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authorLinus Torvalds <torvalds@linux-foundation.org>2008-10-23 10:22:40 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2008-10-23 10:22:40 -0700
commit5ed487bc2c44ca4e9668ef9cb54c830e2a9fac47 (patch)
treeaf19ed28db83e8f52690872ac99336da1cf2fd3b /fs/nfsd/vfs.c
parent5b34653963de7a6d0d8c783527457d68fddc60fb (diff)
parentfd217f4d70172c526478f2bc76859e909fdfa674 (diff)
Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (46 commits) [PATCH] fs: add a sanity check in d_free [PATCH] i_version: remount support [patch] vfs: make security_inode_setattr() calling consistent [patch 1/3] FS_MBCACHE: don't needlessly make it built-in [PATCH] move executable checking into ->permission() [PATCH] fs/dcache.c: update comment of d_validate() [RFC PATCH] touch_mnt_namespace when the mount flags change [PATCH] reiserfs: add missing llseek method [PATCH] fix ->llseek for more directories [PATCH vfs-2.6 6/6] vfs: add LOOKUP_RENAME_TARGET intent [PATCH vfs-2.6 5/6] vfs: remove LOOKUP_PARENT from non LOOKUP_PARENT lookup [PATCH vfs-2.6 4/6] vfs: remove unnecessary fsnotify_d_instantiate() [PATCH vfs-2.6 3/6] vfs: add __d_instantiate() helper [PATCH vfs-2.6 2/6] vfs: add d_ancestor() [PATCH vfs-2.6 1/6] vfs: replace parent == dentry->d_parent by IS_ROOT() [PATCH] get rid of on-stack dentry in udf [PATCH 2/2] anondev: switch to IDA [PATCH 1/2] anondev: init IDR statically [JFFS2] Use d_splice_alias() not d_add() in jffs2_lookup() [PATCH] Optimise NFS readdir hack slightly. ...
Diffstat (limited to 'fs/nfsd/vfs.c')
-rw-r--r--fs/nfsd/vfs.c126
1 files changed, 110 insertions, 16 deletions
diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c
index 9609eb51d72..0bc56f6d927 100644
--- a/fs/nfsd/vfs.c
+++ b/fs/nfsd/vfs.c
@@ -1818,6 +1818,115 @@ out:
}
/*
+ * We do this buffering because we must not call back into the file
+ * system's ->lookup() method from the filldir callback. That may well
+ * deadlock a number of file systems.
+ *
+ * This is based heavily on the implementation of same in XFS.
+ */
+struct buffered_dirent {
+ u64 ino;
+ loff_t offset;
+ int namlen;
+ unsigned int d_type;
+ char name[];
+};
+
+struct readdir_data {
+ char *dirent;
+ size_t used;
+ int full;
+};
+
+static int nfsd_buffered_filldir(void *__buf, const char *name, int namlen,
+ loff_t offset, u64 ino, unsigned int d_type)
+{
+ struct readdir_data *buf = __buf;
+ struct buffered_dirent *de = (void *)(buf->dirent + buf->used);
+ unsigned int reclen;
+
+ reclen = ALIGN(sizeof(struct buffered_dirent) + namlen, sizeof(u64));
+ if (buf->used + reclen > PAGE_SIZE) {
+ buf->full = 1;
+ return -EINVAL;
+ }
+
+ de->namlen = namlen;
+ de->offset = offset;
+ de->ino = ino;
+ de->d_type = d_type;
+ memcpy(de->name, name, namlen);
+ buf->used += reclen;
+
+ return 0;
+}
+
+static int nfsd_buffered_readdir(struct file *file, filldir_t func,
+ struct readdir_cd *cdp, loff_t *offsetp)
+{
+ struct readdir_data buf;
+ struct buffered_dirent *de;
+ int host_err;
+ int size;
+ loff_t offset;
+
+ buf.dirent = (void *)__get_free_page(GFP_KERNEL);
+ if (!buf.dirent)
+ return -ENOMEM;
+
+ offset = *offsetp;
+ cdp->err = nfserr_eof; /* will be cleared on successful read */
+
+ while (1) {
+ unsigned int reclen;
+
+ buf.used = 0;
+ buf.full = 0;
+
+ host_err = vfs_readdir(file, nfsd_buffered_filldir, &buf);
+ if (buf.full)
+ host_err = 0;
+
+ if (host_err < 0)
+ break;
+
+ size = buf.used;
+
+ if (!size)
+ break;
+
+ de = (struct buffered_dirent *)buf.dirent;
+ while (size > 0) {
+ offset = de->offset;
+
+ if (func(cdp, de->name, de->namlen, de->offset,
+ de->ino, de->d_type))
+ goto done;
+
+ if (cdp->err != nfs_ok)
+ goto done;
+
+ reclen = ALIGN(sizeof(*de) + de->namlen,
+ sizeof(u64));
+ size -= reclen;
+ de = (struct buffered_dirent *)((char *)de + reclen);
+ }
+ offset = vfs_llseek(file, 0, SEEK_CUR);
+ if (!buf.full)
+ break;
+ }
+
+ done:
+ free_page((unsigned long)(buf.dirent));
+
+ if (host_err)
+ return nfserrno(host_err);
+
+ *offsetp = offset;
+ return cdp->err;
+}
+
+/*
* Read entries from a directory.
* The NFSv3/4 verifier we ignore for now.
*/
@@ -1826,7 +1935,6 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
struct readdir_cd *cdp, filldir_t func)
{
__be32 err;
- int host_err;
struct file *file;
loff_t offset = *offsetp;
@@ -1840,21 +1948,7 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
goto out_close;
}
- /*
- * Read the directory entries. This silly loop is necessary because
- * readdir() is not guaranteed to fill up the entire buffer, but
- * may choose to do less.
- */
-
- do {
- cdp->err = nfserr_eof; /* will be cleared on successful read */
- host_err = vfs_readdir(file, func, cdp);
- } while (host_err >=0 && cdp->err == nfs_ok);
- if (host_err)
- err = nfserrno(host_err);
- else
- err = cdp->err;
- *offsetp = vfs_llseek(file, 0, 1);
+ err = nfsd_buffered_readdir(file, func, cdp, offsetp);
if (err == nfserr_eof || err == nfserr_toosmall)
err = nfs_ok; /* can still be found in ->err */