| From | Luis Henriques <> | Subject | [PATCH 3.11 116/182] reiserfs: fix race in readdir | Date | Thu, 24 Apr 2014 09:50:41 +0100 |
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3.11.10.9 -stable review patch. If anyone has any objections, please let me know.
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From: Jeff Mahoney <jeffm@suse.com>
commit 01d8885785a60ae8f4c37b0ed75bdc96d0fc6a44 upstream.
jdm-20004 reiserfs_delete_xattrs: Couldn't delete all xattrs (-2)
The -ENOENT is due to readdir calling dir_emit on the same entry twice.
If the dir_emit callback sleeps and the tree is changed underneath us, we won't be able to trust deh_offset(deh) anymore. We need to save next_pos before we might sleep so we can find the next entry.
Signed-off-by: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Luis Henriques <luis.henriques@canonical.com> --- fs/reiserfs/dir.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/fs/reiserfs/dir.c b/fs/reiserfs/dir.c index 03e4ca5..79b7b55 100644 --- a/fs/reiserfs/dir.c +++ b/fs/reiserfs/dir.c @@ -124,6 +124,7 @@ int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx) int d_reclen; char *d_name; ino_t d_ino; + loff_t cur_pos = deh_offset(deh); if (!de_visible(deh)) /* it is hidden entry */ @@ -195,8 +196,9 @@ int reiserfs_readdir_inode(struct inode *inode, struct dir_context *ctx) if (local_buf != small_buf) { kfree(local_buf); } - // next entry should be looked for with such offset - next_pos = deh_offset(deh) + 1; + + /* deh_offset(deh) may be invalid now. */ + next_pos = cur_pos + 1; if (item_moved(&tmp_ih, &path_to_entry)) { set_cpu_key_k_offset(&pos_key, -- 1.9.1
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