int au_reopen_nondir(struct file *file)
{
int err;
aufs_bindex_t bstart;
struct dentry *dentry;
struct file *h_file, *h_file_tmp;
dentry = file->f_dentry;
AuDebugOn(au_special_file(dentry->d_inode->i_mode));
bstart = au_dbstart(dentry);
h_file_tmp = NULL;
if (au_fbstart(file) == bstart) {
h_file = au_hf_top(file);
if (file->f_mode == h_file->f_mode)
return 0; /* success */
h_file_tmp = h_file;
get_file(h_file_tmp);
au_set_h_fptr(file, bstart, NULL);
}
AuDebugOn(au_fi(file)->fi_hdir);
/*
* it can happen
* file exists on both of rw and ro
* open --> dbstart and fbstart are both 0
* prepend a branch as rw, "rw" become ro
* remove rw/file
* delete the top branch, "rw" becomes rw again
* --> dbstart is 1, fbstart is still 0
* write --> fbstart is 0 but dbstart is 1
*/
/* AuDebugOn(au_fbstart(file) < bstart); */
h_file = au_h_open(dentry, bstart, vfsub_file_flags(file) & ~O_TRUNC,
file, /*force_wr*/0);
err = PTR_ERR(h_file);
if (IS_ERR(h_file)) {
if (h_file_tmp) {
atomic_inc(&au_sbr(dentry->d_sb, bstart)->br_count);
au_set_h_fptr(file, bstart, h_file_tmp);
h_file_tmp = NULL;
}
goto out; /* todo: close all? */
}
err = 0;
au_set_fbstart(file, bstart);
au_set_h_fptr(file, bstart, h_file);
au_update_figen(file);
/* todo: necessary? */
/* file->f_ra = h_file->f_ra; */
out:
if (h_file_tmp)
fput(h_file_tmp);
return err;
}
/* common function to regular file and dir */
int au_reval_and_lock_fdi(struct file *file, int (*reopen)(struct file *file),
int wlock)
{
int err;
unsigned int sigen, figen;
aufs_bindex_t bstart;
unsigned char pseudo_link;
struct dentry *dentry;
struct inode *inode;
err = 0;
dentry = file->f_dentry;
inode = dentry->d_inode;
AuDebugOn(au_special_file(inode->i_mode));
sigen = au_sigen(dentry->d_sb);
fi_write_lock(file);
figen = au_figen(file);
di_write_lock_child(dentry);
bstart = au_dbstart(dentry);
pseudo_link = (bstart != au_ibstart(inode));
if (sigen == figen && !pseudo_link && au_fbstart(file) == bstart) {
if (!wlock) {
di_downgrade_lock(dentry, AuLock_IR);
fi_downgrade_lock(file);
}
goto out; /* success */
}
AuDbg("sigen %d, figen %d\n", sigen, figen);
if (sigen != au_digen(dentry)
|| sigen != au_iigen(inode)) {
err = au_reval_dpath(dentry, sigen);
if (unlikely(err < 0))
goto out;
AuDebugOn(au_digen(dentry) != sigen
|| au_iigen(inode) != sigen);
}
err = refresh_file(file, reopen);
if (!err) {
if (!wlock) {
di_downgrade_lock(dentry, AuLock_IR);
fi_downgrade_lock(file);
}
} else {
di_write_unlock(dentry);
fi_write_unlock(file);
}
out:
return err;
}
int au_reopen_nondir(struct file *file)
{
int err;
aufs_bindex_t bstart, bindex, bend;
struct dentry *dentry;
struct file *h_file, *h_file_tmp;
dentry = file->f_dentry;
AuDebugOn(au_special_file(dentry->d_inode->i_mode));
bstart = au_dbstart(dentry);
h_file_tmp = NULL;
if (au_fbstart(file) == bstart) {
h_file = au_h_fptr(file, bstart);
if (file->f_mode == h_file->f_mode)
return 0; /* success */
h_file_tmp = h_file;
get_file(h_file_tmp);
au_set_h_fptr(file, bstart, NULL);
}
AuDebugOn(au_fbstart(file) < bstart
|| au_fi(file)->fi_hfile[0 + bstart].hf_file);
h_file = au_h_open(dentry, bstart, vfsub_file_flags(file) & ~O_TRUNC,
