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linux/fs/ceph/dir.c
Jeff Layton 2a575f138d ceph: fix potential bad pointer deref in async dirops cb's 
The new async dirops callback routines can pass ERR_PTR values to
ceph_mdsc_free_path, which could cause an oops. Make ceph_mdsc_free_path
ignore ERR_PTR values. Also, ensure that the pr_warn messages look sane
even if ceph_mdsc_build_path fails.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Ilya Dryomov <idryomov@gmail.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2020-04-13 19:33:47 +02:00

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51 KiB
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// SPDX-License-Identifier: GPL-2.0
#include <linux/ceph/ceph_debug.h>
#include <linux/spinlock.h>
#include <linux/namei.h>
#include <linux/slab.h>
#include <linux/sched.h>
#include <linux/xattr.h>
#include "super.h"
#include "mds_client.h"
/*
* Directory operations: readdir, lookup, create, link, unlink,
* rename, etc.
*/
/*
* Ceph MDS operations are specified in terms of a base ino and
* relative path. Thus, the client can specify an operation on a
* specific inode (e.g., a getattr due to fstat(2)), or as a path
* relative to, say, the root directory.
*
* Normally, we limit ourselves to strict inode ops (no path component)
* or dentry operations (a single path component relative to an ino). The
* exception to this is open_root_dentry(), which will open the mount
* point by name.
*/
const struct dentry_operations ceph_dentry_ops;
static bool __dentry_lease_is_valid(struct ceph_dentry_info *di);
static int __dir_lease_try_check(const struct dentry *dentry);
/*
* Initialize ceph dentry state.
*/
static int ceph_d_init(struct dentry *dentry)
{
struct ceph_dentry_info *di;
di = kmem_cache_zalloc(ceph_dentry_cachep, GFP_KERNEL);
if (!di)
return -ENOMEM; /* oh well */
di->dentry = dentry;
di->lease_session = NULL;
di->time = jiffies;
dentry->d_fsdata = di;
INIT_LIST_HEAD(&di->lease_list);
return 0;
}
/*
* for f_pos for readdir:
* - hash order:
* (0xff << 52) | ((24 bits hash) << 28) |
* (the nth entry has hash collision);
* - frag+name order;
* ((frag value) << 28) | (the nth entry in frag);
*/
#define OFFSET_BITS 28
#define OFFSET_MASK ((1 << OFFSET_BITS) - 1)
#define HASH_ORDER (0xffull << (OFFSET_BITS + 24))
loff_t ceph_make_fpos(unsigned high, unsigned off, bool hash_order)
{
loff_t fpos = ((loff_t)high << 28) | (loff_t)off;
if (hash_order)
fpos |= HASH_ORDER;
return fpos;
}
static bool is_hash_order(loff_t p)
{
return (p & HASH_ORDER) == HASH_ORDER;
}
static unsigned fpos_frag(loff_t p)
{
return p >> OFFSET_BITS;
}
static unsigned fpos_hash(loff_t p)
{
return ceph_frag_value(fpos_frag(p));
}
static unsigned fpos_off(loff_t p)
{
return p & OFFSET_MASK;
}
static int fpos_cmp(loff_t l, loff_t r)
{
int v = ceph_frag_compare(fpos_frag(l), fpos_frag(r));
if (v)
return v;
return (int)(fpos_off(l) - fpos_off(r));
}
/*
* make note of the last dentry we read, so we can
* continue at the same lexicographical point,
* regardless of what dir changes take place on the
* server.
*/
static int note_last_dentry(struct ceph_dir_file_info *dfi, const char *name,
int len, unsigned next_offset)
{
char *buf = kmalloc(len+1, GFP_KERNEL);
if (!buf)
return -ENOMEM;
kfree(dfi->last_name);
dfi->last_name = buf;
memcpy(dfi->last_name, name, len);
dfi->last_name[len] = 0;
dfi->next_offset = next_offset;
dout("note_last_dentry '%s'\n", dfi->last_name);
return 0;
}
static struct dentry *
__dcache_find_get_entry(struct dentry *parent, u64 idx,
struct ceph_readdir_cache_control *cache_ctl)
{
struct inode *dir = d_inode(parent);
struct dentry *dentry;
unsigned idx_mask = (PAGE_SIZE / sizeof(struct dentry *)) - 1;
loff_t ptr_pos = idx * sizeof(struct dentry *);
pgoff_t ptr_pgoff = ptr_pos >> PAGE_SHIFT;
if (ptr_pos >= i_size_read(dir))
return NULL;
if (!cache_ctl->page || ptr_pgoff != page_index(cache_ctl->page)) {
ceph_readdir_cache_release(cache_ctl);
cache_ctl->page = find_lock_page(&dir->i_data, ptr_pgoff);
if (!cache_ctl->page) {
dout(" page %lu not found\n", ptr_pgoff);
return ERR_PTR(-EAGAIN);
}
/* reading/filling the cache are serialized by
i_mutex, no need to use page lock */
unlock_page(cache_ctl->page);
cache_ctl->dentries = kmap(cache_ctl->page);
}
cache_ctl->index = idx & idx_mask;
rcu_read_lock();
spin_lock(&parent->d_lock);
/* check i_size again here, because empty directory can be
* marked as complete while not holding the i_mutex. */
if (ceph_dir_is_complete_ordered(dir) && ptr_pos < i_size_read(dir))
dentry = cache_ctl->dentries[cache_ctl->index];
else
dentry = NULL;
spin_unlock(&parent->d_lock);
if (dentry && !lockref_get_not_dead(&dentry->d_lockref))
dentry = NULL;
rcu_read_unlock();
return dentry ? : ERR_PTR(-EAGAIN);
}
/*
* When possible, we try to satisfy a readdir by peeking at the
* dcache. We make this work by carefully ordering dentries on
* d_child when we initially get results back from the MDS, and
* falling back to a "normal" sync readdir if any dentries in the dir
* are dropped.
*
* Complete dir indicates that we have all dentries in the dir. It is
* defined IFF we hold CEPH_CAP_FILE_SHARED (which will be revoked by
* the MDS if/when the directory is modified).
