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https://github.com/torvalds/linux.git
synced 2024-11-10 14:11:52 +00:00
Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi: "Because copy up can take a long time, serialized copy ups could be a big performance bottleneck. This update allows concurrent copy up of regular files eliminating this potential problem. There are also minor fixes" * 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs: ovl: drop CAP_SYS_RESOURCE from saved mounter's credentials ovl: properly implement sync_filesystem() ovl: concurrent copy up of regular files ovl: introduce copy up waitqueue ovl: copy up regular file using O_TMPFILE ovl: rearrange code in ovl_copy_up_locked() ovl: check if upperdir fs supports O_TMPFILE
This commit is contained in:
Linus Torvalds
commit
e58bc92783
@ -21,6 +21,7 @@
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#include <linux/fdtable.h>
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#include <linux/ratelimit.h>
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#include "overlayfs.h"
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#include "ovl_entry.h"
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#define OVL_COPY_UP_CHUNK_SIZE (1 << 20)
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@ -233,12 +234,14 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
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static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
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struct dentry *dentry, struct path *lowerpath,
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struct kstat *stat, const char *link)
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struct kstat *stat, const char *link,
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struct kstat *pstat, bool tmpfile)
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{
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struct inode *wdir = workdir->d_inode;
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struct inode *udir = upperdir->d_inode;
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struct dentry *newdentry = NULL;
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struct dentry *upper = NULL;
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struct dentry *temp = NULL;
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int err;
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const struct cred *old_creds = NULL;
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struct cred *new_creds = NULL;
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@ -249,25 +252,30 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
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.link = link
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};
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newdentry = ovl_lookup_temp(workdir, dentry);
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err = PTR_ERR(newdentry);
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if (IS_ERR(newdentry))
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goto out;
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upper = lookup_one_len(dentry->d_name.name, upperdir,
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dentry->d_name.len);
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err = PTR_ERR(upper);
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if (IS_ERR(upper))
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goto out1;
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goto out;
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err = security_inode_copy_up(dentry, &new_creds);
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if (err < 0)
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goto out2;
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goto out1;
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if (new_creds)
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old_creds = override_creds(new_creds);
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err = ovl_create_real(wdir, newdentry, &cattr, NULL, true);
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if (tmpfile)
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temp = ovl_do_tmpfile(upperdir, stat->mode);
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else
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temp = ovl_lookup_temp(workdir, dentry);
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err = PTR_ERR(temp);
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if (IS_ERR(temp))
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goto out1;
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err = 0;
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if (!tmpfile)
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err = ovl_create_real(wdir, temp, &cattr, NULL, true);
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if (new_creds) {
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revert_creds(old_creds);
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@ -282,39 +290,55 @@ static int ovl_copy_up_locked(struct dentry *workdir, struct dentry *upperdir,
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ovl_path_upper(dentry, &upperpath);
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BUG_ON(upperpath.dentry != NULL);
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upperpath.dentry = newdentry;
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upperpath.dentry = temp;
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if (tmpfile) {
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inode_unlock(udir);
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err = ovl_copy_up_data(lowerpath, &upperpath,
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stat->size);
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inode_lock_nested(udir, I_MUTEX_PARENT);
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} else {
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err = ovl_copy_up_data(lowerpath, &upperpath,
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stat->size);
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}
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err = ovl_copy_up_data(lowerpath, &upperpath, stat->size);
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if (err)
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goto out_cleanup;
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}
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err = ovl_copy_xattr(lowerpath->dentry, newdentry);
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err = ovl_copy_xattr(lowerpath->dentry, temp);
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if (err)
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goto out_cleanup;
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inode_lock(newdentry->d_inode);
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err = ovl_set_attr(newdentry, stat);
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inode_unlock(newdentry->d_inode);
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inode_lock(temp->d_inode);
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err = ovl_set_attr(temp, stat);
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inode_unlock(temp->d_inode);
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if (err)
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goto out_cleanup;
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err = ovl_do_rename(wdir, newdentry, udir, upper, 0);
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if (tmpfile)
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err = ovl_do_link(temp, udir, upper, true);
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else
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err = ovl_do_rename(wdir, temp, udir, upper, 0);
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if (err)
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goto out_cleanup;
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newdentry = dget(tmpfile ? upper : temp);
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ovl_dentry_update(dentry, newdentry);
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ovl_inode_update(d_inode(dentry), d_inode(newdentry));
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newdentry = NULL;
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/* Restore timestamps on parent (best effort) */
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ovl_set_timestamps(upperdir, pstat);
