[PATCH 3.12 028/103] don't bother with {get,put}_write_access() on non-regular files
From: Jiri Slaby <hidden>
Date: 2014-05-29 14:13:32
Also in:
lkml
Subsystem:
filesystems (vfs and infrastructure), the rest · Maintainers:
Alexander Viro, Christian Brauner, Linus Torvalds
From: Al Viro <viro@zeniv.linux.org.uk> 3.12-stable review patch. If anyone has any objections, please let me know. =============== commit dd20908a8a06b22c171f6c3fcdbdbd65bed07505 upstream. 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). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Jiri Slaby <redacted> --- fs/file_table.c | 4 ++-- fs/open.c | 26 +++++++------------------- 2 files changed, 9 insertions(+), 21 deletions(-)
diff --git a/fs/file_table.c b/fs/file_table.c
index e900ca518635..05e2ac19b6c4 100644
--- a/fs/file_table.c
+++ b/fs/file_table.c@@ -211,10 +211,10 @@ 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 d420331ca32a..730a5870895d 100644
--- a/fs/open.c
+++ b/fs/open.c@@ -627,23 +627,12 @@ 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; }
@@ -676,12 +665,11 @@ 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;
@@ -722,7 +710,6 @@ cleanup_all: fops_put(f->f_op); file_sb_list_del(f); if (f->f_mode & FMODE_WRITE) { - put_write_access(inode); if (!special_file(inode->i_mode)) { /* * We don't consider this a real
@@ -730,6 +717,7 @@ 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); }
--
1.9.3