| /* |
| * pNFS functions to call and manage layout drivers. |
| * |
| * Copyright (c) 2002 [year of first publication] |
| * The Regents of the University of Michigan |
| * All Rights Reserved |
| * |
| * Dean Hildebrand <dhildebz@umich.edu> |
| * |
| * Permission is granted to use, copy, create derivative works, and |
| * redistribute this software and such derivative works for any purpose, |
| * so long as the name of the University of Michigan is not used in |
| * any advertising or publicity pertaining to the use or distribution |
| * of this software without specific, written prior authorization. If |
| * the above copyright notice or any other identification of the |
| * University of Michigan is included in any copy of any portion of |
| * this software, then the disclaimer below must also be included. |
| * |
| * This software is provided as is, without representation or warranty |
| * of any kind either express or implied, including without limitation |
| * the implied warranties of merchantability, fitness for a particular |
| * purpose, or noninfringement. The Regents of the University of |
| * Michigan shall not be liable for any damages, including special, |
| * indirect, incidental, or consequential damages, with respect to any |
| * claim arising out of or in connection with the use of the software, |
| * even if it has been or is hereafter advised of the possibility of |
| * such damages. |
| */ |
| |
| #include <linux/nfs_fs.h> |
| #include "internal.h" |
| #include "pnfs.h" |
| |
| #define NFSDBG_FACILITY NFSDBG_PNFS |
| |
| /* Locking: |
| * |
| * pnfs_spinlock: |
| * protects pnfs_modules_tbl. |
| */ |
| static DEFINE_SPINLOCK(pnfs_spinlock); |
| |
| /* |
| * pnfs_modules_tbl holds all pnfs modules |
| */ |
| static LIST_HEAD(pnfs_modules_tbl); |
| |
| /* Return the registered pnfs layout driver module matching given id */ |
| static struct pnfs_layoutdriver_type * |
| find_pnfs_driver_locked(u32 id) |
| { |
| struct pnfs_layoutdriver_type *local; |
| |
| list_for_each_entry(local, &pnfs_modules_tbl, pnfs_tblid) |
| if (local->id == id) |
| goto out; |
| local = NULL; |
| out: |
| dprintk("%s: Searching for id %u, found %p\n", __func__, id, local); |
| return local; |
| } |
| |
| static struct pnfs_layoutdriver_type * |
| find_pnfs_driver(u32 id) |
| { |
| struct pnfs_layoutdriver_type *local; |
| |
| spin_lock(&pnfs_spinlock); |
| local = find_pnfs_driver_locked(id); |
| spin_unlock(&pnfs_spinlock); |
| return local; |
| } |
| |
| void |
| unset_pnfs_layoutdriver(struct nfs_server *nfss) |
| { |
| if (nfss->pnfs_curr_ld) { |
| nfss->pnfs_curr_ld->clear_layoutdriver(nfss); |
| module_put(nfss->pnfs_curr_ld->owner); |
| } |
| nfss->pnfs_curr_ld = NULL; |
| } |
| |
| /* |
| * Try to set the server's pnfs module to the pnfs layout type specified by id. |
| * Currently only one pNFS layout driver per filesystem is supported. |
| * |
| * @id layout type. Zero (illegal layout type) indicates pNFS not in use. |
| */ |
| void |
| set_pnfs_layoutdriver(struct nfs_server *server, u32 id) |
| { |
| struct pnfs_layoutdriver_type *ld_type = NULL; |
| |
| if (id == 0) |
| goto out_no_driver; |
| if (!(server->nfs_client->cl_exchange_flags & |
| (EXCHGID4_FLAG_USE_NON_PNFS | EXCHGID4_FLAG_USE_PNFS_MDS))) { |
