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authorAl Viro <viro@zeniv.linux.org.uk>2014-03-14 10:56:20 -0400
committerJiri Slaby <jslaby@suse.cz>2014-05-29 11:38:11 +0200
commit92e9ead530eccbfcc408c60ddb6d40ec4d952119 (patch)
tree2ad55a8edbf48647c2aa55b8e5512e15fb8a8311 /fs
parent39760567d0146b23580d41db26b60cd9f873a4df (diff)
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: Jiri Slaby <jslaby@suse.cz>
Diffstat (limited to 'fs')
-rw-r--r--fs/file_table.c4
-rw-r--r--fs/open.c26
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);
}