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author | Linus Torvalds <torvalds@linux-foundation.org> | 2023-11-07 22:46:31 +0300 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2023-11-07 22:46:31 +0300 |
commit | 7f851936a0ca4b231224ee296cba28f9b1bc555e (patch) | |
tree | 474b2147829e3cef0f5bfc157554c7f446e064c5 /fs/overlayfs/super.c | |
parent | c9d01179e185f72b20af7e37aa4308f4c7ca7eeb (diff) | |
parent | 24e16e385f2272b1a9df51337a5c32d28a29c7ad (diff) | |
download | linux-7f851936a0ca4b231224ee296cba28f9b1bc555e.tar.xz |
Merge tag 'ovl-update-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs updates from Amir Goldstein:
- Overlayfs aio cleanups and fixes
Cleanups and minor fixes in preparation for factoring out of
read/write passthrough code.
- Overlayfs lock ordering changes
Hold mnt_writers only throughout copy up instead of a long lived
elevated refcount.
- Add support for nesting overlayfs private xattrs
There are cases where you want to use an overlayfs mount as a
lowerdir for another overlayfs mount. For example, if the system
rootfs is on overlayfs due to composefs, or to make it volatile (via
tmpfs), then you cannot currently store a lowerdir on the rootfs,
because the inner overlayfs will eat all the whiteouts and overlay
xattrs. This means you can't e.g. store on the rootfs a prepared
container image for use with overlayfs.
This adds support for nesting of overlayfs mounts by escaping the
problematic features and unescaping them when exposing to the
overlayfs user.
- Add new mount options for appending lowerdirs
* tag 'ovl-update-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: add support for appending lowerdirs one by one
ovl: refactor layer parsing helpers
ovl: store and show the user provided lowerdir mount option
ovl: remove unused code in lowerdir param parsing
ovl: Add documentation on nesting of overlayfs mounts
ovl: Add an alternative type of whiteout
ovl: Support escaped overlay.* xattrs
ovl: Add OVL_XATTR_TRUSTED/USER_PREFIX_LEN macros
ovl: Move xattr support to new xattrs.c file
ovl: do not encode lower fh with upper sb_writers held
ovl: do not open/llseek lower file with upper sb_writers held
ovl: reorder ovl_want_write() after ovl_inode_lock()
ovl: split ovl_want_write() into two helpers
ovl: add helper ovl_file_modified()
ovl: protect copying of realinode attributes to ovl inode
ovl: punt write aio completion to workqueue
ovl: propagate IOCB_APPEND flag on writes to realfile
ovl: use simpler function to convert iocb to rw flags
Diffstat (limited to 'fs/overlayfs/super.c')
-rw-r--r-- | fs/overlayfs/super.c | 92 |
1 files changed, 20 insertions, 72 deletions
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c index 17864a8d2b85..a0967bb25003 100644 --- a/fs/overlayfs/super.c +++ b/fs/overlayfs/super.c @@ -445,68 +445,6 @@ static bool ovl_workdir_ok(struct dentry *workdir, struct dentry *upperdir) return ok; } -static int ovl_own_xattr_get(const struct xattr_handler *handler, - struct dentry *dentry, struct inode *inode, - const char *name, void *buffer, size_t size) -{ - return -EOPNOTSUPP; -} - -static int ovl_own_xattr_set(const struct xattr_handler *handler, - struct mnt_idmap *idmap, - struct dentry *dentry, struct inode *inode, - const char *name, const void *value, - size_t size, int flags) -{ - return -EOPNOTSUPP; -} - -static int ovl_other_xattr_get(const struct xattr_handler *handler, - struct dentry *dentry, struct inode *inode, - const char *name, void *buffer, size_t size) -{ - return