| printk(KERN_ERR "%s: id %u cl_exchange_flags 0x%x\n", __func__, |
| id, server->nfs_client->cl_exchange_flags); |
| goto out_no_driver; |
| } |
| ld_type = find_pnfs_driver(id); |
| if (!ld_type) { |
| request_module("%s-%u", LAYOUT_NFSV4_1_MODULE_PREFIX, id); |
| ld_type = find_pnfs_driver(id); |
| if (!ld_type) { |
| dprintk("%s: No pNFS module found for %u.\n", |
| __func__, id); |
| goto out_no_driver; |
| } |
| } |
| if (!try_module_get(ld_type->owner)) { |
| dprintk("%s: Could not grab reference on module\n", __func__); |
| goto out_no_driver; |
| } |
| server->pnfs_curr_ld = ld_type; |
| if (ld_type->set_layoutdriver(server)) { |
| printk(KERN_ERR |
| "%s: Error initializing mount point for layout driver %u.\n", |
| __func__, id); |
| module_put(ld_type->owner); |
| goto out_no_driver; |
| } |
| dprintk("%s: pNFS module for %u set\n", __func__, id); |
| return; |
| |
| out_no_driver: |
| dprintk("%s: Using NFSv4 I/O\n", __func__); |
| server->pnfs_curr_ld = NULL; |
| } |
| |
| int |
| pnfs_register_layoutdriver(struct pnfs_layoutdriver_type *ld_type) |
| { |
| int status = -EINVAL; |
| struct pnfs_layoutdriver_type *tmp; |
| |
| if (ld_type->id == 0) { |
| printk(KERN_ERR "%s id 0 is reserved\n", __func__); |
| return status; |
| } |
| if (!ld_type->alloc_lseg || !ld_type->free_lseg) { |
| printk(KERN_ERR "%s Layout driver must provide " |
| "alloc_lseg and free_lseg.\n", __func__); |
| return status; |
| } |
| |
| spin_lock(&pnfs_spinlock); |
| tmp = find_pnfs_driver_locked(ld_type->id); |
| if (!tmp) { |
| list_add(&ld_type->pnfs_tblid, &pnfs_modules_tbl); |
| status = 0; |
| dprintk("%s Registering id:%u name:%s\n", __func__, ld_type->id, |
| ld_type->name); |
| } else { |
| printk(KERN_ERR "%s Module with id %d already loaded!\n", |
| __func__, ld_type->id); |
| } |
| spin_unlock(&pnfs_spinlock); |
| |
| return status; |
| } |
| EXPORT_SYMBOL_GPL(pnfs_register_layoutdriver); |
| |
| void |
| pnfs_unregister_layoutdriver(struct pnfs_layoutdriver_type *ld_type) |
| { |
| dprintk("%s Deregistering id:%u\n", __func__, ld_type->id); |
| spin_lock(&pnfs_spinlock); |
| list_del(&ld_type->pnfs_tblid); |
| spin_unlock(&pnfs_spinlock); |
| } |
| EXPORT_SYMBOL_GPL(pnfs_unregister_layoutdriver); |
| |
| /* |
| * pNFS client layout cache |
| */ |
| |
| static void |
| get_layout_hdr_locked(struct pnfs_layout_hdr *lo) |
| { |
| assert_spin_locked(&lo->plh_inode->i_lock); |
| lo->plh_refcount++; |
| } |
| |
| static void |
| put_layout_hdr_locked(struct pnfs_layout_hdr *lo) |
| { |
| assert_spin_locked(&lo->plh_inode->i_lock); |
| BUG_ON(lo->plh_refcount == 0); |
| |
| lo->plh_refcount--; |
| if (!lo->plh_refcount) { |
| dprintk("%s: freeing layout cache %p\n", __func__, lo); |
| BUG_ON(!list_empty(&lo->plh_layouts)); |
| NFS_I(lo->plh_inode)->layout = NULL; |
| kfree(lo); |
| } |
| } |
| |
| void |
| put_layout_hdr(struct inode *inode) |
| { |
| spin_lock(&inode->i_lock); |
| put_layout_hdr_locked(NFS_I(inode)->layout); |
| spin_unlock(&inode->i_lock); |
| } |
| |
| static void |
| init_lseg(struct pnfs_layout_hdr *lo, struct pnfs_layout_segment *lseg) |
| { |
| INIT_LIST_HEAD(&lseg->pls_list); |
| kref_init(&lseg->pls_refcount); |
| lseg->pls_layout = lo; |
| } |
| |
