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ANDROID: sdcardfs: Hold i_mutex for i_size_write

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When we call i_size_write, we must be holding i_mutex to avoid
possible lockups on 32 bit/SMP architectures. This is not
necessary on 64 bit architectures.

Change-Id: Ic3b946507c54d81b5c9046f9b57d25d4b0f9feef
Signed-off-by: Daniel Rosenberg <drosen@google.com>
Bug: 73287721
This commit is contained in:
Daniel Rosenberg 2018-02-20 20:25:45 -08:00 committed by Amit Pundir
parent 8295827beb
commit 817be5a7e2
1 changed files with 14 additions and 8 deletions
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22
fs/sdcardfs/file.c
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@ -62,6 +62,7 @@ static ssize_t sdcardfs_write(struct file *file, const char __user *buf,
int err;
struct file *lower_file;
struct dentry *dentry = file->f_path.dentry;
struct inode *inode = d_inode(dentry);
/* check disk space */
if (!check_min_free_space(dentry, count, 0)) {
@ -73,10 +74,12 @@ static ssize_t sdcardfs_write(struct file *file, const char __user *buf,
err = vfs_write(lower_file, buf, count, ppos);
/* update our inode times+sizes upon a successful lower write */
if (err >= 0) {
fsstack_copy_inode_size(d_inode(dentry),
file_inode(lower_file));
fsstack_copy_attr_times(d_inode(dentry),
file_inode(lower_file));
if (sizeof(loff_t) > sizeof(long))
inode_lock(inode);
fsstack_copy_inode_size(inode, file_inode(lower_file));
fsstack_copy_attr_times(inode, file_inode(lower_file));
if (sizeof(loff_t) > sizeof(long))
inode_unlock(inode);
}
return err;
@ -391,6 +394,7 @@ ssize_t sdcardfs_write_iter(struct kiocb *iocb, struct iov_iter *iter)
{
int err;
struct file *file = iocb->ki_filp, *lower_file;
struct inode *inode = file->f_path.dentry->d_inode;
lower_file = sdcardfs_lower_file(file);
if (!lower_file->f_op->write_iter) {
@ -405,10 +409,12 @@ ssize_t sdcardfs_write_iter(struct kiocb *iocb, struct iov_iter *iter)
fput(lower_file);
/* update upper inode times/sizes as needed */
if (err >= 0 || err == -EIOCBQUEUED) {
fsstack_copy_inode_size(file->f_path.dentry->d_inode,
file_inode(lower_file));
fsstack_copy_attr_times(file->f_path.dentry->d_inode,
file_inode(lower_file));
if (sizeof(loff_t) > sizeof(long))
inode_lock(inode);
fsstack_copy_inode_size(inode, file_inode(lower_file));
fsstack_copy_attr_times(inode, file_inode(lower_file));
if (sizeof(loff_t) > sizeof(long))
inode_lock(inode);
}
out:
return err;