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overlayfs update for 5.6 

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Merge tag 'ovl-update-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs update from Miklos Szeredi:

 - Try to preserve holes in sparse files when copying up, thus saving
   disk space and improving performance.

 - Fix a performance regression introduced in v4.19 by preserving
   asynchronicity of IO when fowarding to underlying layers. Add VFS
   helpers to submit async iocbs.

 - Fix a regression in lseek(2) introduced in v4.19 that breaks >2G
   seeks on 32bit kernels.

 - Fix a corner case where st_ino/st_dev was not preserved across copy
   up.

 - Miscellaneous fixes and cleanups.

* tag 'ovl-update-5.6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix lseek overflow on 32bit
  ovl: add splice file read write helper
  ovl: implement async IO routines
  vfs: add vfs_iocb_iter_[read|write] helper functions
  ovl: layer is const
  ovl: fix corner case of non-constant st_dev;st_ino
  ovl: fix corner case of conflicting lower layer uuid
  ovl: generalize the lower_fs[] array
  ovl: simplify ovl_same_sb() helper
  ovl: generalize the lower_layers[] array
  ovl: improving copy-up efficiency for big sparse file
  ovl: use ovl_inode_lock in ovl_llseek()
  ovl: use pr_fmt auto generate prefix
  ovl: fix wrong WARN_ON() in ovl_cache_update_ino()
This commit is contained in:
Linus Torvalds 2020-02-04 11:45:21 +00:00
parent a45ad71e89 a4ac9d45c0
commit 7f879e1a94
13 changed files with 521 additions and 228 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

43
fs/overlayfs/copy_up.c
View File

@ -24,7 +24,7 @@
static int ovl_ccup_set(const char *buf, const struct kernel_param *param)
{
pr_warn("overlayfs: \"check_copy_up\" module option is obsolete\n");
pr_warn("\"check_copy_up\" module option is obsolete\n");
return 0;
}
@ -123,6 +123,9 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
loff_t old_pos = 0;
loff_t new_pos = 0;
loff_t cloned;
loff_t data_pos = -1;
loff_t hole_len;
bool skip_hole = false;
int error = 0;
if (len == 0)
@ -144,7 +147,11 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
goto out;
/* Couldn't clone, so now we try to copy the data */
/* FIXME: copy up sparse files efficiently */
/* Check if lower fs supports seek operation */
if (old_file->f_mode & FMODE_LSEEK &&
old_file->f_op->llseek)
skip_hole = true;
while (len) {
size_t this_len = OVL_COPY_UP_CHUNK_SIZE;
long bytes;
@ -157,6 +164,36 @@ static int ovl_copy_up_data(struct path *old, struct path *new, loff_t len)
break;
}
/*
* Fill zero for hole will cost unnecessary disk space
* and meanwhile slow down the copy-up speed, so we do
* an optimization for hole during copy-up, it relies
* on SEEK_DATA implementation in lower fs so if lower
* fs does not support it, copy-up will behave as before.
*
* Detail logic of hole detection as below:
* When we detect next data position is larger than current
* position we will skip that hole, otherwise we copy
* data in the size of OVL_COPY_UP_CHUNK_SIZE. Actually,
* it may not recognize all kind of holes and sometimes
* only skips partial of hole area. However, it will be
* enough for most of the use cases.
*/
if (skip_hole && data_pos < old_pos) {
data_pos = vfs_llseek(old_file, old_pos, SEEK_DATA);
if (data_pos > old_pos) {
hole_len = data_pos - old_pos;
len -= hole_len;
old_pos = new_pos = data_pos;
continue;
} else if (data_pos == -ENXIO) {
break;
} else if (data_pos < 0) {
skip_hole = false;
}
}
bytes = do_splice_direct(old_file, &old_pos,
new_file, &new_pos,
this_len, SPLICE_F_MOVE);
@ -480,7 +517,7 @@ static int ovl_copy_up_inode(struct ovl_copy_up_ctx *c, struct dentry *temp)
}
inode_lock(temp->d_inode);
if (c->metacopy)
if (S_ISREG(c->stat.mode))
err = ovl_set_size(temp, &c->stat);
if (!err)
err = ovl_set_attr(temp, &c->stat);

10
fs/overlayfs/dir.c
View File

@ -35,7 +35,7 @@ int ovl_cleanup(struct inode *wdir, struct dentry *wdentry)
dput(wdentry);
if (err) {
pr_err("overlayfs: cleanup of '%pd2' failed (%i)\n",
pr_err("cleanup of '%pd2' failed (%i)\n",
wdentry, err);
}
@ -53,7 +53,7 @@ static struct dentry *ovl_lookup_temp(struct dentry *workdir)
temp = lookup_one_len(name, workdir, strlen(name));
if (!IS_ERR(temp) && temp->d_inode) {
pr_err("overlayfs: workdir/%s already exists\n", name);
pr_err("workdir/%s already exists\n", name);
dput(temp);
temp = ERR_PTR(-EIO);
}
@ -134,7 +134,7 @@ static int ovl_mkdir_real(struct inode *dir, struct dentry **newdentry,
d = lookup_one_len(dentry->d_name.name, dentry->d_parent,
dentry->d_name.len);
if (IS_ERR(d)) {
pr_warn("overlayfs: failed lookup after mkdir (%pd2, err=%i).\n",
pr_warn("failed lookup after mkdir (%pd2, err=%i).\n",
dentry, err);
return PTR_ERR(d);
}
@ -267,7 +267,7 @@ static int ovl_instantiate(struct dentry *dentry, struct inode *inode,
d_instantiate(dentry, inode);
if (inode != oip.newinode) {
pr_warn_ratelimited("overlayfs: newly created inode found in cache (%pd2)\n",
pr_warn_ratelimited("newly created inode found in cache (%pd2)\n",
dentry);
}
@ -1009,7 +1009,7 @@ static int ovl_set_redirect(struct dentry *dentry, bool samedir)
spin_unlock(&dentry->d_lock);
} else {
kfree(redirect);
pr_warn_ratelimited("overlayfs: failed to set redirect (%i)\n",
pr_warn_ratelimited("failed to set redirect (%i)\n",
err);
/* Fall back to userspace copy-up */
err = -EXDEV;