| /* Called without i_lock held, as the free_lseg call may sleep */ |
| static void |
| destroy_lseg(struct kref *kref) |
| { |
| struct pnfs_layout_segment *lseg = |
| container_of(kref, struct pnfs_layout_segment, pls_refcount); |
| struct inode *ino = lseg->pls_layout->plh_inode; |
| |
| dprintk("--> %s\n", __func__); |
| NFS_SERVER(ino)->pnfs_curr_ld->free_lseg(lseg); |
| /* Matched by get_layout_hdr in pnfs_insert_layout */ |
| put_layout_hdr(ino); |
| } |
| |
| static void |
| put_lseg(struct pnfs_layout_segment *lseg) |
| { |
| if (!lseg) |
| return; |
| |
| dprintk("%s: lseg %p ref %d\n", __func__, lseg, |
| atomic_read(&lseg->pls_refcount.refcount)); |
| kref_put(&lseg->pls_refcount, destroy_lseg); |
| } |
| |
| static void |
| pnfs_clear_lseg_list(struct pnfs_layout_hdr *lo, struct list_head *tmp_list) |
| { |
| struct pnfs_layout_segment *lseg, *next; |
| struct nfs_client *clp; |
| |
| dprintk("%s:Begin lo %p\n", __func__, lo); |
| |
| assert_spin_locked(&lo->plh_inode->i_lock); |
| list_for_each_entry_safe(lseg, next, &lo->plh_segs, pls_list) { |
| dprintk("%s: freeing lseg %p\n", __func__, lseg); |
| list_move(&lseg->pls_list, tmp_list); |
| } |
| clp = NFS_SERVER(lo->plh_inode)->nfs_client; |
| spin_lock(&clp->cl_lock); |
| /* List does not take a reference, so no need for put here */ |
| list_del_init(&lo->plh_layouts); |
| spin_unlock(&clp->cl_lock); |
| write_seqlock(&lo->plh_seqlock); |
| clear_bit(NFS_LAYOUT_STATEID_SET, &lo->plh_flags); |
| write_sequnlock(&lo->plh_seqlock); |
| |
| dprintk("%s:Return\n", __func__); |
| } |
| |
| static void |
| pnfs_free_lseg_list(struct list_head *tmp_list) |
| { |
| struct pnfs_layout_segment *lseg; |
| |
| while (!list_empty(tmp_list)) { |
| lseg = list_entry(tmp_list->next, struct pnfs_layout_segment, |
| pls_list); |
| dprintk("%s calling put_lseg on %p\n", __func__, lseg); |
| list_del(&lseg->pls_list); |
| put_lseg(lseg); |
| } |
| } |
| |
| void |
| pnfs_destroy_layout(struct nfs_inode *nfsi) |
| { |
| struct pnfs_layout_hdr *lo; |
| LIST_HEAD(tmp_list); |
| |
| spin_lock(&nfsi->vfs_inode.i_lock); |
| lo = nfsi->layout; |
| if (lo) { |
| pnfs_clear_lseg_list(lo, &tmp_list); |
| /* Matched by refcount set to 1 in alloc_init_layout_hdr */ |
| put_layout_hdr_locked(lo); |
| } |
| spin_unlock(&nfsi->vfs_inode.i_lock); |
| pnfs_free_lseg_list(&tmp_list); |
| } |
| |
| /* |
| * Called by the state manger to remove all layouts established under an |
| * expired lease. |
| */ |
| void |
| pnfs_destroy_all_layouts(struct nfs_client *clp) |
| { |
| struct pnfs_layout_hdr *lo; |
| LIST_HEAD(tmp_list); |
| |
| spin_lock(&clp->cl_lock); |
| list_splice_init(&clp->cl_layouts, &tmp_list); |
| spin_unlock(&clp->cl_lock); |
| |
| while (!list_empty(&tmp_list)) { |
| lo = list_entry(tmp_list.next, struct pnfs_layout_hdr, |
| plh_layouts); |
| dprintk("%s freeing layout for inode %lu\n", __func__, |
| lo->plh_inode->i_ino); |
| pnfs_destroy_layout(NFS_I(lo->plh_inode)); |
| } |
| } |
| |
| /* update lo->plh_stateid with new if is more recent |
| * |
| * lo->plh_stateid could be the open stateid, in which case we just use what given. |
| */ |
| static void |
| pnfs_set_layout_stateid(struct pnfs_layout_hdr *lo, |
| const nfs4_stateid *new) |
| { |
| nfs4_stateid *old = &lo->plh_stateid; |
