On Fri 15-11-24 15:08:48, Sergey Senozhatsky wrote:

From: Jan Kara jack@suse.cz

[ Upstream commit 0aba4860b0d0216a1a300484ff536171894d49d8 ]

Currently we allocate name buffer in directory iterators (struct udf_fileident_iter) on stack. These structures are relatively large (some 360 bytes on 64-bit architectures). For udf_rename() which needs to keep three of these structures in parallel the stack usage becomes rather heavy - 1536 bytes in total. Allocate the name buffer in the iterator from heap to avoid excessive stack usage.

Link: https://lore.kernel.org/all/202212200558.lK9x1KW0-lkp@intel.com Reported-by: kernel test robot lkp@intel.com Signed-off-by: Jan Kara jack@suse.cz [ senozhatsky: explicitly include slab.h to address build failure reported by sashal@ ] Signed-off-by: Sergey Senozhatsky senozhatsky@chromium.org

Mauke beat you to this, Greg already queued up his patches :)

[1] https://lore.kernel.org/all/20241114212657.306989-1-hauke@hauke-m.de

Honza

---

fs/udf/directory.c | 24 ++++++++++++++++-------- fs/udf/udfdecl.h | 2 +- 2 files changed, 17 insertions(+), 9 deletions(-)

diff --git a/fs/udf/directory.c b/fs/udf/directory.c index e97ffae07833..a30898debdd1 100644 --- a/fs/udf/directory.c +++ b/fs/udf/directory.c @@ -19,6 +19,7 @@ #include <linux/bio.h> #include <linux/crc-itu-t.h> #include <linux/iversion.h> +#include <linux/slab.h> static int udf_verify_fi(struct udf_fileident_iter *iter) { @@ -248,9 +249,14 @@ int udf_fiiter_init(struct udf_fileident_iter *iter, struct inode *dir, iter->elen = 0; iter->epos.bh = NULL; iter->name = NULL;

• iter->namebuf = kmalloc(UDF_NAME_LEN_CS0, GFP_KERNEL);
• if (!iter->namebuf)

• return -ENOMEM;
  

• if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB)

• return udf_copy_fi(iter);
  

• if (iinfo->i_alloc_type == ICBTAG_FLAG_AD_IN_ICB) {

• err = udf_copy_fi(iter);
  

• goto out;
  

• }

if (inode_bmap(dir, iter->pos >> dir->i_blkbits, &iter->epos, &iter->eloc, &iter->elen, &iter->loffset) != @@ -260,17 +266,17 @@ int udf_fiiter_init(struct udf_fileident_iter *iter, struct inode *dir, udf_err(dir->i_sb, "position %llu not allocated in directory (ino %lu)\n", (unsigned long long)pos, dir->i_ino);

• return -EFSCORRUPTED;
  

• err = -EFSCORRUPTED;
  

• goto out;
  

  } err = udf_fiiter_load_bhs(iter); if (err < 0)

• return err;
  

• goto out;
  

  err = udf_copy_fi(iter);

• if (err < 0) {

+out:

• if (err < 0) udf_fiiter_release(iter);

• return err;
  

• }
• return 0;

• return err;

} int udf_fiiter_advance(struct udf_fileident_iter *iter) @@ -307,6 +313,8 @@ void udf_fiiter_release(struct udf_fileident_iter *iter) brelse(iter->bh[0]); brelse(iter->bh[1]); iter->bh[0] = iter->bh[1] = NULL;

• kfree(iter->namebuf);
• iter->namebuf = NULL;

} static void udf_copy_to_bufs(void *buf1, int len1, void *buf2, int len2, diff --git a/fs/udf/udfdecl.h b/fs/udf/udfdecl.h index f764b4d15094..d35aa42bb577 100644 --- a/fs/udf/udfdecl.h +++ b/fs/udf/udfdecl.h @@ -99,7 +99,7 @@ struct udf_fileident_iter { struct extent_position epos; /* Position after the above extent */ struct fileIdentDesc fi; /* Copied directory entry */ uint8_t *name; /* Pointer to entry name */

• uint8_t namebuf[UDF_NAME_LEN_CS0]; /* Storage for entry name in case

• uint8_t *namebuf; /* Storage for entry name in case * the name is split between two blocks */

};

2.47.0.338.g60cca15819-goog