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authorAl Viro <viro@zeniv.linux.org.uk>2014-03-14 10:56:20 -0400
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-05-31 13:20:29 -0700
commit2419da02f5ff42cb8af85c0b6a3916b6187abf2c (patch)
treed20aa34916f267490fff169b0ff8beca3bb6de58 /fs/open.c
parent7147ad6410de7f330650e47b198815fe0d907a65 (diff)
downloadlinux-linaro-stable-2419da02f5ff42cb8af85c0b6a3916b6187abf2c.tar.gz
don't bother with {get,put}_write_access() on non-regular files
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/open.c')
-rw-r--r--fs/open.c26
1 files changed, 7 insertions, 19 deletions
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);
}