| bool overwrite = false; |
| |
| write_seqlock(&lo->plh_seqlock); |
| if (!test_bit(NFS_LAYOUT_STATEID_SET, &lo->plh_flags) || |
| memcmp(old->stateid.other, new->stateid.other, sizeof(new->stateid.other))) |
| overwrite = true; |
| else { |
| u32 oldseq, newseq; |
| |
| oldseq = be32_to_cpu(old->stateid.seqid); |
| newseq = be32_to_cpu(new->stateid.seqid); |
| if ((int)(newseq - oldseq) > 0) |
| overwrite = true; |
| } |
| if (overwrite) |
| memcpy(&old->stateid, &new->stateid, sizeof(new->stateid)); |
| write_sequnlock(&lo->plh_seqlock); |
| } |
| |
| static void |
| pnfs_layout_from_open_stateid(struct pnfs_layout_hdr *lo, |
| struct nfs4_state *state) |
| { |
| int seq; |
| |
| dprintk("--> %s\n", __func__); |
| write_seqlock(&lo->plh_seqlock); |
| do { |
| seq = read_seqbegin(&state->seqlock); |
| memcpy(lo->plh_stateid.data, state->stateid.data, |
| sizeof(state->stateid.data)); |
| } while (read_seqretry(&state->seqlock, seq)); |
| set_bit(NFS_LAYOUT_STATEID_SET, &lo->plh_flags); |
| write_sequnlock(&lo->plh_seqlock); |
| dprintk("<-- %s\n", __func__); |
| } |
| |
| void |
| pnfs_get_layout_stateid(nfs4_stateid *dst, struct pnfs_layout_hdr *lo, |
| struct nfs4_state *open_state) |
| { |
| int seq; |
| |
| dprintk("--> %s\n", __func__); |
| do { |
| seq = read_seqbegin(&lo->plh_seqlock); |
| if (!test_bit(NFS_LAYOUT_STATEID_SET, &lo->plh_flags)) { |
| /* This will trigger retry of the read */ |
| pnfs_layout_from_open_stateid(lo, open_state); |
| } else |
| memcpy(dst->data, lo->plh_stateid.data, |
| sizeof(lo->plh_stateid.data)); |
| } while (read_seqretry(&lo->plh_seqlock, seq)); |
| dprintk("<-- %s\n", __func__); |
| } |
| |
| /* |
| * Get layout from server. |
| * for now, assume that whole file layouts are requested. |
| * arg->offset: 0 |
| * arg->length: all ones |
| */ |
| static struct pnfs_layout_segment * |
| send_layoutget(struct pnfs_layout_hdr *lo, |
| struct nfs_open_context *ctx, |
| u32 iomode) |
| { |
| struct inode *ino = lo->plh_inode; |
| struct nfs_server *server = NFS_SERVER(ino); |
| struct nfs4_layoutget *lgp; |
| struct pnfs_layout_segment *lseg = NULL; |
| |
| dprintk("--> %s\n", __func__); |
| |
| BUG_ON(ctx == NULL); |
| lgp = kzalloc(sizeof(*lgp), GFP_KERNEL); |
| if (lgp == NULL) { |
| put_layout_hdr(lo->plh_inode); |
| return NULL; |
| } |
| lgp->args.minlength = NFS4_MAX_UINT64; |
| lgp->args.maxcount = PNFS_LAYOUT_MAXSIZE; |
| lgp->args.range.iomode = iomode; |
| lgp->args.range.offset = 0; |
| lgp->args.range.length = NFS4_MAX_UINT64; |
| lgp->args.type = server->pnfs_curr_ld->id; |
| lgp->args.inode = ino; |
| lgp->args.ctx = get_nfs_open_context(ctx); |
| lgp->lsegpp = &lseg; |
| |
| /* Synchronously retrieve layout information from server and |
| * store in lseg. |
| */ |
| nfs4_proc_layoutget(lgp); |
| if (!lseg) { |
| /* remember that LAYOUTGET failed and suspend trying */ |
| set_bit(lo_fail_bit(iomode), &lo->plh_flags); |
| } |
| return lseg; |
| } |
| |
| /* |
| * Compare two layout segments for sorting into layout cache. |
| * We want to preferentially return RW over RO layouts, so ensure those |
| * are seen first. |
| */ |
| static s64 |
| cmp_layout(u32 iomode1, u32 iomode2) |
| { |
| /* read > read/write */ |
| return (int)(iomode2 == IOMODE_READ) - (int)(iomode1 == IOMODE_READ); |