*/
static int __dcache_readdir(struct file *file, struct dir_context *ctx,
int shared_gen)
{
struct ceph_dir_file_info *dfi = file->private_data;
struct dentry *parent = file->f_path.dentry;
struct inode *dir = d_inode(parent);
struct dentry *dentry, *last = NULL;
struct ceph_dentry_info *di;
struct ceph_readdir_cache_control cache_ctl = {};
u64 idx = 0;
int err = 0;
dout("__dcache_readdir %p v%u at %llx\n", dir, (unsigned)shared_gen, ctx->pos);
/* search start position */
if (ctx->pos > 2) {
u64 count = div_u64(i_size_read(dir), sizeof(struct dentry *));
while (count > 0) {
u64 step = count >> 1;
dentry = __dcache_find_get_entry(parent, idx + step,
&cache_ctl);
if (!dentry) {
/* use linar search */
idx = 0;
break;
}
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
}
di = ceph_dentry(dentry);
spin_lock(&dentry->d_lock);
if (fpos_cmp(di->offset, ctx->pos) < 0) {
idx += step + 1;
count -= step + 1;
} else {
count = step;
}
spin_unlock(&dentry->d_lock);
dput(dentry);
}
dout("__dcache_readdir %p cache idx %llu\n", dir, idx);
}
for (;;) {
bool emit_dentry = false;
dentry = __dcache_find_get_entry(parent, idx++, &cache_ctl);
if (!dentry) {
dfi->file_info.flags |= CEPH_F_ATEND;
err = 0;
break;
}
if (IS_ERR(dentry)) {
err = PTR_ERR(dentry);
goto out;
}
spin_lock(&dentry->d_lock);
di = ceph_dentry(dentry);
if (d_unhashed(dentry) ||
d_really_is_negative(dentry) ||
di->lease_shared_gen != shared_gen) {
spin_unlock(&dentry->d_lock);
dput(dentry);
err = -EAGAIN;
goto out;
}
if (fpos_cmp(ctx->pos, di->offset) <= 0) {
__ceph_dentry_dir_lease_touch(di);
emit_dentry = true;
}
spin_unlock(&dentry->d_lock);
if (emit_dentry) {
dout(" %llx dentry %p %pd %p\n", di->offset,
dentry, dentry, d_inode(dentry));
ctx->pos = di->offset;
if (!dir_emit(ctx, dentry->d_name.name,
dentry->d_name.len,
ceph_translate_ino(dentry->d_sb,
d_inode(dentry)->i_ino),
d_inode(dentry)->i_mode >> 12)) {
dput(dentry);
err = 0;
break;
}
ctx->pos++;
if (last)
dput(last);
last = dentry;
} else {
dput(dentry);
}
}
out:
ceph_readdir_cache_release(&cache_ctl);
if (last) {
int ret;
di = ceph_dentry(last);
ret = note_last_dentry(dfi, last->d_name.name, last->d_name.len,
fpos_off(di->offset) + 1);
if (ret < 0)
err = ret;
dput(last);
/* last_name no longer match cache index */
if (dfi->readdir_cache_idx >= 0) {
dfi->readdir_cache_idx = -1;
dfi->dir_release_count = 0;
}
}
return err;
}
static bool need_send_readdir(struct ceph_dir_file_info *dfi, loff_t pos)
{
if (!dfi->last_readdir)
return true;
if (is_hash_order(pos))
return !ceph_frag_contains_value(dfi->frag, fpos_hash(pos));
else
return dfi->frag != fpos_frag(pos);
}
static int ceph_readdir(struct file *file, struct dir_context *ctx)
{
struct ceph_dir_file_info *dfi = file->private_data;
struct inode *inode = file_inode(file);
struct ceph_inode_info *ci = ceph_inode(inode);
struct ceph_fs_client *fsc = ceph_inode_to_client(inode);
struct ceph_mds_client *mdsc = fsc->mdsc;
int i;
int err;
unsigned frag = -1;
struct ceph_mds_reply_info_parsed *rinfo;
dout("readdir %p file %p pos %llx\n", inode, file, ctx->pos);
if (dfi->file_info.flags & CEPH_F_ATEND)
return 0;
/* always start with . and .. */
if (ctx->pos == 0) {
dout("readdir off 0 -> '.'\n");
if (!dir_emit(ctx, ".", 1,
ceph_translate_ino(inode->i_sb, inode->i_ino),
inode->i_mode >> 12))
return 0;
ctx->pos = 1;
}
if (ctx->pos == 1) {
ino_t ino = parent_ino(file->f_path.dentry);
dout("readdir off 1 -> '..'\n");
if (!dir_emit(ctx, "..", 2,
ceph_translate_ino(inode->i_sb, ino),
inode->i_mode >> 12))
return 0;
ctx->pos = 2;
}
spin_lock(&ci->i_ceph_lock);
/* request Fx cap. if have Fx, we don't need to release Fs cap
* for later create/unlink. */
__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_WR);
/* can we use the dcache? */
if (ceph_test_mount_opt(fsc, DCACHE) &&
!ceph_test_mount_opt(fsc, NOASYNCREADDIR) &&
ceph_snap(inode) != CEPH_SNAPDIR &&
__ceph_dir_is_complete_ordered(ci) &&
__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1)) {
int shared_gen = atomic_read(&ci->i_shared_gen);
spin_unlock(&ci->i_ceph_lock);
err = __dcache_readdir(file, ctx, shared_gen);
if (err != -EAGAIN)
return err;
} else {
spin_unlock(&ci->i_ceph_lock);
}
/* proceed with a normal readdir */
more:
/* do we have the correct frag content buffered? */
if (need_send_readdir(dfi, ctx->pos)) {
struct ceph_mds_request *req;
int op = ceph_snap(inode) == CEPH_SNAPDIR ?
CEPH_MDS_OP_LSSNAP : CEPH_MDS_OP_READDIR;
/* discard old result, if any */
if (dfi->last_readdir) {
ceph_mdsc_put_request(dfi->last_readdir);
dfi->last_readdir = NULL;
}
if (is_hash_order(ctx->pos)) {
/* fragtree isn't always accurate. choose frag
* based on previous reply when possible. */
if (frag == (unsigned)-1)
frag = ceph_choose_frag(ci, fpos_hash(ctx->pos),
NULL, NULL);
} else {
frag = fpos_frag(ctx->pos);
}
dout("readdir fetching %llx.%llx frag %x offset '%s'\n",
ceph_vinop(inode), frag, dfi->last_name);
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
if (IS_ERR(req))
return PTR_ERR(req);
err = ceph_alloc_readdir_reply_buffer(req, inode);
if (err) {
ceph_mdsc_put_request(req);
return err;
}
/* hints to request -> mds selection code */
req->r_direct_mode = USE_AUTH_MDS;
if (op == CEPH_MDS_OP_READDIR) {
req->r_direct_hash = ceph_frag_value(frag);
__set_bit(CEPH_MDS_R_DIRECT_IS_HASH, &req->r_req_flags);
req->r_inode_drop = CEPH_CAP_FILE_EXCL;
}
if (dfi->last_name) {
req->r_path2 = kstrdup(dfi->last_name, GFP_KERNEL);
if (!req->r_path2) {
ceph_mdsc_put_request(req);
return -ENOMEM;
}
} else if (is_hash_order(ctx->pos)) {
req->r_args.readdir.offset_hash =
cpu_to_le32(fpos_hash(ctx->pos));
}
req->r_dir_release_cnt = dfi->dir_release_count;
req->r_dir_ordered_cnt = dfi->dir_ordered_count;
req->r_readdir_cache_idx = dfi->readdir_cache_idx;
req->r_readdir_offset = dfi->next_offset;
req->r_args.readdir.frag = cpu_to_le32(frag);
req->r_args.readdir.flags =
cpu_to_le16(CEPH_READDIR_REPLY_BITFLAGS);
req->r_inode = inode;
ihold(inode);
req->r_dentry = dget(file->f_path.dentry);
err = ceph_mdsc_do_request(mdsc, NULL, req);
if (err < 0) {
ceph_mdsc_put_request(req);
return err;
}
dout("readdir got and parsed readdir result=%d on "
"frag %x, end=%d, complete=%d, hash_order=%d\n",
err, frag,
(int)req->r_reply_info.dir_end,
(int)req->r_reply_info.dir_complete,
(int)req->r_reply_info.hash_order);
rinfo = &req->r_reply_info;
if (le32_to_cpu(rinfo->dir_dir->frag) != frag) {
frag = le32_to_cpu(rinfo->dir_dir->frag);
if (!rinfo->hash_order) {
dfi->next_offset = req->r_readdir_offset;
/* adjust ctx->pos to beginning of frag */
ctx->pos = ceph_make_fpos(frag,
dfi->next_offset,
false);
}
}
dfi->frag = frag;
dfi->last_readdir = req;
if (test_bit(CEPH_MDS_R_DID_PREPOPULATE, &req->r_req_flags)) {
dfi->readdir_cache_idx = req->r_readdir_cache_idx;
if (dfi->readdir_cache_idx < 0) {
/* preclude from marking dir ordered */
dfi->dir_ordered_count = 0;
} else if (ceph_frag_is_leftmost(frag) &&
dfi->next_offset == 2) {
/* note dir version at start of readdir so
* we can tell if any dentries get dropped */
dfi->dir_release_count = req->r_dir_release_cnt;
dfi->dir_ordered_count = req->r_dir_ordered_cnt;
}
} else {
dout("readdir !did_prepopulate\n");
/* disable readdir cache */
dfi->readdir_cache_idx = -1;
/* preclude from marking dir complete */
dfi->dir_release_count = 0;
}
/* note next offset and last dentry name */
if (rinfo->dir_nr > 0) {
struct ceph_mds_reply_dir_entry *rde =
rinfo->dir_entries + (rinfo->dir_nr-1);
unsigned next_offset = req->r_reply_info.dir_end ?