28
fs/overlayfs/export.c
View File

@ -30,7 +30,7 @@ static int ovl_encode_maybe_copy_up(struct dentry *dentry)
}
if (err) {
pr_warn_ratelimited("overlayfs: failed to copy up on encode (%pd2, err=%i)\n",
pr_warn_ratelimited("failed to copy up on encode (%pd2, err=%i)\n",
dentry, err);
}
@ -244,7 +244,7 @@ static int ovl_dentry_to_fid(struct dentry *dentry, u32 *fid, int buflen)
return err;
fail:
pr_warn_ratelimited("overlayfs: failed to encode file handle (%pd2, err=%i, buflen=%d, len=%d, type=%d)\n",
pr_warn_ratelimited("failed to encode file handle (%pd2, err=%i, buflen=%d, len=%d, type=%d)\n",
dentry, err, buflen, fh ? (int)fh->fb.len : 0,
fh ? fh->fb.type : 0);
goto out;
@ -358,7 +358,7 @@ static struct dentry *ovl_dentry_real_at(struct dentry *dentry, int idx)
*/
static struct dentry *ovl_lookup_real_one(struct dentry *connected,
struct dentry *real,
struct ovl_layer *layer)
const struct ovl_layer *layer)
{
struct inode *dir = d_inode(connected);
struct dentry *this, *parent = NULL;
@ -406,7 +406,7 @@ static struct dentry *ovl_lookup_real_one(struct dentry *connected,
return this;
fail:
pr_warn_ratelimited("overlayfs: failed to lookup one by real (%pd2, layer=%d, connected=%pd2, err=%i)\n",
pr_warn_ratelimited("failed to lookup one by real (%pd2, layer=%d, connected=%pd2, err=%i)\n",
real, layer->idx, connected, err);
this = ERR_PTR(err);
goto out;
@ -414,17 +414,16 @@ static struct dentry *ovl_lookup_real_one(struct dentry *connected,
static struct dentry *ovl_lookup_real(struct super_block *sb,
struct dentry *real,
struct ovl_layer *layer);
const struct ovl_layer *layer);
/*
* Lookup an indexed or hashed overlay dentry by real inode.
*/
static struct dentry *ovl_lookup_real_inode(struct super_block *sb,
struct dentry *real,
struct ovl_layer *layer)
const struct ovl_layer *layer)
{
struct ovl_fs *ofs = sb->s_fs_info;
struct ovl_layer upper_layer = { .mnt = ofs->upper_mnt };
struct dentry *index = NULL;
struct dentry *this = NULL;
struct inode *inode;
@ -466,7 +465,7 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb,
* recursive call walks back from indexed upper to the topmost
* connected/hashed upper parent (or up to root).
*/
this = ovl_lookup_real(sb, upper, &upper_layer);
this = ovl_lookup_real(sb, upper, &ofs->layers[0]);
dput(upper);
}
@ -487,7 +486,7 @@ static struct dentry *ovl_lookup_real_inode(struct super_block *sb,
*/
static struct dentry *ovl_lookup_real_ancestor(struct super_block *sb,
struct dentry *real,
struct ovl_layer *layer)
const struct ovl_layer *layer)
{
struct dentry *next, *parent = NULL;
struct dentry *ancestor = ERR_PTR(-EIO);
@ -540,7 +539,7 @@ static struct dentry *ovl_lookup_real_ancestor(struct super_block *sb,
*/
static struct dentry *ovl_lookup_real(struct super_block *sb,
struct dentry *real,
struct ovl_layer *layer)
const struct ovl_layer *layer)
{
struct dentry *connected;
int err = 0;
@ -631,7 +630,7 @@ static struct dentry *ovl_lookup_real(struct super_block *sb,
return connected;
fail:
pr_warn_ratelimited("overlayfs: failed to lookup by real (%pd2, layer=%d, connected=%pd2, err=%i)\n",
pr_warn_ratelimited("failed to lookup by real (%pd2, layer=%d, connected=%pd2, err=%i)\n",
real, layer->idx, connected, err);
dput(connected);
return ERR_PTR(err);
@ -646,8 +645,7 @@ static struct dentry *ovl_get_dentry(struct super_block *sb,
struct dentry *index)
{
struct ovl_fs *ofs = sb->s_fs_info;
struct ovl_layer upper_layer = { .mnt = ofs->upper_mnt };
struct ovl_layer *layer = upper ? &upper_layer : lowerpath->layer;
const struct ovl_layer *layer = upper ? &ofs->layers[0] : lowerpath->layer;
struct dentry *real = upper ?: (index ?: lowerpath->dentry);
/*
@ -822,7 +820,7 @@ static struct dentry *ovl_fh_to_dentry(struct super_block *sb, struct fid *fid,
return dentry;
out_err:
pr_warn_ratelimited("overlayfs: failed to decode file handle (len=%d, type=%d, flags=%x, err=%i)\n",
pr_warn_ratelimited("failed to decode file handle (len=%d, type=%d, flags=%x, err=%i)\n",
fh_len, fh_type, flags, err);
dentry = ERR_PTR(err);
goto out;
@ -831,7 +829,7 @@ static struct dentry *ovl_fh_to_dentry(struct super_block *sb, struct fid *fid,
static struct dentry *ovl_fh_to_parent(struct super_block *sb, struct fid *fid,
int fh_len, int fh_type)
{
pr_warn_ratelimited("overlayfs: connectable file handles not supported; use 'no_subtree_check' exportfs option.\n");
pr_warn_ratelimited("connectable file handles not supported; use 'no_subtree_check' exportfs option.\n");
return ERR_PTR(-EACCES);
}

162
fs/overlayfs/file.c
View File

@ -9,8 +9,19 @@
#include <linux/xattr.h>
#include <linux/uio.h>
#include <linux/uaccess.h>
#include <linux/splice.h>
#include <linux/mm.h>
#include <linux/fs.h>
#include "overlayfs.h"
struct ovl_aio_req {
struct kiocb iocb;
struct kiocb *orig_iocb;
struct fd fd;
};
static struct kmem_cache *ovl_aio_request_cachep;
static char ovl_whatisit(struct inode *inode, struct inode *realinode)
{
if (realinode != ovl_inode_upper(inode))
@ -146,7 +157,7 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
struct inode *inode = file_inode(file);
struct fd real;
const struct cred *old_cred;
ssize_t ret;
loff_t ret;
/*
* The two special cases below do not need to involve real fs,
@ -171,7 +182,7 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
* limitations that are more strict than ->s_maxbytes for specific
* files, so we use the real file to perform seeks.
*/
inode_lock(inode);
ovl_inode_lock(inode);
real.file->f_pos = file->f_pos;
old_cred = ovl_override_creds(inode->i_sb);
@ -179,7 +190,7 @@ static loff_t ovl_llseek(struct file *file, loff_t offset, int whence)
revert_creds(old_cred);
file->f_pos = real.file->f_pos;
inode_unlock(inode);
ovl_inode_unlock(inode);
fdput(real);
@ -225,6 +236,33 @@ static rwf_t ovl_iocb_to_rwf(struct kiocb *iocb)
return flags;
}
static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req)
{
struct kiocb *iocb = &aio_req->iocb;
struct kiocb *orig_iocb = aio_req->orig_iocb;
if (iocb->ki_flags & IOCB_WRITE) {
struct inode *inode = file_inode(orig_iocb->ki_filp);
file_end_write(iocb->ki_filp);
ovl_copyattr(ovl_inode_real(inode), inode);
}
orig_iocb->ki_pos = iocb->ki_pos;
fdput(aio_req->fd);
kmem_cache_free(ovl_aio_request_cachep, aio_req);
}
static void ovl_aio_rw_complete(struct kiocb *iocb, long res, long res2)
{
struct ovl_aio_req *aio_req = container_of(iocb,
struct ovl_aio_req, iocb);
struct kiocb *orig_iocb = aio_req->orig_iocb;
ovl_aio_cleanup_handler(aio_req);
orig_iocb->ki_complete(orig_iocb, res, res2);
}
static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
@ -240,10 +278,28 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
return ret;
old_cred = ovl_override_creds(file_inode(file)->i_sb);
ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
ovl_iocb_to_rwf(iocb));
revert_creds(old_cred);
if (is_sync_kiocb(iocb)) {
ret = vfs_iter_read(real.file, iter, &iocb->ki_pos,
ovl_iocb_to_rwf(iocb));
} else {
struct ovl_aio_req *aio_req;
ret = -ENOMEM;
aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
if (!aio_req)
goto out;
aio_req->fd = real;
real.flags = 0;
aio_req->orig_iocb = iocb;
kiocb_clone(&aio_req->iocb, iocb, real.file);
aio_req->iocb.ki_complete = ovl_aio_rw_complete;
ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter);
if (ret != -EIOCBQUEUED)
ovl_aio_cleanup_handler(aio_req);
}
out:
revert_creds(old_cred);
ovl_file_accessed(file);
fdput(real);
@ -274,15 +330,33 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
goto out_unlock;
old_cred = ovl_override_creds(file_inode(file)->i_sb);
file_start_write(real.file);
ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
ovl_iocb_to_rwf(iocb));
file_end_write(real.file);
if (is_sync_kiocb(iocb)) {
file_start_write(real.file);
ret = vfs_iter_write(real.file, iter, &iocb->ki_pos,
ovl_iocb_to_rwf(iocb));
file_end_write(real.file);
/* Update size */
ovl_copyattr(ovl_inode_real(inode), inode);
} else {
struct ovl_aio_req *aio_req;
ret = -ENOMEM;
aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
if (!aio_req)
goto out;
file_start_write(real.file);
aio_req->fd = real;
real.flags = 0;
aio_req->orig_iocb = iocb;
kiocb_clone(&aio_req->iocb, iocb, real.file);
aio_req->iocb.ki_complete = ovl_aio_rw_complete;
ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter);
if (ret != -EIOCBQUEUED)
ovl_aio_cleanup_handler(aio_req);
}
out:
revert_creds(old_cred);
/* Update size */
ovl_copyattr(ovl_inode_real(inode), inode);
fdput(real);
out_unlock:
@ -291,6 +365,48 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
return ret;
}
static ssize_t ovl_splice_read(struct file *in, loff_t *ppos,
struct pipe_inode_info *pipe, size_t len,
unsigned int flags)
{
ssize_t ret;
struct fd real;
const struct cred *old_cred;
ret = ovl_real_fdget(in, &real);
if (ret)
return ret;
old_cred = ovl_override_creds(file_inode(in)->i_sb);
ret = generic_file_splice_read(real.file, ppos, pipe, len, flags);
revert_creds(old_cred);
ovl_file_accessed(in);
fdput(real);
return ret;
}
static ssize_t
ovl_splice_write(struct pipe_inode_info *pipe, struct file *out,
loff_t *ppos, size_t len, unsigned int flags)
{
struct fd real;
const struct cred *old_cred;
ssize_t ret;
ret = ovl_real_fdget(out, &real);
if (ret)
return ret;
old_cred = ovl_override_creds(file_inode(out)->i_sb);
ret = iter_file_splice_write(pipe, real.file, ppos, len, flags);
revert_creds(old_cred);
ovl_file_accessed(out);
fdput(real);
return ret;
}
static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
{
struct fd real;
@ -647,7 +763,25 @@ const struct file_operations ovl_file_operations = {
.fadvise = ovl_fadvise,
.unlocked_ioctl = ovl_ioctl,
.compat_ioctl = ovl_compat_ioctl,
.splice_read = ovl_splice_read,
.splice_write = ovl_splice_write,
.copy_file_range = ovl_copy_file_range,
.remap_file_range = ovl_remap_file_range,
};
int __init ovl_aio_request_cache_init(void)
{
ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req",
sizeof(struct ovl_aio_req),
0, SLAB_HWCACHE_ALIGN, NULL);
if (!ovl_aio_request_cachep)
return -ENOMEM;
return 0;
}
void ovl_aio_request_cache_destroy(void)
{
kmem_cache_destroy(ovl_aio_request_cachep);
}

