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linux/fs/ceph/dir.c
Xiubo Li 4868e537fa ceph: wait for the first reply of inflight async unlink 
In async unlink case the kclient won't wait for the first reply
from MDS and just drop all the links and unhash the dentry and then
succeeds immediately.

For any new create/link/rename,etc requests followed by using the
same file names we must wait for the first reply of the inflight
unlink request, or the MDS possibly will fail these following
requests with -EEXIST if the inflight async unlink request was
delayed for some reasons.

And the worst case is that for the none async openc request it will
successfully open the file if the CDentry hasn't been unlinked yet,
but later the previous delayed async unlink request will remove the
CDenty. That means the just created file is possiblly deleted later
by accident.

We need to wait for the inflight async unlink requests to finish
when creating new files/directories by using the same file names.

Link: https://tracker.ceph.com/issues/55332
Signed-off-by: Xiubo Li <xiubli@redhat.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
2022-08-03 00:54:12 +02:00

2065 lines
53 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;
struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dentry->d_sb);
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);
atomic64_inc(&mdsc->metric.total_dentries);
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_rwsem, 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_rwsem. */
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_present_inode(d_inode(dentry)),
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_present_inode(inode),
inode->i_mode >> 12))
return 0;
ctx->pos = 1;
}
if (ctx->pos == 1) {
u64 ino;
struct dentry *dentry = file->f_path.dentry;
spin_lock(&dentry->d_lock);
ino = ceph_present_inode(dentry->d_parent->d_inode);
spin_unlock(&dentry->d_lock);
dout("readdir off 1 -> '..'\n");
if (!dir_emit(ctx, "..", 2, 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_metric(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) {
ceph_mdsc_put_request(dfi->last_readdir);
dfi->last_readdir = NULL;
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;
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);
if (!dir_emit(ctx, rde->name, rde->name_len,
ceph_present_ino(inode->i_sb, le64_to_cpu(rde->inode.in->ino)),
le32_to_cpu(rde->inode.in->mode) >> 12)) {
/*
* NOTE: Here no need to put the 'dfi->last_readdir',
* because when dir_emit stops us it's most likely
* doesn't have enough memory, etc. So for next readdir
* it will continue.
*/
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;
break;
case SEEK_SET:
break;
case SEEK_END:
retval = -EOPNOTSUPP;
goto out;
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.
*/
struct dentry *ceph_handle_snapdir(struct ceph_mds_request *req,
struct dentry *dentry)
{
struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
struct inode *parent = d_inode(dentry->d_parent); /* we hold i_rwsem */
/* .snap dir? */
if (ceph_snap(parent) == CEPH_NOSNAP &&
strcmp(dentry->d_name.name, fsc->mount_options->snapdir_name) == 0) {
struct dentry *res;
struct inode *inode = ceph_get_snapdir(parent);
res = d_splice_alias(inode, dentry);
dout("ENOENT on snapdir %p '%pd', linking to snapdir %p. Spliced dentry %p\n",
dentry, dentry, inode, res);
if (res)
dentry = res;
}
return dentry;
}
/*
* 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 = ceph_sb_to_mdsc(dir->i_sb);
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_metric(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);
ihold(dir);
req->r_parent = dir;
set_bit(CEPH_MDS_R_PARENT_LOCKED, &req->r_req_flags);
err = ceph_mdsc_do_request(mdsc, NULL, req);
if (err == -ENOENT) {
struct dentry *res;
res = ceph_handle_snapdir(req, dentry);
if (IS_ERR(res)) {
err = PTR_ERR(res);
} else {
dentry = res;
err = 0;
}
}
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 user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode, dev_t rdev)
{
struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
struct ceph_mds_request *req;
struct ceph_acl_sec_ctx as_ctx = {};
int err;
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
err = ceph_wait_on_conflict_unlink(dentry);
if (err)
return err;
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;
ihold(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 user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
