diff options
author | Yu Zhao <yuzhao@google.com> | 2015-09-09 01:03:33 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-09 01:35:28 +0300 |
commit | 44a30220bc0a171c010e8df63d144655abdafe61 (patch) | |
tree | c3f29c56cdf7838b0018f012c9b772a6a4a65a5f /mm | |
parent | 567d117b8b2ab1c3437acc4799505a59bfa5722b (diff) | |
download | linux-44a30220bc0a171c010e8df63d144655abdafe61.tar.xz |
shmem: recalculate file inode when fstat
Shmem uses shmem_recalc_inode to update i_blocks when it allocates page,
undoes range or swaps. But mm can drop clean page without notifying
shmem. This makes fstat sometimes return out-of-date block size.
The problem can be partially solved when we add
inode_operations->getattr which calls shmem_recalc_inode to update
i_blocks for fstat.
shmem_recalc_inode also updates counter used by statfs and
vm_committed_as. For them the situation is not changed. They still
suffer from the discrepancy after dropping clean page and before the
function is called by aforementioned triggers.
Signed-off-by: Yu Zhao <yuzhao@google.com>
Signed-off-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm')
-rw-r--r-- | mm/shmem.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/mm/shmem.c b/mm/shmem.c index dbe0c1e8349c..48ce82926d93 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -542,6 +542,21 @@ void shmem_truncate_range(struct inode *inode, loff_t lstart, loff_t lend) } EXPORT_SYMBOL_GPL(shmem_truncate_range); +static int shmem_getattr(struct vfsmount *mnt, struct dentry *dentry, + struct kstat *stat) +{ + struct inode *inode = dentry->d_inode; + struct shmem_inode_info *info = SHMEM_I(inode); + + spin_lock(&info->lock); + shmem_recalc_inode(inode); + spin_unlock(&info->lock); + + generic_fillattr(inode, stat); + + return 0; +} + static int shmem_setattr(struct dentry *dentry, struct iattr *attr) { struct inode *inode = d_inode(dentry); @@ -3122,6 +3137,7 @@ static const struct file_operations shmem_file_operations = { }; static const struct inode_operations shmem_inode_operations = { + .getattr = shmem_getattr, .setattr = shmem_setattr, #ifdef CONFIG_TMPFS_XATTR .setxattr = shmem_setxattr, |