struct aufs_branch *stobr(struct super_block *sb, aufs_bindex_t bindex)
{
SiMustAnyLock(sb);
AuDebugOn(bindex < 0 || sbend(sb) < bindex
|| !stosi(sb)->si_branch[0 + bindex]);
return stosi(sb)->si_branch[0 + bindex];
}
/* final actions when unmounting a file system */
static void unionfs_put_super(struct super_block *sb)
{
int bindex, bstart, bend;
struct unionfs_sb_info *spd;
print_entry_location();
if ((spd = stopd(sb))) {
/* XXX: Free persistent inode stuff. */
bstart = sbstart(sb);
bend = sbend(sb);
for (bindex = bstart; bindex <= bend; bindex++)
mntput(stohiddenmnt_index(sb, bindex));
/* Make sure we have no leaks of branchget/branchput. */
for (bindex = bstart; bindex <= bend; bindex++)
ASSERT(branch_count(sb, bindex) == 0);
KFREE(stohs_ptr(sb));
KFREE(stohiddenmnt_ptr(sb));
KFREE(spd->usi_sbcount_p);
KFREE(spd->usi_branchperms_p);
KFREE(spd->usi_putmaps);
KFREE(spd);
stopd_lhs(sb) = NULL;
}
fist_dprint(6, "unionfs: released super\n");
print_exit_location();
}
int unionfs_ioctl_branchcount(struct file *file, unsigned int cmd,
unsigned long arg)
{
int err = 0;
int bstart, bend;
int i;
struct super_block *sb = file->f_dentry->d_sb;
print_entry_location();
bstart = sbstart(sb);
bend = sbend(sb);
err = bend + 1;
if (!arg)
goto out;
for (i = bstart; i <= bend; i++) {
if (put_user(branch_count(sb, i), ((int *)arg) + i)) {
err = -EFAULT;
goto out;
}
}
out:
print_exit_status(err);
return err;
}
static int make_xino(struct seq_file *seq, struct sysaufs_args *args,
int *do_size)
{
int err;
struct super_block *sb = args->sb;
aufs_bindex_t bindex, bend;
struct file *xf;
struct inode *xi;
TraceEnter();
AuDebugOn(args->index != SysaufsSb_XINO);
SiMustReadLock(sb);
*do_size = 0;
err = seq_printf(seq, "%lu %lu\n", (unsigned long)sizeof(struct xino),
(unsigned long)atomic_long_read(&stosi(sb)->si_xino));
bend = sbend(sb);
for (bindex = 0; !err && bindex <= bend; bindex++) {
xf = stobr(sb, bindex)->br_xino;
xi = xf->f_dentry->d_inode;
err = seq_printf(seq, "%d: %d, %Lux%d %Ld\n",
bindex, file_count(xf),
(u64)xi->i_blocks, 1 << xi->i_blkbits,
i_size_read(xi));
}
return err;
}
int find_bindex(struct super_block *sb, struct aufs_branch *br)
{
aufs_bindex_t bindex, bend;
bend = sbend(sb);
for (bindex = 0; bindex <= bend; bindex++)
if (stobr(sb, bindex) == br)
return bindex;
return -1;
}
int unionfs_ioctl_rdwrbranch(struct inode *inode, unsigned int cmd,
unsigned long arg)
{
int err;
struct unionfs_rdwrbranch_args *rdwrargs = NULL;
int gen;
print_entry_location();
unionfs_write_lock(inode->i_sb);
lock_dentry(inode->i_sb->s_root);
if ((err = newputmap(inode->i_sb)))
goto out;
err = -ENOMEM;
rdwrargs = KMALLOC(sizeof(struct unionfs_rdwrbranch_args), GFP_KERNEL);
if (!rdwrargs)
goto out;
err = -EFAULT;
if (copy_from_user
(rdwrargs, (const void __user *)arg,
sizeof(struct unionfs_rdwrbranch_args)))
goto out;
err = -EINVAL;
if (rdwrargs->rwb_branch < 0
|| (rdwrargs->rwb_branch > (sbend(inode->i_sb) + 1)))
goto out;
if (rdwrargs->rwb_perms & ~(MAY_READ | MAY_WRITE | MAY_NFSRO))
goto out;
if (!(rdwrargs->rwb_perms & MAY_READ))
goto out;
set_branchperms(inode->i_sb, rdwrargs->rwb_branch, rdwrargs->rwb_perms);
atomic_inc(&stopd(inode->i_sb)->usi_generation);
gen = atomic_read(&stopd(inode->i_sb)->usi_generation);
atomic_set(&dtopd(inode->i_sb->s_root)->udi_generation, gen);
atomic_set(&itopd(inode->i_sb->s_root->d_inode)->uii_generation, gen);
err = 0;
out:
unlock_dentry(inode->i_sb->s_root);
unionfs_write_unlock(inode->i_sb);
KFREE(rdwrargs);
print_exit_status(err);
return err;
}
void __show_inode_counts(const struct inode *inode,
const char *file, const char *fxn, int line)
{
struct inode *lower_inode;
int bindex;
if (unlikely(!inode)) {
pr_debug("SiC: Null inode\n");
return;
}
for (bindex = sbstart(inode->i_sb); bindex <= sbend(inode->i_sb);
bindex++) {
lower_inode = unionfs_lower_inode_idx(inode, bindex);
if (unlikely(!lower_inode))
continue;
pr_debug("SIC(%lu:%d:%d): lc=%d %s:%s:%d\n",
inode->i_ino, bindex,
atomic_read(&(inode)->i_count),
