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author | J. Bruce Fields <bfields@citi.umich.edu> | 2009-01-06 13:37:03 -0500 |
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committer | J. Bruce Fields <bfields@citi.umich.edu> | 2009-01-07 15:40:45 -0500 |
commit | 9a8d248e2d2e9c880ac4561f27fea5dc200655bd (patch) | |
tree | 9033bfd8c10f7077d62095d5295e16acac9a4ab2 | |
parent | 2779e3ae39645515cb6c1126634f47c28c9e7190 (diff) | |
download | kernel_samsung_smdk4412-9a8d248e2d2e9c880ac4561f27fea5dc200655bd.zip kernel_samsung_smdk4412-9a8d248e2d2e9c880ac4561f27fea5dc200655bd.tar.gz kernel_samsung_smdk4412-9a8d248e2d2e9c880ac4561f27fea5dc200655bd.tar.bz2 |
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 4c728ef583b3d8 "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>
-rw-r--r-- | fs/nfsd/vfs.c | 34 |
1 files changed, 31 insertions, 3 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 44aa92a..6e50aaa 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -744,16 +744,44 @@ nfsd_close(struct file *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 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 -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); } /* |