diff --git a/fs/afs/Makefile b/fs/afs/Makefile index cf83e5d63512..73ce561f3ea0 100644 --- a/fs/afs/Makefile +++ b/fs/afs/Makefile @@ -22,6 +22,7 @@ kafs-objs := \ vlclient.o \ vlocation.o \ vnode.o \ - volume.o + volume.o \ + write.o obj-$(CONFIG_AFS_FS) := kafs.o diff --git a/fs/afs/afs_fs.h b/fs/afs/afs_fs.h index 89e0d1650a72..2198006d2d03 100644 --- a/fs/afs/afs_fs.h +++ b/fs/afs/afs_fs.h @@ -18,6 +18,8 @@ enum AFS_FS_Operations { FSFETCHDATA = 130, /* AFS Fetch file data */ FSFETCHSTATUS = 132, /* AFS Fetch file status */ + FSSTOREDATA = 133, /* AFS Store file data */ + FSSTORESTATUS = 135, /* AFS Store file status */ FSREMOVEFILE = 136, /* AFS Remove a file */ FSCREATEFILE = 137, /* AFS Create a file */ FSRENAME = 138, /* AFS Rename or move a file or directory */ diff --git a/fs/afs/dir.c b/fs/afs/dir.c index 51f177af5dd6..2fb31276196b 100644 --- a/fs/afs/dir.c +++ b/fs/afs/dir.c @@ -56,6 +56,7 @@ const struct inode_operations afs_dir_inode_operations = { .rename = afs_rename, .permission = afs_permission, .getattr = afs_getattr, + .setattr = afs_setattr, }; static struct dentry_operations afs_fs_dentry_operations = { diff --git a/fs/afs/file.c b/fs/afs/file.c index 3eb3fc7b36be..3e25795e5a42 100644 --- a/fs/afs/file.c +++ b/fs/afs/file.c @@ -15,32 +15,43 @@ #include #include #include +#include #include "internal.h" static int afs_readpage(struct file *file, struct page *page); static void afs_invalidatepage(struct page *page, unsigned long offset); static int afs_releasepage(struct page *page, gfp_t gfp_flags); +static int afs_launder_page(struct page *page); const struct file_operations afs_file_operations = { .open = afs_open, .release = afs_release, .llseek = generic_file_llseek, .read = do_sync_read, + .write = do_sync_write, .aio_read = generic_file_aio_read, + .aio_write = afs_file_write, .mmap = generic_file_readonly_mmap, .sendfile = generic_file_sendfile, + .fsync = afs_fsync, }; const struct inode_operations afs_file_inode_operations = { .getattr = afs_getattr, + .setattr = afs_setattr, .permission = afs_permission, }; const struct address_space_operations afs_fs_aops = { .readpage = afs_readpage, - .set_page_dirty = __set_page_dirty_nobuffers, + .set_page_dirty = afs_set_page_dirty, + .launder_page = afs_launder_page, .releasepage = afs_releasepage, .invalidatepage = afs_invalidatepage, + .prepare_write = afs_prepare_write, + .commit_write = afs_commit_write, + .writepage = afs_writepage, + .writepages = afs_writepages, }; /* @@ -230,11 +241,6 @@ static void afs_invalidatepage(struct page *page, unsigned long offset) BUG_ON(!PageLocked(page)); if (PagePrivate(page)) { -#ifdef AFS_CACHING_SUPPORT - struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); - cachefs_uncache_page(vnode->cache,page); -#endif - /* We release buffers only if the entire page is being * invalidated. * The get_block cached value has been unconditionally @@ -254,20 +260,34 @@ static void afs_invalidatepage(struct page *page, unsigned long offset) _leave(" = %d", ret); } +/* + * write back a dirty page + */ +static int afs_launder_page(struct page *page) +{ + _enter("{%lu}", page->index); + + return 0; +} + /* * release a page and cleanup its private data */ static int afs_releasepage(struct page *page, gfp_t gfp_flags) { struct afs_vnode *vnode = AFS_FS_I(page->mapping->host); + struct afs_writeback *wb; _enter("{{%x:%u}[%lu],%lx},%x", vnode->fid.vid, vnode->fid.vnode, page->index, page->flags, gfp_flags); if (PagePrivate(page)) { + wb = (struct afs_writeback *) page_private(page); + ASSERT(wb != NULL); set_page_private(page, 0); ClearPagePrivate(page); + afs_put_writeback(wb); } _leave(" = 0"); diff --git a/fs/afs/fsclient.c b/fs/afs/fsclient.c index 1e65fee36413..025b1903d9e1 100644 --- a/fs/afs/fsclient.c +++ b/fs/afs/fsclient.c @@ -33,8 +33,10 @@ static void xdr_decode_AFSFid(const __be32 **_bp, struct afs_fid *fid) */ static void xdr_decode_AFSFetchStatus(const __be32 **_bp, struct afs_file_status *status, - struct afs_vnode *vnode) + struct afs_vnode *vnode, + afs_dataversion_t *store_version) { + afs_dataversion_t expected_version; const __be32 *bp = *_bp; umode_t mode; u64 data_version, size; @@ -101,7 +103,11 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp, vnode->vfs_inode.i_atime = vnode->vfs_inode.i_ctime; } - if (status->data_version != data_version) { + expected_version = status->data_version; + if (store_version) + expected_version = *store_version; + + if (expected_version != data_version) { status->data_version = data_version; if (vnode && !test_bit(AFS_VNODE_UNSET, &vnode->flags)) { _debug("vnode modified %llx on {%x:%u}", @@ -110,6 +116,8 @@ static void xdr_decode_AFSFetchStatus(const __be32 **_bp, set_bit(AFS_VNODE_MODIFIED, &vnode->flags); set_bit(AFS_VNODE_ZAP_DATA, &vnode->flags); } + } else if (store_version) { + status->data_version = data_version; } } @@ -155,6 +163,44 @@ static void xdr_decode_AFSVolSync(const __be32 **_bp, *_bp = bp; } +/* + * encode the requested attributes into an AFSStoreStatus block + */ +static void xdr_encode_AFS_StoreStatus(__be32 **_bp, struct iattr *attr) +{ + __be32 *bp = *_bp; + u32 mask = 0, mtime = 0, owner = 0, group = 0, mode = 0; + + mask = 0; + if (attr->ia_valid & ATTR_MTIME) { + mask |= AFS_SET_MTIME; + mtime = attr->ia_mtime.tv_sec; + } + + if (attr->ia_valid & ATTR_UID) { + mask |= AFS_SET_OWNER; + owner = attr->ia_uid; + } + + if (attr->ia_valid & ATTR_GID) { + mask |= AFS_SET_GROUP; + group = attr->ia_gid; + } + + if (attr->ia_valid & ATTR_MODE) { + mask |= AFS_SET_MODE; + mode = attr->ia_mode & S_IALLUGO; + } + + *bp++ = htonl(mask); + *bp++ = htonl(mtime); + *bp++ = htonl(owner); + *bp++ = htonl(group); + *bp++ = htonl(mode); + *bp++ = 0; /* segment size */ + *_bp = bp; +} + /* * deliver reply data to an FS.FetchStatus */ @@ -175,7 +221,7 @@ static int afs_deliver_fs_fetch_status(struct afs_call *call, /* unmarshall the reply once we've received all of it */ bp = call->buffer; - xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode); + xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode, NULL); xdr_decode_AFSCallBack(&bp, vnode); if (call->reply2) xdr_decode_AFSVolSync(&bp, call->reply2); @@ -295,7 +341,7 @@ static int afs_deliver_fs_fetch_data(struct afs_call *call, } bp = call->buffer; - xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode); + xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode, NULL); xdr_decode_AFSCallBack(&bp, vnode); if (call->reply2) xdr_decode_AFSVolSync(&bp, call->reply2); @@ -479,8 +525,8 @@ static int afs_deliver_fs_create_vnode(struct afs_call *call, /* unmarshall the reply once we've received all of it */ bp = call->buffer; xdr_decode_AFSFid(&bp, call->reply2); - xdr_decode_AFSFetchStatus(&bp, call->reply3, NULL); - xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode); + xdr_decode_AFSFetchStatus(&bp, call->reply3, NULL, NULL); + xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode, NULL); xdr_decode_AFSCallBack_raw(&bp, call->reply4); /* xdr_decode_AFSVolSync(&bp, call->replyX); */ @@ -577,7 +623,7 @@ static int afs_deliver_fs_remove(struct afs_call *call, /* unmarshall the reply once we've received all of it */ bp = call->buffer; - xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode); + xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode, NULL); /* xdr_decode_AFSVolSync(&bp, call->replyX); */ _leave(" = 0 [done]"); @@ -660,8 +706,8 @@ static int afs_deliver_fs_link(struct afs_call *call, /* unmarshall the reply once we've received all of it */ bp = call->buffer; - xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode); - xdr_decode_AFSFetchStatus(&bp, &dvnode->status, dvnode); + xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode, NULL); + xdr_decode_AFSFetchStatus(&bp, &dvnode->status, dvnode, NULL); /* xdr_decode_AFSVolSync(&bp, call->replyX); */ _leave(" = 0 [done]"); @@ -749,8 +795,8 @@ static int afs_deliver_fs_symlink(struct afs_call *call, /* unmarshall the reply once we've received all of it */ bp = call->buffer; xdr_decode_AFSFid(&bp, call->reply2); - xdr_decode_AFSFetchStatus(&bp, call->reply3, NULL); - xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode); + xdr_decode_AFSFetchStatus(&bp, call->reply3, NULL, NULL); + xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode, NULL); /* xdr_decode_AFSVolSync(&bp, call->replyX); */ _leave(" = 0 [done]"); @@ -855,9 +901,10 @@ static int afs_deliver_fs_rename(struct afs_call *call, /* unmarshall the reply once we've received all of it */ bp = call->buffer; - xdr_decode_AFSFetchStatus(&bp, &orig_dvnode->status, orig_dvnode); + xdr_decode_AFSFetchStatus(&bp, &orig_dvnode->status, orig_dvnode, NULL); if (new_dvnode != orig_dvnode) - xdr_decode_AFSFetchStatus(&bp, &new_dvnode->status, new_dvnode); + xdr_decode_AFSFetchStatus(&bp, &new_dvnode->status, new_dvnode, + NULL); /* xdr_decode_AFSVolSync(&bp, call->replyX); */ _leave(" = 0 [done]"); @@ -939,3 +986,262 @@ int afs_fs_rename(struct afs_server *server, return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode); } + +/* + * deliver reply data to an FS.StoreData + */ +static int afs_deliver_fs_store_data(struct afs_call *call, + struct sk_buff *skb, bool last) +{ + struct afs_vnode *vnode = call->reply; + const __be32 *bp; + + _enter(",,%u", last); + + afs_transfer_reply(call, skb); + if (!last) { + _leave(" = 0 [more]"); + return 0; + } + + if (call->reply_size != call->reply_max) { + _leave(" = -EBADMSG [%u != %u]", + call->reply_size, call->reply_max); + return -EBADMSG; + } + + /* unmarshall the reply once we've received all of it */ + bp = call->buffer; + xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode, + &call->store_version); + /* xdr_decode_AFSVolSync(&bp, call->replyX); */ + + afs_pages_written_back(vnode, call); + + _leave(" = 0 [done]"); + return 0; +} + +/* + * FS.StoreData operation type + */ +static const struct afs_call_type afs_RXFSStoreData = { + .name = "FS.StoreData", + .deliver = afs_deliver_fs_store_data, + .abort_to_error = afs_abort_to_error, + .destructor = afs_flat_call_destructor, +}; + +/* + * store a set of pages + */ +int afs_fs_store_data(struct afs_server *server, struct afs_writeback *wb, + pgoff_t first, pgoff_t last, + unsigned offset, unsigned to, + const struct afs_wait_mode *wait_mode) +{ + struct afs_vnode *vnode = wb->vnode; + struct afs_call *call; + loff_t size, pos, i_size; + __be32 *bp; + + _enter(",%x,{%x:%u},,", + key_serial(wb->key), vnode->fid.vid, vnode->fid.vnode); + + size = to - offset; + if (first != last) + size += (loff_t)(last - first) << PAGE_SHIFT; + pos = (loff_t)first << PAGE_SHIFT; + pos += offset; + + i_size = i_size_read(&vnode->vfs_inode); + if (pos + size > i_size) + i_size = size + pos; + + _debug("size %llx, at %llx, i_size %llx", + (unsigned long long) size, (unsigned long long) pos, + (unsigned long long) i_size); + + BUG_ON(i_size > 0xffffffff); // TODO: use 64-bit store + + call = afs_alloc_flat_call(&afs_RXFSStoreData, + (4 + 6 + 3) * 4, + (21 + 6) * 4); + if (!call) + return -ENOMEM; + + call->wb = wb; + call->key = wb->key; + call->reply = vnode; + call->service_id = FS_SERVICE; + call->port = htons(AFS_FS_PORT); + call->mapping = vnode->vfs_inode.i_mapping; + call->first = first; + call->last = last; + call->first_offset = offset; + call->last_to = to; + call->send_pages = true; + call->store_version = vnode->status.data_version + 1; + + /* marshall the parameters */ + bp = call->request; + *bp++ = htonl(FSSTOREDATA); + *bp++ = htonl(vnode->fid.vid); + *bp++ = htonl(vnode->fid.vnode); + *bp++ = htonl(vnode->fid.unique); + + *bp++ = 0; /* mask */ + *bp++ = 0; /* mtime */ + *bp++ = 0; /* owner */ + *bp++ = 0; /* group */ + *bp++ = 0; /* unix mode */ + *bp++ = 0; /* segment size */ + + *bp++ = htonl(pos); + *bp++ = htonl(size); + *bp++ = htonl(i_size); + + return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode); +} + +/* + * deliver reply data to an FS.StoreStatus + */ +static int afs_deliver_fs_store_status(struct afs_call *call, + struct sk_buff *skb, bool last) +{ + afs_dataversion_t *store_version; + struct afs_vnode *vnode = call->reply; + const __be32 *bp; + + _enter(",,%u", last); + + afs_transfer_reply(call, skb); + if (!last) { + _leave(" = 0 [more]"); + return 0; + } + + if (call->reply_size != call->reply_max) { + _leave(" = -EBADMSG [%u != %u]", + call->reply_size, call->reply_max); + return -EBADMSG; + } + + /* unmarshall the reply once we've received all of it */ + store_version = NULL; + if (call->operation_ID == FSSTOREDATA) + store_version = &call->store_version; + + bp = call->buffer; + xdr_decode_AFSFetchStatus(&bp, &vnode->status, vnode, store_version); + /* xdr_decode_AFSVolSync(&bp, call->replyX); */ + + _leave(" = 0 [done]"); + return 0; +} + +/* + * FS.StoreStatus operation type + */ +static const struct afs_call_type afs_RXFSStoreStatus = { + .name = "FS.StoreStatus", + .deliver = afs_deliver_fs_store_status, + .abort_to_error = afs_abort_to_error, + .destructor = afs_flat_call_destructor, +}; + +static const struct afs_call_type afs_RXFSStoreData_as_Status = { + .name = "FS.StoreData", + .deliver = afs_deliver_fs_store_status, + .abort_to_error = afs_abort_to_error, + .destructor = afs_flat_call_destructor, +}; + +/* + * set the attributes on a file, using FS.StoreData rather than FS.StoreStatus + * so as to alter the file size also + */ +static int afs_fs_setattr_size(struct afs_server *server, struct key *key, + struct afs_vnode *vnode, struct iattr *attr, + const struct afs_wait_mode *wait_mode) +{ + struct afs_call *call; + __be32 *bp; + + _enter(",%x,{%x:%u},,", + key_serial(key), vnode->fid.vid, vnode->fid.vnode); + + ASSERT(attr->ia_valid & ATTR_SIZE); + ASSERTCMP(attr->ia_size, <=, 0xffffffff); // TODO: use 64-bit store + + call = afs_alloc_flat_call(&afs_RXFSStoreData_as_Status, + (4 + 6 + 3) * 4, + (21 + 6) * 4); + if (!call) + return -ENOMEM; + + call->key = key; + call->reply = vnode; + call->service_id = FS_SERVICE; + call->port = htons(AFS_FS_PORT); + call->store_version = vnode->status.data_version + 1; + call->operation_ID = FSSTOREDATA; + + /* marshall the parameters */ + bp = call->request; + *bp++ = htonl(FSSTOREDATA); + *bp++ = htonl(vnode->fid.vid); + *bp++ = htonl(vnode->fid.vnode); + *bp++ = htonl(vnode->fid.unique); + + xdr_encode_AFS_StoreStatus(&bp, attr); + + *bp++ = 0; /* position of start of write */ + *bp++ = 0; /* size of write */ + *bp++ = htonl(attr->ia_size); /* new file length */ + + return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode); +} + +/* + * set the attributes on a file, using FS.StoreData if there's a change in file + * size, and FS.StoreStatus otherwise + */ +int afs_fs_setattr(struct afs_server *server, struct key *key, + struct afs_vnode *vnode, struct iattr *attr, + const struct afs_wait_mode *wait_mode) +{ + struct afs_call *call; + __be32 *bp; + + if (attr->ia_valid & ATTR_SIZE) + return afs_fs_setattr_size(server, key, vnode, attr, + wait_mode); + + _enter(",%x,{%x:%u},,", + key_serial(key), vnode->fid.vid, vnode->fid.vnode); + + call = afs_alloc_flat_call(&afs_RXFSStoreStatus, + (4 + 6) * 4, + (21 + 6) * 4); + if (!call) + return -ENOMEM; + + call->key = key; + call->reply = vnode; + call->service_id = FS_SERVICE; + call->port = htons(AFS_FS_PORT); + call->operation_ID = FSSTORESTATUS; + + /* marshall the parameters */ + bp = call->request; + *bp++ = htonl(FSSTORESTATUS); + *bp++ = htonl(vnode->fid.vid); + *bp++ = htonl(vnode->fid.vnode); + *bp++ = htonl(vnode->fid.unique); + + xdr_encode_AFS_StoreStatus(&bp, attr); + + return afs_make_call(&server->addr, call, GFP_NOFS, wait_mode); +} diff --git a/fs/afs/inode.c b/fs/afs/inode.c index 9c984cc42cc9..515a5d12d8fb 100644 --- a/fs/afs/inode.c +++ b/fs/afs/inode.c @@ -209,7 +209,7 @@ bad_inode: */ void afs_zap_data(struct afs_vnode *vnode) { - kenter("zap data {%x:%u}", vnode->fid.vid, vnode->fid.vnode); + _enter("zap data {%x:%u}", vnode->fid.vid, vnode->fid.vnode); /* nuke all the non-dirty pages that aren't locked, mapped or being * written back */ @@ -334,6 +334,7 @@ void afs_clear_inode(struct inode *inode) vnode->server = NULL; } + ASSERT(list_empty(&vnode->writebacks)); ASSERT(!vnode->cb_promised); #ifdef AFS_CACHING_SUPPORT @@ -350,3 +351,47 @@ void afs_clear_inode(struct inode *inode) _leave(""); } + +/* + * set the attributes of an inode + */ +int afs_setattr(struct dentry *dentry, struct iattr *attr) +{ + struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); + struct key *key; + int ret; + + _enter("{%x:%u},{n=%s},%x", + vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name, + attr->ia_valid); + + if (!(attr->ia_valid & (ATTR_SIZE | ATTR_MODE | ATTR_UID | ATTR_GID | + ATTR_MTIME))) { + _leave(" = 0 [unsupported]"); + return 0; + } + + /* flush any dirty data outstanding on a regular file */ + if (S_ISREG(vnode->vfs_inode.i_mode)) { + filemap_write_and_wait(vnode->vfs_inode.i_mapping); + afs_writeback_all(vnode); + } + + if (attr->ia_valid & ATTR_FILE) { + key = attr->ia_file->private_data; + } else { + key = afs_request_key(vnode->volume->cell); + if (IS_ERR(key)) { + ret = PTR_ERR(key); + goto error; + } + } + + ret = afs_vnode_setattr(vnode, key, attr); + if (!(attr->ia_valid & ATTR_FILE)) + key_put(key); + +error: + _leave(" = %d", ret); + return ret; +} diff --git a/fs/afs/internal.h b/fs/afs/internal.h index 9feb5c59d8fc..a30d4fa768e3 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -21,6 +21,7 @@ #define AFS_CELL_MAX_ADDRS 15 +struct pagevec; struct afs_call; typedef enum { @@ -75,12 +76,15 @@ struct afs_call { struct key *key; /* security for this call */ struct afs_server *server; /* server affected by incoming CM call */ void *request; /* request data (first part) */ - void *request2; /* request data (second part) */ + struct address_space *mapping; /* page set */ + struct afs_writeback *wb; /* writeback being performed */ void *buffer; /* reply receive buffer */ void *reply; /* reply buffer (first part) */ void *reply2; /* reply buffer (second part) */ void *reply3; /* reply buffer (third part) */ void *reply4; /* reply buffer (fourth part) */ + pgoff_t first; /* first page in mapping to deal with */ + pgoff_t last; /* last page in mapping to deal with */ enum { /* call state */ AFS_CALL_REQUESTING, /* request is being sent for outgoing call */ AFS_CALL_AWAIT_REPLY, /* awaiting reply to outgoing call */ @@ -97,14 +101,18 @@ struct afs_call { unsigned request_size; /* size of request data */ unsigned reply_max; /* maximum size of reply */ unsigned reply_size; /* current size of reply */ + unsigned first_offset; /* offset