Commit 2ef13294 authored by Artem Bityutskiy's avatar Artem Bityutskiy
Browse files

UBIFS: introduce new flags for RO mounts 



Commit 2fde99cb "UBIFS: mark VFS SB RO too"
introduced regression. This commit made UBIFS set the 'MS_RDONLY' flag in the
VFS superblock when it switches to R/O mode due to an error. This was done
to make VFS show the R/O UBIFS flag in /proc/mounts.

However, several places in UBIFS relied on the 'MS_RDONLY' flag and assume this
flag can only change when we re-mount. For example, 'ubifs_put_super()'.

This patch introduces new UBIFS flag - 'c->ro_mount' which changes only when
we re-mount, and preserves the way UBIFS was originally mounted (R/W or R/O).
This allows us to de-initialize UBIFS cleanly in 'ubifs_put_super()'.

This patch also changes all 'ubifs_assert(!c->ro_media)' assertions to
'ubifs_assert(!c->ro_media && !c->ro_mount)', because we never should write
anything if the FS was mounter R/O.

All the places where we test for 'MS_RDONLY' flag in the VFS SB were changed
and now we test the 'c->ro_mount' flag instead, because it preserves the
original UBIFS mount type, unlike the 'MS_RDONLY' flag.

Signed-off-by: default avatarArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
parent 2680d722

fs/ubifs/commit.c

+1 −1
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ static int do_commit(struct ubifs_info *c) 
	struct ubifs_lp_stats lst;



	dbg_cmt("start");

	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);



	if (c->ro_error) {

		err = -EROFS;

fs/ubifs/file.c

+2 −3
Original line number Diff line number Diff line
@@ -433,7 +433,7 @@ static int ubifs_write_begin(struct file *file, struct address_space *mapping, 
	struct page *page;



	ubifs_assert(ubifs_inode(inode)->ui_size == inode->i_size);

	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);



	if (unlikely(c->ro_error))

		return -EROFS;
@@ -1440,8 +1440,7 @@ static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vm 


	dbg_gen("ino %lu, pg %lu, i_size %lld",	inode->i_ino, page->index,

		i_size_read(inode));

	ubifs_assert(!(inode->i_sb->s_flags & MS_RDONLY));

	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);



	if (unlikely(c->ro_error))

		return VM_FAULT_SIGBUS; /* -EROFS */

fs/ubifs/gc.c

+1 −1
Original line number Diff line number Diff line
@@ -616,7 +616,7 @@ int ubifs_garbage_collect(struct ubifs_info *c, int anyway) 
	struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;



	ubifs_assert_cmt_locked(c);

	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);



	if (ubifs_gc_should_commit(c))

		return -EAGAIN;

fs/ubifs/io.c

+4 −5
Original line number Diff line number Diff line
@@ -356,10 +356,9 @@ int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf) 


	dbg_io("LEB %d:%d, %d bytes, jhead %s",

	       wbuf->lnum, wbuf->offs, wbuf->used, dbg_jhead(wbuf->jhead));

	ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY));

	ubifs_assert(!(wbuf->avail & 7));

	ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size);

	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);



	if (c->ro_error)

		return -EROFS;
@@ -441,7 +440,7 @@ int ubifs_bg_wbufs_sync(struct ubifs_info *c) 
{

	int err, i;



	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);

	if (!c->need_wbuf_sync)

		return 0;

	c->need_wbuf_sync = 0;
@@ -521,7 +520,7 @@ int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len) 
	ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size);

	ubifs_assert(wbuf->avail > 0 && wbuf->avail <= c->min_io_size);

	ubifs_assert(mutex_is_locked(&wbuf->io_mutex));

	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);



	if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) {

		err = -ENOSPC;
@@ -666,7 +665,7 @@ int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum, 
	       buf_len);

	ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);

	ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size);

	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);



	if (c->ro_error)

		return -EROFS;

fs/ubifs/journal.c

+1 −1
Original line number Diff line number Diff line
@@ -122,7 +122,7 @@ static int reserve_space(struct ubifs_info *c, int jhead, int len) 
	 * better to try to allocate space at the ends of eraseblocks. This is

	 * what the squeeze parameter does.

	 */

	ubifs_assert(!c->ro_media);

	ubifs_assert(!c->ro_media && !c->ro_mount);

	squeeze = (jhead == BASEHD);

again:

	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);

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