diff options
Diffstat (limited to 'fs/overlayfs/copy_up.c')
| -rw-r--r-- | fs/overlayfs/copy_up.c | 63 |
1 files changed, 33 insertions, 30 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c index 36795eed40b0..f57043dace62 100644 --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -33,7 +33,7 @@ static int ovl_check_fd(const void *data, struct file *f, unsigned int fd) { const struct dentry *dentry = data; - if (f->f_inode == d_inode(dentry)) + if (file_inode(f) == d_inode(dentry)) pr_warn_ratelimited("overlayfs: Warning: Copying up %pD, but open R/O on fd %u which will cease to be coherent [pid=%d %s]\n", f, fd, current->pid, current->comm); return 0; @@ -153,6 +153,13 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) goto out_fput; } + /* Try to use clone_file_range to clone up within the same fs */ + error = vfs_clone_file_range(old_file, 0, new_file, 0, len); + if (!error) + goto out; + /* Couldn't clone, so now we try to copy the data */ + error = 0; + /* FIXME: copy up sparse files efficiently */ while (len) { size_t this_len = OVL_COPY_UP_CHUNK_SIZE; @@ -177,7 +184,7 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len) len -= bytes; } - +out: if (!error) error = vfs_fsync(new_file, 0); fput(new_file); @@ -231,10 +238,15 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, struct inode *udir = upperdir->d_inode; struct dentry *newdentry = NULL; struct dentry *upper = NULL; - umode_t mode = stat->mode; int err; const struct cred *old_creds = NULL; struct cred *new_creds = NULL; + struct cattr cattr = { + /* Can't properly set mode on creation because of the umask */ + .mode = stat->mode & S_IFMT, + .rdev = stat->rdev, + .link = link + }; newdentry = ovl_lookup_temp(workdir, dentry); err = PTR_ERR(newdentry); @@ -254,10 +266,7 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, if (new_creds) old_creds = override_creds(new_creds); - /* Can't properly set mode on creation because of the umask */ - stat->mode &= S_IFMT; - err = ovl_create_real(wdir, newdentry, stat, link, NULL, true); - stat->mode = mode; + err = ovl_create_real(wdir, newdentry, &cattr, NULL, true); if (new_creds) { revert_creds(old_creds); @@ -296,12 +305,6 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir, ovl_dentry_update(dentry, newdentry); ovl_inode_update(d_inode(dentry), d_inode(newdentry)); newdentry = NULL; - - /* - * Non-directores become opaque when copied up. - */ - if (!S_ISDIR(stat->mode)) - ovl_dentry_set_opaque(dentry, true); out2: dput(upper); out1: @@ -317,20 +320,14 @@ out_cleanup: /* * Copy up a single dentry * - * Directory renames only allowed on "pure upper" (already created on - * upper filesystem, never copied up). Directories which are on lower or - * are merged may not be renamed. For these -EXDEV is returned and - * userspace has to deal with it. This means, when copying up a - * directory we can rely on it and ancestors being stable. - * - * Non-directory renames start with copy up of source if necessary. The - * actual rename will only proceed once the copy up was successful. Copy - * up uses upper parent i_mutex for exclusion. Since rename can change - * d_parent it is possible that the copy up will lock the old parent. At - * that point the file will have already been copied up anyway. + * All renames start with copy up of source if necessary. The actual + * rename will only proceed once the copy up was successful. Copy up uses + * upper parent i_mutex for exclusion. Since rename can change d_parent it + * is possible that the copy up will lock the old parent. At that point + * the file will have already been copied up anyway. */ -int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, - struct path *lowerpath, struct kstat *stat) +static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, + struct path *lowerpath, struct kstat *stat) { DEFINE_DELAYED_CALL(done); struct dentry *workdir = ovl_workdir(dentry); @@ -339,7 +336,6 @@ int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, struct path parentpath; struct dentry *lowerdentry = lowerpath->dentry; struct dentry *upperdir; - struct dentry *upperdentry; const char *link = NULL; if (WARN_ON(!workdir)) @@ -365,8 +361,7 @@ int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry, pr_err("overlayfs: failed to lock workdir+upperdir\n"); goto out_unlock; } - upperdentry = ovl_dentry_upper(dentry); - if (upperdentry) { + if (ovl_dentry_upper(dentry)) { /* Raced with another copy-up? Nothing to do, then... */ err = 0; goto out_unlock; @@ -385,7 +380,7 @@ out_unlock: return err; } -int ovl_copy_up(struct dentry *dentry) +int ovl_copy_up_flags(struct dentry *dentry, int flags) { int err = 0; const struct cred *old_cred = ovl_override_creds(dentry->d_sb); @@ -415,6 +410,9 @@ int ovl_copy_up(struct dentry *dentry) ovl_path_lower(next, &lowerpath); err = vfs_getattr(&lowerpath, &stat); + /* maybe truncate regular file. this has no effect on dirs */ + if (flags & O_TRUNC) + stat.size = 0; if (!err) err = ovl_copy_up_one(parent, next, &lowerpath, &stat); @@ -425,3 +423,8 @@ int ovl_copy_up(struct dentry *dentry) return err; } + +int ovl_copy_up(struct dentry *dentry) +{ + return ovl_copy_up_flags(dentry, 0); +} |