| } |
| |
| static void |
| pnfs_insert_layout(struct pnfs_layout_hdr *lo, |
| struct pnfs_layout_segment *lseg) |
| { |
| struct pnfs_layout_segment *lp; |
| int found = 0; |
| |
| dprintk("%s:Begin\n", __func__); |
| |
| assert_spin_locked(&lo->plh_inode->i_lock); |
| if (list_empty(&lo->plh_segs)) { |
| struct nfs_client *clp = NFS_SERVER(lo->plh_inode)->nfs_client; |
| |
| spin_lock(&clp->cl_lock); |
| BUG_ON(!list_empty(&lo->plh_layouts)); |
| list_add_tail(&lo->plh_layouts, &clp->cl_layouts); |
| spin_unlock(&clp->cl_lock); |
| } |
| list_for_each_entry(lp, &lo->plh_segs, pls_list) { |
| if (cmp_layout(lp->pls_range.iomode, lseg->pls_range.iomode) > 0) |
| continue; |
| list_add_tail(&lseg->pls_list, &lp->pls_list); |
| dprintk("%s: inserted lseg %p " |
| "iomode %d offset %llu length %llu before " |
| "lp %p iomode %d offset %llu length %llu\n", |
| __func__, lseg, lseg->pls_range.iomode, |
| lseg->pls_range.offset, lseg->pls_range.length, |
| lp, lp->pls_range.iomode, lp->pls_range.offset, |
| lp->pls_range.length); |
| found = 1; |
| break; |
| } |
| if (!found) { |
| list_add_tail(&lseg->pls_list, &lo->plh_segs); |
| dprintk("%s: inserted lseg %p " |
| "iomode %d offset %llu length %llu at tail\n", |
| __func__, lseg, lseg->pls_range.iomode, |
| lseg->pls_range.offset, lseg->pls_range.length); |
| } |
| get_layout_hdr_locked(lo); |
| |
| dprintk("%s:Return\n", __func__); |
| } |
| |
| static struct pnfs_layout_hdr * |
| alloc_init_layout_hdr(struct inode *ino) |
| { |
| struct pnfs_layout_hdr *lo; |
| |
| lo = kzalloc(sizeof(struct pnfs_layout_hdr), GFP_KERNEL); |
| if (!lo) |
| return NULL; |
| lo->plh_refcount = 1; |
| INIT_LIST_HEAD(&lo->plh_layouts); |
| INIT_LIST_HEAD(&lo->plh_segs); |
| seqlock_init(&lo->plh_seqlock); |
| lo->plh_inode = ino; |
| return lo; |
| } |
| |
| static struct pnfs_layout_hdr * |
| pnfs_find_alloc_layout(struct inode *ino) |
| { |
| struct nfs_inode *nfsi = NFS_I(ino); |
| struct pnfs_layout_hdr *new = NULL; |
| |
| dprintk("%s Begin ino=%p layout=%p\n", __func__, ino, nfsi->layout); |
| |
| assert_spin_locked(&ino->i_lock); |
| if (nfsi->layout) |
| return nfsi->layout; |
| |
| spin_unlock(&ino->i_lock); |
| new = alloc_init_layout_hdr(ino); |
| spin_lock(&ino->i_lock); |
| |
| if (likely(nfsi->layout == NULL)) /* Won the race? */ |
| nfsi->layout = new; |
| else |
| kfree(new); |
| return nfsi->layout; |
| } |
| |
| /* |
| * iomode matching rules: |
| * iomode lseg match |
| * ----- ----- ----- |
| * ANY READ true |
| * ANY RW true |
| * RW READ false |
| * RW RW true |
| * READ READ true |
| * READ RW true |
| */ |
| static int |
| is_matching_lseg(struct pnfs_layout_segment *lseg, u32 iomode) |
| { |
| return (iomode != IOMODE_RW || lseg->pls_range.iomode == IOMODE_RW); |
| } |
| |
| /* |
| * lookup range in layout |
| */ |
| static struct pnfs_layout_segment * |
| pnfs_has_layout(struct pnfs_layout_hdr *lo, u32 iomode) |
| { |
| struct pnfs_layout_segment *lseg, *ret = NULL; |
| |
| dprintk("%s:Begin\n", __func__); |
| |
| assert_spin_locked(&lo->plh_inode->i_lock); |
| list_for_each_entry(lseg, &lo->plh_segs, pls_list) { |
| if (is_matching_lseg(lseg, iomode)) { |
| ret = lseg; |
| break; |
| } |
| if (cmp_layout(iomode, lseg->pls_range.iomode) > 0) |