atomic_read(&(lower_inode)->i_count),
file, fxn, line);
}
}
static int unionfs_statfs(struct super_block *sb, struct kstatfs *buf)
{
int err = 0;
struct super_block *hidden_sb;
struct kstatfs rsb;
int bindex, bindex1, bstart, bend;
print_entry_location();
memset(buf, 0, sizeof(struct kstatfs));
buf->f_type = UNIONFS_SUPER_MAGIC;
buf->f_frsize = 0;
buf->f_namelen = 0;
bstart = sbstart(sb);
bend = sbend(sb);
for (bindex = bstart; bindex <= bend; bindex++) {
int dup = 0;
hidden_sb = stohs_index(sb, bindex);
/* Ignore duplicate super blocks. */
for (bindex1 = bstart; bindex1 < bindex; bindex1++) {
if (hidden_sb == stohs_index(sb, bindex1)) {
dup = 1;
break;
}
}
if (dup) {
continue;
}
err = vfs_statfs(hidden_sb, &rsb);
fist_dprint(8,
"adding values for bindex:%d bsize:%d blocks:%d bfree:%d bavail:%d\n",
bindex, (int)rsb.f_bsize, (int)rsb.f_blocks,
(int)rsb.f_bfree, (int)rsb.f_bavail);
if (!buf->f_frsize)
buf->f_frsize = rsb.f_frsize;
if (!buf->f_namelen) {
buf->f_namelen = rsb.f_namelen;
} else {
if (buf->f_namelen > rsb.f_namelen)
buf->f_namelen = rsb.f_namelen;
}
if (!buf->f_bsize) {
buf->f_bsize = rsb.f_bsize;
} else {
if (buf->f_bsize < rsb.f_bsize) {
int shifter = 0;
while (buf->f_bsize < rsb.f_bsize) {
shifter++;
rsb.f_bsize >>= 1;
}
rsb.f_blocks <<= shifter;
rsb.f_bfree <<= shifter;
rsb.f_bavail <<= shifter;
} else {
int shifter = 0;
while (buf->f_bsize > rsb.f_bsize) {
shifter++;
rsb.f_bsize <<= 1;
}
rsb.f_blocks >>= shifter;
rsb.f_bfree >>= shifter;
rsb.f_bavail >>= shifter;
}
}
static int newputmap(struct super_block *sb)
{
struct unionfs_sb_info *spd;
struct putmap *newmap;
int count = 0;
int i;
print_entry_location();
spd = stopd(sb);
i = sizeof(int) * (sbend(sb) + 1);
newmap = KMALLOC(sizeof(struct putmap) + i, GFP_UNIONFS);
if (!newmap) {
print_exit_status(-ENOMEM);
return -ENOMEM;
}
if (!spd->usi_firstputmap) {
spd->usi_firstputmap = 1;
spd->usi_lastputmap = 1;
spd->usi_putmaps =
KMALLOC(sizeof(struct putmap *), GFP_UNIONFS);
if (!spd->usi_putmaps) {
KFREE(newmap);
print_exit_status(-ENOMEM);
return -ENOMEM;
}
} else {
struct putmap **newlist;
int newfirst = spd->usi_firstputmap;
while (!spd->usi_putmaps[newfirst - spd->usi_firstputmap] &&
newfirst <= spd->usi_lastputmap) {
newfirst++;
}
newlist =
KMALLOC(sizeof(struct putmap *) *
(1 + spd->usi_lastputmap - newfirst), GFP_UNIONFS);
if (!newlist) {
KFREE(newmap);
print_exit_status(-ENOMEM);
return -ENOMEM;
}
for (i = newfirst; i <= spd->usi_lastputmap; i++) {
newlist[i - newfirst] =
spd->usi_putmaps[i - spd->usi_firstputmap];
}
KFREE(spd->usi_putmaps);
spd->usi_putmaps = newlist;
spd->usi_firstputmap = newfirst;
spd->usi_lastputmap++;
}
newmap->bend = sbend(sb);
for (i = 0; i <= sbend(sb); i++) {
count += branch_count(sb, i);
newmap->map[i] = i;
}
for (i = spd->usi_firstputmap; i < spd->usi_lastputmap; i++) {
struct putmap *cur;
cur = spd->usi_putmaps[i - spd->usi_firstputmap];
if (!cur)
continue;
count -= atomic_read(&cur->count);
}
atomic_set(&newmap->count, count);
spd->usi_putmaps[spd->usi_lastputmap - spd->usi_firstputmap] = newmap;
print_exit_status(0);
return 0;
}
/* This must be called with the super block already locked. */
int unionfs_ioctl_delbranch(struct super_block *sb, unsigned long arg)
{
struct dentry *hidden_dentry;
struct inode *hidden_inode;
struct super_block *hidden_sb;
struct vfsmount *hidden_mnt;
struct dentry *root_dentry;
struct inode *root_inode;
int err = 0;
int pmindex, i, gen;
print_entry("branch = %lu ", arg);
lock_dentry(sb->s_root);
err = -EBUSY;
if (sbmax(sb) == 1)
goto out;
err = -EINVAL;
if (arg < 0 || arg > stopd(sb)->b_end)
goto out;
err = -EBUSY;
if (branch_count(sb, arg))
goto out;
if ((err = newputmap(sb)))
goto out;
pmindex = stopd(sb)->usi_lastputmap;
pmindex -= stopd(sb)->usi_firstputmap;
atomic_inc(&stopd(sb)->usi_generation);
gen = atomic_read(&stopd(sb)->usi_generation);
root_dentry = sb->s_root;
root_inode = sb->s_root->d_inode;
hidden_dentry = dtohd_index(root_dentry, arg);
hidden_mnt = stohiddenmnt_index(sb, arg);
