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nfsd: fix double-locks of directory mutex 

A number of nfsd operations depend on the i_mutex to cover more code
than just the fsync, so the approach of 4c728ef583 "add a vfs_fsync
helper" doesn't work for nfsd.  Revert the parts of those patches that
touch nfsd.

Note: we can't, however, remove the logic from vfs_fsync that was needed
only for the special case of nfsd, because a vfs_fsync(NULL,...) call
can still result indirectly from a stackable filesystem that was called
by nfsd.  (Thanks to Christoph Hellwig for pointing this out.)

Reported-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
This commit is contained in:
J. Bruce Fields 2009-01-06 13:37:03 -05:00
parent 2779e3ae39
commit 9a8d248e2d
1 changed files with 31 additions and 3 deletions
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34
fs/nfsd/vfs.c
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@ -744,16 +744,44 @@ nfsd_close(struct file *filp)
fput(filp); fput(filp);
} }
/*
* Sync a file
* As this calls fsync (not fdatasync) there is no need for a write_inode
* after it.
*/
static inline int nfsd_dosync(struct file *filp, struct dentry *dp,
const struct file_operations *fop)
{
struct inode *inode = dp->d_inode;
int (*fsync) (struct file *, struct dentry *, int);
int err;
err = filemap_fdatawrite(inode->i_mapping);
if (err == 0 && fop && (fsync = fop->fsync))
err = fsync(filp, dp, 0);
if (err == 0)
err = filemap_fdatawait(inode->i_mapping);
return err;
}
static int static int
nfsd_sync(struct file *filp) nfsd_sync(struct file *filp)
{ {
return vfs_fsync(filp, filp->f_path.dentry, 0); int err;
struct inode *inode = filp->f_path.dentry->d_inode;
dprintk("nfsd: sync file %s\n", filp->f_path.dentry->d_name.name);
mutex_lock(&inode->i_mutex);
err=nfsd_dosync(filp, filp->f_path.dentry, filp->f_op);
mutex_unlock(&inode->i_mutex);
return err;
} }
int int
nfsd_sync_dir(struct dentry *dentry) nfsd_sync_dir(struct dentry *dp)
{ {
return vfs_fsync(NULL, dentry, 0); return nfsd_dosync(NULL, dp, dp->d_inode->i_fop);
} }
/* /*