66
fs/overlayfs/inode.c
View File

@ -75,10 +75,9 @@ int ovl_setattr(struct dentry *dentry, struct iattr *attr)
return err;
}
static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat,
struct ovl_layer *lower_layer)
static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat, int fsid)
{
bool samefs = ovl_same_sb(dentry->d_sb);
bool samefs = ovl_same_fs(dentry->d_sb);
unsigned int xinobits = ovl_xino_bits(dentry->d_sb);
if (samefs) {
@ -100,12 +99,10 @@ static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat,
* persistent for a given layer configuration.
*/
if (stat->ino >> shift) {
pr_warn_ratelimited("overlayfs: inode number too big (%pd2, ino=%llu, xinobits=%d)\n",
pr_warn_ratelimited("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->ino |= ((u64)fsid) << shift;
stat->dev = dentry->d_sb->s_dev;
return 0;
}
@ -124,15 +121,14 @@ static int ovl_map_dev_ino(struct dentry *dentry, struct kstat *stat,
*/
stat->dev = dentry->d_sb->s_dev;
stat->ino = dentry->d_inode->i_ino;
} else if (lower_layer && lower_layer->fsid) {
} else {
/*
* 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.
* is unique per underlying fs, so we use the unique anonymous
* bdev assigned to the underlying fs.
*/
stat->dev = lower_layer->fs->pseudo_dev;
stat->dev = OVL_FS(dentry->d_sb)->fs[fsid].pseudo_dev;
}
return 0;
@ -146,8 +142,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
struct path realpath;
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 fsid = 0;
int err;
bool metacopy_blocks = false;
@ -168,9 +163,9 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
* If lower filesystem supports NFS file handles, this also guaranties
* persistent st_ino across mount cycle.
*/
if (!is_dir || samefs || ovl_xino_bits(dentry->d_sb)) {
if (!is_dir || ovl_same_dev(dentry->d_sb)) {
if (!OVL_TYPE_UPPER(type)) {
lower_layer = ovl_layer_lower(dentry);
fsid = ovl_layer_lower(dentry)->fsid;
} else if (OVL_TYPE_ORIGIN(type)) {
struct kstat lowerstat;
u32 lowermask = STATX_INO | STATX_BLOCKS |
@ -200,14 +195,8 @@ 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))) {
lower_layer = ovl_layer_lower(dentry);
/*
* Cannot use origin st_dev;st_ino because
* origin inode content may differ from overlay
* inode content.
*/
if (samefs || lower_layer->fsid)
stat->ino = lowerstat.ino;
fsid = ovl_layer_lower(dentry)->fsid;
stat->ino = lowerstat.ino;
}
/*
@ -241,7 +230,7 @@ int ovl_getattr(const struct path *path, struct kstat *stat,
}
}
err = ovl_map_dev_ino(dentry, stat, lower_layer);
err = ovl_map_dev_ino(dentry, stat, fsid);
if (err)
goto out;
@ -527,6 +516,27 @@ static const struct address_space_operations ovl_aops = {
* [...] &ovl_i_mutex_dir_key[depth] (stack_depth=2)
* [...] &ovl_i_mutex_dir_key[depth]#2 (stack_depth=1)
* [...] &type->i_mutex_dir_key (stack_depth=0)
*
* Locking order w.r.t ovl_want_write() is important for nested overlayfs.
*
* This chain is valid:
* - inode->i_rwsem (inode_lock[2])
* - upper_mnt->mnt_sb->s_writers (ovl_want_write[0])
* - OVL_I(inode)->lock (ovl_inode_lock[2])
* - OVL_I(lowerinode)->lock (ovl_inode_lock[1])
*
* And this chain is valid:
* - inode->i_rwsem (inode_lock[2])
* - OVL_I(inode)->lock (ovl_inode_lock[2])
* - lowerinode->i_rwsem (inode_lock[1])
* - OVL_I(lowerinode)->lock (ovl_inode_lock[1])
*
* But lowerinode->i_rwsem SHOULD NOT be acquired while ovl_want_write() is
* held, because it is in reverse order of the non-nested case using the same
* upper fs:
* - inode->i_rwsem (inode_lock[1])
* - upper_mnt->mnt_sb->s_writers (ovl_want_write[0])
* - OVL_I(inode)->lock (ovl_inode_lock[1])
*/
#define OVL_MAX_NESTING FILESYSTEM_MAX_STACK_DEPTH
@ -565,7 +575,7 @@ static void ovl_fill_inode(struct inode *inode, umode_t mode, dev_t rdev,
* 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 (ovl_same_sb(inode->i_sb) || xinobits) {
if (ovl_same_dev(inode->i_sb)) {
inode->i_ino = ino;
if (xinobits && fsid && !(ino >> (64 - xinobits)))
inode->i_ino |= (unsigned long)fsid << (64 - xinobits);
@ -698,7 +708,7 @@ unsigned int ovl_get_nlink(struct dentry *lowerdentry,
return nlink;
fail:
pr_warn_ratelimited("overlayfs: failed to get index nlink (%pd2, err=%i)\n",
pr_warn_ratelimited("failed to get index nlink (%pd2, err=%i)\n",
upperdentry, err);
return fallback;
}
@ -969,7 +979,7 @@ struct inode *ovl_get_inode(struct super_block *sb,
return inode;
out_err:
pr_warn_ratelimited("overlayfs: failed to get inode (%i)\n", err);
pr_warn_ratelimited("failed to get inode (%i)\n", err);
inode = ERR_PTR(err);
goto out;
}