hidden_inode = itohi_index(root_inode, arg);
hidden_sb = stohs_index(sb, arg);
DPUT(hidden_dentry);
iput(hidden_inode);
mntput(hidden_mnt);
for (i = arg; i <= (sbend(sb) - 1); i++) {
set_branch_count(sb, i, branch_count(sb, i + 1));
set_stohiddenmnt_index(sb, i, stohiddenmnt_index(sb, i + 1));
set_stohs_index(sb, i, stohs_index(sb, i + 1));
set_branchperms(sb, i, branchperms(sb, i + 1));
set_dtohd_index(root_dentry, i,
dtohd_index(root_dentry, i + 1));
set_itohi_index(root_inode, i, itohi_index(root_inode, i + 1));
stopd(sb)->usi_putmaps[pmindex]->map[i + 1] = i;
}
set_dtohd_index(root_dentry, sbend(sb), NULL);
set_itohi_index(root_inode, sbend(sb), NULL);
set_stohiddenmnt_index(sb, sbend(sb), NULL);
set_stohs_index(sb, sbend(sb), NULL);
stopd(sb)->b_end--;
set_dbend(root_dentry, dbend(root_dentry) - 1);
dtopd(root_dentry)->udi_bcount--;
itopd(root_inode)->b_end--;
atomic_set(&dtopd(root_dentry)->udi_generation, gen);
atomic_set(&itopd(root_inode)->uii_generation, gen);
fixputmaps(sb);
/* This doesn't open a file, so we might have to free the map here. */
if (atomic_read(&stopd(sb)->usi_putmaps[pmindex]->count) == 0) {
KFREE(stopd(sb)->usi_putmaps[pmindex]);
stopd(sb)->usi_putmaps[pmindex] = NULL;
}
out:
unlock_dentry(sb->s_root);
print_exit_status(err);
return err;
}
int unionfs_ioctl_addbranch(struct inode *inode, unsigned int cmd,
unsigned long arg)
{
int err;
struct unionfs_addbranch_args *addargs = NULL;
struct nameidata nd;
char *path = NULL;
int gen;
int i;
int count;
int pobjects;
struct vfsmount **new_hidden_mnt = NULL;
struct inode **new_uii_inode = NULL;
struct dentry **new_udi_dentry = NULL;
struct super_block **new_usi_sb = NULL;
int *new_branchperms = NULL;
atomic_t *new_counts = NULL;
print_entry_location();
err = -ENOMEM;
addargs = KMALLOC(sizeof(struct unionfs_addbranch_args), GFP_UNIONFS);
if (!addargs)
goto out;
err = -EFAULT;
if (copy_from_user
(addargs, (void *)arg, sizeof(struct unionfs_addbranch_args)))
goto out;
err = -EINVAL;
if (addargs->ab_perms & ~(MAY_READ | MAY_WRITE))
goto out;
if (!(addargs->ab_perms & MAY_READ))
goto out;
err = -E2BIG;
if (sbend(inode->i_sb) > FD_SETSIZE)
goto out;
err = -ENOMEM;
if (!(path = getname(addargs->ab_path)))
goto out;
err = path_lookup(path, LOOKUP_FOLLOW, &nd);
RECORD_PATH_LOOKUP(&nd);
if (err)
goto out;
if ((err = check_branch(&nd))) {
path_release(&nd);
RECORD_PATH_RELEASE(&nd);
goto out;
}
unionfs_write_lock(inode->i_sb);
lock_dentry(inode->i_sb->s_root);
err = -EINVAL;
if (addargs->ab_branch < 0
|| (addargs->ab_branch > (sbend(inode->i_sb) + 1)))
goto out;
if ((err = newputmap(inode->i_sb)))
goto out;
stopd(inode->i_sb)->b_end++;
dtopd(inode->i_sb->s_root)->udi_bcount++;
set_dbend(inode->i_sb->s_root, dbend(inode->i_sb->s_root) + 1);
itopd(inode->i_sb->s_root->d_inode)->b_end++;
atomic_inc(&stopd(inode->i_sb)->usi_generation);
gen = atomic_read(&stopd(inode->i_sb)->usi_generation);
pobjects = (sbend(inode->i_sb) + 1) - UNIONFS_INLINE_OBJECTS;
if (pobjects > 0) {
/* Reallocate the dynamic structures. */
new_hidden_mnt =
KMALLOC(sizeof(struct vfsmount *) * pobjects, GFP_UNIONFS);
new_udi_dentry =
KMALLOC(sizeof(struct dentry *) * pobjects, GFP_UNIONFS);
new_uii_inode =
KMALLOC(sizeof(struct inode *) * pobjects, GFP_UNIONFS);
new_usi_sb =
KMALLOC(sizeof(struct super_block *) * pobjects,
GFP_UNIONFS);
new_counts = KMALLOC(sizeof(atomic_t) * pobjects, GFP_UNIONFS);
new_branchperms = KMALLOC(sizeof(int) * pobjects, GFP_UNIONFS);
if (!new_hidden_mnt || !new_udi_dentry || !new_uii_inode
|| !new_counts || !new_usi_sb || !new_branchperms) {
err = -ENOMEM;
goto out;
}
memset(new_hidden_mnt, 0, sizeof(struct vfsmount *) * pobjects);
memset(new_udi_dentry, 0, sizeof(struct dentry *) * pobjects);
memset(new_uii_inode, 0, sizeof(struct inode *) * pobjects);
memset(new_usi_sb, 0, sizeof(struct super_block *) * pobjects);
memset(new_branchperms, 0, sizeof(int) * pobjects);
}
/* Copy the in-place values to our new structure. */
