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Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs
Pull overlayfs updates from Miklos Szeredi:
"In addition to bug fixes and cleanups there are two new features from
Amir:
- Consistent inode number support for the case when layers are not
all on the same filesystem (feature is dubbed "xino").
- Optimize overlayfs file handle decoding. This one touches the
exportfs interface to allow detecting the disconnected directory
case"
* 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
ovl: update documentation w.r.t "xino" feature
ovl: add support for "xino" mount and config options
ovl: consistent d_ino for non-samefs with xino
ovl: consistent i_ino for non-samefs with xino
ovl: constant st_ino for non-samefs with xino
ovl: allocate anon bdev per unique lower fs
ovl: factor out ovl_map_dev_ino() helper
ovl: cleanup ovl_update_time()
ovl: add WARN_ON() for non-dir redirect cases
ovl: cleanup setting OVL_INDEX
ovl: set d->is_dir and d->opaque for last path element
ovl: Do not check for redirect if this is last layer
ovl: lookup in inode cache first when decoding lower file handle
ovl: do not try to reconnect a disconnected origin dentry
ovl: disambiguate ovl_encode_fh()
ovl: set lower layer st_dev only if setting lower st_ino
ovl: fix lookup with middle layer opaque dir and absolute path redirects
ovl: Set d->last properly during lookup
ovl: set i_ino to the value of st_ino for NFS export
This commit is contained in:
Linus Torvalds
commit
48023102b7
@ -14,9 +14,13 @@ The result will inevitably fail to look exactly like a normal
|
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filesystem for various technical reasons. The expectation is that
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many use cases will be able to ignore these differences.
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This approach is 'hybrid' because the objects that appear in the
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filesystem do not all appear to belong to that filesystem. In many
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cases an object accessed in the union will be indistinguishable
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Overlay objects
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---------------
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The overlay filesystem approach is 'hybrid', because the objects that
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appear in the filesystem do not always appear to belong to that filesystem.
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In many cases, an object accessed in the union will be indistinguishable
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from accessing the corresponding object from the original filesystem.
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This is most obvious from the 'st_dev' field returned by stat(2).
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@ -34,6 +38,19 @@ make the overlay mount more compliant with filesystem scanners and
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overlay objects will be distinguishable from the corresponding
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objects in the original filesystem.
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On 64bit systems, even if all overlay layers are not on the same
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underlying filesystem, the same compliant behavior could be achieved
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with the "xino" feature. The "xino" feature composes a unique object
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identifier from the real object st_ino and an underlying fsid index.
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If all underlying filesystems support NFS file handles and export file
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handles with 32bit inode number encoding (e.g. ext4), overlay filesystem
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will use the high inode number bits for fsid. Even when the underlying
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filesystem uses 64bit inode numbers, users can still enable the "xino"
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feature with the "-o xino=on" overlay mount option. That is useful for the
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case of underlying filesystems like xfs and tmpfs, which use 64bit inode
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numbers, but are very unlikely to use the high inode number bit.
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Upper and Lower
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---------------
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@ -290,10 +307,19 @@ Non-standard behavior
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---------------------
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The copy_up operation essentially creates a new, identical file and
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moves it over to the old name. The new file may be on a different
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filesystem, so both st_dev and st_ino of the file may change.
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moves it over to the old name. Any open files referring to this inode
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will access the old data.
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Any open files referring to this inode will access the old data.
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The new file may be on a different filesystem, so both st_dev and st_ino
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of the real file may change. The values of st_dev and st_ino returned by
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stat(2) on an overlay object are often not the same as the real file
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stat(2) values to prevent the values from changing on copy_up.
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Unless "xino" feature is enabled, when overlay layers are not all on the
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same underlying filesystem, the value of st_dev may be different for two
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non-directory objects in the same overlay filesystem and the value of
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st_ino for directory objects may be non persistent and could change even
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while the overlay filesystem is still mounted.
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Unless "inode index" feature is enabled, if a file with multiple hard
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links is copied up, then this will "break" the link. Changes will not be
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@ -302,6 +328,7 @@ propagated to other names referring to the same inode.
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Unless "redirect_dir" feature is enabled, rename(2) on a lower or merged
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directory will fail with EXDEV.
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Changes to underlying filesystems
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---------------------------------
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@ -435,6 +435,15 @@ struct dentry *exportfs_decode_fh(struct vfsmount *mnt, struct fid *fid,
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if (IS_ERR_OR_NULL(result))
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return ERR_PTR(-ESTALE);
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/*
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* If no acceptance criteria was specified by caller, a disconnected
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* dentry is also accepatable. Callers may use this mode to query if
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* file handle is stale or to get a reference to an inode without
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* risking the high overhead caused by directory reconnect.
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*/
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if (!acceptable)
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return result;
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if (d_is_dir(result)) {
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/*
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* This request is for a directory.
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@ -86,3 +86,20 @@ config OVERLAY_FS_NFS_EXPORT
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case basis with the "nfs_export=on" mount option.
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Say N unless you fully understand the consequences.
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config OVERLAY_FS_XINO_AUTO
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bool "Overlayfs: auto enable inode number mapping"
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default n
|
||||
depends on OVERLAY_FS
|
||||
help
|
||||
If this config option is enabled then overlay filesystems will use
|
||||
unused high bits in undelying filesystem inode numbers to map all
|
||||
inodes to a unified address space. The mapped 64bit inode numbers
|
||||
might not be compatible with applications that expect 32bit inodes.
|
||||
|
||||
If compatibility with applications that expect 32bit inodes is not an
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||||
issue, then it is safe and recommended to say Y here.
|
||||
|
||||
For more information, see Documentation/filesystems/overlayfs.txt
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||||
|
||||
If unsure, say N.
|
||||
|
||||
@ -232,7 +232,7 @@ int ovl_set_attr(struct dentry *upperdentry, struct kstat *stat)
|
||||
return err;
|
||||
}
|
||||
|
||||
struct ovl_fh *ovl_encode_fh(struct dentry *real, bool is_upper)
|
||||
struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper)
|
||||
{
|
||||
struct ovl_fh *fh;
|
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int fh_type, fh_len, dwords;
|
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@ -300,7 +300,7 @@ int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
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* up and a pure upper inode.
