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authorLinus Torvalds <torvalds@linux-foundation.org>2024-01-08 11:11:51 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2024-01-08 11:11:51 -0800
commitbb93c5ed457fe76597c14717eb994fc5aef22716 (patch)
tree99774d9b73c3b7900711d88ee1680d51f23f6b32 /fs/open.c
parent8c9440fea77440772542d6dbcb5c36182495c164 (diff)
parentc39e2ae3943d4ee278af4e1b1dcfd5946da1089b (diff)
Merge tag 'vfs-6.8.rw' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs rw updates from Christian Brauner: "This contains updates from Amir for read-write backing file helpers for stacking filesystems such as overlayfs: - Fanotify is currently in the process of introducing pre content events. Roughly, a new permission event will be added indicating that it is safe to write to the file being accessed. These events are used by hierarchical storage managers to e.g., fill the content of files on first access. During that work we noticed that our current permission checking is inconsistent in rw_verify_area() and remap_verify_area(). Especially in the splice code permission checking is done multiple times. For example, one time for the whole range and then again for partial ranges inside the iterator. In addition, we mostly do permission checking before we call file_start_write() except for a few places where we call it after. For pre-content events we need such permission checking to be done before file_start_write(). So this is a nice reason to clean this all up. After this series, all permission checking is done before file_start_write(). As part of this cleanup we also massaged the splice code a bit. We got rid of a few helpers because we are alredy drowning in special read-write helpers. We also cleaned up the return types for splice helpers. - Introduce generic read-write helpers for backing files. This lifts some overlayfs code to common code so it can be used by the FUSE passthrough work coming in over the next cycles. Make Amir and Miklos the maintainers for this new subsystem of the vfs" * tag 'vfs-6.8.rw' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (30 commits) fs: fix __sb_write_started() kerneldoc formatting fs: factor out backing_file_mmap() helper fs: factor out backing_file_splice_{read,write}() helpers fs: factor out backing_file_{read,write}_iter() helpers fs: prepare for stackable filesystems backing file helpers fsnotify: optionally pass access range in file permission hooks fsnotify: assert that file_start_write() is not held in permission hooks fsnotify: split fsnotify_perm() into two hooks fs: use splice_copy_file_range() inline helper splice: return type ssize_t from all helpers fs: use do_splice_direct() for nfsd/ksmbd server-side-copy fs: move file_start_write() into direct_splice_actor() fs: fork splice_file_range() from do_splice_direct() fs: create {sb,file}_write_not_started() helpers fs: create file_write_started() helper fs: create __sb_write_started() helper fs: move kiocb_start_write() into vfs_iocb_iter_write() fs: move permission hook out of do_iter_read() fs: move permission hook out of do_iter_write() fs: move file_start_write() into vfs_iter_write() ...
Diffstat (limited to 'fs/open.c')
-rw-r--r--fs/open.c42
1 files changed, 4 insertions, 38 deletions
diff --git a/fs/open.c b/fs/open.c
index 954d8fcbb635..a84d21e55c39 100644
--- a/fs/open.c
+++ b/fs/open.c
@@ -304,6 +304,10 @@ int vfs_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
if (ret)
return ret;
+ ret = fsnotify_file_area_perm(file, MAY_WRITE, &offset, len);
+ if (ret)
+ return ret;
+
if (S_ISFIFO(inode->i_mode))
return -ESPIPE;
@@ -1178,44 +1182,6 @@ struct file *kernel_file_open(const struct path *path, int flags,
}
EXPORT_SYMBOL_GPL(kernel_file_open);
-/**
- * backing_file_open - open a backing file for kernel internal use
- * @user_path: path that the user reuqested to open
- * @flags: open flags
- * @real_path: path of the backing file
- * @cred: credentials for open
- *
- * Open a backing file for a stackable filesystem (e.g., overlayfs).
- * @user_path may be on the stackable filesystem and @real_path on the
- * underlying filesystem. In this case, we want to be able to return the
- * @user_path of the stackable filesystem. This is done by embedding the
- * returned file into a container structure that also stores the stacked
- * file's path, which can be retrieved using backing_file_user_path().
- */
-struct file *backing_file_open(const struct path *user_path, int flags,
- const struct path *real_path,
- const struct cred *cred)
-{
- struct file *f;
- int error;
-
- f = alloc_empty_backing_file(flags, cred);
- if (IS_ERR(f))
- return f;
-
- path_get(user_path);
- *backing_file_user_path(f) = *user_path;
- f->f_path = *real_path;
- error = do_dentry_open(f, d_inode(real_path->dentry), NULL);
- if (error) {
- fput(f);
- f = ERR_PTR(error);
- }
-
- return f;
-}
-EXPORT_SYMBOL_GPL(backing_file_open);
-
#define WILL_CREATE(flags) (flags & (O_CREAT | __O_TMPFILE))
#define O_PATH_FLAGS (O_DIRECTORY | O_NOFOLLOW | O_PATH | O_CLOEXEC)