for (i = UNIONFS_INLINE_OBJECTS; i < addargs->ab_branch; i++) {
int j = i - UNIONFS_INLINE_OBJECTS;
count = branch_count(inode->i_sb, i);
atomic_set(&(new_counts[j]), count);
new_branchperms[j] = branchperms(inode->i_sb, i);
new_hidden_mnt[j] = stohiddenmnt_index(inode->i_sb, i);
new_usi_sb[j] = stohs_index(inode->i_sb, i);
new_udi_dentry[j] = dtohd_index(inode->i_sb->s_root, i);
new_uii_inode[j] = itohi_index(inode->i_sb->s_root->d_inode, i);
}
/* Shift the ends to the right (only handle reallocated bits). */
for (i = sbend(inode->i_sb) - 1; i >= (int)addargs->ab_branch; i--) {
int j = i + 1;
int perms;
struct vfsmount *hm;
struct super_block *hs;
struct dentry *hd;
struct inode *hi;
int pmindex;
count = branch_count(inode->i_sb, i);
perms = branchperms(inode->i_sb, i);
hm = stohiddenmnt_index(inode->i_sb, i);
hs = stohs_index(inode->i_sb, i);
hd = dtohd_index(inode->i_sb->s_root, i);
hi = itohi_index(inode->i_sb->s_root->d_inode, i);
/* Update the newest putmap, so it is correct for later. */
pmindex = stopd(inode->i_sb)->usi_lastputmap;
pmindex -= stopd(inode->i_sb)->usi_firstputmap;
stopd(inode->i_sb)->usi_putmaps[pmindex]->map[i] = j;
if (j >= UNIONFS_INLINE_OBJECTS) {
j -= UNIONFS_INLINE_OBJECTS;
atomic_set(&(new_counts[j]), count);
new_branchperms[j] = perms;
new_hidden_mnt[j] = hm;
new_usi_sb[j] = hs;
new_udi_dentry[j] = hd;
new_uii_inode[j] = hi;
} else {
set_branch_count(inode->i_sb, j, count);
set_branchperms(inode->i_sb, j, perms);
set_stohiddenmnt_index(inode->i_sb, j, hm);
set_stohs_index(inode->i_sb, j, hs);
set_dtohd_index(inode->i_sb->s_root, j, hd);
set_itohi_index(inode->i_sb->s_root->d_inode, j, hi);
}
}
/* Now we can free the old ones. */
KFREE(dtopd(inode->i_sb->s_root)->udi_dentry_p);
KFREE(itopd(inode->i_sb->s_root->d_inode)->uii_inode_p);
KFREE(stopd(inode->i_sb)->usi_hidden_mnt_p);
KFREE(stopd(inode->i_sb)->usi_sb_p);
KFREE(stopd(inode->i_sb)->usi_sbcount_p);
KFREE(stopd(inode->i_sb)->usi_branchperms_p);
/* Update the real pointers. */
dtohd_ptr(inode->i_sb->s_root) = new_udi_dentry;
itohi_ptr(inode->i_sb->s_root->d_inode) = new_uii_inode;
stohiddenmnt_ptr(inode->i_sb) = new_hidden_mnt;
stohs_ptr(inode->i_sb) = new_usi_sb;
stopd(inode->i_sb)->usi_sbcount_p = new_counts;
stopd(inode->i_sb)->usi_branchperms_p = new_branchperms;
/* Re-NULL the new ones so we don't try to free them. */
new_hidden_mnt = NULL;
new_udi_dentry = NULL;
new_usi_sb = NULL;
new_uii_inode = NULL;
new_counts = NULL;
new_branchperms = NULL;
/* Put the new dentry information into it's slot. */
set_dtohd_index(inode->i_sb->s_root, addargs->ab_branch, nd.dentry);
set_itohi_index(inode->i_sb->s_root->d_inode, addargs->ab_branch,
igrab(nd.dentry->d_inode));
set_branchperms(inode->i_sb, addargs->ab_branch, addargs->ab_perms);
set_branch_count(inode->i_sb, addargs->ab_branch, 0);
set_stohiddenmnt_index(inode->i_sb, addargs->ab_branch, nd.mnt);
set_stohs_index(inode->i_sb, addargs->ab_branch, nd.dentry->d_sb);
atomic_set(&dtopd(inode->i_sb->s_root)->udi_generation, gen);
atomic_set(&itopd(inode->i_sb->s_root->d_inode)->uii_generation, gen);
fixputmaps(inode->i_sb);
out:
unlock_dentry(inode->i_sb->s_root);
unionfs_write_unlock(inode->i_sb);
KFREE(new_hidden_mnt);
KFREE(new_udi_dentry);
KFREE(new_uii_inode);
KFREE(new_usi_sb);
KFREE(new_counts);
KFREE(new_branchperms);
KFREE(addargs);
if (path)
putname(path);
print_exit_status(err);
return err;
}
/*
* our custom d_alloc_root work-alike
*
* we can't use d_alloc_root if we want to use our own interpose function
* unchanged, so we simply call our own "fake" d_alloc_root
*/
static struct dentry *unionfs_d_alloc_root(struct super_block *sb)
{
struct dentry *ret = NULL;
if (sb) {
static const struct qstr name = {
.name = "/",
.len = 1
};
ret = d_alloc(NULL, &name);
if (likely(ret)) {
ret->d_op = &unionfs_dops;
ret->d_sb = sb;
ret->d_parent = ret;
}
}
return ret;
}
/*
* There is no need to lock the unionfs_super_info's rwsem as there is no
* way anyone can have a reference to the superblock at this point in time.