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*/
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if (ovl_can_decode_fh(lower->d_sb)) {
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fh = ovl_encode_fh(lower, false);
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fh = ovl_encode_real_fh(lower, false);
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if (IS_ERR(fh))
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return PTR_ERR(fh);
|
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}
|
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@ -321,7 +321,7 @@ static int ovl_set_upper_fh(struct dentry *upper, struct dentry *index)
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const struct ovl_fh *fh;
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int err;
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||||
fh = ovl_encode_fh(upper, true);
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fh = ovl_encode_real_fh(upper, true);
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if (IS_ERR(fh))
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return PTR_ERR(fh);
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||||
|
||||
|
||||
@ -228,8 +228,8 @@ static int ovl_d_to_fh(struct dentry *dentry, char *buf, int buflen)
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goto fail;
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||||
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||||
/* Encode an upper or lower file handle */
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fh = ovl_encode_fh(enc_lower ? ovl_dentry_lower(dentry) :
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ovl_dentry_upper(dentry), !enc_lower);
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fh = ovl_encode_real_fh(enc_lower ? ovl_dentry_lower(dentry) :
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ovl_dentry_upper(dentry), !enc_lower);
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err = PTR_ERR(fh);
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if (IS_ERR(fh))
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goto fail;
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||||
@ -267,8 +267,8 @@ static int ovl_dentry_to_fh(struct dentry *dentry, u32 *fid, int *max_len)
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||||
return OVL_FILEID;
|
||||
}
|
||||
|
||||
static int ovl_encode_inode_fh(struct inode *inode, u32 *fid, int *max_len,
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||||
struct inode *parent)
|
||||
static int ovl_encode_fh(struct inode *inode, u32 *fid, int *max_len,
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struct inode *parent)
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{
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struct dentry *dentry;
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int type;
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@ -305,15 +305,12 @@ static struct dentry *ovl_obtain_alias(struct super_block *sb,
|
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if (d_is_dir(upper ?: lower))
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return ERR_PTR(-EIO);
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|
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inode = ovl_get_inode(sb, dget(upper), lower, index, !!lower);
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inode = ovl_get_inode(sb, dget(upper), lowerpath, index, !!lower);
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if (IS_ERR(inode)) {
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dput(upper);
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return ERR_CAST(inode);
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}
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if (index)
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ovl_set_flag(OVL_INDEX, inode);
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dentry = d_find_any_alias(inode);
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if (!dentry) {
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dentry = d_alloc_anon(inode->i_sb);
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@ -685,7 +682,7 @@ static struct dentry *ovl_upper_fh_to_d(struct super_block *sb,
|
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if (!ofs->upper_mnt)
|
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return ERR_PTR(-EACCES);
|
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|
||||
upper = ovl_decode_fh(fh, ofs->upper_mnt);
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upper = ovl_decode_real_fh(fh, ofs->upper_mnt, true);
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if (IS_ERR_OR_NULL(upper))
|
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return upper;
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@ -703,25 +700,39 @@ static struct dentry *ovl_lower_fh_to_d(struct super_block *sb,
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struct ovl_path *stack = &origin;
|
||||
struct dentry *dentry = NULL;
|
||||
struct dentry *index = NULL;
|
||||
struct inode *inode = NULL;
|
||||
bool is_deleted = false;
|
||||
struct inode *inode;
|
||||
int err;
|
||||
|
||||
/* First lookup indexed upper by fh */
|
||||
/* First lookup overlay inode in inode cache by origin fh */
|
||||
err = ovl_check_origin_fh(ofs, fh, false, NULL, &stack);
|
||||
if (err)
|
||||
return ERR_PTR(err);
|
||||
|
||||
if (!d_is_dir(origin.dentry) ||
|
||||
!(origin.dentry->d_flags & DCACHE_DISCONNECTED)) {
|
||||
inode = ovl_lookup_inode(sb, origin.dentry, false);
|
||||
err = PTR_ERR(inode);
|
||||
if (IS_ERR(inode))
|
||||
goto out_err;
|
||||
if (inode) {
|
||||
dentry = d_find_any_alias(inode);
|
||||
iput(inode);
|
||||
if (dentry)
|
||||
goto out;
|
||||
}
|
||||
}
|
||||
|
||||
/* Then lookup indexed upper/whiteout by origin fh */
|
||||
if (ofs->indexdir) {
|
||||
index = ovl_get_index_fh(ofs, fh);
|
||||
err = PTR_ERR(index);
|
||||
if (IS_ERR(index)) {
|
||||
if (err != -ESTALE)
|
||||
return ERR_PTR(err);
|
||||
|
||||
/* Found a whiteout index - treat as deleted inode */
|
||||
is_deleted = true;
|
||||
index = NULL;
|
||||
goto out_err;
|
||||
}
|
||||
}
|
||||
|
||||
/* Then try to get upper dir by index */
|
||||
/* Then try to get a connected upper dir by index */
|
||||
if (index && d_is_dir(index)) {
|
||||
struct dentry *upper = ovl_index_upper(ofs, index);
|
||||
|
||||
@ -734,24 +745,19 @@ static struct dentry *ovl_lower_fh_to_d(struct super_block *sb,
|
||||
goto out;
|
||||
}
|
||||
|
||||
/* Then lookup origin by fh */
|
||||
err = ovl_check_origin_fh(ofs, fh, NULL, &stack);
|
||||
if (err) {
|
||||
goto out_err;
|
||||
} else if (index) {
|
||||
/* Otherwise, get a connected non-upper dir or disconnected non-dir */
|
||||
if (d_is_dir(origin.dentry) &&
|
||||
(origin.dentry->d_flags & DCACHE_DISCONNECTED)) {
|
||||
dput(origin.dentry);
|
||||
origin.dentry = NULL;
|
||||
err = ovl_check_origin_fh(ofs, fh, true, NULL, &stack);
|
||||
if (err)
|
||||
goto out_err;
|
||||
}
|
||||
if (index) {
|
||||
err = ovl_verify_origin(index, origin.dentry, false);
|
||||
if (err)
|
||||
goto out_err;
|
||||
} else if (is_deleted) {
|
||||
/* Lookup deleted non-dir by origin inode */
|
||||
if (!d_is_dir(origin.dentry))
|
||||
inode = ovl_lookup_inode(sb, origin.dentry, false);
|
||||
err = -ESTALE;
|
||||
if (!inode || atomic_read(&inode->i_count) == 1)
|
||||
goto out_err;
|
||||
|
||||
/* Deleted but still open? */
|
||||
index = dget(ovl_i_dentry_upper(inode));
|
||||
}
|
||||
|
||||
dentry = ovl_get_dentry(sb, NULL, &origin, index);
|
||||
@ -759,7 +765,6 @@ static struct dentry *ovl_lower_fh_to_d(struct super_block *sb,
|
||||
out:
|
||||
dput(origin.dentry);
|
||||
dput(index);
|
||||
iput(inode);
|
||||
return dentry;
|
||||
|
||||
out_err:
|
||||
@ -829,7 +834,7 @@ static struct dentry *ovl_get_parent(struct dentry *dentry)
|
||||
}
|
||||
|
||||
const struct export_operations ovl_export_operations = {
|
||||
.encode_fh = ovl_encode_inode_fh,
|
||||
.encode_fh = ovl_encode_fh,
|
||||
.fh_to_dentry = ovl_fh_to_dentry,
|
||||
.fh_to_parent = ovl_fh_to_parent,
|
||||
.get_name = ovl_get_name,
|
||||
|
||||
@ -16,13 +16,6 @@
|
||||
#include "overlayfs.h"
|
||||
|
||||
|
||||
static dev_t ovl_get_pseudo_dev(struct dentry *dentry)
|
||||
{
|
||||
struct ovl_entry *oe = dentry->d_fsdata;
|
||||
|
||||
return oe->lowerstack[0].layer->pseudo_dev;
|
||||
}
|
||||
|
||||
int ovl_setattr(struct dentry *dentry, struct iattr *attr)
|
||||
{
|
||||
int err;
|
||||
@ -66,6 +59,69 @@ out:
|
||||
return err;
|
||||
}
|
||||
|
||||
static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat,
|
||||
struct ovl_layer *lower_layer)
|
||||
{
|
||||
bool samefs = ovl_same_sb(dentry->d_sb);
|
||||
unsigned int xinobits = ovl_xino_bits(dentry->d_sb);
|
||||
|
||||
if (samefs) {
|
||||
/*
|
||||
* When all layers are on the same fs, all real inode
|
||||
* number are unique, so we use the overlay st_dev,
|
||||
* which is friendly to du -x.
|
||||
*/
|
||||
stat->dev = dentry->d_sb->s_dev;
|
||||
return 0;
|
||||
} else if (xinobits) {
|
||||
unsigned int shift = 64 - xinobits;
|
||||
/*
|
||||
* All inode numbers of underlying fs should not be using the
|
||||
* high xinobits, so we use high xinobits to partition the
|
||||
* overlay st_ino address space. The high bits holds the fsid
|
||||
* (upper fsid is 0). This way overlay inode numbers are unique
|
||||
* and all inodes use overlay st_dev. Inode numbers are also
|
||||
* persistent for a given layer configuration.
|
||||
*/
|
||||
if (stat->ino >> shift) {
|
||||
pr_warn_ratelimited("overlayfs: inode number too big (%pd2, ino=%llu, xinobits=%d)\n",
|
||||
dentry, stat->ino, xinobits);
|
||||
} else {
|
||||
if (lower_layer)
|
||||
stat->ino |= ((u64)lower_layer->fsid) << shift;
|
||||
|
||||
stat->dev = dentry->d_sb->s_dev;
|
||||
return 0;
|
||||
}
|
||||
}
|
||||
|
||||
/* The inode could not be mapped to a unified st_ino address space */
|
||||
if (S_ISDIR(dentry->d_inode->i_mode)) {
|
||||
/*
|
||||
* Always use the overlay st_dev for directories, so 'find
|
||||
* -xdev' will scan the entire overlay mount and won't cross the
|
||||
* overlay mount boundaries.