2 : (fpos_off(rde->offset) + 1);
err = note_last_dentry(dfi, rde->name, rde->name_len,
next_offset);
if (err)
return err;
} else if (req->r_reply_info.dir_end) {
dfi->next_offset = 2;
/* keep last name */
}
}
rinfo = &dfi->last_readdir->r_reply_info;
dout("readdir frag %x num %d pos %llx chunk first %llx\n",
dfi->frag, rinfo->dir_nr, ctx->pos,
rinfo->dir_nr ? rinfo->dir_entries[0].offset : 0LL);
i = 0;
/* search start position */
if (rinfo->dir_nr > 0) {
int step, nr = rinfo->dir_nr;
while (nr > 0) {
step = nr >> 1;
if (rinfo->dir_entries[i + step].offset < ctx->pos) {
i += step + 1;
nr -= step + 1;
} else {
nr = step;
}
}
}
for (; i < rinfo->dir_nr; i++) {
struct ceph_mds_reply_dir_entry *rde = rinfo->dir_entries + i;
struct ceph_vino vino;
ino_t ino;
u32 ftype;
BUG_ON(rde->offset < ctx->pos);
ctx->pos = rde->offset;
dout("readdir (%d/%d) -> %llx '%.*s' %p\n",
i, rinfo->dir_nr, ctx->pos,
rde->name_len, rde->name, &rde->inode.in);
BUG_ON(!rde->inode.in);
ftype = le32_to_cpu(rde->inode.in->mode) >> 12;
vino.ino = le64_to_cpu(rde->inode.in->ino);
vino.snap = le64_to_cpu(rde->inode.in->snapid);
ino = ceph_vino_to_ino(vino);
if (!dir_emit(ctx, rde->name, rde->name_len,
ceph_translate_ino(inode->i_sb, ino), ftype)) {
dout("filldir stopping us...\n");
return 0;
}
ctx->pos++;
}
ceph_mdsc_put_request(dfi->last_readdir);
dfi->last_readdir = NULL;
if (dfi->next_offset > 2) {
frag = dfi->frag;
goto more;
}
/* more frags? */
if (!ceph_frag_is_rightmost(dfi->frag)) {
frag = ceph_frag_next(dfi->frag);
if (is_hash_order(ctx->pos)) {
loff_t new_pos = ceph_make_fpos(ceph_frag_value(frag),
dfi->next_offset, true);
if (new_pos > ctx->pos)
ctx->pos = new_pos;
/* keep last_name */
} else {
ctx->pos = ceph_make_fpos(frag, dfi->next_offset,
false);
kfree(dfi->last_name);
dfi->last_name = NULL;
}
dout("readdir next frag is %x\n", frag);
goto more;
}
dfi->file_info.flags |= CEPH_F_ATEND;
/*
* if dir_release_count still matches the dir, no dentries
* were released during the whole readdir, and we should have
* the complete dir contents in our cache.
*/
if (atomic64_read(&ci->i_release_count) ==
dfi->dir_release_count) {
spin_lock(&ci->i_ceph_lock);
if (dfi->dir_ordered_count ==
atomic64_read(&ci->i_ordered_count)) {
dout(" marking %p complete and ordered\n", inode);
/* use i_size to track number of entries in
* readdir cache */
BUG_ON(dfi->readdir_cache_idx < 0);
i_size_write(inode, dfi->readdir_cache_idx *
sizeof(struct dentry*));
} else {
dout(" marking %p complete\n", inode);
}
__ceph_dir_set_complete(ci, dfi->dir_release_count,
dfi->dir_ordered_count);
spin_unlock(&ci->i_ceph_lock);
}
dout("readdir %p file %p done.\n", inode, file);
return 0;
}
static void reset_readdir(struct ceph_dir_file_info *dfi)
{
if (dfi->last_readdir) {
ceph_mdsc_put_request(dfi->last_readdir);
dfi->last_readdir = NULL;
}
kfree(dfi->last_name);
dfi->last_name = NULL;
dfi->dir_release_count = 0;
dfi->readdir_cache_idx = -1;
dfi->next_offset = 2; /* compensate for . and .. */
dfi->file_info.flags &= ~CEPH_F_ATEND;
}
/*
* discard buffered readdir content on seekdir(0), or seek to new frag,
* or seek prior to current chunk
*/
static bool need_reset_readdir(struct ceph_dir_file_info *dfi, loff_t new_pos)
{
struct ceph_mds_reply_info_parsed *rinfo;
loff_t chunk_offset;
if (new_pos == 0)
return true;
if (is_hash_order(new_pos)) {
/* no need to reset last_name for a forward seek when
* dentries are sotred in hash order */
} else if (dfi->frag != fpos_frag(new_pos)) {
return true;
}
rinfo = dfi->last_readdir ? &dfi->last_readdir->r_reply_info : NULL;
if (!rinfo || !rinfo->dir_nr)
return true;
chunk_offset = rinfo->dir_entries[0].offset;
return new_pos < chunk_offset ||
is_hash_order(new_pos) != is_hash_order(chunk_offset);
}
static loff_t ceph_dir_llseek(struct file *file, loff_t offset, int whence)
{
struct ceph_dir_file_info *dfi = file->private_data;
struct inode *inode = file->f_mapping->host;
loff_t retval;
inode_lock(inode);
retval = -EINVAL;
switch (whence) {
case SEEK_CUR:
offset += file->f_pos;
case SEEK_SET:
break;
case SEEK_END:
retval = -EOPNOTSUPP;
default:
goto out;
}
if (offset >= 0) {
if (need_reset_readdir(dfi, offset)) {
dout("dir_llseek dropping %p content\n", file);
reset_readdir(dfi);
} else if (is_hash_order(offset) && offset > file->f_pos) {
/* for hash offset, we don't know if a forward seek
* is within same frag */
dfi->dir_release_count = 0;
dfi->readdir_cache_idx = -1;
}
if (offset != file->f_pos) {
file->f_pos = offset;
file->f_version = 0;
dfi->file_info.flags &= ~CEPH_F_ATEND;
}
retval = offset;
}
out:
inode_unlock(inode);
return retval;
}
/*
* Handle lookups for the hidden .snap directory.
*/
int ceph_handle_snapdir(struct ceph_mds_request *req,
struct dentry *dentry, int err)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
struct inode *parent = d_inode(dentry->d_parent); /* we hold i_mutex */
/* .snap dir? */
if (err == -ENOENT &&
ceph_snap(parent) == CEPH_NOSNAP &&
strcmp(dentry->d_name.name,
fsc->mount_options->snapdir_name) == 0) {
struct inode *inode = ceph_get_snapdir(parent);
dout("ENOENT on snapdir %p '%pd', linking to snapdir %p\n",
dentry, dentry, inode);
BUG_ON(!d_unhashed(dentry));
d_add(dentry, inode);
err = 0;
}
return err;
}
/*
* Figure out final result of a lookup/open request.