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out2:
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dput(upper);
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dput(temp);
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out1:
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dput(newdentry);
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dput(upper);
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out:
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return err;
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out_cleanup:
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ovl_cleanup(wdir, newdentry);
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if (!tmpfile)
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ovl_cleanup(wdir, temp);
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goto out2;
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}
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@ -338,6 +362,7 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
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struct dentry *lowerdentry = lowerpath->dentry;
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struct dentry *upperdir;
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const char *link = NULL;
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struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
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if (WARN_ON(!workdir))
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return -EROFS;
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@ -358,6 +383,25 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
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return PTR_ERR(link);
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}
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/* Should we copyup with O_TMPFILE or with workdir? */
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if (S_ISREG(stat->mode) && ofs->tmpfile) {
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err = ovl_copy_up_start(dentry);
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/* err < 0: interrupted, err > 0: raced with another copy-up */
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if (unlikely(err)) {
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pr_debug("ovl_copy_up_start(%pd2) = %i\n", dentry, err);
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if (err > 0)
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err = 0;
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goto out_done;
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}
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inode_lock_nested(upperdir->d_inode, I_MUTEX_PARENT);
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err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,
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stat, link, &pstat, true);
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inode_unlock(upperdir->d_inode);
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ovl_copy_up_end(dentry);
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goto out_done;
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}
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err = -EIO;
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if (lock_rename(workdir, upperdir) != NULL) {
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pr_err("overlayfs: failed to lock workdir+upperdir\n");
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@ -370,13 +414,10 @@ static int ovl_copy_up_one(struct dentry *parent, struct dentry *dentry,
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}
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err = ovl_copy_up_locked(workdir, upperdir, dentry, lowerpath,
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stat, link);
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if (!err) {
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/* Restore timestamps on parent (best effort) */
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ovl_set_timestamps(upperdir, &pstat);
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}
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stat, link, &pstat, false);
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out_unlock:
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unlock_rename(workdir, upperdir);
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out_done:
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do_delayed_call(&done);
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return err;
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@ -127,6 +127,15 @@ static inline int ovl_do_whiteout(struct inode *dir, struct dentry *dentry)
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return err;
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}
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static inline struct dentry *ovl_do_tmpfile(struct dentry *dentry, umode_t mode)
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{
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struct dentry *ret = vfs_tmpfile(dentry, mode, 0);
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int err = IS_ERR(ret) ? PTR_ERR(ret) : 0;
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pr_debug("tmpfile(%pd2, 0%o) = %i\n", dentry, mode, err);
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return ret;
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}
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static inline struct inode *ovl_inode_real(struct inode *inode, bool *is_upper)
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{
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unsigned long x = (unsigned long) READ_ONCE(inode->i_private);
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@ -169,6 +178,8 @@ void ovl_dentry_version_inc(struct dentry *dentry);
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u64 ovl_dentry_version_get(struct dentry *dentry);
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bool ovl_is_whiteout(struct dentry *dentry);
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struct file *ovl_path_open(struct path *path, int flags);
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int ovl_copy_up_start(struct dentry *dentry);
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void ovl_copy_up_end(struct dentry *dentry);
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/* namei.c */
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int ovl_path_next(int idx, struct dentry *dentry, struct path *path);
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@ -27,6 +27,8 @@ struct ovl_fs {
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struct ovl_config config;
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/* creds of process who forced instantiation of super block */
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const struct cred *creator_cred;
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bool tmpfile;
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wait_queue_head_t copyup_wq;
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};
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/* private information held for every overlayfs dentry */
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@ -38,6 +40,7 @@ struct ovl_entry {
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u64 version;
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const char *redirect;
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bool opaque;
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bool copying;
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};
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struct rcu_head rcu;
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};
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@ -161,6 +161,25 @@ static void ovl_put_super(struct super_block *sb)
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kfree(ufs);
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}
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static int ovl_sync_fs(struct super_block *sb, int wait)
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{
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struct ovl_fs *ufs = sb->s_fs_info;
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struct super_block *upper_sb;
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int ret;