|
||||
*
|
||||
* If not all layers are on the same fs the pair {real st_ino;
|
||||
* overlay st_dev} is not unique, so use the non persistent
|
||||
* overlay st_ino for directories.
|
||||
*/
|
||||
stat->dev = dentry->d_sb->s_dev;
|
||||
stat->ino = dentry->d_inode->i_ino;
|
||||
} else if (lower_layer && lower_layer->fsid) {
|
||||
/*
|
||||
* For non-samefs setup, if we cannot map all layers st_ino
|
||||
* to a unified address space, we need to make sure that st_dev
|
||||
* is unique per lower fs. Upper layer uses real st_dev and
|
||||
* lower layers use the unique anonymous bdev assigned to the
|
||||
* lower fs.
|
||||
*/
|
||||
stat->dev = lower_layer->fs->pseudo_dev;
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
int ovl_getattr(const struct path *path, struct kstat *stat,
|
||||
u32 request_mask, unsigned int flags)
|
||||
{
|
||||
@ -75,6 +131,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
|
||||
const struct cred *old_cred;
|
||||
bool is_dir = S_ISDIR(dentry->d_inode->i_mode);
|
||||
bool samefs = ovl_same_sb(dentry->d_sb);
|
||||
struct ovl_layer *lower_layer = NULL;
|
||||
int err;
|
||||
|
||||
type = ovl_path_real(dentry, &realpath);
|
||||
@ -84,14 +141,18 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
|
||||
goto out;
|
||||
|
||||
/*
|
||||
* For non-dir or same fs, we use st_ino of the copy up origin, if we
|
||||
* know it. This guaranties constant st_dev/st_ino across copy up.
|
||||
* For non-dir or same fs, we use st_ino of the copy up origin.
|
||||
* This guaranties constant st_dev/st_ino across copy up.
|
||||
* With xino feature and non-samefs, we use st_ino of the copy up
|
||||
* origin masked with high bits that represent the layer id.
|
||||
*
|
||||
* If filesystem supports NFS export ops, this also guaranties
|
||||
* If lower filesystem supports NFS file handles, this also guaranties
|
||||
* persistent st_ino across mount cycle.
|
||||
*/
|
||||
if (!is_dir || samefs) {
|
||||
if (OVL_TYPE_ORIGIN(type)) {
|
||||
if (!is_dir || samefs || ovl_xino_bits(dentry->d_sb)) {
|
||||
if (!OVL_TYPE_UPPER(type)) {
|
||||
lower_layer = ovl_layer_lower(dentry);
|
||||
} else if (OVL_TYPE_ORIGIN(type)) {
|
||||
struct kstat lowerstat;
|
||||
u32 lowermask = STATX_INO | (!is_dir ? STATX_NLINK : 0);
|
||||
|
||||
@ -118,43 +179,17 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
|
||||
*/
|
||||
if (ovl_test_flag(OVL_INDEX, d_inode(dentry)) ||
|
||||
(!ovl_verify_lower(dentry->d_sb) &&
|
||||
(is_dir || lowerstat.nlink == 1)))
|
||||
(is_dir || lowerstat.nlink == 1))) {
|
||||
stat->ino = lowerstat.ino;
|
||||
|
||||
if (samefs)
|
||||
WARN_ON_ONCE(stat->dev != lowerstat.dev);
|
||||
else
|
||||
stat->dev = ovl_get_pseudo_dev(dentry);
|
||||
lower_layer = ovl_layer_lower(dentry);
|
||||
}
|
||||
}
|
||||
if (samefs) {
|
||||
/*
|
||||
* When all layers are on the same fs, all real inode
|
||||
* number are unique, so we use the overlay st_dev,
|
||||
* which is friendly to du -x.
|
||||
*/
|
||||
stat->dev = dentry->d_sb->s_dev;
|
||||
} else if (!OVL_TYPE_UPPER(type)) {
|
||||
/*
|
||||
* For non-samefs setup, to make sure that st_dev/st_ino
|
||||
* pair is unique across the system, we use a unique
|
||||
* anonymous st_dev for lower layer inode.
|
||||
*/
|
||||
stat->dev = ovl_get_pseudo_dev(dentry);
|
||||
}
|
||||
} else {
|
||||
/*
|
||||
* Always use the overlay st_dev for directories, so 'find
|
||||
* -xdev' will scan the entire overlay mount and won't cross the
|
||||
* overlay mount boundaries.
|
||||
*
|
||||
* If not all layers are on the same fs the pair {real st_ino;
|
||||
* overlay st_dev} is not unique, so use the non persistent
|
||||
* overlay st_ino for directories.
|
||||
*/
|
||||
stat->dev = dentry->d_sb->s_dev;
|
||||
stat->ino = dentry->d_inode->i_ino;
|
||||
}
|
||||
|
||||
err = ovl_map_dev_ino(dentry, stat, lower_layer);
|
||||
if (err)
|
||||
goto out;
|
||||
|
||||
/*
|
||||
* It's probably not worth it to count subdirs to get the
|
||||
* correct link count. nlink=1 seems to pacify 'find' and
|
||||
@ -383,24 +418,18 @@ int ovl_open_maybe_copy_up(struct dentry *dentry, unsigned int file_flags)
|
||||
|
||||
int ovl_update_time(struct inode *inode, struct timespec *ts, int flags)
|
||||
{
|
||||
struct dentry *alias;
|
||||
struct path upperpath;
|
||||
if (flags & S_ATIME) {
|
||||
struct ovl_fs *ofs = inode->i_sb->s_fs_info;
|
||||
struct path upperpath = {
|
||||
.mnt = ofs->upper_mnt,
|
||||
.dentry = ovl_upperdentry_dereference(OVL_I(inode)),
|
||||
};
|
||||
|
||||
if (!(flags & S_ATIME))
|
||||
return 0;
|
||||
|
||||
alias = d_find_any_alias(inode);
|
||||
if (!alias)
|
||||
return 0;
|
||||
|
||||
ovl_path_upper(alias, &upperpath);
|
||||
if (upperpath.dentry) {
|
||||
touch_atime(&upperpath);
|
||||
inode->i_atime = d_inode(upperpath.dentry)->i_atime;
|
||||
if (upperpath.dentry) {
|
||||
touch_atime(&upperpath);
|
||||
inode->i_atime = d_inode(upperpath.dentry)->i_atime;
|
||||
}
|
||||
}
|
||||
|
||||
dput(alias);
|
||||
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -459,9 +488,27 @@ static inline void ovl_lockdep_annotate_inode_mutex_key(struct inode *inode)
|
||||
#endif
|
||||
}
|
||||
|
||||
static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev)
|
||||
static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev,
|
||||
unsigned long ino, int fsid)
|
||||
{
|
||||
inode->i_ino = get_next_ino();
|
||||
int xinobits = ovl_xino_bits(inode->i_sb);
|
||||
|
||||
/*
|
||||
* When NFS export is enabled and d_ino is consistent with st_ino
|
||||
* (samefs or i_ino has enough bits to encode layer), set the same
|
||||
* value used for d_ino to i_ino, because nfsd readdirplus compares
|
||||
* d_ino values to i_ino values of child entries. When called from
|
||||
* ovl_new_inode(), ino arg is 0, so i_ino will be updated to real
|
||||
* upper inode i_ino on ovl_inode_init() or ovl_inode_update().
