diff options
| author | Jan Kara <jack@suse.cz> | 2011-12-10 02:30:48 +0100 |
|---|---|---|
| committer | Jan Kara <jack@suse.cz> | 2012-01-09 13:52:08 +0100 |
| commit | d2eb8c359309ec45d6bf5b147303ab8e13be86ea (patch) | |
| tree | 4725da2f9f5728b41960cff7b628d0997812504c /fs/udf/inode.c | |
| parent | udf: Cleanup calling convention of inode_getblk() (diff) | |
| download | linux-d2eb8c359309ec45d6bf5b147303ab8e13be86ea.tar.xz linux-d2eb8c359309ec45d6bf5b147303ab8e13be86ea.zip | |
udf: Fix deadlock when converting file from in-ICB one to normal one
During BKL removal in 2.6.38, conversion of files from in-ICB format to normal
format got broken. We call ->writepage with i_data_sem held but udf_get_block()
also acquires i_data_sem thus creating A-A deadlock.
We fix the problem by dropping i_data_sem before calling ->writepage() which is
safe since i_mutex still protects us against any changes in the file. Also fix
pagelock - i_data_sem lock inversion in udf_expand_file_adinicb() by dropping
i_data_sem before calling find_or_create_page().
CC: stable@kernel.org
Reported-by: Matthias Matiak <netzpython@mail-on.us>
Tested-by: Matthias Matiak <netzpython@mail-on.us>
Reviewed-by: Namjae Jeon <linkinjeon@gmail.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Diffstat (limited to 'fs/udf/inode.c')
| -rw-r--r-- | fs/udf/inode.c | 21 |
1 files changed, 18 insertions, 3 deletions
diff --git a/fs/udf/inode.c b/fs/udf/inode.c index 1bd2c42f3b48..4f7b1ffd9e37 100644 --- a/fs/udf/inode.c +++ b/fs/udf/inode.c @@ -150,6 +150,12 @@ const struct address_space_operations udf_aops = { .bmap = udf_bmap, }; +/* + * Expand file stored in ICB to a normal one-block-file + * + * This function requires i_data_sem for writing and releases it. + * This function requires i_mutex held + */ int udf_expand_file_adinicb(struct inode *inode) { struct page *page; @@ -168,9 +174,15 @@ int udf_expand_file_adinicb(struct inode *inode) iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG; /* from now on we have normal address_space methods */ inode->i_data.a_ops = &udf_aops; + up_write(&iinfo->i_data_sem); mark_inode_dirty(inode); return 0; } + /* + * Release i_data_sem so that we can lock a page - page lock ranks + * above i_data_sem. i_mutex still protects us against file changes. + */ + up_write(&iinfo->i_data_sem); page = find_or_create_page(inode->i_mapping, 0, GFP_NOFS); if (!page) @@ -186,6 +198,7 @@ int udf_expand_file_adinicb(struct inode *inode) SetPageUptodate(page); kunmap(page); } + down_write(&iinfo->i_data_sem); memset(iinfo->i_ext.i_data + iinfo->i_lenEAttr, 0x00, iinfo->i_lenAlloc); iinfo->i_lenAlloc = 0; @@ -195,17 +208,20 @@ int udf_expand_file_adinicb(struct inode *inode) iinfo->i_alloc_type = ICBTAG_FLAG_AD_LONG; /* from now on we have normal address_space methods */ inode->i_data.a_ops = &udf_aops; + up_write(&iinfo->i_data_sem); err = inode->i_data.a_ops->writepage(page, &udf_wbc); if (err) { /* Restore everything back so that we don't lose data... */ lock_page(page); kaddr = kmap(page); + down_write(&iinfo->i_data_sem); memcpy(iinfo->i_ext.i_data + iinfo->i_lenEAttr, kaddr, inode->i_size); kunmap(page); unlock_page(page); iinfo->i_alloc_type = ICBTAG_FLAG_AD_IN_ICB; inode->i_data.a_ops = &udf_adinicb_aops; + up_write(&iinfo->i_data_sem); } page_cache_release(page); mark_inode_dirty(inode); @@ -1105,10 +1121,9 @@ int udf_setsize(struct inode *inode, loff_t newsize) if (bsize < (udf_file_entry_alloc_offset(inode) + newsize)) { err = udf_expand_file_adinicb(inode); - if (err) { - up_write(&iinfo->i_data_sem); + if (err) return err; - } + down_write(&iinfo->i_data_sem); } else iinfo->i_lenAlloc = newsize; } |