*/
static int unionfs_read_super(struct super_block *sb, void *raw_data,
int silent)
{
int err = 0;
struct unionfs_dentry_info *lower_root_info = NULL;
int bindex, bstart, bend;
if (!raw_data) {
printk(KERN_ERR
"unionfs: read_super: missing data argument\n");
err = -EINVAL;
goto out;
}
/* Allocate superblock private data */
sb->s_fs_info = kzalloc(sizeof(struct unionfs_sb_info), GFP_KERNEL);
if (unlikely(!UNIONFS_SB(sb))) {
printk(KERN_CRIT "unionfs: read_super: out of memory\n");
err = -ENOMEM;
goto out;
}
UNIONFS_SB(sb)->bend = -1;
atomic_set(&UNIONFS_SB(sb)->generation, 1);
init_rwsem(&UNIONFS_SB(sb)->rwsem);
UNIONFS_SB(sb)->high_branch_id = -1; /* -1 == invalid branch ID */
lower_root_info = unionfs_parse_options(sb, raw_data);
if (IS_ERR(lower_root_info)) {
printk(KERN_ERR
"unionfs: read_super: error while parsing options "
"(err = %ld)\n", PTR_ERR(lower_root_info));
err = PTR_ERR(lower_root_info);
lower_root_info = NULL;
goto out_free;
}
if (lower_root_info->bstart == -1) {
err = -ENOENT;
goto out_free;
}
/* set the lower superblock field of upper superblock */
bstart = lower_root_info->bstart;
BUG_ON(bstart != 0);
sbend(sb) = bend = lower_root_info->bend;
for (bindex = bstart; bindex <= bend; bindex++) {
struct dentry *d = lower_root_info->lower_paths[bindex].dentry;
atomic_inc(&d->d_sb->s_active);
unionfs_set_lower_super_idx(sb, bindex, d->d_sb);
}
/* max Bytes is the maximum bytes from highest priority branch */
sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes;
/*
* Our c/m/atime granularity is 1 ns because we may stack on file
* systems whose granularity is as good. This is important for our
* time-based cache coherency.
*/
sb->s_time_gran = 1;
sb->s_op = &unionfs_sops;
/* See comment next to the definition of unionfs_d_alloc_root */
sb->s_root = unionfs_d_alloc_root(sb);
if (unlikely(!sb->s_root)) {
err = -ENOMEM;
goto out_dput;
}
/* link the upper and lower dentries */
sb->s_root->d_fsdata = NULL;
err = new_dentry_private_data(sb->s_root, UNIONFS_DMUTEX_ROOT);
if (unlikely(err))
goto out_freedpd;
/* Set the lower dentries for s_root */
for (bindex = bstart; bindex <= bend; bindex++) {
struct dentry *d;
struct vfsmount *m;
d = lower_root_info->lower_paths[bindex].dentry;
m = lower_root_info->lower_paths[bindex].mnt;
unionfs_set_lower_dentry_idx(sb->s_root, bindex, d);
unionfs_set_lower_mnt_idx(sb->s_root, bindex, m);
}
dbstart(sb->s_root) = bstart;
dbend(sb->s_root) = bend;
/* Set the generation number to one, since this is for the mount. */
atomic_set(&UNIONFS_D(sb->s_root)->generation, 1);
/*
* Call interpose to create the upper level inode. Only
* INTERPOSE_LOOKUP can return a value other than 0 on err.
