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authorLinus Torvalds <torvalds@linux-foundation.org>2016-12-16 21:58:12 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2016-12-16 21:58:12 +0300
commitff0f962ca3c38239b299a70e7eea27abfbb979c3 (patch)
treeab37876cf2e8af4900f11f44ac4b96cb0f15e548 /fs/overlayfs/copy_up.c
parent087a76d390cbb8c0d21ea0cb3672ab4a7bb76362 (diff)
parentc3c8699664800a68600f1988302173067eaeaffa (diff)
downloadlinux-ff0f962ca3c38239b299a70e7eea27abfbb979c3.tar.xz
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi: "This update contains: - try to clone on copy-up - allow renaming a directory - split source into managable chunks - misc cleanups and fixes It does not contain the read-only fd data inconsistency fix, which Al didn't like. I'll leave that to the next year..." * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: (36 commits) ovl: fix reStructuredText syntax errors in documentation ovl: fix return value of ovl_fill_super ovl: clean up kstat usage ovl: fold ovl_copy_up_truncate() into ovl_copy_up() ovl: create directories inside merged parent opaque ovl: opaque cleanup ovl: show redirect_dir mount option ovl: allow setting max size of redirect ovl: allow redirect_dir to default to "on" ovl: check for emptiness of redirect dir ovl: redirect on rename-dir ovl: lookup redirects ovl: consolidate lookup for underlying layers ovl: fix nested overlayfs mount ovl: check namelen ovl: split super.c ovl: use d_is_dir() ovl: simplify lookup ovl: check lower existence of rename target ovl: rename: simplify handling of lower/merged directory ...
Diffstat (limited to 'fs/overlayfs/copy_up.c')
-rw-r--r--fs/overlayfs/copy_up.c61
1 files changed, 32 insertions, 29 deletions
diff --git a/fs/overlayfs/copy_up.c b/fs/overlayfs/copy_up.c
index 2838bddb1f91..f57043dace62 100644
--- a/fs/overlayfs/copy_up.c
+++ b/fs/overlayfs/copy_up.c
@@ -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);
+}