ovl_xattr_get(dentry, inode, name, buffer, size); -} - -static int ovl_other_xattr_set(const struct xattr_handler *handler, - struct mnt_idmap *idmap, - struct dentry *dentry, struct inode *inode, - const char *name, const void *value, - size_t size, int flags) -{ - return ovl_xattr_set(dentry, inode, name, value, size, flags); -} - -static const struct xattr_handler ovl_own_trusted_xattr_handler = { - .prefix = OVL_XATTR_TRUSTED_PREFIX, - .get = ovl_own_xattr_get, - .set = ovl_own_xattr_set, -}; - -static const struct xattr_handler ovl_own_user_xattr_handler = { - .prefix = OVL_XATTR_USER_PREFIX, - .get = ovl_own_xattr_get, - .set = ovl_own_xattr_set, -}; - -static const struct xattr_handler ovl_other_xattr_handler = { - .prefix = "", /* catch all */ - .get = ovl_other_xattr_get, - .set = ovl_other_xattr_set, -}; - -static const struct xattr_handler * const ovl_trusted_xattr_handlers[] = { - &ovl_own_trusted_xattr_handler, - &ovl_other_xattr_handler, - NULL -}; - -static const struct xattr_handler * const ovl_user_xattr_handlers[] = { - &ovl_own_user_xattr_handler, - &ovl_other_xattr_handler, - NULL -}; - static int ovl_setup_trap(struct super_block *sb, struct dentry *dir, struct inode **ptrap, const char *name) { @@ -647,7 +585,7 @@ static int ovl_check_rename_whiteout(struct ovl_fs *ofs) if (IS_ERR(whiteout)) goto cleanup_temp; - err = ovl_is_whiteout(whiteout); + err = ovl_upper_is_whiteout(ofs, whiteout); /* Best effort cleanup of whiteout and temp file */ if (err) @@ -887,15 +825,20 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, { struct vfsmount *mnt = ovl_upper_mnt(ofs); struct dentry *indexdir; + struct dentry *origin = ovl_lowerstack(oe)->dentry; + const struct ovl_fh *fh; int err; + fh = ovl_get_origin_fh(ofs, origin); + if (IS_ERR(fh)) + return PTR_ERR(fh); + err = mnt_want_write(mnt); if (err) - return err; + goto out_free_fh; /* Verify lower root is upper root origin */ - err = ovl_verify_origin(ofs, upperpath->dentry, - ovl_lowerstack(oe)->dentry, true); + err = ovl_verify_origin_fh(ofs, upperpath->dentry, fh, true); if (err) { pr_err("failed to verify upper root origin\n"); goto out; @@ -927,9 +870,10 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, * directory entries. */ if (ovl_check_origin_xattr(ofs, ofs->indexdir)) { - err = ovl_verify_set_fh(ofs, ofs->indexdir, - OVL_XATTR_ORIGIN, - upperpath->dentry, true, false); + err = ovl_verify_origin_xattr(ofs, ofs->indexdir, + OVL_XATTR_ORIGIN, + upperpath->dentry, true, + false); if (err) pr_err("failed to verify index dir 'origin' xattr\n"); } @@ -947,6 +891,8 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs, out: mnt_drop_write(mnt); +out_free_fh: + kfree(fh); return err; } @@ -1382,8 +1328,11 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) ofs->layers = layers; /* * Layer 0 is reserved for upper even if there's no upper. - * For consistency, config.lowerdirs[0] is NULL. + * config.lowerdirs[0] is used for storing the user provided colon + * separated lowerdir string. */ + ofs->config.lowerdirs[0] = ctx->lowerdir_all; + ctx->lowerdir_all = NULL; ofs->numlayer = 1; sb->s_stack_depth = 0; @@ -1493,8 +1442,7 @@ int ovl_fill_super(struct super_block *sb, struct fs_context *fc) cap_lower(cred->cap_effective, CAP_SYS_RESOURCE); sb->s_magic = OVERLAYFS_SUPER_MAGIC; - sb->s_xattr = ofs->config.userxattr ? ovl_user_xattr_handlers : - ovl_trusted_xattr_handlers; + sb->s_xattr = ovl_xattr_handlers(ofs); sb->s_fs_info = ofs; #ifdef CONFIG_FS_POSIX_ACL sb->s_flags |= SB_POSIXACL; |