diff options
author | Miklos Szeredi <mszeredi@redhat.com> | 2016-12-16 11:02:56 +0100 |
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committer | Miklos Szeredi <mszeredi@redhat.com> | 2016-12-16 11:02:56 +0100 |
commit | bbb1e54dd53cf83863e856dd5518ce5e58791115 (patch) | |
tree | f8b7c50ac58b2e88de8293d1423fb3150032e241 /fs/overlayfs/util.c | |
parent | 2b8c30e9ef1492c34099b97365115504f6cd6995 (diff) |
ovl: split super.c
fs/overlayfs/super.c is the biggest of the overlayfs source files and it
contains various utility functions as well as the rather complicated lookup
code. Split these parts out to separate files.
Before:
1446 fs/overlayfs/super.c
After:
919 fs/overlayfs/super.c
267 fs/overlayfs/namei.c
235 fs/overlayfs/util.c
51 fs/overlayfs/ovl_entry.h
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Diffstat (limited to 'fs/overlayfs/util.c')
-rw-r--r-- | fs/overlayfs/util.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c new file mode 100644 index 000000000000..0d45a84468d2 --- /dev/null +++ b/fs/overlayfs/util.c @@ -0,0 +1,235 @@ +/* + * Copyright (C) 2011 Novell Inc. + * Copyright (C) 2016 Red Hat, Inc. + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 as published by + * the Free Software Foundation. + */ + +#include <linux/fs.h> +#include <linux/mount.h> +#include <linux/slab.h> +#include <linux/xattr.h> +#include "overlayfs.h" +#include "ovl_entry.h" + +int ovl_want_write(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + return mnt_want_write(ofs->upper_mnt); +} + +void ovl_drop_write(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + mnt_drop_write(ofs->upper_mnt); +} + +struct dentry *ovl_workdir(struct dentry *dentry) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + return ofs->workdir; +} + +const struct cred *ovl_override_creds(struct super_block *sb) +{ + struct ovl_fs *ofs = sb->s_fs_info; + + return override_creds(ofs->creator_cred); +} + +struct ovl_entry *ovl_alloc_entry(unsigned int numlower) +{ + size_t size = offsetof(struct ovl_entry, lowerstack[numlower]); + struct ovl_entry *oe = kzalloc(size, GFP_KERNEL); + + if (oe) + oe->numlower = numlower; + + return oe; +} + +bool ovl_dentry_remote(struct dentry *dentry) +{ + return dentry->d_flags & + (DCACHE_OP_REVALIDATE | DCACHE_OP_WEAK_REVALIDATE | + DCACHE_OP_REAL); +} + +bool ovl_dentry_weird(struct dentry *dentry) +{ + return dentry->d_flags & (DCACHE_NEED_AUTOMOUNT | + DCACHE_MANAGE_TRANSIT | + DCACHE_OP_HASH | + DCACHE_OP_COMPARE); +} + +enum ovl_path_type ovl_path_type(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + enum ovl_path_type type = 0; + + if (oe->__upperdentry) { + type = __OVL_PATH_UPPER; + + /* + * Non-dir dentry can hold lower dentry from previous + * location. + */ + if (oe->numlower && d_is_dir(dentry)) + type |= __OVL_PATH_MERGE; + } else { + if (oe->numlower > 1) + type |= __OVL_PATH_MERGE; + } + return type; +} + +void ovl_path_upper(struct dentry *dentry, struct path *path) +{ + struct ovl_fs *ofs = dentry->d_sb->s_fs_info; + struct ovl_entry *oe = dentry->d_fsdata; + + path->mnt = ofs->upper_mnt; + path->dentry = ovl_upperdentry_dereference(oe); +} + +void ovl_path_lower(struct dentry *dentry, struct path *path) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + *path = oe->numlower ? oe->lowerstack[0] : (struct path) { NULL, NULL }; +} + +enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path) +{ + enum ovl_path_type type = ovl_path_type(dentry); + + if (!OVL_TYPE_UPPER(type)) + ovl_path_lower(dentry, path); + else + ovl_path_upper(dentry, path); + + return type; +} + +struct dentry *ovl_dentry_upper(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + return ovl_upperdentry_dereference(oe); +} + +static struct dentry *__ovl_dentry_lower(struct ovl_entry *oe) +{ + return oe->numlower ? oe->lowerstack[0].dentry : NULL; +} + +struct dentry *ovl_dentry_lower(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + return __ovl_dentry_lower(oe); +} + +struct dentry *ovl_dentry_real(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + struct dentry *realdentry; + + realdentry = ovl_upperdentry_dereference(oe); + if (!realdentry) + realdentry = __ovl_dentry_lower(oe); + + return realdentry; +} + +struct ovl_dir_cache *ovl_dir_cache(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + return oe->cache; +} + +void ovl_set_dir_cache(struct dentry *dentry, struct ovl_dir_cache *cache) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + oe->cache = cache; +} + +bool ovl_dentry_is_opaque(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + return oe->opaque; +} + +bool ovl_dentry_is_whiteout(struct dentry *dentry) +{ + return !dentry->d_inode && ovl_dentry_is_opaque(dentry); +} + +void ovl_dentry_set_opaque(struct dentry *dentry, bool opaque) +{ + struct ovl_entry *oe = dentry->d_fsdata; + oe->opaque = opaque; +} + +void ovl_dentry_update(struct dentry *dentry, struct dentry *upperdentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + WARN_ON(!inode_is_locked(upperdentry->d_parent->d_inode)); + WARN_ON(oe->__upperdentry); + /* + * Make sure upperdentry is consistent before making it visible to + * ovl_upperdentry_dereference(). + */ + smp_wmb(); + oe->__upperdentry = upperdentry; +} + +void ovl_inode_init(struct inode *inode, struct inode *realinode, bool is_upper) +{ + WRITE_ONCE(inode->i_private, (unsigned long) realinode | + (is_upper ? OVL_ISUPPER_MASK : 0)); +} + +void ovl_inode_update(struct inode *inode, struct inode *upperinode) +{ + WARN_ON(!upperinode); + WARN_ON(!inode_unhashed(inode)); + WRITE_ONCE(inode->i_private, + (unsigned long) upperinode | OVL_ISUPPER_MASK); + if (!S_ISDIR(upperinode->i_mode)) + __insert_inode_hash(inode, (unsigned long) upperinode); +} + +void ovl_dentry_version_inc(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + WARN_ON(!inode_is_locked(dentry->d_inode)); + oe->version++; +} + +u64 ovl_dentry_version_get(struct dentry *dentry) +{ + struct ovl_entry *oe = dentry->d_fsdata; + + WARN_ON(!inode_is_locked(dentry->d_inode)); + return oe->version; +} + +bool ovl_is_whiteout(struct dentry *dentry) +{ + struct inode *inode = dentry->d_inode; + + return inode && IS_WHITEOUT(inode); +} + +struct file *ovl_path_open(struct path *path, int flags) +{ + return dentry_open(path, flags | O_NOATIME, current_cred()); +} |