*
* Mainly, make sure we return the final req->r_dentry (if it already
* existed) in place of the original VFS-provided dentry when they
* differ.
*
* Gracefully handle the case where the MDS replies with -ENOENT and
* no trace (which it may do, at its discretion, e.g., if it doesn't
* care to issue a lease on the negative dentry).
*/
struct dentry *ceph_finish_lookup(struct ceph_mds_request *req,
struct dentry *dentry, int err)
{
if (err == -ENOENT) {
/* no trace? */
err = 0;
if (!req->r_reply_info.head->is_dentry) {
dout("ENOENT and no trace, dentry %p inode %p\n",
dentry, d_inode(dentry));
if (d_really_is_positive(dentry)) {
d_drop(dentry);
err = -ENOENT;
} else {
d_add(dentry, NULL);
}
}
}
if (err)
dentry = ERR_PTR(err);
else if (dentry != req->r_dentry)
dentry = dget(req->r_dentry); /* we got spliced */
else
dentry = NULL;
return dentry;
}
static bool is_root_ceph_dentry(struct inode *inode, struct dentry *dentry)
{
return ceph_ino(inode) == CEPH_INO_ROOT &&
strncmp(dentry->d_name.name, ".ceph", 5) == 0;
}
/*
* Look up a single dir entry. If there is a lookup intent, inform
* the MDS so that it gets our 'caps wanted' value in a single op.
*/
static struct dentry *ceph_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
int op;
int mask;
int err;
dout("lookup %p dentry %p '%pd'\n",
dir, dentry, dentry);
if (dentry->d_name.len > NAME_MAX)
return ERR_PTR(-ENAMETOOLONG);
/* can we conclude ENOENT locally? */
if (d_really_is_negative(dentry)) {
struct ceph_inode_info *ci = ceph_inode(dir);
struct ceph_dentry_info *di = ceph_dentry(dentry);
spin_lock(&ci->i_ceph_lock);
dout(" dir %p flags are 0x%lx\n", dir, ci->i_ceph_flags);
if (strncmp(dentry->d_name.name,
fsc->mount_options->snapdir_name,
dentry->d_name.len) &&
!is_root_ceph_dentry(dir, dentry) &&
ceph_test_mount_opt(fsc, DCACHE) &&
__ceph_dir_is_complete(ci) &&
(__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1))) {
__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
spin_unlock(&ci->i_ceph_lock);
dout(" dir %p complete, -ENOENT\n", dir);
d_add(dentry, NULL);
di->lease_shared_gen = atomic_read(&ci->i_shared_gen);
return NULL;
}
spin_unlock(&ci->i_ceph_lock);
}
op = ceph_snap(dir) == CEPH_SNAPDIR ?
CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
if (IS_ERR(req))
return ERR_CAST(req);
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
if (ceph_security_xattr_wanted(dir))
mask |= CEPH_CAP_XATTR_SHARED;
req->r_args.getattr.mask = cpu_to_le32(mask);
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
err = ceph_mdsc_do_request(mdsc, NULL, req);
err = ceph_handle_snapdir(req, dentry, err);
dentry = ceph_finish_lookup(req, dentry, err);
ceph_mdsc_put_request(req); /* will dput(dentry) */
dout("lookup result=%p\n", dentry);
return dentry;
}
/*
* If we do a create but get no trace back from the MDS, follow up with
* a lookup (the VFS expects us to link up the provided dentry).
*/
int ceph_handle_notrace_create(struct inode *dir, struct dentry *dentry)
{
struct dentry *result = ceph_lookup(dir, dentry, 0);
if (result && !IS_ERR(result)) {
/*
* We created the item, then did a lookup, and found
* it was already linked to another inode we already
* had in our cache (and thus got spliced). To not
* confuse VFS (especially when inode is a directory),
* we don't link our dentry to that inode, return an
* error instead.
*
* This event should be rare and it happens only when
* we talk to old MDS. Recent MDS does not send traceless
* reply for request that creates new inode.
*/
d_drop(result);
return -ESTALE;
}
return PTR_ERR(result);
}
static int ceph_mknod(struct inode *dir, struct dentry *dentry,
umode_t mode, dev_t rdev)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct ceph_acl_sec_ctx as_ctx = {};
int err;
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
if (ceph_quota_is_max_files_exceeded(dir)) {
err = -EDQUOT;
goto out;
}
err = ceph_pre_init_acls(dir, &mode, &as_ctx);
if (err < 0)
goto out;
err = ceph_security_init_secctx(dentry, mode, &as_ctx);
if (err < 0)
goto out;
dout("mknod in dir %p dentry %p mode 0%ho rdev %d\n",
dir, dentry, mode, rdev);
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_MKNOD, USE_AUTH_MDS);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
}
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_args.mknod.mode = cpu_to_le32(mode);
req->r_args.mknod.rdev = cpu_to_le32(rdev);
req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
if (as_ctx.pagelist) {
req->r_pagelist = as_ctx.pagelist;
as_ctx.pagelist = NULL;
}
err = ceph_mdsc_do_request(mdsc, dir, req);
if (!err && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
ceph_mdsc_put_request(req);
out:
if (!err)
ceph_init_inode_acls(d_inode(dentry), &as_ctx);
else
d_drop(dentry);
ceph_release_acl_sec_ctx(&as_ctx);
return err;
}
static int ceph_create(struct inode *dir, struct dentry *dentry, umode_t mode,
bool excl)
{
return ceph_mknod(dir, dentry, mode, 0);
}
static int ceph_symlink(struct inode *dir, struct dentry *dentry,
const char *dest)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct ceph_acl_sec_ctx as_ctx = {};
int err;
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
if (ceph_quota_is_max_files_exceeded(dir)) {
err = -EDQUOT;
goto out;
}
err = ceph_security_init_secctx(dentry, S_IFLNK | 0777, &as_ctx);
if (err < 0)
goto out;
dout("symlink in dir %p dentry %p to '%s'\n", dir, dentry, dest);
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_SYMLINK, USE_AUTH_MDS);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
}
req->r_path2 = kstrdup(dest, GFP_KERNEL);
if (!req->r_path2) {
err = -ENOMEM;
ceph_mdsc_put_request(req);
goto out;
}
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
err = ceph_mdsc_do_request(mdsc, dir, req);
if (!err && !req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
ceph_mdsc_put_request(req);
out:
if (err)
d_drop(dentry);
ceph_release_acl_sec_ctx(&as_ctx);
return err;
}
static int ceph_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
struct ceph_acl_sec_ctx as_ctx = {};
int err = -EROFS;
int op;
if (ceph_snap(dir) == CEPH_SNAPDIR) {
/* mkdir .snap/foo is a MKSNAP */
op = CEPH_MDS_OP_MKSNAP;
dout("mksnap dir %p snap '%pd' dn %p\n", dir,
dentry, dentry);
} else if (ceph_snap(dir) == CEPH_NOSNAP) {
dout("mkdir dir %p dn %p mode 0%ho\n", dir, dentry, mode);
op = CEPH_MDS_OP_MKDIR;
} else {
goto out;
}
if (op == CEPH_MDS_OP_MKDIR &&
ceph_quota_is_max_files_exceeded(dir)) {
err = -EDQUOT;
goto out;
}
mode |= S_IFDIR;
err = ceph_pre_init_acls(dir, &mode, &as_ctx);
if (err < 0)
goto out;
err = ceph_security_init_secctx(dentry, mode, &as_ctx);
if (err < 0)
goto out;
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
}
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_args.mkdir.mode = cpu_to_le32(mode);