file);
err = PTR_ERR(h_file);
if (IS_ERR(h_file))
goto out; /* todo: close all? */
err = 0;
au_set_fbstart(file, bstart);
au_set_h_fptr(file, bstart, h_file);
au_update_figen(file);
/* todo: necessary? */
/* file->f_ra = h_file->f_ra; */
/* close lower files */
bend = au_fbend(file);
for (bindex = bstart + 1; bindex <= bend; bindex++)
au_set_h_fptr(file, bindex, NULL);
au_set_fbend(file, bstart);
out:
if (h_file_tmp)
fput(h_file_tmp);
return err;
}
int au_reopen_nondir(struct file *file)
{
int err;
aufs_bindex_t bstart;
struct dentry *dentry;
struct file *h_file, *h_file_tmp;
dentry = file->f_dentry;
AuDebugOn(au_special_file(dentry->d_inode->i_mode));
bstart = au_dbstart(dentry);
h_file_tmp = NULL;
if (au_fbstart(file) == bstart) {
h_file = au_hf_top(file);
if (file->f_mode == h_file->f_mode)
return 0; /* success */
h_file_tmp = h_file;
get_file(h_file_tmp);
au_set_h_fptr(file, bstart, NULL);
}
AuDebugOn(au_fi(file)->fi_hdir);
AuDebugOn(au_fbstart(file) < bstart);
h_file = au_h_open(dentry, bstart, file->f_flags & ~O_TRUNC, file);
err = PTR_ERR(h_file);
if (IS_ERR(h_file))
goto out; /* todo: close all? */
err = 0;
au_set_fbstart(file, bstart);
au_set_h_fptr(file, bstart, h_file);
au_update_figen(file);
/* todo: necessary? */
/* file->f_ra = h_file->f_ra; */
out:
if (h_file_tmp)
fput(h_file_tmp);
return err;
}
/* common functions to regular file and dir */
struct file *au_h_open(struct dentry *dentry, aufs_bindex_t bindex, int flags,
struct file *file)
{
struct file *h_file;
struct dentry *h_dentry;
struct inode *h_inode;
struct super_block *sb;
struct au_branch *br;
struct path h_path;
int err, exec_flag;
/* a race condition can happen between open and unlink/rmdir */
h_file = ERR_PTR(-ENOENT);
h_dentry = au_h_dptr(dentry, bindex);
if (au_test_nfsd() && !h_dentry)
goto out;
h_inode = h_dentry->d_inode;
if (au_test_nfsd() && !h_inode)
goto out;
spin_lock(&h_dentry->d_lock);
err = (!d_unhashed(dentry) && d_unlinked(h_dentry))
|| !h_inode
/* || !dentry->d_inode->i_nlink */
;
spin_unlock(&h_dentry->d_lock);
if (unlikely(err))
goto out;
sb = dentry->d_sb;
br = au_sbr(sb, bindex);
h_file = ERR_PTR(-EACCES);
exec_flag = flags & __FMODE_EXEC;
if (exec_flag && (br->br_mnt->mnt_flags & MNT_NOEXEC))
goto out;
/* drop flags for writing */
if (au_test_ro(sb, bindex, dentry->d_inode))
flags = au_file_roflags(flags);
flags &= ~O_CREAT;
atomic_inc(&br->br_count);
h_path.dentry = h_dentry;
h_path.mnt = br->br_mnt;
if (!au_special_file(h_inode->i_mode))
h_file = vfsub_dentry_open(&h_path, flags);
else {
/* this block depends upon the configuration */
di_read_unlock(dentry, AuLock_IR);
fi_write_unlock(file);
si_read_unlock(sb);
h_file = vfsub_dentry_open(&h_path, flags);
si_noflush_read_lock(sb);
fi_write_lock(file);
di_read_lock_child(dentry, AuLock_IR);
}
if (IS_ERR(h_file))
goto out_br;
if (exec_flag) {
err = deny_write_access(h_file);
if (unlikely(err)) {
fput(h_file);
h_file = ERR_PTR(err);
goto out_br;
}
}
fsnotify_open(h_file);
goto out; /* success */
out_br:
atomic_dec(&br->br_count);
out:
return h_file;
}
/*
* prepare the @file for writing.