return ceph_mknod(mnt_userns, dir, dentry, mode, 0);
}
static int ceph_symlink(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, const char *dest)
{
struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
struct ceph_mds_request *req;
struct ceph_acl_sec_ctx as_ctx = {};
int err;
if (ceph_snap(dir) != CEPH_NOSNAP)
return -EROFS;
err = ceph_wait_on_conflict_unlink(dentry);
if (err)
return err;
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;
ihold(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;
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)
d_drop(dentry);
ceph_release_acl_sec_ctx(&as_ctx);
return err;
}
static int ceph_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
struct dentry *dentry, umode_t mode)
{
struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
struct ceph_mds_request *req;
struct ceph_acl_sec_ctx as_ctx = {};
int err;
int op;
err = ceph_wait_on_conflict_unlink(dentry);
if (err)
return err;
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 {
err = -EROFS;
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;
ihold(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_mds_client *mdsc = ceph_sb_to_mdsc(dir->i_sb);
struct ceph_mds_request *req;
int err;
err = ceph_wait_on_conflict_unlink(dentry);
if (err)
return 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;
ihold(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)
{
struct dentry *dentry = req->r_dentry;
struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
struct ceph_dentry_info *di = ceph_dentry(dentry);
int result = req->r_err ? req->r_err :
le32_to_cpu(req->r_reply_info.head->result);
if (!test_bit(CEPH_DENTRY_ASYNC_UNLINK_BIT, &di->flags))
pr_warn("%s dentry %p:%pd async unlink bit is not set\n",
__func__, dentry, dentry);
spin_lock(&fsc->async_unlink_conflict_lock);
hash_del_rcu(&di->hnode);
spin_unlock(&fsc->async_unlink_conflict_lock);
spin_lock(&dentry->d_lock);
di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
wake_up_bit(&di->flags, CEPH_DENTRY_ASYNC_UNLINK_BIT);
spin_unlock(&dentry->d_lock);
synchronize_rcu();
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(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(dentry))
d_drop(dentry);
/* mark inode itself for an error (since metadata is bogus) */
mapping_set_error(req->r_old_inode->i_mapping, result);
pr_warn("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;
ihold(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))) {
struct ceph_dentry_info *di = ceph_dentry(dentry);
dout("async unlink on %llu/%.*s caps=%s", ceph_ino(dir),
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);
spin_lock(&dentry->d_lock);
di->flags |= CEPH_DENTRY_ASYNC_UNLINK;
spin_unlock(&dentry->d_lock);
spin_lock(&fsc->async_unlink_conflict_lock);
hash_add_rcu(fsc->async_unlink_conflict, &di->hnode,
dentry->d_name.hash);
spin_unlock(&fsc->async_unlink_conflict_lock);
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 {
spin_lock(&fsc->async_unlink_conflict_lock);
hash_del_rcu(&di->hnode);
spin_unlock(&fsc->async_unlink_conflict_lock);
spin_lock(&dentry->d_lock);
di->flags &= ~CEPH_DENTRY_ASYNC_UNLINK;
spin_unlock(&dentry->d_lock);
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 user_namespace *mnt_userns, struct inode *old_dir,
struct dentry *old_dentry, struct inode *new_dir,
struct dentry *new_dentry, unsigned int flags)
{
struct ceph_mds_client *mdsc = ceph_sb_to_mdsc(old_dir->i_sb);
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;
err = ceph_wait_on_conflict_unlink(new_dentry);
if (err)
return err;
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;
ihold(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;
gen = atomic_read(&session->s_cap_gen);
ttl = session->s_cap_ttl;
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;
percpu_counter_inc(&mdsc->metric.d_lease_mis);
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;
ihold(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);
}
} else {
percpu_counter_inc(&mdsc->metric.d_lease_hit);
}
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);
struct ceph_fs_client *fsc = ceph_sb_to_client(dentry->d_sb);
dout("d_release %p\n", dentry);
atomic64_dec(&fsc->mdsc->metric.total_dentries);
spin_lock(&dentry->d_lock);
__dentry_lease_unlist(di);
dentry->d_fsdata = NULL;
spin_unlock(&dentry->d_lock);
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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