req->r_dentry_drop = CEPH_CAP_FILE_SHARED | CEPH_CAP_AUTH_EXCL;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
if (as_ctx.pagelist) {
req->r_pagelist = as_ctx.pagelist;
as_ctx.pagelist = NULL;
}
err = ceph_mdsc_do_request(mdsc, dir, req);
if (!err &&
!req->r_reply_info.head->is_target &&
!req->r_reply_info.head->is_dentry)
err = ceph_handle_notrace_create(dir, dentry);
ceph_mdsc_put_request(req);
out:
if (!err)
ceph_init_inode_acls(d_inode(dentry), &as_ctx);
else
d_drop(dentry);
ceph_release_acl_sec_ctx(&as_ctx);
return err;
}
static int ceph_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *dentry)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
int err;
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
dout("link in dir %p old_dentry %p dentry %p\n", dir,
old_dentry, dentry);
req = ceph_mdsc_create_request(mdsc, CEPH_MDS_OP_LINK, USE_AUTH_MDS);
if (IS_ERR(req)) {
d_drop(dentry);
return PTR_ERR(req);
}
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_old_dentry = dget(old_dentry);
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
/* release LINK_SHARED on source inode (mds will lock it) */
req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
err = ceph_mdsc_do_request(mdsc, dir, req);
if (err) {
d_drop(dentry);
} else if (!req->r_reply_info.head->is_dentry) {
ihold(d_inode(old_dentry));
d_instantiate(dentry, d_inode(old_dentry));
}
ceph_mdsc_put_request(req);
return err;
}
static void ceph_async_unlink_cb(struct ceph_mds_client *mdsc,
struct ceph_mds_request *req)
{
int result = req->r_err ? req->r_err :
le32_to_cpu(req->r_reply_info.head->result);
if (result == -EJUKEBOX)
goto out;
/* If op failed, mark everyone involved for errors */
if (result) {
int pathlen = 0;
u64 base = 0;
char *path = ceph_mdsc_build_path(req->r_dentry, &pathlen,
&base, 0);
/* mark error on parent + clear complete */
mapping_set_error(req->r_parent->i_mapping, result);
ceph_dir_clear_complete(req->r_parent);
/* drop the dentry -- we don't know its status */
if (!d_unhashed(req->r_dentry))
d_drop(req->r_dentry);
/* mark inode itself for an error (since metadata is bogus) */
mapping_set_error(req->r_old_inode->i_mapping, result);
pr_warn("ceph: async unlink failure path=(%llx)%s result=%d!\n",
base, IS_ERR(path) ? "<<bad>>" : path, result);
ceph_mdsc_free_path(path, pathlen);
}
out:
iput(req->r_old_inode);
ceph_mdsc_release_dir_caps(req);
}
static int get_caps_for_async_unlink(struct inode *dir, struct dentry *dentry)
{
struct ceph_inode_info *ci = ceph_inode(dir);
struct ceph_dentry_info *di;
int got = 0, want = CEPH_CAP_FILE_EXCL | CEPH_CAP_DIR_UNLINK;
spin_lock(&ci->i_ceph_lock);
if ((__ceph_caps_issued(ci, NULL) & want) == want) {
ceph_take_cap_refs(ci, want, false);
got = want;
}
spin_unlock(&ci->i_ceph_lock);
/* If we didn't get anything, return 0 */
if (!got)
return 0;
spin_lock(&dentry->d_lock);
di = ceph_dentry(dentry);
/*
* - We are holding Fx, which implies Fs caps.
* - Only support async unlink for primary linkage
*/
if (atomic_read(&ci->i_shared_gen) != di->lease_shared_gen ||
!(di->flags & CEPH_DENTRY_PRIMARY_LINK))
want = 0;
spin_unlock(&dentry->d_lock);
/* Do we still want what we've got? */
if (want == got)
return got;
ceph_put_cap_refs(ci, got);
return 0;
}
/*
* rmdir and unlink are differ only by the metadata op code
*/
static int ceph_unlink(struct inode *dir, struct dentry *dentry)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct inode *inode = d_inode(dentry);
struct ceph_mds_request *req;
bool try_async = ceph_test_mount_opt(fsc, ASYNC_DIROPS);
int err = -EROFS;
int op;
if (ceph_snap(dir) == CEPH_SNAPDIR) {
/* rmdir .snap/foo is RMSNAP */
dout("rmsnap dir %p '%pd' dn %p\n", dir, dentry, dentry);
op = CEPH_MDS_OP_RMSNAP;
} else if (ceph_snap(dir) == CEPH_NOSNAP) {
dout("unlink/rmdir dir %p dn %p inode %p\n",
dir, dentry, inode);
op = d_is_dir(dentry) ?
CEPH_MDS_OP_RMDIR : CEPH_MDS_OP_UNLINK;
} else
goto out;
retry:
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
if (IS_ERR(req)) {
err = PTR_ERR(req);
goto out;
}
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_parent = dir;
req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
req->r_inode_drop = ceph_drop_caps_for_unlink(inode);
if (try_async && op == CEPH_MDS_OP_UNLINK &&
(req->r_dir_caps = get_caps_for_async_unlink(dir, dentry))) {
dout("async unlink on %lu/%.*s caps=%s", dir->i_ino,
dentry->d_name.len, dentry->d_name.name,
ceph_cap_string(req->r_dir_caps));
set_bit(CEPH_MDS_R_ASYNC, &req->r_req_flags);
req->r_callback = ceph_async_unlink_cb;
req->r_old_inode = d_inode(dentry);
ihold(req->r_old_inode);
err = ceph_mdsc_submit_request(mdsc, dir, req);
if (!err) {
/*
* We have enough caps, so we assume that the unlink
* will succeed. Fix up the target inode and dcache.
*/
drop_nlink(inode);
d_delete(dentry);
} else if (err == -EJUKEBOX) {
try_async = false;
ceph_mdsc_put_request(req);
goto retry;
}
} else {
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
err = ceph_mdsc_do_request(mdsc, dir, req);
if (!err && !req->r_reply_info.head->is_dentry)
d_delete(dentry);
}
ceph_mdsc_put_request(req);
out:
return err;
}
static int ceph_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry,
unsigned int flags)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(old_dir->i_sb);
struct ceph_mds_client *mdsc = fsc->mdsc;
struct ceph_mds_request *req;
int op = CEPH_MDS_OP_RENAME;
int err;
if (flags)
return -EINVAL;
if (ceph_snap(old_dir) != ceph_snap(new_dir))
return -EXDEV;
if (ceph_snap(old_dir) != CEPH_NOSNAP) {
if (old_dir == new_dir && ceph_snap(old_dir) == CEPH_SNAPDIR)
op = CEPH_MDS_OP_RENAMESNAP;
else
return -EROFS;
}
/* don't allow cross-quota renames */
if ((old_dir != new_dir) &&
(!ceph_quota_is_same_realm(old_dir, new_dir)))
return -EXDEV;
dout("rename dir %p dentry %p to dir %p dentry %p\n",
old_dir, old_dentry, new_dir, new_dentry);
req = ceph_mdsc_create_request(mdsc, op, USE_AUTH_MDS);
if (IS_ERR(req))
return PTR_ERR(req);
ihold(old_dir);
req->r_dentry = dget(new_dentry);
req->r_num_caps = 2;
req->r_old_dentry = dget(old_dentry);
req->r_old_dentry_dir = old_dir;
req->r_parent = new_dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
req->r_old_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_old_dentry_unless = CEPH_CAP_FILE_EXCL;
req->r_dentry_drop = CEPH_CAP_FILE_SHARED;
req->r_dentry_unless = CEPH_CAP_FILE_EXCL;
/* release LINK_RDCACHE on source inode (mds will lock it) */
req->r_old_inode_drop = CEPH_CAP_LINK_SHARED | CEPH_CAP_LINK_EXCL;
if (d_really_is_positive(new_dentry)) {
req->r_inode_drop =
ceph_drop_caps_for_unlink(d_inode(new_dentry));
}
err = ceph_mdsc_do_request(mdsc, old_dir, req);
if (!err && !req->r_reply_info.head->is_dentry) {
/*
* Normally d_move() is done by fill_trace (called by
* do_request, above). If there is no trace, we need
* to do it here.