| break; |
| } |
| |
| dprintk("%s:Return lseg %p ref %d\n", |
| __func__, ret, ret ? atomic_read(&ret->pls_refcount.refcount) : 0); |
| return ret; |
| } |
| |
| /* |
| * Layout segment is retreived from the server if not cached. |
| * The appropriate layout segment is referenced and returned to the caller. |
| */ |
| struct pnfs_layout_segment * |
| pnfs_update_layout(struct inode *ino, |
| struct nfs_open_context *ctx, |
| enum pnfs_iomode iomode) |
| { |
| struct nfs_inode *nfsi = NFS_I(ino); |
| struct pnfs_layout_hdr *lo; |
| struct pnfs_layout_segment *lseg = NULL; |
| |
| if (!pnfs_enabled_sb(NFS_SERVER(ino))) |
| return NULL; |
| spin_lock(&ino->i_lock); |
| lo = pnfs_find_alloc_layout(ino); |
| if (lo == NULL) { |
| dprintk("%s ERROR: can't get pnfs_layout_hdr\n", __func__); |
| goto out_unlock; |
| } |
| |
| /* Check to see if the layout for the given range already exists */ |
| lseg = pnfs_has_layout(lo, iomode); |
| if (lseg) { |
| dprintk("%s: Using cached lseg %p for iomode %d)\n", |
| __func__, lseg, iomode); |
| goto out_unlock; |
| } |
| |
| /* if LAYOUTGET already failed once we don't try again */ |
| if (test_bit(lo_fail_bit(iomode), &nfsi->layout->plh_flags)) |
| goto out_unlock; |
| |
| get_layout_hdr_locked(lo); /* Matched in nfs4_layoutget_release */ |
| spin_unlock(&ino->i_lock); |
| |
| lseg = send_layoutget(lo, ctx, iomode); |
| out: |
| dprintk("%s end, state 0x%lx lseg %p\n", __func__, |
| nfsi->layout->plh_flags, lseg); |
| return lseg; |
| out_unlock: |
| spin_unlock(&ino->i_lock); |
| goto out; |
| } |
| |
| int |
| pnfs_layout_process(struct nfs4_layoutget *lgp) |
| { |
| struct pnfs_layout_hdr *lo = NFS_I(lgp->args.inode)->layout; |
| struct nfs4_layoutget_res *res = &lgp->res; |
| struct pnfs_layout_segment *lseg; |
| struct inode *ino = lo->plh_inode; |
| int status = 0; |
| |
| /* Inject layout blob into I/O device driver */ |
| lseg = NFS_SERVER(ino)->pnfs_curr_ld->alloc_lseg(lo, res); |
| if (!lseg || IS_ERR(lseg)) { |
| if (!lseg) |
| status = -ENOMEM; |
| else |
| status = PTR_ERR(lseg); |
| dprintk("%s: Could not allocate layout: error %d\n", |
| __func__, status); |
| goto out; |
| } |
| |
| spin_lock(&ino->i_lock); |
| init_lseg(lo, lseg); |
| lseg->pls_range = res->range; |
| *lgp->lsegpp = lseg; |
| pnfs_insert_layout(lo, lseg); |
| |
| /* Done processing layoutget. Set the layout stateid */ |
| pnfs_set_layout_stateid(lo, &res->stateid); |
| spin_unlock(&ino->i_lock); |
| out: |
| return status; |
| } |
| |
| /* |
| * Device ID cache. Currently supports one layout type per struct nfs_client. |
| * Add layout type to the lookup key to expand to support multiple types. |
| */ |
| int |
| pnfs_alloc_init_deviceid_cache(struct nfs_client *clp, |
| void (*free_callback)(struct pnfs_deviceid_node *)) |
| { |
| struct pnfs_deviceid_cache *c; |
| |
| c = kzalloc(sizeof(struct pnfs_deviceid_cache), GFP_KERNEL); |
| if (!c) |
| return -ENOMEM; |
| spin_lock(&clp->cl_lock); |
| if (clp->cl_devid_cache != NULL) { |
| atomic_inc(&clp->cl_devid_cache->dc_ref); |
| dprintk("%s [kref [%d]]\n", __func__, |
| atomic_read(&clp->cl_devid_cache->dc_ref)); |
| kfree(c); |
| } else { |
| /* kzalloc initializes hlists */ |
| spin_lock_init(&c->dc_lock); |