38
fs/overlayfs/namei.c
View File

@ -141,10 +141,10 @@ static struct ovl_fh *ovl_get_fh(struct dentry *dentry, const char *name)
return NULL;
fail:
pr_warn_ratelimited("overlayfs: failed to get origin (%i)\n", res);
pr_warn_ratelimited("failed to get origin (%i)\n", res);
goto out;
invalid:
pr_warn_ratelimited("overlayfs: invalid origin (%*phN)\n", res, fh);
pr_warn_ratelimited("invalid origin (%*phN)\n", res, fh);
goto out;
}
@ -322,16 +322,16 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
struct dentry *origin = NULL;
int i;
for (i = 0; i < ofs->numlower; i++) {
for (i = 1; i < ofs->numlayer; i++) {
/*
* If lower fs uuid is not unique among lower fs we cannot match
* fh->uuid to layer.
*/
if (ofs->lower_layers[i].fsid &&
ofs->lower_layers[i].fs->bad_uuid)
if (ofs->layers[i].fsid &&
ofs->layers[i].fs->bad_uuid)
continue;
origin = ovl_decode_real_fh(fh, ofs->lower_layers[i].mnt,
origin = ovl_decode_real_fh(fh, ofs->layers[i].mnt,
connected);
if (origin)
break;
@ -354,13 +354,13 @@ int ovl_check_origin_fh(struct ovl_fs *ofs, struct ovl_fh *fh, bool connected,
}
**stackp = (struct ovl_path){
.dentry = origin,
.layer = &ofs->lower_layers[i]
.layer = &ofs->layers[i]
};
return 0;
invalid:
pr_warn_ratelimited("overlayfs: invalid origin (%pd2, ftype=%x, origin ftype=%x).\n",
pr_warn_ratelimited("invalid origin (%pd2, ftype=%x, origin ftype=%x).\n",
upperdentry, d_inode(upperdentry)->i_mode & S_IFMT,
d_inode(origin)->i_mode & S_IFMT);
dput(origin);
@ -449,7 +449,7 @@ int ovl_verify_set_fh(struct dentry *dentry, const char *name,
fail:
inode = d_inode(real);
pr_warn_ratelimited("overlayfs: failed to verify %s (%pd2, ino=%lu, err=%i)\n",
pr_warn_ratelimited("failed to verify %s (%pd2, ino=%lu, err=%i)\n",
is_upper ? "upper" : "origin", real,
inode ? inode->i_ino : 0, err);
goto out;
@ -475,7 +475,7 @@ struct dentry *ovl_index_upper(struct ovl_fs *ofs, struct dentry *index)
return upper ?: ERR_PTR(-ESTALE);
if (!d_is_dir(upper)) {
pr_warn_ratelimited("overlayfs: invalid index upper (%pd2, upper=%pd2).\n",
pr_warn_ratelimited("invalid index upper (%pd2, upper=%pd2).\n",
index, upper);
dput(upper);
return ERR_PTR(-EIO);
@ -589,12 +589,12 @@ int ovl_verify_index(struct ovl_fs *ofs, struct dentry *index)
return err;
fail:
pr_warn_ratelimited("overlayfs: failed to verify index (%pd2, ftype=%x, err=%i)\n",
pr_warn_ratelimited("failed to verify index (%pd2, ftype=%x, err=%i)\n",
index, d_inode(index)->i_mode & S_IFMT, err);
goto out;
orphan:
pr_warn_ratelimited("overlayfs: orphan index entry (%pd2, ftype=%x, nlink=%u)\n",
pr_warn_ratelimited("orphan index entry (%pd2, ftype=%x, nlink=%u)\n",
index, d_inode(index)->i_mode & S_IFMT,
d_inode(index)->i_nlink);
err = -ENOENT;
@ -696,7 +696,7 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
index = NULL;
goto out;
}
pr_warn_ratelimited("overlayfs: failed inode index lookup (ino=%lu, key=%.*s, err=%i);\n"
pr_warn_ratelimited("failed inode index lookup (ino=%lu, key=%.*s, err=%i);\n"
"overlayfs: mount with '-o index=off' to disable inodes index.\n",
d_inode(origin)->i_ino, name.len, name.name,
err);
@ -723,13 +723,13 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
* unlinked, which means that finding a lower origin on lookup
* whose index is a whiteout should be treated as an error.
*/
pr_warn_ratelimited("overlayfs: bad index found (index=%pd2, ftype=%x, origin ftype=%x).\n",
pr_warn_ratelimited("bad index found (index=%pd2, ftype=%x, origin ftype=%x).\n",
index, d_inode(index)->i_mode & S_IFMT,
d_inode(origin)->i_mode & S_IFMT);
goto fail;
} else if (is_dir && verify) {
if (!upper) {
pr_warn_ratelimited("overlayfs: suspected uncovered redirected dir found (origin=%pd2, index=%pd2).\n",
pr_warn_ratelimited("suspected uncovered redirected dir found (origin=%pd2, index=%pd2).\n",
origin, index);
goto fail;
}
@ -738,7 +738,7 @@ struct dentry *ovl_lookup_index(struct ovl_fs *ofs, struct dentry *upper,
err = ovl_verify_upper(index, upper, false);
if (err) {
if (err == -ESTALE) {
pr_warn_ratelimited("overlayfs: suspected multiply redirected dir found (upper=%pd2, origin=%pd2, index=%pd2).\n",
pr_warn_ratelimited("suspected multiply redirected dir found (upper=%pd2, origin=%pd2, index=%pd2).\n",
upper, origin, index);
}
goto fail;
@ -885,7 +885,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
if (!d.stop && poe->numlower) {
err = -ENOMEM;
stack = kcalloc(ofs->numlower, sizeof(struct ovl_path),
stack = kcalloc(ofs->numlayer - 1, sizeof(struct ovl_path),
GFP_KERNEL);
if (!stack)
goto out_put_upper;
@ -967,7 +967,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
*/
err = -EPERM;
if (d.redirect && !ofs->config.redirect_follow) {
pr_warn_ratelimited("overlayfs: refusing to follow redirect for (%pd2)\n",
pr_warn_ratelimited("refusing to follow redirect for (%pd2)\n",
dentry);
goto out_put;
}
@ -994,7 +994,7 @@ struct dentry *ovl_lookup(struct inode *dir, struct dentry *dentry,
err = -EPERM;
if (!ofs->config.metacopy) {
pr_warn_ratelimited("overlay: refusing to follow metacopy origin for (%pd2)\n",
pr_warn_ratelimited("refusing to follow metacopy origin for (%pd2)\n",
dentry);
goto out_put;
}

24
fs/overlayfs/overlayfs.h
View File

@ -9,6 +9,9 @@
#include <linux/fs.h>
#include "ovl_entry.h"
#undef pr_fmt
#define pr_fmt(fmt) "overlayfs: " fmt
enum ovl_path_type {
__OVL_PATH_UPPER = (1 << 0),
__OVL_PATH_MERGE = (1 << 1),
@ -221,7 +224,6 @@ int ovl_want_write(struct dentry *dentry);
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);
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);
@ -237,7 +239,7 @@ 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 dentry *ovl_dentry_lowerdata(struct dentry *dentry);
struct ovl_layer *ovl_layer_lower(struct dentry *dentry);
const 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);
@ -299,11 +301,21 @@ static inline bool ovl_is_impuredir(struct dentry *dentry)
return ovl_check_dir_xattr(dentry, OVL_XATTR_IMPURE);
}
/* All layers on same fs? */
static inline bool ovl_same_fs(struct super_block *sb)
{
return OVL_FS(sb)->xino_mode == 0;
}
/* All overlay inodes have same st_dev? */
static inline bool ovl_same_dev(struct super_block *sb)
{
return OVL_FS(sb)->xino_mode >= 0;
}
static inline unsigned int ovl_xino_bits(struct super_block *sb)
{
struct ovl_fs *ofs = sb->s_fs_info;
return ofs->xino_bits;
return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0;
}
static inline int ovl_inode_lock(struct inode *inode)
@ -438,6 +450,8 @@ struct dentry *ovl_create_temp(struct dentry *workdir, struct ovl_cattr *attr);
/* file.c */
extern const struct file_operations ovl_file_operations;
int __init ovl_aio_request_cache_init(void);
void ovl_aio_request_cache_destroy(void);
/* copy_up.c */
int ovl_copy_up(struct dentry *dentry);