|
||||
*/
|
||||
if (inode->i_sb->s_export_op &&
|
||||
(ovl_same_sb(inode->i_sb) || xinobits)) {
|
||||
inode->i_ino = ino;
|
||||
if (xinobits && fsid && !(ino >> (64 - xinobits)))
|
||||
inode->i_ino |= (unsigned long)fsid << (64 - xinobits);
|
||||
} else {
|
||||
inode->i_ino = get_next_ino();
|
||||
}
|
||||
inode->i_mode = mode;
|
||||
inode->i_flags |= S_NOCMTIME;
|
||||
#ifdef CONFIG_FS_POSIX_ACL
|
||||
@ -597,7 +644,7 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev)
|
||||
|
||||
inode = new_inode(sb);
|
||||
if (inode)
|
||||
ovl_fill_inode(inode, mode, rdev);
|
||||
ovl_fill_inode(inode, mode, rdev, 0, 0);
|
||||
|
||||
return inode;
|
||||
}
|
||||
@ -703,13 +750,16 @@ static bool ovl_hash_bylower(struct super_block *sb, struct dentry *upper,
|
||||
}
|
||||
|
||||
struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
|
||||
struct dentry *lowerdentry, struct dentry *index,
|
||||
struct ovl_path *lowerpath, struct dentry *index,
|
||||
unsigned int numlower)
|
||||
{
|
||||
struct inode *realinode = upperdentry ? d_inode(upperdentry) : NULL;
|
||||
struct inode *inode;
|
||||
struct dentry *lowerdentry = lowerpath ? lowerpath->dentry : NULL;
|
||||
bool bylower = ovl_hash_bylower(sb, upperdentry, lowerdentry, index);
|
||||
int fsid = bylower ? lowerpath->layer->fsid : 0;
|
||||
bool is_dir;
|
||||
unsigned long ino = 0;
|
||||
|
||||
if (!realinode)
|
||||
realinode = d_inode(lowerdentry);
|
||||
@ -748,18 +798,22 @@ struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
|
||||
if (!is_dir)
|
||||
nlink = ovl_get_nlink(lowerdentry, upperdentry, nlink);
|
||||
set_nlink(inode, nlink);
|
||||
ino = key->i_ino;
|
||||
} else {
|
||||
/* Lower hardlink that will be broken on copy up */
|
||||
inode = new_inode(sb);
|
||||
if (!inode)
|
||||
goto out_nomem;
|
||||
}
|
||||
ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev);
|
||||
ovl_fill_inode(inode, realinode->i_mode, realinode->i_rdev, ino, fsid);
|
||||
ovl_inode_init(inode, upperdentry, lowerdentry);
|
||||
|
||||
if (upperdentry && ovl_is_impuredir(upperdentry))
|
||||
ovl_set_flag(OVL_IMPURE, inode);
|
||||
|
||||
if (index)
|
||||
ovl_set_flag(OVL_INDEX, inode);
|
||||
|
||||
/* Check for non-merge dir that may have whiteouts */
|
||||
if (is_dir) {
|
||||
if (((upperdentry && lowerdentry) || numlower > 1) ||
|
||||
|
||||
@ -56,6 +56,15 @@ static int ovl_check_redirect(struct dentry *dentry, struct ovl_lookup_data *d,
|
||||
if (s == next)
|
||||
goto invalid;
|
||||
}
|
||||
/*
|
||||
* One of the ancestor path elements in an absolute path
|
||||
* lookup in ovl_lookup_layer() could have been opaque and
|
||||
* that will stop further lookup in lower layers (d->stop=true)
|
||||
* But we have found an absolute redirect in decendant path
|
||||
* element and that should force continue lookup in lower
|
||||
* layers (reset d->stop).
|
||||
*/
|
||||
d->stop = false;
|
||||
} else {
|
||||
if (strchr(buf, '/') != NULL)
|
||||
goto invalid;
|
||||
@ -171,7 +180,8 @@ invalid:
|
||||
goto out;
|
||||
}
|
||||
|
||||
struct dentry *ovl_decode_fh(struct ovl_fh *fh, struct vfsmount *mnt)
|
||||
struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
|
||||
bool connected)
|
||||
{
|
||||
struct dentry *real;
|
||||
int bytes;
|
||||
@ -186,7 +196,7 @@ struct dentry *ovl_decode_fh(struct ovl_fh *fh, struct vfsmount *mnt)
|
||||
bytes = (fh->len - offsetof(struct ovl_fh, fid));
|
||||
real = exportfs_decode_fh(mnt, (struct fid *)fh->fid,
|
||||
bytes >> 2, (int)fh->type,
|
||||
ovl_acceptable, mnt);
|
||||
connected ? ovl_acceptable : NULL, mnt);
|
||||
if (IS_ERR(real)) {
|
||||
/*
|
||||
* Treat stale file handle to lower file as "origin unknown".
|
||||
@ -220,6 +230,7 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
|
||||
{
|
||||
struct dentry *this;
|
||||
int err;
|
||||
bool last_element = !post[0];
|
||||
|
||||
this = lookup_one_len_unlocked(name, base, namelen);
|
||||
if (IS_ERR(this)) {
|
||||
@ -245,11 +256,23 @@ static int ovl_lookup_single(struct dentry *base, struct ovl_lookup_data *d,
|
||||
d->stop = true;
|
||||
if (d->is_dir)
|
||||
goto put_and_out;
|
||||
|
||||
/*
|
||||
* NB: handle failure to lookup non-last element when non-dir
|
||||
* redirects become possible
|
||||
*/
|
||||
WARN_ON(!last_element);
|
||||
goto out;
|
||||
}
|
||||
d->is_dir = true;
|
||||
if (!d->last && ovl_is_opaquedir(this)) {
|
||||
d->stop = d->opaque = true;
|
||||
if (last_element)
|
||||
d->is_dir = true;
|
||||
if (d->last)
|
||||
goto out;
|
||||
|
||||
if (ovl_is_opaquedir(this)) {
|
||||
d->stop = true;
|
||||
if (last_element)
|
||||
d->opaque = true;
|
||||
goto out;
|
||||
}
|
||||
err = ovl_check_redirect(this, d, prelen, post);
|
||||
@ -310,14 +333,15 @@ static int ovl_lookup_layer(struct dentry *base, struct ovl_lookup_data *d,
|
||||
}
|
||||
|
||||
|
||||
int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
|
||||
int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
|
||||
struct dentry *upperdentry, struct ovl_path **stackp)
|
||||
{
|
||||
struct dentry *origin = NULL;
|
||||
int i;
|
||||
|
||||
for (i = 0; i < ofs->numlower; i++) {
|
||||
origin = ovl_decode_fh(fh, ofs->lower_layers[i].mnt);
|
||||
origin = ovl_decode_real_fh(fh, ofs->lower_layers[i].mnt,
|
||||
connected);
|
||||
if (origin)
|
||||
break;
|
||||
}
|
||||
@ -361,7 +385,7 @@ static int ovl_check_origin(struct ovl_fs *ofs, struct dentry *upperdentry,
|
||||
if (IS_ERR_OR_NULL(fh))
|
||||
return PTR_ERR(fh);
|
||||
|
||||
err = ovl_check_origin_fh(ofs, fh, upperdentry, stackp);
|
||||
err = ovl_check_origin_fh(ofs, fh, false, upperdentry, stackp);
|
||||
kfree(fh);
|
||||
|
||||
if (err) {
|
||||
@ -415,7 +439,7 @@ int ovl_verify_set_fh(struct dentry *dentry, const char *name,
|
||||
struct ovl_fh *fh;
|
||||
int err;
|
||||
|
||||
fh = ovl_encode_fh(real, is_upper);
|
||||
fh = ovl_encode_real_fh(real, is_upper);
|
||||
err = PTR_ERR(fh);
|
||||
if (IS_ERR(fh))
|
||||
goto fail;
|
||||
@ -451,7 +475,7 @@ struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index)
|
||||
if (IS_ERR_OR_NULL(fh))
|
||||
return ERR_CAST(fh);
|
||||
|
||||
upper = ovl_decode_fh(fh, ofs->upper_mnt);
|
||||
upper = ovl_decode_real_fh(fh, ofs->upper_mnt, true);
|
||||
kfree(fh);
|
||||
|
||||
if (IS_ERR_OR_NULL(upper))
|
||||
@ -558,7 +582,7 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index)
|
||||
|
||||
/* Check if non-dir index is orphan and don't warn before cleaning it */
|
||||
if (!d_is_dir(index) && d_inode(index)->i_nlink == 1) {
|
||||
err = ovl_check_origin_fh(ofs, fh, index, &stack);
|
||||
err = ovl_check_origin_fh(ofs, fh, false, index, &stack);
|
||||
if (err)
|
||||
goto fail;
|
||||
|
||||
@ -619,7 +643,7 @@ int ovl_get_index_name(struct dentry *origin, struct qstr *name)
|
||||
struct ovl_fh *fh;
|
||||
int err;
|
||||
|
||||
fh = ovl_encode_fh(origin, false);
|
||||
fh = ovl_encode_real_fh(origin, false);
|
||||
if (IS_ERR(fh))
|
||||
return PTR_ERR(fh);
|
||||
|
||||
@ -815,7 +839,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
|
||||
.is_dir = false,
|
||||
.opaque = false,
|
||||
.stop = false,
|
||||
.last = !poe->numlower,
|
||||