*/
d_move(old_dentry, new_dentry);
}
ceph_mdsc_put_request(req);
return err;
}
/*
* Move dentry to tail of mdsc->dentry_leases list when lease is updated.
* Leases at front of the list will expire first. (Assume all leases have
* similar duration)
*
* Called under dentry->d_lock.
*/
void __ceph_dentry_lease_touch(struct ceph_dentry_info *di)
{
struct dentry *dn = di->dentry;
struct ceph_mds_client *mdsc;
dout("dentry_lease_touch %p %p '%pd'\n", di, dn, dn);
di->flags |= CEPH_DENTRY_LEASE_LIST;
if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
di->flags |= CEPH_DENTRY_REFERENCED;
return;
}
mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
spin_lock(&mdsc->dentry_list_lock);
list_move_tail(&di->lease_list, &mdsc->dentry_leases);
spin_unlock(&mdsc->dentry_list_lock);
}
static void __dentry_dir_lease_touch(struct ceph_mds_client* mdsc,
struct ceph_dentry_info *di)
{
di->flags &= ~(CEPH_DENTRY_LEASE_LIST | CEPH_DENTRY_REFERENCED);
di->lease_gen = 0;
di->time = jiffies;
list_move_tail(&di->lease_list, &mdsc->dentry_dir_leases);
}
/*
* When dir lease is used, add dentry to tail of mdsc->dentry_dir_leases
* list if it's not in the list, otherwise set 'referenced' flag.
*
* Called under dentry->d_lock.
*/
void __ceph_dentry_dir_lease_touch(struct ceph_dentry_info *di)
{
struct dentry *dn = di->dentry;
struct ceph_mds_client *mdsc;
dout("dentry_dir_lease_touch %p %p '%pd' (offset 0x%llx)\n",
di, dn, dn, di->offset);
if (!list_empty(&di->lease_list)) {
if (di->flags & CEPH_DENTRY_LEASE_LIST) {
/* don't remove dentry from dentry lease list
* if its lease is valid */
if (__dentry_lease_is_valid(di))
return;
} else {
di->flags |= CEPH_DENTRY_REFERENCED;
return;
}
}
if (di->flags & CEPH_DENTRY_SHRINK_LIST) {
di->flags |= CEPH_DENTRY_REFERENCED;
di->flags &= ~CEPH_DENTRY_LEASE_LIST;
return;
}
mdsc = ceph_sb_to_client(dn->d_sb)->mdsc;
spin_lock(&mdsc->dentry_list_lock);
__dentry_dir_lease_touch(mdsc, di),
spin_unlock(&mdsc->dentry_list_lock);
}
static void __dentry_lease_unlist(struct ceph_dentry_info *di)
{
struct ceph_mds_client *mdsc;
if (di->flags & CEPH_DENTRY_SHRINK_LIST)
return;
if (list_empty(&di->lease_list))
return;
mdsc = ceph_sb_to_client(di->dentry->d_sb)->mdsc;
spin_lock(&mdsc->dentry_list_lock);
list_del_init(&di->lease_list);
spin_unlock(&mdsc->dentry_list_lock);
}
enum {
KEEP = 0,
DELETE = 1,
TOUCH = 2,
STOP = 4,
};
struct ceph_lease_walk_control {
bool dir_lease;
bool expire_dir_lease;
unsigned long nr_to_scan;
unsigned long dir_lease_ttl;
};
static unsigned long
__dentry_leases_walk(struct ceph_mds_client *mdsc,
struct ceph_lease_walk_control *lwc,
int (*check)(struct dentry*, void*))
{
struct ceph_dentry_info *di, *tmp;
struct dentry *dentry, *last = NULL;
struct list_head* list;
LIST_HEAD(dispose);
unsigned long freed = 0;
int ret = 0;
list = lwc->dir_lease ? &mdsc->dentry_dir_leases : &mdsc->dentry_leases;
spin_lock(&mdsc->dentry_list_lock);
list_for_each_entry_safe(di, tmp, list, lease_list) {
if (!lwc->nr_to_scan)
break;
--lwc->nr_to_scan;
dentry = di->dentry;
if (last == dentry)
break;
if (!spin_trylock(&dentry->d_lock))
continue;
if (__lockref_is_dead(&dentry->d_lockref)) {
list_del_init(&di->lease_list);
goto next;
}
ret = check(dentry, lwc);
if (ret & TOUCH) {
/* move it into tail of dir lease list */
__dentry_dir_lease_touch(mdsc, di);
if (!last)
last = dentry;
}
if (ret & DELETE) {
/* stale lease */
di->flags &= ~CEPH_DENTRY_REFERENCED;
if (dentry->d_lockref.count > 0) {
/* update_dentry_lease() will re-add
* it to lease list, or
* ceph_d_delete() will return 1 when
* last reference is dropped */
list_del_init(&di->lease_list);
} else {
di->flags |= CEPH_DENTRY_SHRINK_LIST;
list_move_tail(&di->lease_list, &dispose);
dget_dlock(dentry);
}
}
next:
spin_unlock(&dentry->d_lock);
if (ret & STOP)
break;
}
spin_unlock(&mdsc->dentry_list_lock);
while (!list_empty(&dispose)) {
di = list_first_entry(&dispose, struct ceph_dentry_info,
lease_list);
dentry = di->dentry;
spin_lock(&dentry->d_lock);
list_del_init(&di->lease_list);
di->flags &= ~CEPH_DENTRY_SHRINK_LIST;
if (di->flags & CEPH_DENTRY_REFERENCED) {
spin_lock(&mdsc->dentry_list_lock);
if (di->flags & CEPH_DENTRY_LEASE_LIST) {
list_add_tail(&di->lease_list,
&mdsc->dentry_leases);
} else {
__dentry_dir_lease_touch(mdsc, di);
}
spin_unlock(&mdsc->dentry_list_lock);
} else {
freed++;
}
spin_unlock(&dentry->d_lock);
/* ceph_d_delete() does the trick */
dput(dentry);
}
return freed;
}
static int __dentry_lease_check(struct dentry *dentry, void *arg)
{
struct ceph_dentry_info *di = ceph_dentry(dentry);
int ret;
if (__dentry_lease_is_valid(di))
return STOP;
ret = __dir_lease_try_check(dentry);
if (ret == -EBUSY)
return KEEP;
if (ret > 0)
return TOUCH;
return DELETE;
}
static int __dir_lease_check(struct dentry *dentry, void *arg)
{
struct ceph_lease_walk_control *lwc = arg;
struct ceph_dentry_info *di = ceph_dentry(dentry);
int ret = __dir_lease_try_check(dentry);
if (ret == -EBUSY)
return KEEP;
if (ret > 0) {
if (time_before(jiffies, di->time + lwc->dir_lease_ttl))
return STOP;
/* Move dentry to tail of dir lease list if we don't want
* to delete it. So dentries in the list are checked in a
* round robin manner */
if (!lwc->expire_dir_lease)
return TOUCH;
if (dentry->d_lockref.count > 0 ||
(di->flags & CEPH_DENTRY_REFERENCED))
return TOUCH;
/* invalidate dir lease */
di->lease_shared_gen = 0;
}
return DELETE;
}
int ceph_trim_dentries(struct ceph_mds_client *mdsc)
{
struct ceph_lease_walk_control lwc;
unsigned long count;
unsigned long freed;
spin_lock(&mdsc->caps_list_lock);
if (mdsc->caps_use_max > 0 &&
mdsc->caps_use_count > mdsc->caps_use_max)
count = mdsc->caps_use_count - mdsc->caps_use_max;
else
count = 0;
spin_unlock(&mdsc->caps_list_lock);
lwc.dir_lease = false;
lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE * 2;
freed = __dentry_leases_walk(mdsc, &lwc, __dentry_lease_check);
if (!lwc.nr_to_scan) /* more invalid leases */
return -EAGAIN;
if (lwc.nr_to_scan < CEPH_CAPS_PER_RELEASE)
lwc.nr_to_scan = CEPH_CAPS_PER_RELEASE;
lwc.dir_lease = true;
lwc.expire_dir_lease = freed < count;
lwc.dir_lease_ttl = mdsc->fsc->mount_options->caps_wanted_delay_max * HZ;
freed +=__dentry_leases_walk(mdsc, &lwc, __dir_lease_check);
if (!lwc.nr_to_scan) /* more to check */
return -EAGAIN;
return freed > 0 ? 1 : 0;
}
/*
* Ensure a dentry lease will no longer revalidate.