23
fs/overlayfs/ovl_entry.h
View File

@ -24,6 +24,8 @@ struct ovl_sb {
dev_t pseudo_dev;
/* Unusable (conflicting) uuid */
bool bad_uuid;
/* Used as a lower layer (but maybe also as upper) */
bool is_lower;
};
struct ovl_layer {
@ -38,18 +40,18 @@ struct ovl_layer {
};
struct ovl_path {
struct ovl_layer *layer;
const struct ovl_layer *layer;
struct dentry *dentry;
};
/* private information held for overlayfs's superblock */
struct ovl_fs {
struct vfsmount *upper_mnt;
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;
unsigned int numlayer;
/* Number of unique fs among layers including upper fs */
unsigned int numfs;
const struct ovl_layer *layers;
struct ovl_sb *fs;
/* workbasedir is the path at workdir= mount option */
struct dentry *workbasedir;
/* workdir is the 'work' directory under workbasedir */
@ -71,10 +73,15 @@ struct ovl_fs {
struct inode *workbasedir_trap;
struct inode *workdir_trap;
struct inode *indexdir_trap;
/* Inode numbers in all layers do not use the high xino_bits */
unsigned int xino_bits;
/* -1: disabled, 0: same fs, 1..32: number of unused ino bits */
int xino_mode;
};
static inline struct ovl_fs *OVL_FS(struct super_block *sb)
{
return (struct ovl_fs *)sb->s_fs_info;
}
/* private information held for every overlayfs dentry */
struct ovl_entry {
union {

22
fs/overlayfs/readdir.c
View File

@ -441,7 +441,7 @@ 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",
pr_warn_ratelimited("d_ino too big (%.*s, ino=%llu, xinobits=%d)\n",
namelen, name, ino, xinobits);
return ino;
}
@ -469,7 +469,7 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
int xinobits = ovl_xino_bits(dir->d_sb);
int err = 0;
if (!ovl_same_sb(dir->d_sb) && !xinobits)
if (!ovl_same_dev(dir->d_sb))
goto out;
if (p->name[0] == '.') {
@ -504,7 +504,13 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
if (err)
goto fail;
WARN_ON_ONCE(dir->d_sb->s_dev != stat.dev);
/*
* Directory inode is always on overlay st_dev.
* Non-dir with ovl_same_dev() could be on pseudo st_dev in case
* of xino bits overflow.
*/
WARN_ON_ONCE(S_ISDIR(stat.mode) &&
dir->d_sb->s_dev != stat.dev);
ino = stat.ino;
} else if (xinobits && !OVL_TYPE_UPPER(type)) {
ino = ovl_remap_lower_ino(ino, xinobits,
@ -518,7 +524,7 @@ static int ovl_cache_update_ino(struct path *path, struct ovl_cache_entry *p)
return err;
fail:
pr_warn_ratelimited("overlayfs: failed to look up (%s) for ino (%i)\n",
pr_warn_ratelimited("failed to look up (%s) for ino (%i)\n",
p->name, err);
goto out;
}
@ -685,7 +691,7 @@ 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);
const struct ovl_layer *lower_layer = ovl_layer_lower(dir);
struct ovl_readdir_translate rdt = {
.ctx.actor = ovl_fill_real,
.orig_ctx = ctx,
@ -738,7 +744,7 @@ static int ovl_iterate(struct file *file, struct dir_context *ctx)
* entries.
*/
if (ovl_xino_bits(dentry->d_sb) ||
(ovl_same_sb(dentry->d_sb) &&
(ovl_same_fs(dentry->d_sb) &&
(ovl_is_impure_dir(file) ||
OVL_TYPE_MERGE(ovl_path_type(dentry->d_parent))))) {
return ovl_iterate_real(file, ctx);
@ -965,7 +971,7 @@ void ovl_cleanup_whiteouts(struct dentry *upper, struct list_head *list)
dentry = lookup_one_len(p->name, upper, p->len);
if (IS_ERR(dentry)) {
pr_err("overlayfs: lookup '%s/%.*s' failed (%i)\n",
pr_err("lookup '%s/%.*s' failed (%i)\n",
upper->d_name.name, p->len, p->name,
(int) PTR_ERR(dentry));
continue;
@ -1147,6 +1153,6 @@ int ovl_indexdir_cleanup(struct ovl_fs *ofs)
out:
ovl_cache_free(&list);
if (err)
pr_err("overlayfs: failed index dir cleanup (%i)\n", err);
pr_err("failed index dir cleanup (%i)\n", err);
return err;
}