*/
int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
{
int err;
aufs_bindex_t bstart, bcpup, dbstart;
struct dentry *dentry, *parent, *h_dentry;
struct inode *h_inode, *inode;
struct super_block *sb;
struct file *h_file;
dentry = file->f_dentry;
sb = dentry->d_sb;
inode = dentry->d_inode;
AuDebugOn(au_special_file(inode->i_mode));
bstart = au_fbstart(file);
err = au_test_ro(sb, bstart, inode);
if (!err && (au_hf_top(file)->f_mode & FMODE_WRITE)) {
err = au_pin(pin, dentry, bstart, AuOpt_UDBA_NONE, /*flags*/0);
goto out;
}
/* need to cpup or reopen */
parent = dget_parent(dentry);
di_write_lock_parent(parent);
err = AuWbrCopyup(au_sbi(sb), dentry);
bcpup = err;
if (unlikely(err < 0))
goto out_dgrade;
err = 0;
if (!d_unhashed(dentry) && !au_h_dptr(parent, bcpup)) {
err = au_cpup_dirs(dentry, bcpup);
if (unlikely(err))
goto out_dgrade;
}
err = au_pin(pin, dentry, bcpup, AuOpt_UDBA_NONE,
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
if (unlikely(err))
goto out_dgrade;
h_dentry = au_hf_top(file)->f_dentry;
h_inode = h_dentry->d_inode;
dbstart = au_dbstart(dentry);
if (dbstart <= bcpup) {
h_dentry = au_h_dptr(dentry, bcpup);
AuDebugOn(!h_dentry);
h_inode = h_dentry->d_inode;
AuDebugOn(!h_inode);
bstart = bcpup;
}
if (dbstart <= bcpup /* just reopen */
|| !d_unhashed(dentry) /* copyup and reopen */
) {
mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
h_file = au_h_open_pre(dentry, bstart);
if (IS_ERR(h_file)) {
err = PTR_ERR(h_file);
h_file = NULL;
} else {
di_downgrade_lock(parent, AuLock_IR);
if (dbstart > bcpup)
err = au_sio_cpup_simple(dentry, bcpup, len,
AuCpup_DTIME);
if (!err)
err = au_reopen_nondir(file);
}
mutex_unlock(&h_inode->i_mutex);
au_h_open_post(dentry, bstart, h_file);
} else { /* copyup as wh and reopen */
/*
* since writable hfsplus branch is not supported,
* h_open_pre/post() are unnecessary.
*/
mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
err = au_ready_to_write_wh(file, len, bcpup);
di_downgrade_lock(parent, AuLock_IR);
mutex_unlock(&h_inode->i_mutex);
}
if (!err) {
au_pin_set_parent_lflag(pin, /*lflag*/0);
goto out_dput; /* success */
}
au_unpin(pin);
goto out_unlock;
out_dgrade:
di_downgrade_lock(parent, AuLock_IR);
out_unlock:
di_read_unlock(parent, AuLock_IR);
out_dput:
dput(parent);
out:
return err;
}
/*
* prepare the @file for writing.
*/
int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
{
int err;
aufs_bindex_t bstart, bcpup;
struct dentry *dentry, *parent, *h_dentry;
struct inode *h_inode, *inode;
struct super_block *sb;
dentry = file->f_dentry;
sb = dentry->d_sb;
inode = dentry->d_inode;
AuDebugOn(au_special_file(inode->i_mode));
bstart = au_fbstart(file);
err = au_test_ro(sb, bstart, inode);
if (!err && (au_h_fptr(file, bstart)->f_mode & FMODE_WRITE)) {
err = au_pin(pin, dentry, bstart, AuOpt_UDBA_NONE, /*flags*/0);
goto out;
}
/* need to cpup */
parent = dget_parent(dentry);
di_write_lock_parent(parent);
err = AuWbrCopyup(au_sbi(sb), dentry);
bcpup = err;
if (unlikely(err < 0))
goto out_dgrade;
err = 0;
if (!au_h_dptr(parent, bcpup)) {
err = au_cpup_dirs(dentry, bcpup);
if (unlikely(err))
goto out_dgrade;
}
err = au_pin(pin, dentry, bcpup, AuOpt_UDBA_NONE,
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
if (unlikely(err))
goto out_dgrade;
h_dentry = au_h_fptr(file, bstart)->f_dentry;
h_inode = h_dentry->d_inode;
mutex_lock_nested(&h_inode->i_mutex, AuLsc_I_CHILD);
if (d_unhashed(dentry) /* || d_unhashed(h_dentry) */
/* || !h_inode->i_nlink */) {
err = au_ready_to_write_wh(file, len, bcpup);
di_downgrade_lock(parent, AuLock_IR);
} else {
di_downgrade_lock(parent, AuLock_IR);
if (!au_h_dptr(dentry, bcpup))
err = au_sio_cpup_simple(dentry, bcpup, len,
AuCpup_DTIME);
if (!err)
err = au_reopen_nondir(file);
}
mutex_unlock(&h_inode->i_mutex);
if (!err) {
au_pin_set_parent_lflag(pin, /*lflag*/0);
goto out_dput; /* success */
}
au_unpin(pin);
goto out_unlock;
out_dgrade:
di_downgrade_lock(parent, AuLock_IR);
out_unlock:
di_read_unlock(parent, AuLock_IR);
out_dput:
dput(parent);
out:
return err;
}
static int au_ready_to_write_wh(struct file *file, loff_t len,
aufs_bindex_t bcpup, struct au_pin *pin)
{
int err;
struct inode *inode, *h_inode;
struct dentry *h_dentry, *hi_wh;
struct au_cp_generic cpg = {
.dentry = file->f_dentry,
.bdst = bcpup,
.bsrc = -1,
.len = len,
.pin = pin
};
au_update_dbstart(cpg.dentry);
inode = cpg.dentry->d_inode;
h_inode = NULL;
if (au_dbstart(cpg.dentry) <= bcpup
&& au_dbend(cpg.dentry) >= bcpup) {
h_dentry = au_h_dptr(cpg.dentry, bcpup);
if (h_dentry)
h_inode = h_dentry->d_inode;
}
hi_wh = au_hi_wh(inode, bcpup);
if (!hi_wh && !h_inode)
err = au_sio_cpup_wh(&cpg, file);
else
/* already copied-up after unlink */
err = au_reopen_wh(file, bcpup, hi_wh);
if (!err
&& inode->i_nlink > 1
&& au_opt_test(au_mntflags(cpg.dentry->d_sb), PLINK))
au_plink_append(inode, bcpup, au_h_dptr(cpg.dentry, bcpup));
return err;
}
/*
* prepare the @file for writing.