| atomic_set(&c->dc_ref, 1); |
| c->dc_free_callback = free_callback; |
| clp->cl_devid_cache = c; |
| dprintk("%s [new]\n", __func__); |
| } |
| spin_unlock(&clp->cl_lock); |
| return 0; |
| } |
| EXPORT_SYMBOL_GPL(pnfs_alloc_init_deviceid_cache); |
| |
| /* |
| * Called from pnfs_layoutdriver_type->free_lseg |
| * last layout segment reference frees deviceid |
| */ |
| void |
| pnfs_put_deviceid(struct pnfs_deviceid_cache *c, |
| struct pnfs_deviceid_node *devid) |
| { |
| struct nfs4_deviceid *id = &devid->de_id; |
| struct pnfs_deviceid_node *d; |
| struct hlist_node *n; |
| long h = nfs4_deviceid_hash(id); |
| |
| dprintk("%s [%d]\n", __func__, atomic_read(&devid->de_ref)); |
| if (!atomic_dec_and_lock(&devid->de_ref, &c->dc_lock)) |
| return; |
| |
| hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[h], de_node) |
| if (!memcmp(&d->de_id, id, sizeof(*id))) { |
| hlist_del_rcu(&d->de_node); |
| spin_unlock(&c->dc_lock); |
| synchronize_rcu(); |
| c->dc_free_callback(devid); |
| return; |
| } |
| spin_unlock(&c->dc_lock); |
| /* Why wasn't it found in the list? */ |
| BUG(); |
| } |
| EXPORT_SYMBOL_GPL(pnfs_put_deviceid); |
| |
| /* Find and reference a deviceid */ |
| struct pnfs_deviceid_node * |
| pnfs_find_get_deviceid(struct pnfs_deviceid_cache *c, struct nfs4_deviceid *id) |
| { |
| struct pnfs_deviceid_node *d; |
| struct hlist_node *n; |
| long hash = nfs4_deviceid_hash(id); |
| |
| dprintk("--> %s hash %ld\n", __func__, hash); |
| rcu_read_lock(); |
| hlist_for_each_entry_rcu(d, n, &c->dc_deviceids[hash], de_node) { |
| if (!memcmp(&d->de_id, id, sizeof(*id))) { |
| if (!atomic_inc_not_zero(&d->de_ref)) { |
| goto fail; |
| } else { |
| rcu_read_unlock(); |
| return d; |
| } |
| } |
| } |
| fail: |
| rcu_read_unlock(); |
| return NULL; |
| } |
| EXPORT_SYMBOL_GPL(pnfs_find_get_deviceid); |
| |
| /* |
| * Add a deviceid to the cache. |
| * GETDEVICEINFOs for same deviceid can race. If deviceid is found, discard new |
| */ |
| struct pnfs_deviceid_node * |
| pnfs_add_deviceid(struct pnfs_deviceid_cache *c, struct pnfs_deviceid_node *new) |
| { |
| struct pnfs_deviceid_node *d; |
| long hash = nfs4_deviceid_hash(&new->de_id); |
| |
| dprintk("--> %s hash %ld\n", __func__, hash); |
| spin_lock(&c->dc_lock); |
| d = pnfs_find_get_deviceid(c, &new->de_id); |
| if (d) { |
| spin_unlock(&c->dc_lock); |
| dprintk("%s [discard]\n", __func__); |
| c->dc_free_callback(new); |
| return d; |
| } |
| INIT_HLIST_NODE(&new->de_node); |
| atomic_set(&new->de_ref, 1); |
| hlist_add_head_rcu(&new->de_node, &c->dc_deviceids[hash]); |
| spin_unlock(&c->dc_lock); |
| dprintk("%s [new]\n", __func__); |
| return new; |
| } |
| EXPORT_SYMBOL_GPL(pnfs_add_deviceid); |
| |
| void |
| pnfs_put_deviceid_cache(struct nfs_client *clp) |
| { |
| struct pnfs_deviceid_cache *local = clp->cl_devid_cache; |
| |
| dprintk("--> %s cl_devid_cache %p\n", __func__, clp->cl_devid_cache); |
| if (atomic_dec_and_lock(&local->dc_ref, &clp->cl_lock)) { |
| int i; |
| /* Verify cache is empty */ |
| for (i = 0; i < NFS4_DEVICE_ID_HASH_SIZE; i++) |
| BUG_ON(!hlist_empty(&local->dc_deviceids[i])); |
| clp->cl_devid_cache = NULL; |
| spin_unlock(&clp->cl_lock); |
| kfree(local); |
| } |
| } |
| EXPORT_SYMBOL_GPL(pnfs_put_deviceid_cache); |