233
fs/overlayfs/super.c
View File

@ -224,14 +224,14 @@ 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++) {
iput(ofs->lower_layers[i].trap);
mntput(ofs->lower_layers[i].mnt);
for (i = 1; i < ofs->numlayer; i++) {
iput(ofs->layers[i].trap);
mntput(ofs->layers[i].mnt);
}
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->layers);
for (i = 0; i < ofs->numfs; i++)
free_anon_bdev(ofs->fs[i].pseudo_dev);
kfree(ofs->fs);
kfree(ofs->config.lowerdir);
kfree(ofs->config.upperdir);
@ -358,7 +358,7 @@ 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())
if (ofs->config.xino != ovl_xino_def() && !ovl_same_fs(sb))
seq_printf(m, ",xino=%s", ovl_xino_str[ofs->config.xino]);
if (ofs->config.metacopy != ovl_metacopy_def)
seq_printf(m, ",metacopy=%s",
@ -462,7 +462,7 @@ static int ovl_parse_redirect_mode(struct ovl_config *config, const char *mode)
if (ovl_redirect_always_follow)
config->redirect_follow = true;
} else if (strcmp(mode, "nofollow") != 0) {
pr_err("overlayfs: bad mount option \"redirect_dir=%s\"\n",
pr_err("bad mount option \"redirect_dir=%s\"\n",
mode);
return -EINVAL;
}
@ -560,14 +560,15 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
break;
default:
pr_err("overlayfs: unrecognized mount option \"%s\" or missing value\n", p);
pr_err("unrecognized mount option \"%s\" or missing value\n",
p);
return -EINVAL;
}
}
/* Workdir is useless in non-upper mount */
if (!config->upperdir && config->workdir) {
pr_info("overlayfs: option \"workdir=%s\" is useless in a non-upper mount, ignore\n",
pr_info("option \"workdir=%s\" is useless in a non-upper mount, ignore\n",
config->workdir);
kfree(config->workdir);
config->workdir = NULL;
@ -587,7 +588,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
/* Resolve metacopy -> redirect_dir dependency */
if (config->metacopy && !config->redirect_dir) {
if (metacopy_opt && redirect_opt) {
pr_err("overlayfs: conflicting options: metacopy=on,redirect_dir=%s\n",
pr_err("conflicting options: metacopy=on,redirect_dir=%s\n",
config->redirect_mode);
return -EINVAL;
}
@ -596,7 +597,7 @@ static int ovl_parse_opt(char *opt, struct ovl_config *config)
* There was an explicit redirect_dir=... that resulted
* in this conflict.
*/
pr_info("overlayfs: disabling metacopy due to redirect_dir=%s\n",
pr_info("disabling metacopy due to redirect_dir=%s\n",
config->redirect_mode);
config->metacopy = false;
} else {
@ -692,7 +693,7 @@ static struct dentry *ovl_workdir_create(struct ovl_fs *ofs,
out_dput:
dput(work);
out_err:
pr_warn("overlayfs: failed to create directory %s/%s (errno: %i); mounting read-only\n",
pr_warn("failed to create directory %s/%s (errno: %i); mounting read-only\n",
ofs->config.workdir, name, -err);
work = NULL;
goto out_unlock;
@ -716,21 +717,21 @@ static int ovl_mount_dir_noesc(const char *name, struct path *path)
int err = -EINVAL;
if (!*name) {
pr_err("overlayfs: empty lowerdir\n");
pr_err("empty lowerdir\n");
goto out;
}
err = kern_path(name, LOOKUP_FOLLOW, path);
if (err) {
pr_err("overlayfs: failed to resolve '%s': %i\n", name, err);
pr_err("failed to resolve '%s': %i\n", name, err);
goto out;
}
err = -EINVAL;
if (ovl_dentry_weird(path->dentry)) {
pr_err("overlayfs: filesystem on '%s' not supported\n", name);
pr_err("filesystem on '%s' not supported\n", name);
goto out_put;
}
if (!d_is_dir(path->dentry)) {
pr_err("overlayfs: '%s' not a directory\n", name);
pr_err("'%s' not a directory\n", name);
goto out_put;
}
return 0;
@ -752,7 +753,7 @@ static int ovl_mount_dir(const char *name, struct path *path)
if (!err)
if (ovl_dentry_remote(path->dentry)) {
pr_err("overlayfs: filesystem on '%s' not supported as upperdir\n",
pr_err("filesystem on '%s' not supported as upperdir\n",
tmp);
path_put_init(path);
err = -EINVAL;
@ -769,7 +770,7 @@ static int ovl_check_namelen(struct path *path, struct ovl_fs *ofs,
int err = vfs_statfs(path, &statfs);
if (err)
pr_err("overlayfs: statfs failed on '%s'\n", name);
pr_err("statfs failed on '%s'\n", name);
else
ofs->namelen = max(ofs->namelen, statfs.f_namelen);
@ -804,13 +805,13 @@ static int ovl_lower_dir(const char *name, struct path *path,
(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",
pr_warn("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;
ofs->xino_mode = -1;
return 0;
@ -996,7 +997,7 @@ static int ovl_setup_trap(struct super_block *sb, struct dentry *dir,
err = PTR_ERR_OR_ZERO(trap);
if (err) {
if (err == -ELOOP)
pr_err("overlayfs: conflicting %s path\n", name);
pr_err("conflicting %s path\n", name);
return err;
}
@ -1013,11 +1014,11 @@ static int ovl_setup_trap(struct super_block *sb, struct dentry *dir,
static int ovl_report_in_use(struct ovl_fs *ofs, const char *name)
{
if (ofs->config.index) {
pr_err("overlayfs: %s is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection.\n",
pr_err("%s is in-use as upperdir/workdir of another mount, mount with '-o index=off' to override exclusive upperdir protection.\n",
name);
return -EBUSY;
} else {
pr_warn("overlayfs: %s is in-use as upperdir/workdir of another mount, accessing files from both mounts will result in undefined behavior.\n",
pr_warn("%s is in-use as upperdir/workdir of another mount, accessing files from both mounts will result in undefined behavior.\n",
name);
return 0;
}
@ -1035,7 +1036,7 @@ static int ovl_get_upper(struct super_block *sb, struct ovl_fs *ofs,
/* Upper fs should not be r/o */
if (sb_rdonly(upperpath->mnt->mnt_sb)) {
pr_err("overlayfs: upper fs is r/o, try multi-lower layers mount\n");
pr_err("upper fs is r/o, try multi-lower layers mount\n");
err = -EINVAL;
goto out;
}
@ -1052,7 +1053,7 @@ static int ovl_get_upper(struct super_block *sb, struct ovl_fs *ofs,
upper_mnt = clone_private_mount(upperpath);
err = PTR_ERR(upper_mnt);
if (IS_ERR(upper_mnt)) {
pr_err("overlayfs: failed to clone upperpath\n");
pr_err("failed to clone upperpath\n");
goto out;
}
@ -1108,7 +1109,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
* kernel upgrade. So warn instead of erroring out.
*/
if (!err)
pr_warn("overlayfs: upper fs needs to support d_type.\n");
pr_warn("upper fs needs to support d_type.\n");
/* Check if upper/work fs supports O_TMPFILE */
temp = ovl_do_tmpfile(ofs->workdir, S_IFREG | 0);
@ -1116,7 +1117,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
if (ofs->tmpfile)
dput(temp);
else
pr_warn("overlayfs: upper fs does not support tmpfile.\n");
pr_warn("upper fs does not support tmpfile.\n");
/*
* Check if upper/work fs supports trusted.overlay.* xattr
@ -1126,7 +1127,7 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
ofs->noxattr = true;
ofs->config.index = false;
ofs->config.metacopy = false;
pr_warn("overlayfs: upper fs does not support xattr, falling back to index=off and metacopy=off.\n");
pr_warn("upper fs does not support xattr, falling back to index=off and metacopy=off.\n");
err = 0;
} else {
vfs_removexattr(ofs->workdir, OVL_XATTR_OPAQUE);
@ -1136,16 +1137,16 @@ static int ovl_make_workdir(struct super_block *sb, struct ovl_fs *ofs,
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");
pr_warn("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;
ofs->xino_mode = -1;
/* 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");
pr_warn("NFS export requires \"index=on\", falling back to nfs_export=off.\n");
ofs->config.nfs_export = false;
}
out:
@ -1165,11 +1166,11 @@ static int ovl_get_workdir(struct super_block *sb, struct ovl_fs *ofs,
err = -EINVAL;
if (upperpath->mnt != workpath.mnt) {
pr_err("overlayfs: workdir and upperdir must reside under the same mount\n");
pr_err("workdir and upperdir must reside under the same mount\n");
goto out;
}
if (!ovl_workdir_ok(workpath.dentry, upperpath->dentry)) {
pr_err("overlayfs: workdir and upperdir must be separate subtrees\n");
pr_err("workdir and upperdir must be separate subtrees\n");
goto out;
}
@ -1210,7 +1211,7 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
err = ovl_verify_origin(upperpath->dentry, oe->lowerstack[0].dentry,
true);
if (err) {
pr_err("overlayfs: failed to verify upper root origin\n");
pr_err("failed to verify upper root origin\n");
goto out;
}
@ -1233,18 +1234,18 @@ static int ovl_get_indexdir(struct super_block *sb, struct ovl_fs *ofs,
err = ovl_verify_set_fh(ofs->indexdir, OVL_XATTR_ORIGIN,
upperpath->dentry, true, false);
if (err)
pr_err("overlayfs: failed to verify index dir 'origin' xattr\n");
pr_err("failed to verify index dir 'origin' xattr\n");
}
err = ovl_verify_upper(ofs->indexdir, upperpath->dentry, true);
if (err)
pr_err("overlayfs: failed to verify index dir 'upper' xattr\n");
pr_err("failed to verify index dir 'upper' xattr\n");
/* Cleanup bad/stale/orphan index entries */
if (!err)
err = ovl_indexdir_cleanup(ofs);
}
if (err || !ofs->indexdir)
pr_warn("overlayfs: try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
pr_warn("try deleting index dir or mounting with '-o index=off' to disable inodes index.\n");
out:
mnt_drop_write(mnt);
@ -1258,7 +1259,7 @@ static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid)
if (!ofs->config.nfs_export && !ofs->upper_mnt)
return true;
