overlayfs fixes for 5.6-rc6

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Merge tag 'ovl-fixes-5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs fixes from Miklos Szeredi:
 "Fix three bugs introduced in this cycle"

* tag 'ovl-fixes-5.6-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: fix lockdep warning for async write
  ovl: fix some xino configurations
  ovl: fix lock in ovl_llseek()
This commit is contained in:
Linus Torvalds 2020-03-13 15:17:21 -07:00
commit 2af82177af
5 changed files with 23 additions and 4 deletions

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@ -93,6 +93,7 @@ config OVERLAY_FS_XINO_AUTO
bool "Overlayfs: auto enable inode number mapping"
default n
depends on OVERLAY_FS
depends on 64BIT
help
If this config option is enabled then overlay filesystems will use
unused high bits in undelying filesystem inode numbers to map all

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@ -244,6 +244,9 @@ static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req)
if (iocb->ki_flags & IOCB_WRITE) {
struct inode *inode = file_inode(orig_iocb->ki_filp);
/* Actually acquired in ovl_write_iter() */
__sb_writers_acquired(file_inode(iocb->ki_filp)->i_sb,
SB_FREEZE_WRITE);
file_end_write(iocb->ki_filp);
ovl_copyattr(ovl_inode_real(inode), inode);
}
@ -346,6 +349,9 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
goto out;
file_start_write(real.file);
/* Pacify lockdep, same trick as done in aio_write() */
__sb_writers_release(file_inode(real.file)->i_sb,
SB_FREEZE_WRITE);
aio_req->fd = real;
real.flags = 0;
aio_req->orig_iocb = iocb;

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@ -318,7 +318,12 @@ static inline unsigned int ovl_xino_bits(struct super_block *sb)
return ovl_same_dev(sb) ? OVL_FS(sb)->xino_mode : 0;
}
static inline int ovl_inode_lock(struct inode *inode)
static inline void ovl_inode_lock(struct inode *inode)
{
mutex_lock(&OVL_I(inode)->lock);
}
static inline int ovl_inode_lock_interruptible(struct inode *inode)
{
return mutex_lock_interruptible(&OVL_I(inode)->lock);
}

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@ -1411,6 +1411,8 @@ static int ovl_get_layers(struct super_block *sb, struct ovl_fs *ofs,
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_OFF) {
ofs->xino_mode = -1;
} else if (ofs->config.xino == OVL_XINO_ON && ofs->xino_mode < 0) {
/*
* This is a roundup of number of bits needed for encoding
@ -1623,8 +1625,13 @@ static int ovl_fill_super(struct super_block *sb, void *data, int silent)
sb->s_stack_depth = 0;
sb->s_maxbytes = MAX_LFS_FILESIZE;
/* Assume underlaying fs uses 32bit inodes unless proven otherwise */
if (ofs->config.xino != OVL_XINO_OFF)
if (ofs->config.xino != OVL_XINO_OFF) {
ofs->xino_mode = BITS_PER_LONG - 32;
if (!ofs->xino_mode) {
pr_warn("xino not supported on 32bit kernel, falling back to xino=off.\n");
ofs->config.xino = OVL_XINO_OFF;
}
}
/* alloc/destroy_inode needed for setting up traps in inode cache */
sb->s_op = &ovl_super_operations;

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@ -509,7 +509,7 @@ int ovl_copy_up_start(struct dentry *dentry, int flags)
struct inode *inode = d_inode(dentry);
int err;
err = ovl_inode_lock(inode);
err = ovl_inode_lock_interruptible(inode);
if (!err && ovl_already_copied_up_locked(dentry, flags)) {
err = 1; /* Already copied up */
ovl_inode_unlock(inode);
@ -764,7 +764,7 @@ int ovl_nlink_start(struct dentry *dentry)
return err;
}
err = ovl_inode_lock(inode);
err = ovl_inode_lock_interruptible(inode);
if (err)
return err;