mirrors/linux
2
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2026-09-10 05:11:55 -04:00
Code Issues Packages Projects Releases Wiki Activity

cifs: add cifs_resize_file_locked() to guard fscache_resize_cookie() under i_rwsem

Browse Source 
cifs_setsize() calls fscache_resize_cookie() without holding i_rwsem.
When the fscache cookie is active (FSCACHE_COOKIE_IS_CACHING is set),
fscache_resize_cookie() performs a real resize that requires i_rwsem
held exclusively.  If another file descriptor has the same inode open,
fscache_use_cookie() was already called from that cifs_open(), making
the cookie active.  In that case, calling cifs_setsize() from
cifs_do_truncate() (invoked from cifs_open() without i_rwsem) races
against concurrent fscache I/O.

Strip fscache_resize_cookie() from cifs_setsize(), making it a pure
size/page-cache helper.  Add cifs_resize_file_locked() for callers
that already hold i_rwsem: it calls netfs_resize_file() and
cifs_setsize(), then temporarily activates the cookie with
fscache_use_cookie() to perform the resize under the lock, then
deactivates it with cifs_fscache_unuse_inode_cookie().  Using
fscache_use_cookie() before the resize ensures correctness whether or
not another fd already holds the cookie active.

Switch cifs_file_set_size(), smb2_duplicate_extents(), and both size-
extension branches of smb3_simple_falloc() to the new wrapper; those
paths already hold i_rwsem via VFS setattr, lock_two_nondirectories(),
or cifs_fallocate() respectively.  cifs_do_truncate() continues to
call cifs_setsize() followed by cifs_invalidate_cache(), since it runs
without i_rwsem.

Fixes: fa724e235c ("cifs: add fscache_resize_cookie() to cifs_setsize()")
Cc: stable@vger.kernel.org
Cc: David Howells <dhowells@redhat.com>
Cc: Paulo Alcantara <pc@manguebit.com>
Signed-off-by: Frank Sorenson <sorenson@redhat.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Paulo Alcantara <pc@manguebit.org>
This commit is contained in:
Frank Sorenson
2026-07-31 12:12:29 -05:00
committed by Paulo Alcantara
parent 364b183230
commit 32a7af68df
3 changed files with 23 additions and 11 deletions
Download Patch File Download Diff File Expand all files Collapse all files

1
fs/smb/client/cifsfs.h
View File

@@ -147,6 +147,7 @@ ssize_t cifs_file_copychunk_range(unsigned int xid, struct file *src_file,
long cifs_ioctl(struct file *filep, unsigned int command, unsigned long arg);
void cifs_setsize(struct inode *inode, loff_t offset);
void cifs_resize_file_locked(struct inode *inode, loff_t offset);
struct fs_context;
struct smb3_fs_context;

24
fs/smb/client/inode.c
View File

@@ -3059,7 +3059,23 @@ void cifs_setsize(struct inode *inode, loff_t offset)
inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
truncate_pagecache(inode, offset);
netfs_wait_for_outstanding_io(inode);
fscache_resize_cookie(cifs_inode_cookie(inode), offset);
}
void cifs_resize_file_locked(struct inode *inode, loff_t offset)
{
struct fscache_cookie *cookie = cifs_inode_cookie(inode);
lockdep_assert_held_write(&inode->i_rwsem);
netfs_resize_file(netfs_inode(inode), offset, true);
cifs_setsize(inode, offset);
if (!cookie)
return;
fscache_use_cookie(cookie, true);
fscache_resize_cookie(cookie, offset);
cifs_fscache_unuse_inode_cookie(inode, true);
}
int cifs_file_set_size(const unsigned int xid, struct dentry *dentry,
@@ -3125,10 +3141,8 @@ int cifs_file_set_size(const unsigned int xid, struct dentry *dentry,
cifs_put_tlink(tlink);
set_size_out:
if (rc == 0) {
netfs_resize_file(&cifsInode->netfs, size, true);
cifs_setsize(inode, size);
}
if (rc == 0)
cifs_resize_file_locked(inode, size);
return rc;
}

9
fs/smb/client/smb2ops.c
View File

@@ -2222,8 +2222,7 @@ smb2_duplicate_extents(const unsigned int xid,
rc = smb2_set_file_size(xid, tcon, trgtfile, dest_off + len, false);
if (rc)
goto duplicate_extents_out;
netfs_resize_file(netfs_inode(inode), dest_off + len, true);
cifs_setsize(inode, dest_off + len);
cifs_resize_file_locked(inode, dest_off + len);
}
rc = SMB2_ioctl(xid, tcon, trgtfile->fid.persistent_fid,
trgtfile->fid.volatile_fid,
@@ -3776,8 +3775,7 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon,
}
new_eof = off + len;
netfs_resize_file(&cifsi->netfs, new_eof, true);
cifs_setsize(inode, new_eof);
cifs_resize_file_locked(inode, new_eof);
qrc = SMB2_query_info(xid, tcon,
cfile->fid.persistent_fid,
@@ -3825,8 +3823,7 @@ static long smb3_simple_falloc(struct file *file, struct cifs_tcon *tcon,
if (rc)
goto out;
netfs_resize_file(&cifsi->netfs, new_eof, true);
cifs_setsize(inode, new_eof);
cifs_resize_file_locked(inode, new_eof);
qrc = SMB2_query_info(xid, tcon,
cfile->fid.persistent_fid,