for (i = 0; i < ofs->numlowerfs; i++) {
for (i = 0; i < ofs->numfs; i++) {
/*
* We use uuid to associate an overlay lower file handle with a
* lower layer, so we can accept lower fs with null uuid as long
@ -1266,8 +1267,9 @@ static bool ovl_lower_uuid_ok(struct ovl_fs *ofs, const uuid_t *uuid)
* if we detect multiple lower fs with the same uuid, we
* disable lower file handle decoding on all of them.
*/
if (uuid_equal(&ofs->lower_fs[i].sb->s_uuid, uuid)) {
ofs->lower_fs[i].bad_uuid = true;
if (ofs->fs[i].is_lower &&
uuid_equal(&ofs->fs[i].sb->s_uuid, uuid)) {
ofs->fs[i].bad_uuid = true;
return false;
}
}
@ -1283,13 +1285,9 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
int err;
bool bad_uuid = false;
/* 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;
for (i = 0; i < ofs->numfs; i++) {
if (ofs->fs[i].sb == sb)
return i;
}
if (!ovl_lower_uuid_ok(ofs, &sb->s_uuid)) {
@ -1297,7 +1295,7 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
if (ofs->config.index || ofs->config.nfs_export) {
ofs->config.index = false;
ofs->config.nfs_export = false;
pr_warn("overlayfs: %s uuid detected in lower fs '%pd2', falling back to index=off,nfs_export=off.\n",
pr_warn("%s uuid detected in lower fs '%pd2', falling back to index=off,nfs_export=off.\n",
uuid_is_null(&sb->s_uuid) ? "null" :
"conflicting",
path->dentry);
@ -1306,34 +1304,58 @@ static int ovl_get_fsid(struct ovl_fs *ofs, const struct path *path)
err = get_anon_bdev(&dev);
if (err) {
pr_err("overlayfs: failed to get anonymous bdev for lowerpath\n");
pr_err("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->lower_fs[ofs->numlowerfs].bad_uuid = bad_uuid;
ofs->numlowerfs++;
ofs->fs[ofs->numfs].sb = sb;
ofs->fs[ofs->numfs].pseudo_dev = dev;
ofs->fs[ofs->numfs].bad_uuid = bad_uuid;
return ofs->numlowerfs;
return ofs->numfs++;
}
static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
struct path *stack, unsigned int numlower)
static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
struct path *stack, unsigned int numlower)
{
int err;
unsigned int i;
struct ovl_layer *layers;
err = -ENOMEM;
ofs->lower_layers = kcalloc(numlower, sizeof(struct ovl_layer),
GFP_KERNEL);
if (ofs->lower_layers == NULL)
layers = kcalloc(numlower + 1, sizeof(struct ovl_layer), GFP_KERNEL);
if (!layers)
goto out;
ofs->layers = layers;
ofs->fs = kcalloc(numlower + 1, sizeof(struct ovl_sb), GFP_KERNEL);
if (ofs->fs == NULL)
goto out;
ofs->lower_fs = kcalloc(numlower, sizeof(struct ovl_sb),
GFP_KERNEL);
if (ofs->lower_fs == NULL)
/* idx/fsid 0 are reserved for upper fs even with lower only overlay */
ofs->numfs++;
layers[0].mnt = ofs->upper_mnt;
layers[0].idx = 0;
layers[0].fsid = 0;
ofs->numlayer = 1;
/*
* All lower layers that share the same fs as upper layer, use the same
* pseudo_dev as upper layer. Allocate fs[0].pseudo_dev even for lower
* only overlay to simplify ovl_fs_free().
* is_lower will be set if upper fs is shared with a lower layer.
*/
err = get_anon_bdev(&ofs->fs[0].pseudo_dev);
if (err) {
pr_err("failed to get anonymous bdev for upper fs\n");
goto out;
}
if (ofs->upper_mnt) {
ofs->fs[0].sb = ofs->upper_mnt->mnt_sb;
ofs->fs[0].is_lower = false;
}
for (i = 0; i < numlower; i++) {
struct vfsmount *mnt;
@ -1357,7 +1379,7 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
mnt = clone_private_mount(&stack[i]);
err = PTR_ERR(mnt);
if (IS_ERR(mnt)) {
pr_err("overlayfs: failed to clone lowerpath\n");
pr_err("failed to clone lowerpath\n");
iput(trap);
goto out;
}
@ -1368,15 +1390,13 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
*/
mnt->mnt_flags |= MNT_READONLY | MNT_NOATIME;
ofs->lower_layers[ofs->numlower].trap = trap;
ofs->lower_layers[ofs->numlower].mnt = mnt;
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++;
layers[ofs->numlayer].trap = trap;
layers[ofs->numlayer].mnt = mnt;
layers[ofs->numlayer].idx = ofs->numlayer;
layers[ofs->numlayer].fsid = fsid;
layers[ofs->numlayer].fs = &ofs->fs[fsid];
ofs->numlayer++;
ofs->fs[fsid].is_lower = true;
}
/*
@ -1387,22 +1407,23 @@ static int ovl_get_lower_layers(struct super_block *sb, struct ovl_fs *ofs,
* 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) {
if (ofs->numfs - !ofs->upper_mnt == 1) {
if (ofs->config.xino == OVL_XINO_ON)
pr_info("\"xino=on\" is useless with all layers on same fs, ignore.\n");
ofs->xino_mode = 0;
} else if (ofs->config.xino == OVL_XINO_ON && ofs->xino_mode < 0) {
/*
* 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.
* This is a roundup of number of bits needed for encoding
* fsid, where fsid 0 is reserved for upper fs even with
* lower only overlay.
*/
BUILD_BUG_ON(ilog2(OVL_MAX_STACK) > 31);
ofs->xino_bits = ilog2(ofs->numlowerfs) + 1;
ofs->xino_mode = ilog2(ofs->numfs - 1) + 1;
}
if (ofs->xino_bits) {
pr_info("overlayfs: \"xino\" feature enabled using %d upper inode bits.\n",
ofs->xino_bits);
if (ofs->xino_mode > 0) {
pr_info("\"xino\" feature enabled using %d upper inode bits.\n",
ofs->xino_mode);
}
err = 0;
@ -1428,15 +1449,15 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
err = -EINVAL;
stacklen = ovl_split_lowerdirs(lowertmp);
if (stacklen > OVL_MAX_STACK) {
pr_err("overlayfs: too many lower directories, limit is %d\n",
pr_err("too many lower directories, limit is %d\n",
OVL_MAX_STACK);
goto out_err;
} else if (!ofs->config.upperdir && stacklen == 1) {
pr_err("overlayfs: at least 2 lowerdir are needed while upperdir nonexistent\n");
pr_err("at least 2 lowerdir are needed while upperdir nonexistent\n");
goto out_err;
} else if (!ofs->config.upperdir && ofs->config.nfs_export &&
ofs->config.redirect_follow) {
pr_warn("overlayfs: NFS export requires \"redirect_dir=nofollow\" on non-upper mount, falling back to nfs_export=off.\n");
pr_warn("NFS export requires \"redirect_dir=nofollow\" on non-upper mount, falling back to nfs_export=off.\n");
ofs->config.nfs_export = false;
}
@ -1459,11 +1480,11 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
err = -EINVAL;
sb->s_stack_depth++;
if (sb->s_stack_depth > FILESYSTEM_MAX_STACK_DEPTH) {
pr_err("overlayfs: maximum fs stacking depth exceeded\n");
pr_err("maximum fs stacking depth exceeded\n");
goto out_err;
}
err = ovl_get_lower_layers(sb, ofs, stack, numlower);
err = ovl_get_layers(sb, ofs, stack, numlower);
if (err)
goto out_err;
@ -1474,7 +1495,7 @@ static struct ovl_entry *ovl_get_lowerstack(struct super_block *sb,
for (i = 0; i < numlower; i++) {
oe->lowerstack[i].dentry = dget(stack[i].dentry);
oe->lowerstack[i].layer = &ofs->lower_layers[i];
oe->lowerstack[i].layer = &ofs->layers[i+1];
}
if (remote)
@ -1515,7 +1536,7 @@ static int ovl_check_layer(struct super_block *sb, struct ovl_fs *ofs,
while (!err && parent != next) {
if (ovl_lookup_trap_inode(sb, parent)) {
err = -ELOOP;
pr_err("overlayfs: overlapping %s path\n", name);
pr_err("overlapping %s path\n", name);
} else if (ovl_is_inuse(parent)) {
err = ovl_report_in_use(ofs, name);
}
@ -1555,9 +1576,9 @@ static int ovl_check_overlapping_layers(struct super_block *sb,
return err;
}
for (i = 0; i < ofs->numlower; i++) {
for (i = 1; i < ofs->numlayer; i++) {
err = ovl_check_layer(sb, ofs,
ofs->lower_layers[i].mnt->mnt_root,
ofs->layers[i].mnt->mnt_root,
"lowerdir");
if (err)
return err;
@ -1595,7 +1616,7 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
err = -EINVAL;
if (!ofs->config.lowerdir) {
if (!silent)
pr_err("overlayfs: missing 'lowerdir'\n");
pr_err("missing 'lowerdir'\n");
goto out_err;
}
@ -1603,14 +1624,14 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
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;
ofs->xino_mode = BITS_PER_LONG - 32;
/* alloc/destroy_inode needed for setting up traps in inode cache */
sb->s_op = &ovl_super_operations;
if (ofs->config.upperdir) {
if (!ofs->config.workdir) {
pr_err("overlayfs: missing 'workdir'\n");
pr_err("missing 'workdir'\n");
goto out_err;
}
@ -1660,13 +1681,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
if (!ofs->indexdir) {
ofs->config.index = false;
if (ofs->upper_mnt && ofs->config.nfs_export) {
pr_warn("overlayfs: NFS export requires an index dir, falling back to nfs_export=off.\n");
pr_warn("NFS export requires an index dir, falling back to nfs_export=off.\n");
ofs->config.nfs_export = false;
}
}
if (ofs->config.metacopy && ofs->config.nfs_export) {
pr_warn("overlayfs: NFS export is not supported with metadata only copy up, falling back to nfs_export=off.\n");
pr_warn("NFS export is not supported with metadata only copy up, falling back to nfs_export=off.\n");
ofs->config.nfs_export = false;
}
@ -1749,9 +1770,15 @@ static int __init ovl_init(void)
if (ovl_inode_cachep == NULL)
return -ENOMEM;
err = register_filesystem(&ovl_fs_type);
if (err)
kmem_cache_destroy(ovl_inode_cachep);
err = ovl_aio_request_cache_init();
if (!err) {
err = register_filesystem(&ovl_fs_type);
if (!err)
return 0;
ovl_aio_request_cache_destroy();
}
kmem_cache_destroy(ovl_inode_cachep);
return err;
}
@ -1766,7 +1793,7 @@ static void __exit ovl_exit(void)
*/
rcu_barrier();
kmem_cache_destroy(ovl_inode_cachep);
ovl_aio_request_cache_destroy();
}
module_init(ovl_init);