.last = ofs->config.redirect_follow ? false : !poe->numlower,
|
||||
.redirect = NULL,
|
||||
};
|
||||
|
||||
@ -873,7 +897,11 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
|
||||
for (i = 0; !d.stop && i < poe->numlower; i++) {
|
||||
struct ovl_path lower = poe->lowerstack[i];
|
||||
|
||||
d.last = i == poe->numlower - 1;
|
||||
if (!ofs->config.redirect_follow)
|
||||
d.last = i == poe->numlower - 1;
|
||||
else
|
||||
d.last = lower.layer->idx == roe->numlower;
|
||||
|
||||
err = ovl_lookup_layer(lower.dentry, &d, &this);
|
||||
if (err)
|
||||
goto out_put;
|
||||
@ -976,17 +1004,18 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
|
||||
upperdentry = dget(index);
|
||||
|
||||
if (upperdentry || ctr) {
|
||||
if (ctr)
|
||||
origin = stack[0].dentry;
|
||||
inode = ovl_get_inode(dentry->d_sb, upperdentry, origin, index,
|
||||
inode = ovl_get_inode(dentry->d_sb, upperdentry, stack, index,
|
||||
ctr);
|
||||
err = PTR_ERR(inode);
|
||||
if (IS_ERR(inode))
|
||||
goto out_free_oe;
|
||||
|
||||
/*
|
||||
* NB: handle redirected hard links when non-dir redirects
|
||||
* become possible
|
||||
*/
|
||||
WARN_ON(OVL_I(inode)->redirect);
|
||||
OVL_I(inode)->redirect = upperredirect;
|
||||
if (index)
|
||||
ovl_set_flag(OVL_INDEX, inode);
|
||||
}
|
||||
|
||||
revert_creds(old_cred);
|
||||
|
||||
@ -202,7 +202,7 @@ void ovl_drop_write(struct dentry *dentry);
|
||||
struct dentry *ovl_workdir(struct dentry *dentry);
|
||||
const struct cred *ovl_override_creds(struct super_block *sb);
|
||||
struct super_block *ovl_same_sb(struct super_block *sb);
|
||||
bool ovl_can_decode_fh(struct super_block *sb);
|
||||
int ovl_can_decode_fh(struct super_block *sb);
|
||||
struct dentry *ovl_indexdir(struct super_block *sb);
|
||||
bool ovl_index_all(struct super_block *sb);
|
||||
bool ovl_verify_lower(struct super_block *sb);
|
||||
@ -215,6 +215,7 @@ void ovl_path_lower(struct dentry *dentry, struct path *path);
|
||||
enum ovl_path_type ovl_path_real(struct dentry *dentry, struct path *path);
|
||||
struct dentry *ovl_dentry_upper(struct dentry *dentry);
|
||||
struct dentry *ovl_dentry_lower(struct dentry *dentry);
|
||||
struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
|
||||
struct dentry *ovl_dentry_real(struct dentry *dentry);
|
||||
struct dentry *ovl_i_dentry_upper(struct inode *inode);
|
||||
struct inode *ovl_inode_upper(struct inode *inode);
|
||||
@ -263,11 +264,19 @@ static inline bool ovl_is_impuredir(struct dentry *dentry)
|
||||
return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
|
||||
}
|
||||
|
||||
static inline unsigned int ovl_xino_bits(struct super_block *sb)
|
||||
{
|
||||
struct ovl_fs *ofs = sb->s_fs_info;
|
||||
|
||||
return ofs->xino_bits;
|
||||
}
|
||||
|
||||
|
||||
/* namei.c */
|
||||
int ovl_check_fh_len(struct ovl_fh *fh, int fh_len);
|
||||
struct dentry *ovl_decode_fh(struct ovl_fh *fh, struct vfsmount *mnt);
|
||||
int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh,
|
||||
struct dentry *ovl_decode_real_fh(struct ovl_fh *fh, struct vfsmount *mnt,
|
||||
bool connected);
|
||||
int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
|
||||
struct dentry *upperdentry, struct ovl_path **stackp);
|
||||
int ovl_verify_set_fh(struct dentry *dentry, const char *name,
|
||||
struct dentry *real, bool is_upper, bool set);
|
||||
@ -329,7 +338,7 @@ struct inode *ovl_new_inode(struct super_block *sb, umode_t mode, dev_t rdev);
|
||||
struct inode *ovl_lookup_inode(struct super_block *sb, struct dentry *real,
|
||||
bool is_upper);
|
||||
struct inode *ovl_get_inode(struct super_block *sb, struct dentry *upperdentry,
|
||||
struct dentry *lowerdentry, struct dentry *index,
|
||||
struct ovl_path *lowerpath, struct dentry *index,
|
||||
unsigned int numlower);
|
||||
static inline void ovl_copyattr(struct inode *from, struct inode *to)
|
||||
{
|
||||
@ -361,7 +370,7 @@ int ovl_copy_up(struct dentry *dentry);
|
||||
int ovl_copy_up_flags(struct dentry *dentry, int flags);
|
||||
int ovl_copy_xattr(struct dentry *old, struct dentry *new);
|
||||
int ovl_set_attr(struct dentry *upper, struct kstat *stat);
|
||||
struct ovl_fh *ovl_encode_fh(struct dentry *real, bool is_upper);
|
||||
struct ovl_fh *ovl_encode_real_fh(struct dentry *real, bool is_upper);
|
||||
int ovl_set_origin(struct dentry *dentry, struct dentry *lower,
|
||||
struct dentry *upper);
|
||||
|
||||
|
||||
@ -18,13 +18,21 @@ struct ovl_config {
|
||||
const char *redirect_mode;
|
||||
bool index;
|
||||
bool nfs_export;
|
||||
int xino;
|
||||
};
|
||||
|
||||
struct ovl_sb {
|
||||
struct super_block *sb;
|
||||
dev_t pseudo_dev;
|
||||
};
|
||||
|
||||
struct ovl_layer {
|
||||
struct vfsmount *mnt;
|
||||
dev_t pseudo_dev;
|
||||
/* Index of this layer in fs root (upper == 0) */
|
||||
struct ovl_sb *fs;
|
||||
/* Index of this layer in fs root (upper idx == 0) */
|
||||
int idx;
|
||||
/* One fsid per unique underlying sb (upper fsid == 0) */
|
||||
int fsid;
|
||||
};
|
||||
|
||||
struct ovl_path {
|
||||
@ -35,8 +43,11 @@ struct ovl_path {
|
||||
/* private information held for overlayfs's superblock */
|
||||
struct ovl_fs {
|
||||
struct vfsmount *upper_mnt;
|
||||
unsigned numlower;
|
||||
unsigned int numlower;
|
||||
/* Number of unique lower sb that differ from upper sb */
|
||||
unsigned int numlowerfs;
|
||||
struct ovl_layer *lower_layers;
|
||||
struct ovl_sb *lower_fs;
|
||||
/* workbasedir is the path at workdir= mount option */
|
||||
struct dentry *workbasedir;
|
||||
/* workdir is the 'work' directory under workbasedir */
|
||||
@ -50,11 +61,11 @@ struct ovl_fs {
|
||||
const struct cred *creator_cred;
|
||||
bool tmpfile;
|
||||
bool noxattr;
|
||||
/* sb common to all layers */
|
||||
struct super_block *same_sb;
|
||||
/* Did we take the inuse lock? */
|
||||
bool upperdir_locked;
|
||||
bool workdir_locked;
|
||||
/* Inode numbers in all layers do not use the high xino_bits */
|
||||
unsigned int xino_bits;
|
||||
};
|
||||
|
||||
/* private information held for every overlayfs dentry */
|
||||
|
||||
@ -120,6 +120,10 @@ static bool ovl_calc_d_ino(struct ovl_readdir_data *rdd,
|
||||
if (!rdd->dentry)
|
||||
return false;
|
||||
|
||||
/* Always recalc d_ino when remapping lower inode numbers */
|
||||
if (ovl_xino_bits(rdd->dentry->d_sb))
|
||||
return true;
|
||||
|
||||
/* Always recalc d_ino for parent */
|
||||
if (strcmp(p->name, "..") == 0)
|
||||
return true;
|
||||
@ -435,6 +439,19 @@ static struct ovl_dir_cache *ovl_cache_get(struct dentry *dentry)
|
||||
return cache;
|
||||
}
|
||||
|
||||
/* Map inode number to lower fs unique range */
|
||||
static u64 ovl_remap_lower_ino(u64 ino, int xinobits, int fsid,
|
||||
const char *name, int namelen)
|
||||
{
|
||||
if (ino >> (64 - xinobits)) {
|
||||
pr_warn_ratelimited("overlayfs: d_ino too big (%.*s, ino=%llu, xinobits=%d)\n",
|
||||
namelen, name, ino, xinobits);
|
||||
return ino;
|
||||
}
|
||||
|
||||
return ino | ((u64)fsid) << (64 - xinobits);
|
||||
}
|
||||
|
||||
/*
|
||||
* Set d_ino for upper entries. Non-upper entries should always report
|
||||
* the uppermost real inode ino and should not call this function.
