6.7-stable review patch. If anyone has any objections, please let me know.
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From: Sandeep Dhavale dhavale@google.com
commit 56ee7db31187dc36d501622cb5f1415e88e01c2a upstream.
In erofs_find_target_block() when erofs_dirnamecmp() returns 0, we do not assign the target metabuf. This causes the caller erofs_namei()'s erofs_put_metabuf() at the end to be not effective leaving the refcount on the page. As the page from metabuf (buf->page) is never put, such page cannot be migrated or reclaimed. Fix it now by putting the metabuf from previous loop and assigning the current metabuf to target before returning so caller erofs_namei() can do the final put as it was intended.
Fixes: 500edd095648 ("erofs: use meta buffers for inode lookup") Cc: stable@vger.kernel.org # 5.18+ Signed-off-by: Sandeep Dhavale dhavale@google.com Reviewed-by: Gao Xiang hsiangkao@linux.alibaba.com Reviewed-by: Jingbo Xu jefflexu@linux.alibaba.com Reviewed-by: Chao Yu chao@kernel.org Link: https://lore.kernel.org/r/20240221210348.3667795-1-dhavale@google.com Signed-off-by: Gao Xiang hsiangkao@linux.alibaba.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/erofs/namei.c | 28 ++++++++++++++-------------- 1 file changed, 14 insertions(+), 14 deletions(-)
--- a/fs/erofs/namei.c +++ b/fs/erofs/namei.c @@ -130,24 +130,24 @@ static void *erofs_find_target_block(str /* string comparison without already matched prefix */ diff = erofs_dirnamecmp(name, &dname, &matched);
- if (!diff) { - *_ndirents = 0; - goto out; - } else if (diff > 0) { - head = mid + 1; - startprfx = matched; - - if (!IS_ERR(candidate)) - erofs_put_metabuf(target); - *target = buf; - candidate = de; - *_ndirents = ndirents; - } else { + if (diff < 0) { erofs_put_metabuf(&buf); - back = mid - 1; endprfx = matched; + continue; + } + + if (!IS_ERR(candidate)) + erofs_put_metabuf(target); + *target = buf; + if (!diff) { + *_ndirents = 0; + return de; } + head = mid + 1; + startprfx = matched; + candidate = de; + *_ndirents = ndirents; continue; } out: /* free if the candidate is valid */