*/
err = PTR_ERR(unionfs_interpose(sb->s_root, sb, 0));
unionfs_unlock_dentry(sb->s_root);
if (!err)
goto out;
/* else fall through */
out_freedpd:
if (UNIONFS_D(sb->s_root)) {
kfree(UNIONFS_D(sb->s_root)->lower_paths);
free_dentry_private_data(sb->s_root);
}
dput(sb->s_root);
out_dput:
if (lower_root_info && !IS_ERR(lower_root_info)) {
for (bindex = lower_root_info->bstart;
bindex <= lower_root_info->bend; bindex++) {
struct dentry *d;
struct vfsmount *m;
d = lower_root_info->lower_paths[bindex].dentry;
m = lower_root_info->lower_paths[bindex].mnt;
dput(d);
/* initializing: can't use unionfs_mntput here */
mntput(m);
/* drop refs we took earlier */
atomic_dec(&d->d_sb->s_active);
}
kfree(lower_root_info->lower_paths);
kfree(lower_root_info);
lower_root_info = NULL;
}
out_free:
kfree(UNIONFS_SB(sb)->data);
kfree(UNIONFS_SB(sb));
sb->s_fs_info = NULL;
out:
if (lower_root_info && !IS_ERR(lower_root_info)) {
kfree(lower_root_info->lower_paths);
kfree(lower_root_info);
}
return err;
}
int unionfs_ioctl_addbranch(struct inode *inode, unsigned int cmd,
unsigned long arg)
{
int err;
struct unionfs_addbranch_args *addargs = NULL;
struct nameidata nd;
char *path = NULL;
int gen;
int i;
int pobjects;
struct unionfs_usi_data *new_data = NULL;
struct dentry **new_udi_dentry = NULL;
struct inode **new_uii_inode = NULL;
struct dentry *root = NULL;
struct dentry *hidden_root = NULL;
print_entry_location();
err = -ENOMEM;
addargs = KMALLOC(sizeof(struct unionfs_addbranch_args), GFP_KERNEL);
if (!addargs)
goto out;
err = -EFAULT;
if (copy_from_user
(addargs, (const void __user *)arg,
sizeof(struct unionfs_addbranch_args)))
goto out;
err = -EINVAL;
if (addargs->ab_perms & ~(MAY_READ | MAY_WRITE | MAY_NFSRO))
goto out;
if (!(addargs->ab_perms & MAY_READ))
goto out;
err = -E2BIG;
if (sbend(inode->i_sb) > FD_SETSIZE)
goto out;
err = -ENOMEM;
if (!(path = getname((const char __user *)addargs->ab_path)))
goto out;
err = path_lookup(path, LOOKUP_FOLLOW, &nd);
RECORD_PATH_LOOKUP(&nd);
if (err)
goto out;
if ((err = check_branch(&nd))) {
path_release(&nd);
RECORD_PATH_RELEASE(&nd);
goto out;
}
unionfs_write_lock(inode->i_sb);
lock_dentry(inode->i_sb->s_root);
root = inode->i_sb->s_root;
for (i = dbstart(inode->i_sb->s_root); i <= dbend(inode->i_sb->s_root);
i++) {
hidden_root = dtohd_index(root, i);
if (is_branch_overlap(hidden_root, nd.dentry)) {
err = -EINVAL;
goto out;
}
}
err = -EINVAL;
if (addargs->ab_branch < 0
|| (addargs->ab_branch > (sbend(inode->i_sb) + 1)))
goto out;
if ((err = newputmap(inode->i_sb)))
goto out;
stopd(inode->i_sb)->b_end++;
dtopd(inode->i_sb->s_root)->udi_bcount++;
set_dbend(inode->i_sb->s_root, dbend(inode->i_sb->s_root) + 1);
itopd(inode->i_sb->s_root->d_inode)->b_end++;
atomic_inc(&stopd(inode->i_sb)->usi_generation);
gen = atomic_read(&stopd(inode->i_sb)->usi_generation);
pobjects = sbend(inode->i_sb) + 1;
/* Reallocate the dynamic structures. */
new_data = alloc_new_data(pobjects);
new_udi_dentry = alloc_new_dentries(pobjects);
new_uii_inode = KZALLOC(sizeof(struct inode *) * pobjects, GFP_KERNEL);
if (!new_udi_dentry || !new_uii_inode || !new_data) {
err = -ENOMEM;
goto out;
}
/* Copy the in-place values to our new structure. */
for (i = 0; i < addargs->ab_branch; i++) {
atomic_set(&(new_data[i].sbcount),
branch_count(inode->i_sb, i));
new_data[i].branchperms = branchperms(inode->i_sb, i);
new_data[i].hidden_mnt = stohiddenmnt_index(inode->i_sb, i);
new_data[i].sb = stohs_index(inode->i_sb, i);
new_udi_dentry[i] = dtohd_index(inode->i_sb->s_root, i);
new_uii_inode[i] = itohi_index(inode->i_sb->s_root->d_inode, i);
}
/* Shift the ends to the right (only handle reallocated bits). */
for (i = sbend(inode->i_sb) - 1; i >= (int)addargs->ab_branch; i--) {
int j = i + 1;
int pmindex;
atomic_set(&new_data[j].sbcount, branch_count(inode->i_sb, i));
new_data[j].branchperms = branchperms(inode->i_sb, i);
new_data[j].hidden_mnt = stohiddenmnt_index(inode->i_sb, i);
new_data[j].sb = stohs_index(inode->i_sb, i);
new_udi_dentry[j] = dtohd_index(inode->i_sb->s_root, i);
new_uii_inode[j] = itohi_index(inode->i_sb->s_root->d_inode, i);
/* Update the newest putmap, so it is correct for later. */
pmindex = stopd(inode->i_sb)->usi_lastputmap;
pmindex -= stopd(inode->i_sb)->usi_firstputmap;
stopd(inode->i_sb)->usi_putmaps[pmindex]->map[i] = j;
}
/* Now we can free the old ones. */
KFREE(dtopd(inode->i_sb->s_root)->udi_dentry);
KFREE(itopd(inode->i_sb->s_root->d_inode)->uii_inode);
KFREE(stopd(inode->i_sb)->usi_data);
/* Update the real pointers. */
dtohd_ptr(inode->i_sb->s_root) = new_udi_dentry;
itohi_ptr(inode->i_sb->s_root->d_inode) = new_uii_inode;
stopd(inode->i_sb)->usi_data = new_data;
/* Re-NULL the new ones so we don't try to free them. */
new_data = NULL;
new_udi_dentry = NULL;
new_uii_inode = NULL;
/* Put the new dentry information into it's slot. */
set_dtohd_index(inode->i_sb->s_root, addargs->ab_branch, nd.dentry);
set_itohi_index(inode->i_sb->s_root->d_inode, addargs->ab_branch,
IGRAB(nd.dentry->d_inode));
set_branchperms(inode->i_sb, addargs->ab_branch, addargs->ab_perms);
set_branch_count(inode->i_sb, addargs->ab_branch, 0);
set_stohiddenmnt_index(inode->i_sb, addargs->ab_branch, nd.mnt);
set_stohs_index(inode->i_sb, addargs->ab_branch, nd.dentry->d_sb);
atomic_set(&dtopd(inode->i_sb->s_root)->udi_generation, gen);
atomic_set(&itopd(inode->i_sb->s_root->d_inode)->uii_generation, gen);
fixputmaps(inode->i_sb);
out:
unlock_dentry(inode->i_sb->s_root);
unionfs_write_unlock(inode->i_sb);
KFREE(new_udi_dentry);
KFREE(new_uii_inode);
KFREE(new_data);
KFREE(addargs);
if (path)
putname(path);
print_exit_status(err);
return err;
}
/*
* There is no need to lock the unionfs_super_info's rwsem as there is no
* way anyone can have a reference to the superblock at this point in time.