28
fs/overlayfs/util.c
View File

@ -40,18 +40,6 @@ const struct cred *ovl_override_creds(struct super_block *sb)
return override_creds(ofs->creator_cred);
}
struct super_block *ovl_same_sb(struct super_block *sb)
{
struct ovl_fs *ofs = sb->s_fs_info;
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;
}
/*
* Check if underlying fs supports file handles and try to determine encoding
* type, in order to deduce maximum inode number used by fs.
@ -198,7 +186,7 @@ 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)
const struct ovl_layer *ovl_layer_lower(struct dentry *dentry)
{
struct ovl_entry *oe = dentry->d_fsdata;
@ -576,7 +564,7 @@ int ovl_check_setxattr(struct dentry *dentry, struct dentry *upperdentry,
err = ovl_do_setxattr(upperdentry, name, value, size, 0);
if (err == -EOPNOTSUPP) {
pr_warn("overlayfs: cannot set %s xattr on upper\n", name);
pr_warn("cannot set %s xattr on upper\n", name);
ofs->noxattr = true;
return xerr;
}
@ -700,7 +688,7 @@ static void ovl_cleanup_index(struct dentry *dentry)
inode = d_inode(upperdentry);
if (!S_ISDIR(inode->i_mode) && inode->i_nlink != 1) {
pr_warn_ratelimited("overlayfs: cleanup linked index (%pd2, ino=%lu, nlink=%u)\n",
pr_warn_ratelimited("cleanup linked index (%pd2, ino=%lu, nlink=%u)\n",
upperdentry, inode->i_ino, inode->i_nlink);
/*
* We either have a bug with persistent union nlink or a lower
@ -739,7 +727,7 @@ static void ovl_cleanup_index(struct dentry *dentry)
return;
fail:
pr_err("overlayfs: cleanup index of '%pd2' failed (%i)\n", dentry, err);
pr_err("cleanup index of '%pd2' failed (%i)\n", dentry, err);
goto out;
}
@ -830,7 +818,7 @@ int ovl_lock_rename_workdir(struct dentry *workdir, struct dentry *upperdir)
err_unlock:
unlock_rename(workdir, upperdir);
err:
pr_err("overlayfs: failed to lock workdir+upperdir\n");
pr_err("failed to lock workdir+upperdir\n");
return -EIO;
}
@ -852,7 +840,7 @@ int ovl_check_metacopy_xattr(struct dentry *dentry)
return 1;
out:
pr_warn_ratelimited("overlayfs: failed to get metacopy (%i)\n", res);
pr_warn_ratelimited("failed to get metacopy (%i)\n", res);
return res;
}
@ -899,7 +887,7 @@ ssize_t ovl_getxattr(struct dentry *dentry, char *name, char **value,
return res;
fail:
pr_warn_ratelimited("overlayfs: failed to get xattr %s: err=%zi)\n",
pr_warn_ratelimited("failed to get xattr %s: err=%zi)\n",
name, res);
kfree(buf);
return res;
@ -931,7 +919,7 @@ char *ovl_get_redirect_xattr(struct dentry *dentry, int padding)
return buf;
invalid:
pr_warn_ratelimited("overlayfs: invalid redirect (%s)\n", buf);
pr_warn_ratelimited("invalid redirect (%s)\n", buf);
res = -EINVAL;
kfree(buf);
return ERR_PTR(res);

56
fs/read_write.c
View File

@ -939,6 +939,34 @@ static ssize_t do_iter_read(struct file *file, struct iov_iter *iter,
return ret;
}
ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
struct iov_iter *iter)
{
size_t tot_len;
ssize_t ret = 0;
if (!file->f_op->read_iter)
return -EINVAL;
if (!(file->f_mode & FMODE_READ))
return -EBADF;
if (!(file->f_mode & FMODE_CAN_READ))
return -EINVAL;
tot_len = iov_iter_count(iter);
if (!tot_len)
goto out;
ret = rw_verify_area(READ, file, &iocb->ki_pos, tot_len);
if (ret < 0)
return ret;
ret = call_read_iter(file, iocb, iter);
out:
if (ret >= 0)
fsnotify_access(file);
return ret;
}
EXPORT_SYMBOL(vfs_iocb_iter_read);
ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
rwf_t flags)
{
@ -975,6 +1003,34 @@ static ssize_t do_iter_write(struct file *file, struct iov_iter *iter,
return ret;
}
ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
struct iov_iter *iter)
{
size_t tot_len;
ssize_t ret = 0;
if (!file->f_op->write_iter)
return -EINVAL;
if (!(file->f_mode & FMODE_WRITE))
return -EBADF;
if (!(file->f_mode & FMODE_CAN_WRITE))
return -EINVAL;
tot_len = iov_iter_count(iter);
if (!tot_len)
return 0;
ret = rw_verify_area(WRITE, file, &iocb->ki_pos, tot_len);
if (ret < 0)
return ret;
ret = call_write_iter(file, iocb, iter);
if (ret > 0)
fsnotify_modify(file);
return ret;
}
EXPORT_SYMBOL(vfs_iocb_iter_write);
ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
rwf_t flags)
{

16
include/linux/fs.h
View File

@ -2078,6 +2078,18 @@ static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
};
}
static inline void kiocb_clone(struct kiocb *kiocb, struct kiocb *kiocb_src,
struct file *filp)
{
*kiocb = (struct kiocb) {
.ki_filp = filp,
.ki_flags = kiocb_src->ki_flags,
.ki_hint = kiocb_src->ki_hint,
.ki_ioprio = kiocb_src->ki_ioprio,
.ki_pos = kiocb_src->ki_pos,
};
}
/*
* Inode state bits. Protected by inode->i_lock
*
@ -3108,6 +3120,10 @@ ssize_t vfs_iter_read(struct file *file, struct iov_iter *iter, loff_t *ppos,
rwf_t flags);
ssize_t vfs_iter_write(struct file *file, struct iov_iter *iter, loff_t *ppos,
rwf_t flags);
ssize_t vfs_iocb_iter_read(struct file *file, struct kiocb *iocb,
struct iov_iter *iter);
ssize_t vfs_iocb_iter_write(struct file *file, struct kiocb *iocb,
struct iov_iter *iter);
/* fs/block_dev.c */
extern ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to);