|
||||
@ -452,9 +469,10 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
|
||||
struct dentry *this = NULL;
|
||||
enum ovl_path_type type;
|
||||
u64 ino = p->real_ino;
|
||||
int xinobits = ovl_xino_bits(dir->d_sb);
|
||||
int err = 0;
|
||||
|
||||
if (!ovl_same_sb(dir->d_sb))
|
||||
if (!ovl_same_sb(dir->d_sb) && !xinobits)
|
||||
goto out;
|
||||
|
||||
if (p->name[0] == '.') {
|
||||
@ -491,6 +509,10 @@ get:
|
||||
|
||||
WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
|
||||
ino = stat.ino;
|
||||
} else if (xinobits && !OVL_TYPE_UPPER(type)) {
|
||||
ino = ovl_remap_lower_ino(ino, xinobits,
|
||||
ovl_layer_lower(this)->fsid,
|
||||
p->name, p->len);
|
||||
}
|
||||
|
||||
out:
|
||||
@ -618,6 +640,8 @@ struct ovl_readdir_translate {
|
||||
struct ovl_dir_cache *cache;
|
||||
struct dir_context ctx;
|
||||
u64 parent_ino;
|
||||
int fsid;
|
||||
int xinobits;
|
||||
};
|
||||
|
||||
static int ovl_fill_real(struct dir_context *ctx, const char *name,
|
||||
@ -628,14 +652,17 @@ static int ovl_fill_real(struct dir_context *ctx, const char *name,
|
||||
container_of(ctx, struct ovl_readdir_translate, ctx);
|
||||
struct dir_context *orig_ctx = rdt->orig_ctx;
|
||||
|
||||
if (rdt->parent_ino && strcmp(name, "..") == 0)
|
||||
if (rdt->parent_ino && strcmp(name, "..") == 0) {
|
||||
ino = rdt->parent_ino;
|
||||
else if (rdt->cache) {
|
||||
} else if (rdt->cache) {
|
||||
struct ovl_cache_entry *p;
|
||||
|
||||
p = ovl_cache_entry_find(&rdt->cache->root, name, namelen);
|
||||
if (p)
|
||||
ino = p->ino;
|
||||
} else if (rdt->xinobits) {
|
||||
ino = ovl_remap_lower_ino(ino, rdt->xinobits, rdt->fsid,
|
||||
name, namelen);
|
||||
}
|
||||
|
||||
return orig_ctx->actor(orig_ctx, name, namelen, offset, ino, d_type);
|
||||
@ -646,11 +673,16 @@ static int ovl_iterate_real(struct file *file, struct dir_context *ctx)
|
||||
int err;
|
||||
struct ovl_dir_file *od = file->private_data;
|
||||
struct dentry *dir = file->f_path.dentry;
|
||||
struct ovl_layer *lower_layer = ovl_layer_lower(dir);
|
||||
struct ovl_readdir_translate rdt = {
|
||||
.ctx.actor = ovl_fill_real,
|
||||
.orig_ctx = ctx,
|
||||
.xinobits = ovl_xino_bits(dir->d_sb),
|
||||
};
|
||||
|
||||
if (rdt.xinobits && lower_layer)
|
||||
rdt.fsid = lower_layer->fsid;
|
||||
|
||||
if (OVL_TYPE_MERGE(ovl_path_type(dir->d_parent))) {
|
||||
struct kstat stat;
|
||||
struct path statpath = file->f_path;
|
||||
@ -693,9 +725,10 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
|
||||
* dir is impure then need to adjust d_ino for copied up
|
||||
* entries.
|
||||
*/
|
||||
if (ovl_same_sb(dentry->d_sb) &&
|
||||
(ovl_test_flag(OVL_IMPURE, d_inode(dentry)) ||
|
||||
OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent)))) {
|
||||
if (ovl_xino_bits(dentry->d_sb) ||
|
||||
(ovl_same_sb(dentry->d_sb) &&
|
||||
(ovl_test_flag(OVL_IMPURE, d_inode(dentry)) ||
|
||||
OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) {
|
||||
return ovl_iterate_real(file, ctx);
|
||||
}
|
||||
return iterate_dir(od->realfile, ctx);
|
||||
|
||||
@ -17,6 +17,7 @@
|
||||
#include <linux/statfs.h>
|
||||
#include <linux/seq_file.h>
|
||||
#include <linux/posix_acl_xattr.h>
|
||||
#include <linux/exportfs.h>
|
||||
#include "overlayfs.h"
|
||||
|
||||
MODULE_AUTHOR("Miklos Szeredi <miklos@szeredi.hu>");
|
||||
@ -50,6 +51,11 @@ module_param_named(nfs_export, ovl_nfs_export_def, bool, 0644);
|
||||
MODULE_PARM_DESC(ovl_nfs_export_def,
|
||||
"Default to on or off for the NFS export feature");
|
||||
|
||||
static bool ovl_xino_auto_def = IS_ENABLED(CONFIG_OVERLAY_FS_XINO_AUTO);
|
||||
module_param_named(xino_auto, ovl_xino_auto_def, bool, 0644);
|
||||
MODULE_PARM_DESC(ovl_xino_auto_def,
|
||||
"Auto enable xino feature");
|
||||
|
||||
static void ovl_entry_stack_free(struct ovl_entry *oe)
|
||||
{
|
||||
unsigned int i;
|
||||
@ -236,11 +242,12 @@ static void ovl_free_fs(struct ovl_fs *ofs)
|
||||
if (ofs->upperdir_locked)
|
||||
ovl_inuse_unlock(ofs->upper_mnt->mnt_root);
|
||||
mntput(ofs->upper_mnt);
|
||||
for (i = 0; i < ofs->numlower; i++) {
|
||||
for (i = 0; i < ofs->numlower; i++)
|
||||
mntput(ofs->lower_layers[i].mnt);
|
||||
free_anon_bdev(ofs->lower_layers[i].pseudo_dev);
|
||||
}
|
||||
for (i = 0; i < ofs->numlowerfs; i++)
|
||||
free_anon_bdev(ofs->lower_fs[i].pseudo_dev);
|
||||
kfree(ofs->lower_layers);
|
||||
kfree(ofs->lower_fs);
|
||||
|
||||
kfree(ofs->config.lowerdir);
|
||||
kfree(ofs->config.upperdir);
|
||||
@ -325,6 +332,23 @@ static const char *ovl_redirect_mode_def(void)
|
||||
return ovl_redirect_dir_def ? "on" : "off";
|
||||
}
|
||||
|
||||
enum {
|
||||
OVL_XINO_OFF,
|
||||
OVL_XINO_AUTO,
|
||||
OVL_XINO_ON,
|
||||
};
|
||||
|
||||
static const char * const ovl_xino_str[] = {
|
||||
"off",
|
||||
"auto",
|
||||
"on",
|
||||
};
|
||||
|
||||
static inline int ovl_xino_def(void)
|
||||
{
|
||||
return ovl_xino_auto_def ? OVL_XINO_AUTO : OVL_XINO_OFF;
|
||||
}
|
||||
|
||||
/**
|
||||
* ovl_show_options
|
||||
*
|
||||
@ -350,6 +374,8 @@ static int ovl_show_options(struct seq_file *m, struct dentry *dentry)
|
||||
if (ofs->config.nfs_export != ovl_nfs_export_def)
|
||||
seq_printf(m, ",nfs_export=%s", ofs->config.nfs_export ?