*/
static int unionfs_read_super(struct super_block *sb, void *raw_data,
int silent)
{
int err = 0;
struct unionfs_dentry_info *lower_root_info = NULL;
int bindex, bstart, bend;
struct inode *inode = NULL;
if (!raw_data) {
printk(KERN_ERR
"unionfs: read_super: missing data argument\n");
err = -EINVAL;
goto out;
}
/* Allocate superblock private data */
sb->s_fs_info = kzalloc(sizeof(struct unionfs_sb_info), GFP_KERNEL);
if (unlikely(!UNIONFS_SB(sb))) {
printk(KERN_CRIT "unionfs: read_super: out of memory\n");
err = -ENOMEM;
goto out;
}
UNIONFS_SB(sb)->bend = -1;
atomic_set(&UNIONFS_SB(sb)->generation, 1);
init_rwsem(&UNIONFS_SB(sb)->rwsem);
UNIONFS_SB(sb)->high_branch_id = -1; /* -1 == invalid branch ID */
lower_root_info = unionfs_parse_options(sb, raw_data);
if (IS_ERR(lower_root_info)) {
printk(KERN_ERR
"unionfs: read_super: error while parsing options "
"(err = %ld)\n", PTR_ERR(lower_root_info));
err = PTR_ERR(lower_root_info);
lower_root_info = NULL;
goto out_free;
}
if (lower_root_info->bstart == -1) {
err = -ENOENT;
goto out_free;
}
/* set the lower superblock field of upper superblock */
bstart = lower_root_info->bstart;
BUG_ON(bstart != 0);
sbend(sb) = bend = lower_root_info->bend;
for (bindex = bstart; bindex <= bend; bindex++) {
struct dentry *d = lower_root_info->lower_paths[bindex].dentry;
atomic_inc(&d->d_sb->s_active);
unionfs_set_lower_super_idx(sb, bindex, d->d_sb);
}
/* max Bytes is the maximum bytes from highest priority branch */
sb->s_maxbytes = unionfs_lower_super_idx(sb, 0)->s_maxbytes;
/*
* Our c/m/atime granularity is 1 ns because we may stack on file
* systems whose granularity is as good. This is important for our
* time-based cache coherency.
*/
sb->s_time_gran = 1;
sb->s_op = &unionfs_sops;
/* get a new inode and allocate our root dentry */
inode = unionfs_iget(sb, iunique(sb, UNIONFS_ROOT_INO));
if (IS_ERR(inode)) {
err = PTR_ERR(inode);
goto out_dput;
}
sb->s_root = d_make_root(inode);
if (unlikely(!sb->s_root)) {
err = -ENOMEM;
goto out_iput;
}
d_set_d_op(sb->s_root, &unionfs_dops);
/* link the upper and lower dentries */
sb->s_root->d_fsdata = NULL;
err = new_dentry_private_data(sb->s_root, UNIONFS_DMUTEX_ROOT);
if (unlikely(err))
goto out_freedpd;
/* if get here: cannot have error */
/* Set the lower dentries for s_root */
for (bindex = bstart; bindex <= bend; bindex++) {
struct dentry *d;
struct vfsmount *m;
d = lower_root_info->lower_paths[bindex].dentry;
m = lower_root_info->lower_paths[bindex].mnt;
unionfs_set_lower_dentry_idx(sb->s_root, bindex, d);
unionfs_set_lower_mnt_idx(sb->s_root, bindex, m);
}
dbstart(sb->s_root) = bstart;
dbend(sb->s_root) = bend;
/* Set the generation number to one, since this is for the mount. */
atomic_set(&UNIONFS_D(sb->s_root)->generation, 1);
if (atomic_read(&inode->i_count) <= 1)
unionfs_fill_inode(sb->s_root, inode);
/*
* No need to call interpose because we already have a positive
* dentry, which was instantiated by d_alloc_root. Just need to
* d_rehash it.