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if (!ufs->upper_mnt)
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return 0;
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upper_sb = ufs->upper_mnt->mnt_sb;
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if (!upper_sb->s_op->sync_fs)
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return 0;
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/* real inodes have already been synced by sync_filesystem(ovl_sb) */
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down_read(&upper_sb->s_umount);
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ret = upper_sb->s_op->sync_fs(upper_sb, wait);
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up_read(&upper_sb->s_umount);
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return ret;
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}
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/**
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* ovl_statfs
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* @sb: The overlayfs super block
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@ -223,6 +242,7 @@ static int ovl_remount(struct super_block *sb, int *flags, char *data)
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static const struct super_operations ovl_super_operations = {
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.put_super = ovl_put_super,
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.sync_fs = ovl_sync_fs,
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.statfs = ovl_statfs,
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.show_options = ovl_show_options,
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.remount_fs = ovl_remount,
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@ -702,6 +722,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
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unsigned int stacklen = 0;
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unsigned int i;
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bool remote = false;
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struct cred *cred;
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int err;
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err = -ENOMEM;
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@ -709,6 +730,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
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if (!ufs)
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goto out;
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init_waitqueue_head(&ufs->copyup_wq);
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ufs->config.redirect_dir = ovl_redirect_dir_def;
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err = ovl_parse_opt((char *) data, &ufs->config);
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if (err)
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@ -826,6 +848,8 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
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* creation of workdir in previous step.
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*/
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if (ufs->workdir) {
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struct dentry *temp;
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err = ovl_check_d_type_supported(&workpath);
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if (err < 0)
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goto out_put_workdir;
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@ -837,6 +861,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
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*/
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if (!err)
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pr_warn("overlayfs: upper fs needs to support d_type.\n");
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/* Check if upper/work fs supports O_TMPFILE */
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temp = ovl_do_tmpfile(ufs->workdir, S_IFREG | 0);
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ufs->tmpfile = !IS_ERR(temp);
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if (ufs->tmpfile)
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dput(temp);
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else
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pr_warn("overlayfs: upper fs does not support tmpfile.\n");
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}
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}
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@ -871,10 +903,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
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else
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sb->s_d_op = &ovl_dentry_operations;
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ufs->creator_cred = prepare_creds();
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if (!ufs->creator_cred)
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ufs->creator_cred = cred = prepare_creds();
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if (!cred)
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goto out_put_lower_mnt;
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/* Never override disk quota limits or use reserved space */
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cap_lower(cred->cap_effective, CAP_SYS_RESOURCE);
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err = -ENOMEM;
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oe = ovl_alloc_entry(numlower);
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if (!oe)
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@ -12,6 +12,7 @@
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#include <linux/slab.h>
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#include <linux/cred.h>
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#include <linux/xattr.h>
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#include <linux/sched/signal.h>
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#include "overlayfs.h"
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#include "ovl_entry.h"
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@ -264,3 +265,33 @@ struct file *ovl_path_open(struct path *path, int flags)
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{
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return dentry_open(path, flags | O_NOATIME, current_cred());
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}
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int ovl_copy_up_start(struct dentry *dentry)
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{
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struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
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struct ovl_entry *oe = dentry->d_fsdata;
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int err;
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spin_lock(&ofs->copyup_wq.lock);
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err = wait_event_interruptible_locked(ofs->copyup_wq, !oe->copying);
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if (!err) {
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if (oe->__upperdentry)
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err = 1; /* Already copied up */
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else
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oe->copying = true;
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}
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spin_unlock(&ofs->copyup_wq.lock);
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return err;
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}
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void ovl_copy_up_end(struct dentry *dentry)
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{
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struct ovl_fs *ofs = dentry->d_sb->s_fs_info;
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struct ovl_entry *oe = dentry->d_fsdata;
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spin_lock(&ofs->copyup_wq.lock);
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oe->copying = false;
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wake_up_locked(&ofs->copyup_wq);
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spin_unlock(&ofs->copyup_wq.lock);
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}
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