summaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--fs/internal.h11
-rw-r--r--fs/open.c31
2 files changed, 34 insertions, 8 deletions
diff --git a/fs/internal.h b/fs/internal.h
index f08d8fe3ae5e..4e93a685bdaa 100644
--- a/fs/internal.h
+++ b/fs/internal.h
@@ -96,13 +96,20 @@ struct file *alloc_empty_file_noaccount(int flags, const struct cred *cred);
struct file *alloc_empty_backing_file(int flags, const struct cred *cred);
void release_empty_file(struct file *f);
+static inline void file_put_write_access(struct file *file)
+{
+ put_write_access(file->f_inode);
+ mnt_put_write_access(file->f_path.mnt);
+ if (unlikely(file->f_mode & FMODE_BACKING))
+ mnt_put_write_access(backing_file_real_path(file)->mnt);
+}
+
static inline void put_file_access(struct file *file)
{
if ((file->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
i_readcount_dec(file->f_inode);
} else if (file->f_mode & FMODE_WRITER) {
- put_write_access(file->f_inode);
- mnt_put_write_access(file->f_path.mnt);
+ file_put_write_access(file);
}
}
diff --git a/fs/open.c b/fs/open.c
index a65ce47810cf..fe63e236da22 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -870,6 +870,30 @@ SYSCALL_DEFINE3(fchown, unsigned int, fd, uid_t, user, gid_t, group)
return ksys_fchown(fd, user, group);
}
+static inline int file_get_write_access(struct file *f)
+{
+ int error;
+
+ error = get_write_access(f->f_inode);
+ if (unlikely(error))
+ return error;
+ error = mnt_get_write_access(f->f_path.mnt);
+ if (unlikely(error))
+ goto cleanup_inode;
+ if (unlikely(f->f_mode & FMODE_BACKING)) {
+ error = mnt_get_write_access(backing_file_real_path(f)->mnt);
+ if (unlikely(error))
+ goto cleanup_mnt;
+ }
+ return 0;
+
+cleanup_mnt:
+ mnt_put_write_access(f->f_path.mnt);
+cleanup_inode:
+ put_write_access(f->f_inode);
+ return error;
+}
+
static int do_dentry_open(struct file *f,
struct inode *inode,
int (*open)(struct inode *, struct file *))
@@ -892,14 +916,9 @@ static int do_dentry_open(struct file *f,
if ((f->f_mode & (FMODE_READ | FMODE_WRITE)) == FMODE_READ) {
i_readcount_inc(inode);
} else if (f->f_mode & FMODE_WRITE && !special_file(inode->i_mode)) {
- error = get_write_access(inode);
+ error = file_get_write_access(f);
if (unlikely(error))
goto cleanup_file;
- error = mnt_get_write_access(f->f_path.mnt);
- if (unlikely(error)) {
- put_write_access(inode);
- goto cleanup_file;
- }
f->f_mode |= FMODE_WRITER;
}