*/
d_rehash(sb->s_root);
unionfs_unlock_dentry(sb->s_root);
goto out; /* all is well */
out_freedpd:
if (UNIONFS_D(sb->s_root)) {
kfree(UNIONFS_D(sb->s_root)->lower_paths);
free_dentry_private_data(sb->s_root);
}
dput(sb->s_root);
out_iput:
iput(inode);
out_dput:
if (lower_root_info && !IS_ERR(lower_root_info)) {
for (bindex = lower_root_info->bstart;
bindex <= lower_root_info->bend; bindex++) {
struct dentry *d;
d = lower_root_info->lower_paths[bindex].dentry;
/* drop refs we took earlier */
atomic_dec(&d->d_sb->s_active);
path_put(&lower_root_info->lower_paths[bindex]);
}
kfree(lower_root_info->lower_paths);
kfree(lower_root_info);
lower_root_info = NULL;
}
out_free:
kfree(UNIONFS_SB(sb)->data);
kfree(UNIONFS_SB(sb));
sb->s_fs_info = NULL;
out:
if (lower_root_info && !IS_ERR(lower_root_info)) {
kfree(lower_root_info->lower_paths);
kfree(lower_root_info);
}
return err;
}
static struct dentry *unionfs_d_alloc_root(struct super_block *sb)
{
struct dentry *ret = NULL;
if (sb) {
static const struct qstr name = {.name = "/",.len = 1 };
ret = d_alloc(NULL, &name);
if (ret) {
ret->d_op = &unionfs_dops;
ret->d_sb = sb;
ret->d_parent = ret;
}
}
return ret;
}
static int unionfs_read_super(struct super_block *sb, void *raw_data,
int silent)
{
int err = 0;
struct unionfs_dentry_info *hidden_root_info = NULL;
int bindex, bstart, bend;
unsigned long long maxbytes;
print_entry_location();
if (!raw_data) {
printk(KERN_WARNING
"unionfs_read_super: missing data argument\n");
err = -EINVAL;
goto out;
}
/*
* Allocate superblock private data
*/
stopd_lhs(sb) = KZALLOC(sizeof(struct unionfs_sb_info), GFP_KERNEL);
if (!stopd(sb)) {
printk(KERN_WARNING "%s: out of memory\n", __FUNCTION__);
err = -ENOMEM;
goto out;
}
stopd(sb)->b_end = -1;
atomic_set(&stopd(sb)->usi_generation, 1);
init_rwsem(&stopd(sb)->usi_rwsem);
hidden_root_info = unionfs_parse_options(sb, raw_data);
if (IS_ERR(hidden_root_info)) {
printk(KERN_WARNING
"unionfs_read_super: error while parsing options (err = %ld)\n",
PTR_ERR(hidden_root_info));
err = PTR_ERR(hidden_root_info);
hidden_root_info = NULL;
goto out_free;
}
if (hidden_root_info->udi_bstart == -1) {
err = -ENOENT;
goto out_free;
}
/* set the hidden superblock field of upper superblock */
bstart = hidden_root_info->udi_bstart;
BUG_ON(bstart != 0);
sbend(sb) = bend = hidden_root_info->udi_bend;
for (bindex = bstart; bindex <= bend; bindex++) {
struct dentry *d;
d = hidden_root_info->udi_dentry[bindex];
set_stohs_index(sb, bindex, d->d_sb);
}
/* Unionfs: Max Bytes is the maximum bytes from among all the branches */
maxbytes = -1;
for (bindex = bstart; bindex <= bend; bindex++)
if (maxbytes < stohs_index(sb, bindex)->s_maxbytes)
maxbytes = stohs_index(sb, bindex)->s_maxbytes;
sb->s_maxbytes = maxbytes;
sb->s_op = &unionfs_sops;
sb->s_export_op = &unionfs_export_ops;
/*
* we can't use d_alloc_root if we want to use
* our own interpose function unchanged,
* so we simply call our own "fake" d_alloc_root
*/
sb->s_root = unionfs_d_alloc_root(sb);
if (!sb->s_root) {
err = -ENOMEM;
goto out_dput;
}
/* link the upper and lower dentries */
dtopd_lhs(sb->s_root) = NULL;
if ((err = new_dentry_private_data(sb->s_root)))
goto out_freedpd;
/* Set the hidden dentries for s_root */
for (bindex = bstart; bindex <= bend; bindex++) {
struct dentry *d;
d = hidden_root_info->udi_dentry[bindex];
set_dtohd_index(sb->s_root, bindex, d);
}
set_dbstart(sb->s_root, bstart);
set_dbend(sb->s_root, bend);
/* Set the generation number to one, since this is for the mount. */
atomic_set(&dtopd(sb->s_root)->udi_generation, 1);
/* call interpose to create the upper level inode */
if ((err = unionfs_interpose(sb->s_root, sb, 0)))
goto out_freedpd;
unlock_dentry(sb->s_root);
goto out;
out_freedpd:
if (dtopd(sb->s_root)) {
KFREE(dtohd_ptr(sb->s_root));
free_dentry_private_data(dtopd(sb->s_root));
}
DPUT(sb->s_root);
out_dput:
if (hidden_root_info && !IS_ERR(hidden_root_info)) {
for (bindex = hidden_root_info->udi_bstart;
bindex <= hidden_root_info->udi_bend; bindex++) {
struct dentry *d;
d = hidden_root_info->udi_dentry[bindex];
if (d)
DPUT(d);
if (stopd(sb) && stohiddenmnt_index(sb, bindex))
mntput(stohiddenmnt_index(sb, bindex));
}
KFREE(hidden_root_info->udi_dentry);
KFREE(hidden_root_info);
hidden_root_info = NULL;
}
out_free:
KFREE(stopd(sb)->usi_data);
KFREE(stopd(sb));
stopd_lhs(sb) = NULL;
out:
if (hidden_root_info && !IS_ERR(hidden_root_info)) {
KFREE(hidden_root_info->udi_dentry);
KFREE(hidden_root_info);
}
print_exit_status(err);
return err;
}