*/
void ceph_invalidate_dentry_lease(struct dentry *dentry)
{
struct ceph_dentry_info *di = ceph_dentry(dentry);
spin_lock(&dentry->d_lock);
di->time = jiffies;
di->lease_shared_gen = 0;
di->flags &= ~CEPH_DENTRY_PRIMARY_LINK;
__dentry_lease_unlist(di);
spin_unlock(&dentry->d_lock);
}
/*
* Check if dentry lease is valid. If not, delete the lease. Try to
* renew if the least is more than half up.
*/
static bool __dentry_lease_is_valid(struct ceph_dentry_info *di)
{
struct ceph_mds_session *session;
if (!di->lease_gen)
return false;
session = di->lease_session;
if (session) {
u32 gen;
unsigned long ttl;
spin_lock(&session->s_gen_ttl_lock);
gen = session->s_cap_gen;
ttl = session->s_cap_ttl;
spin_unlock(&session->s_gen_ttl_lock);
if (di->lease_gen == gen &&
time_before(jiffies, ttl) &&
time_before(jiffies, di->time))
return true;
}
di->lease_gen = 0;
return false;
}
static int dentry_lease_is_valid(struct dentry *dentry, unsigned int flags)
{
struct ceph_dentry_info *di;
struct ceph_mds_session *session = NULL;
u32 seq = 0;
int valid = 0;
spin_lock(&dentry->d_lock);
di = ceph_dentry(dentry);
if (di && __dentry_lease_is_valid(di)) {
valid = 1;
if (di->lease_renew_after &&
time_after(jiffies, di->lease_renew_after)) {
/*
* We should renew. If we're in RCU walk mode
* though, we can't do that so just return
* -ECHILD.
*/
if (flags & LOOKUP_RCU) {
valid = -ECHILD;
} else {
session = ceph_get_mds_session(di->lease_session);
seq = di->lease_seq;
di->lease_renew_after = 0;
di->lease_renew_from = jiffies;
}
}
}
spin_unlock(&dentry->d_lock);
if (session) {
ceph_mdsc_lease_send_msg(session, dentry,
CEPH_MDS_LEASE_RENEW, seq);
ceph_put_mds_session(session);
}
dout("dentry_lease_is_valid - dentry %p = %d\n", dentry, valid);
return valid;
}
/*
* Called under dentry->d_lock.
*/
static int __dir_lease_try_check(const struct dentry *dentry)
{
struct ceph_dentry_info *di = ceph_dentry(dentry);
struct inode *dir;
struct ceph_inode_info *ci;
int valid = 0;
if (!di->lease_shared_gen)
return 0;
if (IS_ROOT(dentry))
return 0;
dir = d_inode(dentry->d_parent);
ci = ceph_inode(dir);
if (spin_trylock(&ci->i_ceph_lock)) {
if (atomic_read(&ci->i_shared_gen) == di->lease_shared_gen &&
__ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 0))
valid = 1;
spin_unlock(&ci->i_ceph_lock);
} else {
valid = -EBUSY;
}
if (!valid)
di->lease_shared_gen = 0;
return valid;
}
/*
* Check if directory-wide content lease/cap is valid.
*/
static int dir_lease_is_valid(struct inode *dir, struct dentry *dentry,
struct ceph_mds_client *mdsc)
{
struct ceph_inode_info *ci = ceph_inode(dir);
int valid;
int shared_gen;
spin_lock(&ci->i_ceph_lock);
valid = __ceph_caps_issued_mask(ci, CEPH_CAP_FILE_SHARED, 1);
if (valid) {
__ceph_touch_fmode(ci, mdsc, CEPH_FILE_MODE_RD);
shared_gen = atomic_read(&ci->i_shared_gen);
}
spin_unlock(&ci->i_ceph_lock);
if (valid) {
struct ceph_dentry_info *di;
spin_lock(&dentry->d_lock);
di = ceph_dentry(dentry);
if (dir == d_inode(dentry->d_parent) &&
di && di->lease_shared_gen == shared_gen)
__ceph_dentry_dir_lease_touch(di);
else
valid = 0;
spin_unlock(&dentry->d_lock);
}
dout("dir_lease_is_valid dir %p v%u dentry %p = %d\n",
dir, (unsigned)atomic_read(&ci->i_shared_gen), dentry, valid);
return valid;
}
/*
* Check if cached dentry can be trusted.
*/
static int ceph_d_revalidate(struct dentry *dentry, unsigned int flags)
{
int valid = 0;
struct dentry *parent;
struct inode *dir, *inode;
struct ceph_mds_client *mdsc;
if (flags & LOOKUP_RCU) {
parent = READ_ONCE(dentry->d_parent);
dir = d_inode_rcu(parent);
if (!dir)
return -ECHILD;
inode = d_inode_rcu(dentry);
} else {
parent = dget_parent(dentry);
dir = d_inode(parent);
inode = d_inode(dentry);
}
dout("d_revalidate %p '%pd' inode %p offset 0x%llx\n", dentry,
dentry, inode, ceph_dentry(dentry)->offset);
mdsc = ceph_sb_to_client(dir->i_sb)->mdsc;
/* always trust cached snapped dentries, snapdir dentry */
if (ceph_snap(dir) != CEPH_NOSNAP) {
dout("d_revalidate %p '%pd' inode %p is SNAPPED\n", dentry,
dentry, inode);
valid = 1;
} else if (inode && ceph_snap(inode) == CEPH_SNAPDIR) {
valid = 1;
} else {
valid = dentry_lease_is_valid(dentry, flags);
if (valid == -ECHILD)
return valid;
if (valid || dir_lease_is_valid(dir, dentry, mdsc)) {
if (inode)
valid = ceph_is_any_caps(inode);
else
valid = 1;
}
}
if (!valid) {
struct ceph_mds_request *req;
int op, err;
u32 mask;
if (flags & LOOKUP_RCU)
return -ECHILD;
op = ceph_snap(dir) == CEPH_SNAPDIR ?
