orangefs: fix deadlock; do not write i_size in read_iter

commit 6793f1c450b1533a5e9c2493490de771d38b24f9 upstream.

After do_readv_writev, the inode cache is invalidated anyway, so i_size
will never be read.  It will be fetched from the server which will also
know about updates from other machines.

Fixes deadlock on 32-bit SMP.

See https://marc.info/?l=linux-fsdevel&m=151268557427760&w=2

Signed-off-by: Martin Brandenburg <martin@omnibond.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Mike Marshall <hubcap@omnibond.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/orangefs/file.c b/fs/orangefs/file.c
index e4a8e6a7eb17b6aaa4b0ab5bf34e16b514c0ea82..962bf4824283d04fa302679dac93dae629cf378e 100644 (file)
--- a/fs/orangefs/file.c
+++ b/fs/orangefs/file.c
@@ -446,7 +446,7 @@ ssize_t orangefs_inode_read(struct inode *inode,
 static ssize_t orangefs_file_read_iter(struct kiocb *iocb, struct iov_iter *iter)
 {
        struct file *file = iocb->ki_filp;
-       loff_t pos = *(&iocb->ki_pos);
+       loff_t pos = iocb->ki_pos;
        ssize_t rc = 0;
 
        BUG_ON(iocb->private);
@@ -486,9 +486,6 @@ static ssize_t orangefs_file_write_iter(struct kiocb *iocb, struct iov_iter *ite
                }
        }
 
-       if (file->f_pos > i_size_read(file->f_mapping->host))
-               orangefs_i_size_write(file->f_mapping->host, file->f_pos);
-
        rc = generic_write_checks(iocb, iter);
 
        if (rc <= 0) {
@@ -502,7 +499,7 @@ static ssize_t orangefs_file_write_iter(struct kiocb *iocb, struct iov_iter *ite
         * pos to the end of the file, so we will wait till now to set
         * pos...
         */
-       pos = *(&iocb->ki_pos);
+       pos = iocb->ki_pos;
 
        rc = do_readv_writev(ORANGEFS_IO_WRITE,
                             file,

diff --git a/fs/orangefs/orangefs-kernel.h b/fs/orangefs/orangefs-kernel.h
index 004af348fb80ec5204a662b5787dfddec3aff153..c244bbf494bc501b33d3573b63c72be0482cd9f1 100644 (file)
--- a/fs/orangefs/orangefs-kernel.h
+++ b/fs/orangefs/orangefs-kernel.h
@@ -566,17 +566,6 @@ do {                                                                       \
        sys_attr.mask = ORANGEFS_ATTR_SYS_ALL_SETABLE;                  \
 } while (0)
 
-static inline void orangefs_i_size_write(struct inode *inode, loff_t i_size)
-{
-#if BITS_PER_LONG == 32 && defined(CONFIG_SMP)
-       inode_lock(inode);
-#endif
-       i_size_write(inode, i_size);
-#if BITS_PER_LONG == 32 && defined(CONFIG_SMP)
-       inode_unlock(inode);
-#endif
-}
-
 static inline void orangefs_set_timeout(struct dentry *dentry)
 {
        unsigned long time = jiffies + orangefs_dcache_timeout_msecs*HZ/1000;