into mapping[first] */ + unsigned last_to; /* amount of mapping[last] */ unsigned short offset; /* offset into received data store */ unsigned char unmarshall; /* unmarshalling phase */ bool incoming; /* T if incoming call */ + bool send_pages; /* T if data from mapping should be sent */ u16 service_id; /* RxRPC service ID to call */ __be16 port; /* target UDP port */ __be32 operation_ID; /* operation ID for an incoming call */ u32 count; /* count for use in unmarshalling */ __be32 tmp; /* place to extract temporary data */ + afs_dataversion_t store_version; /* updated version expected from store */ }; struct afs_call_type { @@ -123,6 +131,32 @@ struct afs_call_type { void (*destructor)(struct afs_call *call); }; +/* + * record of an outstanding writeback on a vnode + */ +struct afs_writeback { + struct list_head link; /* link in vnode->writebacks */ + struct work_struct writer; /* work item to perform the writeback */ + struct afs_vnode *vnode; /* vnode to which this write applies */ + struct key *key; /* owner of this write */ + wait_queue_head_t waitq; /* completion and ready wait queue */ + pgoff_t first; /* first page in batch */ + pgoff_t point; /* last page in current store op */ + pgoff_t last; /* last page in batch (inclusive) */ + unsigned offset_first; /* offset into first page of start of write */ + unsigned to_last; /* offset into last page of end of write */ + int num_conflicts; /* count of conflicting writes in list */ + int usage; + bool conflicts; /* T if has dependent conflicts */ + enum { + AFS_WBACK_SYNCING, /* synchronisation being performed */ + AFS_WBACK_PENDING, /* write pending */ + AFS_WBACK_CONFLICTING, /* conflicting writes posted */ + AFS_WBACK_WRITING, /* writing back */ + AFS_WBACK_COMPLETE /* the writeback record has been unlinked */ + } state __attribute__((packed)); +}; + /* * AFS superblock private data * - there's one superblock per volume @@ -305,6 +339,7 @@ struct afs_vnode { wait_queue_head_t update_waitq; /* status fetch waitqueue */ int update_cnt; /* number of outstanding ops that will update the * status */ + spinlock_t writeback_lock; /* lock for writebacks */ spinlock_t lock; /* waitqueue/flags lock */ unsigned long flags; #define AFS_VNODE_CB_BROKEN 0 /* set if vnode's callback was broken */ @@ -316,6 +351,8 @@ struct afs_vnode { long acl_order; /* ACL check count (callback break count) */ + struct list_head writebacks; /* alterations in pagecache that need writing */ + /* outstanding callback notification on this file */ struct rb_node server_rb; /* link in server->fs_vnodes */ struct rb_node cb_promise; /* link in server->cb_promises */ @@ -463,6 +500,12 @@ extern int afs_fs_rename(struct afs_server *, struct key *, struct afs_vnode *, const char *, struct afs_vnode *, const char *, const struct afs_wait_mode *); +extern int afs_fs_store_data(struct afs_server *, struct afs_writeback *, + pgoff_t, pgoff_t, unsigned, unsigned, + const struct afs_wait_mode *); +extern int afs_fs_setattr(struct afs_server *, struct key *, + struct afs_vnode *, struct iattr *, + const struct afs_wait_mode *); /* * inode.c @@ -473,6 +516,7 @@ extern struct inode *afs_iget(struct super_block *, struct key *, extern void afs_zap_data(struct afs_vnode *); extern int afs_validate(struct afs_vnode *, struct key *); extern int afs_getattr(struct vfsmount *, struct dentry *, struct kstat *); +extern int afs_setattr(struct dentry *, struct iattr *); extern void afs_clear_inode(struct inode *); /* @@ -625,6 +669,9 @@ extern int afs_vnode_symlink(struct afs_vnode *, struct key *, const char *, struct afs_file_status *, struct afs_server **); extern int afs_vnode_rename(struct afs_vnode *, struct afs_vnode *, struct key *, const char *, const char *); +extern int afs_vnode_store_data(struct afs_writeback *, pgoff_t, pgoff_t, + unsigned, unsigned); +extern int afs_vnode_setattr(struct afs_vnode *, struct key *, struct iattr *); /* * volume.c @@ -641,6 +688,23 @@ extern struct afs_server *afs_volume_pick_fileserver(struct afs_vnode *); extern int afs_volume_release_fileserver(struct afs_vnode *, struct afs_server *, int); +/* + * write.c + */ +extern int afs_set_page_dirty(struct page *); +extern void afs_put_writeback(struct afs_writeback *); +extern int afs_prepare_write(struct file *, struct page *, unsigned, unsigned); +extern int afs_commit_write(struct file *, struct page *, unsigned, unsigned); +extern int afs_writepage(struct page *, struct writeback_control *); +extern int afs_writepages(struct address_space *, struct writeback_control *); +extern int afs_write_inode(struct inode *, int); +extern void afs_pages_written_back(struct afs_vnode *, struct afs_call *); +extern ssize_t afs_file_write(struct kiocb *, const struct iovec *, + unsigned long, loff_t); +extern int afs_writeback_all(struct afs_vnode *); +extern int afs_fsync(struct file *, struct dentry *, int); + + /*****************************************************************************/ /* * debug tracing diff --git a/fs/afs/rxrpc.c b/fs/afs/rxrpc.c index 222c1a3abbb8..04189c47d6a0 100644 --- a/fs/afs/rxrpc.c +++ b/fs/afs/rxrpc.c @@ -236,6 +236,70 @@ void afs_flat_call_destructor(struct afs_call *call) call->buffer = NULL; } +/* + * attach the data from a bunch of pages on an inode to a call + */ +int afs_send_pages(struct afs_call *call, struct msghdr *msg, struct kvec *iov) +{ + struct page *pages[8]; + unsigned count, n, loop, offset, to; + pgoff_t first = call->first, last = call->last; + int ret; + + _enter(""); + + offset = call->first_offset; + call->first_offset = 0; + + do { + _debug("attach %lx-%lx", first, last); + + count = last - first + 1; + if (count > ARRAY_SIZE(pages)) + count = ARRAY_SIZE(pages); + n = find_get_pages_contig(call->mapping, first, count, pages); + ASSERTCMP(n, ==, count); + + loop = 0; + do { + msg->msg_flags = 0; + to = PAGE_SIZE; + if (first + loop >= last) + to = call->last_to; + else + msg->msg_flags = MSG_MORE; + iov->iov_base = kmap(pages[loop]) + offset; + iov->iov_len = to - offset; + offset = 0; + + _debug("- range %u-%u%s", + offset, to, msg->msg_flags ? " [more]" : ""); + msg->msg_iov = (struct iovec *) iov; + msg->msg_iovlen = 1; + + /* have to change the state *before* sending the last + * packet as RxRPC might give us the reply before it + * returns from sending the request */ + if (first + loop >= last) + call->state = AFS_CALL_AWAIT_REPLY; + ret = rxrpc_kernel_send_data(call->rxcall, msg, + to - offset); + kunmap(pages[loop]); + if (ret < 0) + break; + } while (++loop < count); + first += count; + + for (loop = 0; loop < count; loop++) + put_page(pages[loop]); + if (ret < 0) + break; + } while (first < last); + + _leave(" = %d", ret); + return ret; +} + /* * initiate a call */ @@ -253,8 +317,9 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp, ASSERT(call->type != NULL); ASSERT(call->type->name != NULL); - _debug("MAKE %p{%s} [%d]", - call, call->type->name, atomic_read(&afs_outstanding_calls)); + _debug("____MAKE %p{%s,%x} [%d]____", + call, call->type->name, key_serial(call->key), + atomic_read(&afs_outstanding_calls)); call->wait_mode = wait_mode; INIT_WORK(&call->async_work, afs_process_async_call); @@ -289,16 +354,23 @@ int afs_make_call(struct in_addr *addr, struct afs_call *call, gfp_t gfp, msg.msg_iovlen = 1; msg.msg_control = NULL; msg.msg_controllen = 0; - msg.msg_flags = 0; + msg.msg_flags = (call->send_pages ? MSG_MORE : 0); /* have to change the state *before* sending the last packet as RxRPC * might give us the reply before it returns from sending the * request */ - call->state = AFS_CALL_AWAIT_REPLY; + if (!call->send_pages) + call->state = AFS_CALL_AWAIT_REPLY; ret = rxrpc_kernel_send_data(rxcall, &msg, call->request_size); if (ret < 0) goto error_do_abort; + if (call->send_pages) { + ret = afs_send_pages(call, &msg, iov); + if (ret < 0) + goto error_do_abort; + } + /* at this point, an async call may no longer exist as it may have * already completed */ return wait_mode->wait(call); diff --git a/fs/afs/super.c b/fs/afs/super.c index 7030d76155fc..d24be334b608 100644 --- a/fs/afs/super.c +++ b/fs/afs/super.c @@ -50,6 +50,7 @@ static const struct super_operations afs_super_ops = { .statfs = simple_statfs, .alloc_inode = afs_alloc_inode, .drop_inode = generic_delete_inode, + .write_inode = afs_write_inode, .destroy_inode = afs_destroy_inode, .clear_inode = afs_clear_inode, .umount_begin = afs_umount_begin, @@ -66,7 +67,7 @@ enum { afs_opt_vol, }; -static const match_table_t afs_options_list = { +static match_table_t afs_options_list = { { afs_opt_cell, "cell=%s" }, { afs_opt_rwpath, "rwpath" }, { afs_opt_vol, "vol=%s" }, @@ -459,7 +460,9 @@ static void afs_i_init_once(void *_vnode, struct kmem_cache *cachep, init_waitqueue_head(&vnode->update_waitq); mutex_init(&vnode->permits_lock); mutex_init(&vnode->validate_lock); + spin_lock_init(&vnode->writeback_lock); spin_lock_init(&vnode->lock); + INIT_LIST_HEAD(&vnode->writebacks); INIT_WORK(&vnode->cb_broken_work, afs_broken_callback_work); } } diff --git a/fs/afs/vnode.c b/fs/afs/vnode.c index 0e37f9949cb7..ec814660209f 100644 --- a/fs/afs/vnode.c +++ b/fs/afs/vnode.c @@ -753,3 +753,110 @@ no_server: _leave(" = %ld [cnt %d]", PTR_ERR(server), orig_dvnode->update_cnt); return PTR_ERR(server); } + +/* + * write to a file + */ +int afs_vnode_store_data(struct afs_writeback *wb, pgoff_t first, pgoff_t last, + unsigned offset, unsigned to) +{ + struct afs_server *server; + struct afs_vnode *vnode = wb->vnode; + int ret; + + _enter("%s{%x:%u.