*/
int au_ready_to_write(struct file *file, loff_t len, struct au_pin *pin)
{
int err;
aufs_bindex_t dbstart;
struct dentry *parent, *h_dentry;
struct inode *inode;
struct super_block *sb;
struct file *h_file;
struct au_cp_generic cpg = {
.dentry = file->f_dentry,
.bdst = -1,
.bsrc = -1,
.len = len,
.pin = pin,
.flags = AuCpup_DTIME
};
sb = cpg.dentry->d_sb;
inode = cpg.dentry->d_inode;
AuDebugOn(au_special_file(inode->i_mode));
cpg.bsrc = au_fbstart(file);
err = au_test_ro(sb, cpg.bsrc, inode);
if (!err && (au_hf_top(file)->f_mode & FMODE_WRITE)) {
err = au_pin(pin, cpg.dentry, cpg.bsrc, AuOpt_UDBA_NONE,
/*flags*/0);
goto out;
}
/* need to cpup or reopen */
parent = dget_parent(cpg.dentry);
di_write_lock_parent(parent);
err = AuWbrCopyup(au_sbi(sb), cpg.dentry);
cpg.bdst = err;
if (unlikely(err < 0))
goto out_dgrade;
err = 0;
if (!d_unhashed(cpg.dentry) && !au_h_dptr(parent, cpg.bdst)) {
err = au_cpup_dirs(cpg.dentry, cpg.bdst);
if (unlikely(err))
goto out_dgrade;
}
err = au_pin(pin, cpg.dentry, cpg.bdst, AuOpt_UDBA_NONE,
AuPin_DI_LOCKED | AuPin_MNT_WRITE);
if (unlikely(err))
goto out_dgrade;
h_dentry = au_hf_top(file)->f_dentry;
dbstart = au_dbstart(cpg.dentry);
if (dbstart <= cpg.bdst) {
h_dentry = au_h_dptr(cpg.dentry, cpg.bdst);
AuDebugOn(!h_dentry);
cpg.bsrc = cpg.bdst;
}
if (dbstart <= cpg.bdst /* just reopen */
|| !d_unhashed(cpg.dentry) /* copyup and reopen */
) {
h_file = au_h_open_pre(cpg.dentry, cpg.bsrc, /*force_wr*/0);
if (IS_ERR(h_file))
err = PTR_ERR(h_file);
else {
di_downgrade_lock(parent, AuLock_IR);
if (dbstart > cpg.bdst)
err = au_sio_cpup_simple(&cpg);
if (!err)
err = au_reopen_nondir(file);
au_h_open_post(cpg.dentry, cpg.bsrc, h_file);
}
} else { /* copyup as wh and reopen */
/*
* since writable hfsplus branch is not supported,
* h_open_pre/post() are unnecessary.
*/
err = au_ready_to_write_wh(file, len, cpg.bdst, pin);
di_downgrade_lock(parent, AuLock_IR);
}
if (!err) {
au_pin_set_parent_lflag(pin, /*lflag*/0);
goto out_dput; /* success */
}
au_unpin(pin);
goto out_unlock;
out_dgrade:
di_downgrade_lock(parent, AuLock_IR);
out_unlock:
di_read_unlock(parent, AuLock_IR);
out_dput:
dput(parent);
out:
return err;
}
/* ---------------------------------------------------------------------- */
int au_do_flush(struct file *file, fl_owner_t id,
int (*flush)(struct file *file, fl_owner_t id))
{
int err;
struct super_block *sb;
struct inode *inode;
inode = file_inode(file);
sb = inode->i_sb;
si_noflush_read_lock(sb);
fi_read_lock(file);
ii_read_lock_child(inode);
err = flush(file, id);
au_cpup_attr_timesizes(inode);
ii_read_unlock(inode);
fi_read_unlock(file);
si_read_unlock(sb);
return err;
}