path.dentry->d_inode; - if (f->f_mode & FMODE_WRITE) { + if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) { error = __get_file_write_access(inode, f->f_path.mnt); if (error) goto cleanup_file; - if (!special_file(inode->i_mode)) - file_take_write(f); + file_take_write(f); } f->f_mapping = inode->i_mapping; @@ -742,7 +730,6 @@ static int do_dentry_open(struct file *f, cleanup_all: fops_put(f->f_op); if (f->f_mode & FMODE_WRITE) { - put_write_access(inode); if (!special_file(inode->i_mode)) { /* * We don't consider this a real @@ -750,6 +737,7 @@ cleanup_all: * because it all happenend right * here, so just reset the state. */ + put_write_access(inode); file_reset_write(f); __mnt_drop_write(f->f_path.mnt); } |