CEPH_MDS_OP_LOOKUPSNAP : CEPH_MDS_OP_LOOKUP;
req = ceph_mdsc_create_request(mdsc, op, USE_ANY_MDS);
if (!IS_ERR(req)) {
req->r_dentry = dget(dentry);
req->r_num_caps = 2;
req->r_parent = dir;
mask = CEPH_STAT_CAP_INODE | CEPH_CAP_AUTH_SHARED;
if (ceph_security_xattr_wanted(dir))
mask |= CEPH_CAP_XATTR_SHARED;
req->r_args.getattr.mask = cpu_to_le32(mask);
err = ceph_mdsc_do_request(mdsc, NULL, req);
switch (err) {
case 0:
if (d_really_is_positive(dentry) &&
d_inode(dentry) == req->r_target_inode)
valid = 1;
break;
case -ENOENT:
if (d_really_is_negative(dentry))
valid = 1;
/* Fallthrough */
default:
break;
}
ceph_mdsc_put_request(req);
dout("d_revalidate %p lookup result=%d\n",
dentry, err);
}
}
dout("d_revalidate %p %s\n", dentry, valid ? "valid" : "invalid");
if (!valid)
ceph_dir_clear_complete(dir);
if (!(flags & LOOKUP_RCU))
dput(parent);
return valid;
}
/*
* Delete unused dentry that doesn't have valid lease
*
* Called under dentry->d_lock.
*/
static int ceph_d_delete(const struct dentry *dentry)
{
struct ceph_dentry_info *di;
/* won't release caps */
if (d_really_is_negative(dentry))
return 0;
if (ceph_snap(d_inode(dentry)) != CEPH_NOSNAP)
return 0;
/* vaild lease? */
di = ceph_dentry(dentry);
if (di) {
if (__dentry_lease_is_valid(di))
return 0;
if (__dir_lease_try_check(dentry))
return 0;
}
return 1;
}
/*
* Release our ceph_dentry_info.
*/
static void ceph_d_release(struct dentry *dentry)
{
struct ceph_dentry_info *di = ceph_dentry(dentry);
dout("d_release %p\n", dentry);
spin_lock(&dentry->d_lock);
__dentry_lease_unlist(di);
dentry->d_fsdata = NULL;
spin_unlock(&dentry->d_lock);
if (di->lease_session)
ceph_put_mds_session(di->lease_session);
kmem_cache_free(ceph_dentry_cachep, di);
}
/*
* When the VFS prunes a dentry from the cache, we need to clear the
* complete flag on the parent directory.
*
* Called under dentry->d_lock.
*/
static void ceph_d_prune(struct dentry *dentry)
{
struct ceph_inode_info *dir_ci;
struct ceph_dentry_info *di;
dout("ceph_d_prune %pd %p\n", dentry, dentry);
/* do we have a valid parent? */
if (IS_ROOT(dentry))
return;
/* we hold d_lock, so d_parent is stable */
dir_ci = ceph_inode(d_inode(dentry->d_parent));
if (dir_ci->i_vino.snap == CEPH_SNAPDIR)
return;
/* who calls d_delete() should also disable dcache readdir */
if (d_really_is_negative(dentry))
return;
/* d_fsdata does not get cleared until d_release */
if (!d_unhashed(dentry)) {
__ceph_dir_clear_complete(dir_ci);
return;
}
/* Disable dcache readdir just in case that someone called d_drop()
* or d_invalidate(), but MDS didn't revoke CEPH_CAP_FILE_SHARED
* properly (dcache readdir is still enabled) */
di = ceph_dentry(dentry);
if (di->offset > 0 &&
di->lease_shared_gen == atomic_read(&dir_ci->i_shared_gen))
__ceph_dir_clear_ordered(dir_ci);
}
/*
* read() on a dir. This weird interface hack only works if mounted
* with '-o dirstat'.
*/
static ssize_t ceph_read_dir(struct file *file, char __user *buf, size_t size,
loff_t *ppos)
{
struct ceph_dir_file_info *dfi = file->private_data;
struct inode *inode = file_inode(file);
struct ceph_inode_info *ci = ceph_inode(inode);
int left;
const int bufsize = 1024;
if (!ceph_test_mount_opt(ceph_sb_to_client(inode->i_sb), DIRSTAT))
return -EISDIR;
if (!dfi->dir_info) {
dfi->dir_info = kmalloc(bufsize, GFP_KERNEL);
if (!dfi->dir_info)
return -ENOMEM;
dfi->dir_info_len =
snprintf(dfi->dir_info, bufsize,
"entries: %20lld\n"
" files: %20lld\n"
" subdirs: %20lld\n"
"rentries: %20lld\n"
" rfiles: %20lld\n"
" rsubdirs: %20lld\n"
"rbytes: %20lld\n"
"rctime: %10lld.%09ld\n",
ci->i_files + ci->i_subdirs,
ci->i_files,
ci->i_subdirs,
ci->i_rfiles + ci->i_rsubdirs,
ci->i_rfiles,
ci->i_rsubdirs,
ci->i_rbytes,
ci->i_rctime.tv_sec,
ci->i_rctime.tv_nsec);
}
if (*ppos >= dfi->dir_info_len)
return 0;
size = min_t(unsigned, size, dfi->dir_info_len-*ppos);
left = copy_to_user(buf, dfi->dir_info + *ppos, size);
if (left == size)
return -EFAULT;
*ppos += (size - left);
return size - left;
}
/*
* Return name hash for a given dentry. This is dependent on
* the parent directory's hash function.
*/
unsigned ceph_dentry_hash(struct inode *dir, struct dentry *dn)
{
struct ceph_inode_info *dci = ceph_inode(dir);
unsigned hash;
switch (dci->i_dir_layout.dl_dir_hash) {
case 0: /* for backward compat */
case CEPH_STR_HASH_LINUX:
return dn->d_name.hash;
default:
spin_lock(&dn->d_lock);
hash = ceph_str_hash(dci->i_dir_layout.dl_dir_hash,
dn->d_name.name, dn->d_name.len);
spin_unlock(&dn->d_lock);
return hash;
}
}
const struct file_operations ceph_dir_fops = {
.read = ceph_read_dir,
.iterate = ceph_readdir,
.llseek = ceph_dir_llseek,
.open = ceph_open,
.release = ceph_release,
.unlocked_ioctl = ceph_ioctl,
.compat_ioctl = compat_ptr_ioctl,
.fsync = ceph_fsync,
.lock = ceph_lock,
.flock = ceph_flock,
};
const struct file_operations ceph_snapdir_fops = {
.iterate = ceph_readdir,
.llseek = ceph_dir_llseek,
.open = ceph_open,
.release = ceph_release,
};
const struct inode_operations ceph_dir_iops = {
.lookup = ceph_lookup,
.permission = ceph_permission,
.getattr = ceph_getattr,
.setattr = ceph_setattr,
.listxattr = ceph_listxattr,
.get_acl = ceph_get_acl,
.set_acl = ceph_set_acl,
.mknod = ceph_mknod,
.symlink = ceph_symlink,
.mkdir = ceph_mkdir,
.link = ceph_link,
.unlink = ceph_unlink,
.rmdir = ceph_unlink,
.rename = ceph_rename,
.create = ceph_create,
.atomic_open = ceph_atomic_open,
};
const struct inode_operations ceph_snapdir_iops = {
.lookup = ceph_lookup,
.permission = ceph_permission,
.getattr = ceph_getattr,
.mkdir = ceph_mkdir,
.rmdir = ceph_unlink,
.rename = ceph_rename,
};
const struct dentry_operations ceph_dentry_ops = {
.d_revalidate = ceph_d_revalidate,
.d_delete = ceph_d_delete,
.d_release = ceph_d_release,
.d_prune = ceph_d_prune,
.d_init = ceph_d_init,
};
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