|
||||
"on" : "off");
|
||||
if (ofs->config.xino != ovl_xino_def())
|
||||
seq_printf(m, ",xino=%s", ovl_xino_str[ofs->config.xino]);
|
||||
return 0;
|
||||
}
|
||||
|
||||
@ -384,6 +410,9 @@ enum {
|
||||
OPT_INDEX_OFF,
|
||||
OPT_NFS_EXPORT_ON,
|
||||
OPT_NFS_EXPORT_OFF,
|
||||
OPT_XINO_ON,
|
||||
OPT_XINO_OFF,
|
||||
OPT_XINO_AUTO,
|
||||
OPT_ERR,
|
||||
};
|
||||
|
||||
@ -397,6 +426,9 @@ static const match_table_t ovl_tokens = {
|
||||
{OPT_INDEX_OFF, "index=off"},
|
||||
{OPT_NFS_EXPORT_ON, "nfs_export=on"},
|
||||
{OPT_NFS_EXPORT_OFF, "nfs_export=off"},
|
||||
{OPT_XINO_ON, "xino=on"},
|
||||
{OPT_XINO_OFF, "xino=off"},
|
||||
{OPT_XINO_AUTO, "xino=auto"},
|
||||
{OPT_ERR, NULL}
|
||||
};
|
||||
|
||||
@ -511,6 +543,18 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
|
||||
config->nfs_export = false;
|
||||
break;
|
||||
|
||||
case OPT_XINO_ON:
|
||||
config->xino = OVL_XINO_ON;
|
||||
break;
|
||||
|
||||
case OPT_XINO_OFF:
|
||||
config->xino = OVL_XINO_OFF;
|
||||
break;
|
||||
|
||||
case OPT_XINO_AUTO:
|
||||
config->xino = OVL_XINO_AUTO;
|
||||
break;
|
||||
|
||||
default:
|
||||
pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p);
|
||||
return -EINVAL;
|
||||
@ -700,6 +744,7 @@ static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs,
|
||||
static int ovl_lower_dir(const char *name, struct path *path,
|
||||
struct ovl_fs *ofs, int *stack_depth, bool *remote)
|
||||
{
|
||||
int fh_type;
|
||||
int err;
|
||||
|
||||
err = ovl_mount_dir_noesc(name, path);
|
||||
@ -719,15 +764,19 @@ static int ovl_lower_dir(const char *name, struct path *path,
|
||||
* The inodes index feature and NFS export need to encode and decode
|
||||
* file handles, so they require that all layers support them.
|
||||
*/
|
||||
fh_type = ovl_can_decode_fh(path->dentry->d_sb);
|
||||
if ((ofs->config.nfs_export ||
|
||||
(ofs->config.index && ofs->config.upperdir)) &&
|
||||
!ovl_can_decode_fh(path->dentry->d_sb)) {
|
||||
(ofs->config.index && ofs->config.upperdir)) && !fh_type) {
|
||||
ofs->config.index = false;
|
||||
ofs->config.nfs_export = false;
|
||||
pr_warn("overlayfs: fs on '%s' does not support file handles, falling back to index=off,nfs_export=off.\n",
|
||||
name);
|
||||
}
|
||||
|
||||
/* Check if lower fs has 32bit inode numbers */
|
||||
if (fh_type != FILEID_INO32_GEN)
|
||||
ofs->xino_bits = 0;
|
||||
|
||||
return 0;
|
||||
|
||||
out_put:
|
||||
@ -951,6 +1000,7 @@ static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
|
||||
{
|
||||
struct vfsmount *mnt = ofs->upper_mnt;
|
||||
struct dentry *temp;
|
||||
int fh_type;
|
||||
int err;
|
||||
|
||||
err = mnt_want_write(mnt);
|
||||
@ -1000,12 +1050,16 @@ static int ovl_make_workdir(struct ovl_fs *ofs, struct path *workpath)
|
||||
}
|
||||
|
||||
/* Check if upper/work fs supports file handles */
|
||||
if (ofs->config.index &&
|
||||
!ovl_can_decode_fh(ofs->workdir->d_sb)) {
|
||||
fh_type = ovl_can_decode_fh(ofs->workdir->d_sb);
|
||||
if (ofs->config.index && !fh_type) {
|
||||
ofs->config.index = false;
|
||||
pr_warn("overlayfs: upper fs does not support file handles, falling back to index=off.\n");
|
||||
}
|
||||
|
||||
/* Check if upper fs has 32bit inode numbers */
|
||||
if (fh_type != FILEID_INO32_GEN)
|
||||
ofs->xino_bits = 0;
|
||||
|
||||
/* NFS export of r/w mount depends on index */
|
||||
if (ofs->config.nfs_export && !ofs->config.index) {
|
||||
pr_warn("overlayfs: NFS export requires \"index=on\", falling back to nfs_export=off.\n");
|
||||
@ -1108,6 +1162,35 @@ out:
|
||||
return err;
|
||||
}
|
||||
|
||||
/* Get a unique fsid for the layer */
|
||||
static int ovl_get_fsid(struct ovl_fs *ofs, struct super_block *sb)
|
||||
{
|
||||
unsigned int i;
|
||||
dev_t dev;
|
||||
int err;
|
||||
|
||||
/* fsid 0 is reserved for upper fs even with non upper overlay */
|
||||
if (ofs->upper_mnt && ofs->upper_mnt->mnt_sb == sb)
|
||||
return 0;
|
||||
|
||||
for (i = 0; i < ofs->numlowerfs; i++) {
|
||||
if (ofs->lower_fs[i].sb == sb)
|
||||
return i + 1;
|
||||
}
|
||||
|
||||
err = get_anon_bdev(&dev);
|
||||
if (err) {
|
||||
pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");
|
||||
return err;
|
||||
}
|
||||
|
||||
ofs->lower_fs[ofs->numlowerfs].sb = sb;
|
||||
ofs->lower_fs[ofs->numlowerfs].pseudo_dev = dev;
|
||||
ofs->numlowerfs++;
|
||||
|
||||
return ofs->numlowerfs;
|
||||
}
|
||||
|
||||
static int ovl_get_lower_layers(struct ovl_fs *ofs, struct path *stack,
|
||||
unsigned int numlower)
|
||||
{
|
||||
@ -1119,23 +1202,27 @@ static int ovl_get_lower_layers(struct ovl_fs *ofs, struct path *stack,
|
||||
GFP_KERNEL);
|
||||
if (ofs->lower_layers == NULL)
|
||||
goto out;
|
||||
|
||||
ofs->lower_fs = kcalloc(numlower, sizeof(struct ovl_sb),
|
||||
GFP_KERNEL);
|
||||
if (ofs->lower_fs == NULL)
|
||||
goto out;
|
||||
|
||||
for (i = 0; i < numlower; i++) {
|
||||
struct vfsmount *mnt;
|
||||
dev_t dev;
|
||||
int fsid;
|
||||
|
||||
err = get_anon_bdev(&dev);
|
||||
if (err) {
|
||||
pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");
|
||||
err = fsid = ovl_get_fsid(ofs, stack[i].mnt->mnt_sb);
|
||||
if (err < 0)
|
||||
goto out;
|
||||
}
|
||||
|
||||
mnt = clone_private_mount(&stack[i]);
|
||||
err = PTR_ERR(mnt);
|
||||
if (IS_ERR(mnt)) {
|
||||
pr_err("overlayfs: failed to clone lowerpath\n");
|
||||
free_anon_bdev(dev);
|
||||
goto out;
|
||||
}
|
||||
|
||||
/*
|
||||
* Make lower layers R/O. That way fchmod/fchown on lower file
|
||||
* will fail instead of modifying lower fs.
|
||||
@ -1143,16 +1230,41 @@ static int ovl_get_lower_layers(struct ovl_fs *ofs, struct path *stack,
|
||||
mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;
|
||||
|
||||
ofs->lower_layers[ofs->numlower].mnt = mnt;
|
||||
ofs->lower_layers[ofs->numlower].pseudo_dev = dev;
|
||||
ofs->lower_layers[ofs->numlower].idx = i + 1;
|
||||
ofs->lower_layers[ofs->numlower].fsid = fsid;
|
||||
if (fsid) {
|
||||
ofs->lower_layers[ofs->numlower].fs =
|
||||
&ofs->lower_fs[fsid - 1];
|
||||
}
|
||||
ofs->numlower++;
|
||||
|
||||
/* Check if all lower layers are on same sb */
|
||||
if (i == 0)
|
||||
ofs->same_sb = mnt->mnt_sb;
|
||||
else if (ofs->same_sb != mnt->mnt_sb)
|
||||
ofs->same_sb = NULL;
|
||||
}
|
||||
|
||||
/*
|
||||
* When all layers on same fs, overlay can use real inode numbers.
|
||||
* With mount option "xino=on", mounter declares that there are enough
|
||||
* free high bits in underlying fs to hold the unique fsid.
|
||||
* If overlayfs does encounter underlying inodes using the high xino
|
||||
* bits reserved for fsid, it emits a warning and uses the original
|
||||
* inode number.
|
||||
*/
|
||||
if (!ofs->numlowerfs || (ofs->numlowerfs == 1 && !ofs->upper_mnt)) {
|
||||
ofs->xino_bits = 0;
|
||||
ofs->config.xino = OVL_XINO_OFF;
|
||||
} else if (ofs->config.xino == OVL_XINO_ON && !ofs->xino_bits) {
|
||||
/*
|
||||
* This is a roundup of number of bits needed for numlowerfs+1
|
||||
* (i.e. ilog2(numlowerfs+1 - 1) + 1). fsid 0 is reserved for
|
||||
* upper fs even with non upper overlay.
|
||||
*/
|
||||
BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 31);
|
||||
ofs->xino_bits = ilog2(ofs->numlowerfs) + 1;
|
||||
}
|
||||
|
||||
if (ofs->xino_bits) {
|
||||
pr_info("overlayfs: \"xino\" feature enabled using %d upper inode bits.\n",
|
||||
ofs->xino_bits);
|
||||
}
|
||||
|
||||
err = 0;
|
||||
out:
|
||||
return err;
|
||||
@ -1263,6 +1375,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
|
||||
|
||||
ofs->config.index = ovl_index_def;
|
||||
ofs->config.nfs_export = ovl_nfs_export_def;
|
||||
ofs->config.xino = ovl_xino_def();
|
||||
err = ovl_parse_opt((char *) data, &ofs->config);
|
||||
if (err)
|
||||
goto out_err;
|
||||
@ -1276,6 +1389,10 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
|
||||
|
||||
sb->s_stack_depth = 0;
|
||||
sb->s_maxbytes = MAX_LFS_FILESIZE;
|
||||
/* Assume underlaying fs uses 32bit inodes unless proven otherwise */
|
||||
if (ofs->config.xino != OVL_XINO_OFF)
|
||||
ofs->xino_bits = BITS_PER_LONG - 32;
|
||||
|
||||
if (ofs->config.upperdir) {
|
||||
if (!ofs->config.workdir) {
|
||||
pr_err("overlayfs: missing 'workdir'\n");
|
||||
@ -1305,8 +1422,6 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
|
||||
/* If the upper fs is nonexistent, we mark overlayfs r/o too */
|
||||
if (!ofs->upper_mnt)
|
||||
sb->s_flags |= SB_RDONLY;
|
||||
else if (ofs->upper_mnt->mnt_sb != ofs->same_sb)
|
||||
ofs->same_sb = NULL;
|
||||
|
||||
if (!(ovl_force_readonly(ofs)) && ofs->config.index) {
|
||||
err = ovl_get_indexdir(ofs, oe, &upperpath);
|
||||
|
||||
@ -47,13 +47,29 @@ struct super_block *ovl_same_sb(struct super_block *sb)
|
||||
{
|
||||
struct ovl_fs *ofs = sb->s_fs_info;
|
||||
|
||||
return ofs->same_sb;
|
||||
if (!ofs->numlowerfs)
|
||||
return ofs->upper_mnt->mnt_sb;
|
||||
else if (ofs->numlowerfs == 1 && !ofs->upper_mnt)
|
||||
return ofs->lower_fs[0].sb;
|
||||
else
|
||||
return NULL;
|
||||
}
|
||||
|
||||
bool ovl_can_decode_fh(struct super_block *sb)
|
||||
/*
|
||||
* Check if underlying fs supports file handles and try to determine encoding
|
||||
* type, in order to deduce maximum inode number used by fs.
|
||||
*
|
||||
* Return 0 if file handles are not supported.
|
||||
* Return 1 (FILEID_INO32_GEN) if fs uses the default 32bit inode encoding.
|
||||
* Return -1 if fs uses a non default encoding with unknown inode size.
|
||||
*/
|
||||
int ovl_can_decode_fh(struct super_block *sb)
|
||||
{
|
||||
return (sb->s_export_op && sb->s_export_op->fh_to_dentry &&
|
||||
!uuid_is_null(&sb->s_uuid));
|
||||
if (!sb->s_export_op || !sb->s_export_op->fh_to_dentry ||
|
||||
uuid_is_null(&sb->s_uuid))
|
||||
return 0;
|
||||
|
||||
return sb->s_export_op->encode_fh ? -1 : FILEID_INO32_GEN;
|
||||
}
|
||||
|
||||
struct dentry *ovl_indexdir(struct super_block *sb)
|
||||
@ -172,6 +188,13 @@ struct dentry *ovl_dentry_lower(struct dentry *dentry)
|
||||
return oe->numlower ? oe->lowerstack[0].dentry : NULL;
|
||||
}
|
||||
|
||||
struct ovl_layer *ovl_layer_lower(struct dentry *dentry)
|
||||
{
|
||||
struct ovl_entry *oe = dentry->d_fsdata;
|
||||
|
||||
return oe->numlower ? oe->lowerstack[0].layer : NULL;
|
||||
}
|
||||
|
||||
struct dentry *ovl_dentry_real(struct dentry *dentry)
|
||||
{
|
||||
return ovl_dentry_upper(dentry) ?: ovl_dentry_lower(dentry);
|
||||
@ -279,12 +302,16 @@ void ovl_dentry_set_redirect(struct dentry *dentry, const char *redirect)
|
||||
void ovl_inode_init(struct inode *inode, struct dentry *upperdentry,
|
||||
struct dentry *lowerdentry)
|
||||
{
|
||||
struct inode *realinode = d_inode(upperdentry ?: lowerdentry);
|
||||
|
||||
if (upperdentry)
|
||||
OVL_I(inode)->__upperdentry = upperdentry;
|
||||
if (lowerdentry)
|
||||
OVL_I(inode)->lower = igrab(d_inode(lowerdentry));
|
||||
|
||||
ovl_copyattr(d_inode(upperdentry ?: lowerdentry), inode);
|
||||
ovl_copyattr(realinode, inode);
|
||||
if (!inode->i_ino)
|
||||
inode->i_ino = realinode->i_ino;
|
||||
}
|
||||
|
||||
void ovl_inode_update(struct inode *inode, struct dentry *upperdentry)
|
||||
@ -299,6 +326,8 @@ void ovl_inode_update(struct inode *inode, struct dentry *upperdentry)
|
||||
smp_wmb();
|
||||
OVL_I(inode)->__upperdentry = upperdentry;
|
||||
if (inode_unhashed(inode)) {
|
||||
if (!inode->i_ino)
|
||||
inode->i_ino = upperinode->i_ino;
|
||||
inode->i_private = upperinode;
|
||||
__insert_inode_hash(inode, (unsigned long) upperinode);
|
||||
}
|
||||
|
||||
Loading…
Reference in New Issue
Block a user