%u},%x,%lx,%lx,%x,%x", + vnode->volume->vlocation->vldb.name, + vnode->fid.vid, + vnode->fid.vnode, + vnode->fid.unique, + key_serial(wb->key), + first, last, offset, to); + + /* this op will fetch the status */ + spin_lock(&vnode->lock); + vnode->update_cnt++; + spin_unlock(&vnode->lock); + + do { + /* pick a server to query */ + server = afs_volume_pick_fileserver(vnode); + if (IS_ERR(server)) + goto no_server; + + _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr)); + + ret = afs_fs_store_data(server, wb, first, last, offset, to, + &afs_sync_call); + + } while (!afs_volume_release_fileserver(vnode, server, ret)); + + /* adjust the flags */ + if (ret == 0) { + afs_vnode_finalise_status_update(vnode, server); + afs_put_server(server); + } else { + afs_vnode_status_update_failed(vnode, ret); + } + + _leave(" = %d", ret); + return ret; + +no_server: + spin_lock(&vnode->lock); + vnode->update_cnt--; + ASSERTCMP(vnode->update_cnt, >=, 0); + spin_unlock(&vnode->lock); + return PTR_ERR(server); +} + +/* + * set the attributes on a file + */ +int afs_vnode_setattr(struct afs_vnode *vnode, struct key *key, + struct iattr *attr) +{ + struct afs_server *server; + int ret; + + _enter("%s{%x:%u.%u},%x", + vnode->volume->vlocation->vldb.name, + vnode->fid.vid, + vnode->fid.vnode, + vnode->fid.unique, + key_serial(key)); + + /* this op will fetch the status */ + spin_lock(&vnode->lock); + vnode->update_cnt++; + spin_unlock(&vnode->lock); + + do { + /* pick a server to query */ + server = afs_volume_pick_fileserver(vnode); + if (IS_ERR(server)) + goto no_server; + + _debug("USING SERVER: %08x\n", ntohl(server->addr.s_addr)); + + ret = afs_fs_setattr(server, key, vnode, attr, &afs_sync_call); + + } while (!afs_volume_release_fileserver(vnode, server, ret)); + + /* adjust the flags */ + if (ret == 0) { + afs_vnode_finalise_status_update(vnode, server); + afs_put_server(server); + } else { + afs_vnode_status_update_failed(vnode, ret); + } + + _leave(" = %d", ret); + return ret; + +no_server: + spin_lock(&vnode->lock); + vnode->update_cnt--; + ASSERTCMP(vnode->update_cnt, >=, 0); + spin_unlock(&vnode->lock); + return PTR_ERR(server); +} diff --git a/fs/afs/write.c b/fs/afs/write.c new file mode 100644 index 000000000000..83ff29262816 --- /dev/null +++ b/fs/afs/write.c @@ -0,0 +1,835 @@ +/* handling of writes to regular files and writing back to the server + * + * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved. + * Written by David Howells (dhowells@redhat.com) + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License + * as published by the Free Software Foundation; either version + * 2 of the License, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include "internal.h" + +static int afs_write_back_from_locked_page(struct afs_writeback *wb, + struct page *page); + +/* + * mark a page as having been made dirty and thus needing writeback + */ +int afs_set_page_dirty(struct page *page) +{ + _enter(""); + return __set_page_dirty_nobuffers(page); +} + +/* + * unlink a writeback record because its usage has reached zero + * - must be called with the wb->vnode->writeback_lock held + */ +static void afs_unlink_writeback(struct afs_writeback *wb) +{ + struct afs_writeback *front; + struct afs_vnode *vnode = wb->vnode; + + list_del_init(&wb->link); + if (!list_empty(&vnode->writebacks)) { + /* if an fsync rises to the front of the queue then wake it + * up */ + front = list_entry(vnode->writebacks.next, + struct afs_writeback, link); + if (front->state == AFS_WBACK_SYNCING) { + _debug("wake up sync"); + front->state = AFS_WBACK_COMPLETE; + wake_up(&front->waitq); + } + } +} + +/* + * free a writeback record + */ +static void afs_free_writeback(struct afs_writeback *wb) +{ + _enter(""); + key_put(wb->key); + kfree(wb); +} + +/* + * dispose of a reference to a writeback record + */ +void afs_put_writeback(struct afs_writeback *wb) +{ + struct afs_vnode *vnode = wb->vnode; + + _enter("{%d}", wb->usage); + + spin_lock(&vnode->writeback_lock); + if (--wb->usage == 0) + afs_unlink_writeback(wb); + else + wb = NULL; + spin_unlock(&vnode->writeback_lock); + if (wb) + afs_free_writeback(wb); +} + +/* + * partly or wholly fill a page that's under preparation for writing + */ +static int afs_fill_page(struct afs_vnode *vnode, struct key *key, + unsigned start, unsigned len, struct page *page) +{ + int ret; + + _enter(",,%u,%u", start, len); + + ASSERTCMP(start + len, <=, PAGE_SIZE); + + ret = afs_vnode_fetch_data(vnode, key, start, len, page); + if (ret < 0) { + if (ret == -ENOENT) { + _debug("got NOENT from server" + " - marking file deleted and stale"); + set_bit(AFS_VNODE_DELETED, &vnode->flags); + ret = -ESTALE; + } + } + + _leave(" = %d", ret); + return ret; +} + +/* + * prepare a page for being written to + */ +static int afs_prepare_page(struct afs_vnode *vnode, struct page *page, + struct key *key, unsigned offset, unsigned to) +{ + unsigned eof, tail, start, stop, len; + loff_t i_size, pos; + void *p; + int ret; + + _enter(""); + + if (offset == 0 && to == PAGE_SIZE) + return 0; + + p = kmap(page); + + i_size = i_size_read(&vnode->vfs_inode); + pos = (loff_t) page->index << PAGE_SHIFT; + if (pos >= i_size) { + /* partial write, page beyond EOF */ + _debug("beyond"); + if (offset > 0) + memset(p, 0, offset); + if (to < PAGE_SIZE) + memset(p + to, 0, PAGE_SIZE - to); + kunmap(page); + return 0; + } + + if (i_size - pos >= PAGE_SIZE) { + /* partial write, page entirely before EOF */ + _debug("before"); + tail = eof = PAGE_SIZE; + } else { + /* partial write, page overlaps EOF */ + eof = i_size - pos; + _debug("overlap %u", eof); + tail = max(eof, to); + if (tail < PAGE_SIZE) + memset(p + tail, 0, PAGE_SIZE - tail); + if (offset > eof) + memset(p + eof, 0, PAGE_SIZE - eof); + } + + kunmap(p); + + ret = 0; + if (offset > 0 || eof > to) { + /* need to fill one or two bits that aren't going to be written + * (cover both fillers in one read if there are two) */ + start = (offset > 0) ? 0 : to; + stop = (eof > to) ? eof : offset; + len = stop - start; + _debug("wr=%u-%u av=0-%u rd=%u@%u", + offset, to, eof, start, len); + ret = afs_fill_page(vnode, key, start, len, page); + } + + _leave(" = %d", ret); + return ret; +} + +/* + * prepare to perform part of a write to a page + * - the caller holds the page locked, preventing it from being written out or + * modified by anyone else + */ +int afs_prepare_write(struct file *file, struct page *page, + unsigned offset, unsigned to) +{ + struct afs_writeback *candidate, *wb; + struct afs_vnode *vnode = AFS_FS_I(file->f_dentry->d_inode); + struct key *key = file->private_data; + pgoff_t index; + int ret; + + _enter("{%x:%u},{%lx},%u,%u", + vnode->fid.vid, vnode->fid.vnode, page->index, offset, to); + + candidate = kzalloc(sizeof(*candidate), GFP_KERNEL); + if (!candidate) + return -ENOMEM; + candidate->vnode = vnode; + candidate->first = candidate->last = page->index; + candidate->offset_first = offset; + candidate->to_last = to; + candidate->usage = 1; + candidate->state = AFS_WBACK_PENDING; + init_waitqueue_head(&candidate->waitq); + + if (!PageUptodate(page)) { + _debug("not up to date"); + ret = afs_prepare_page(vnode, page, key, offset, to); + if (ret < 0) { + kfree(candidate); + _leave(" = %d [prep]", ret); + return ret; + } + SetPageUptodate(page); + } + +try_again: + index = page->index; + spin_lock(&vnode->writeback_lock); + + /* see if this page is already pending a writeback under a suitable key + * - if so we can just join onto that one */ + wb = (struct afs_writeback *) page_private(page); + if (wb) { + if (wb->key == key && wb->state == AFS_WBACK_PENDING) + goto subsume_in_current_wb; + goto flush_conflicting_wb; + } + + if (index > 0) { + /* see if we can find an already pending writeback that we can + * append this page to */ + list_for_each_entry(wb, &vnode->writebacks, link) { + if (wb->last == index - 1 && wb->key == key && + wb->state == AFS_WBACK_PENDING) + goto append_to_previous_wb; + } + } + + list_add_tail(&candidate->link, &vnode->writebacks); + candidate->key = key_get(key); + spin_unlock(&vnode->writeback_lock); + SetPagePrivate(page); + set_page_private(page, (unsigned long) candidate); + _leave(" = 0 [new]"); + return 0; + +subsume_in_current_wb: + _debug("subsume"); + ASSERTRANGE(wb->first, <=, index, <=, wb->last); + if (index == wb->first && offset < wb->offset_first) + wb->offset_first = offset; + if (index == wb->last && to > wb->to_last) + wb->to_last = to; + spin_unlock(&vnode->writeback_lock); + kfree(candidate); + _leave(" = 0 [sub]"); + return 0; + +append_to_previous_wb: + _debug("append into %lx-%lx", wb->first, wb->last); + wb->usage++; + wb->last++; + wb->to_last = to; + spin_unlock(&vnode->writeback_lock); + SetPagePrivate(page); + set_page_private(page, (unsigned long) wb); + kfree(candidate); + _leave(" = 0 [app]"); + return 0; + + /* the page is currently bound to another context, so if it's dirty we + * need to flush it before we can use the new context */ +flush_conflicting_wb: + _debug("flush conflict"); + if (wb->state == AFS_WBACK_PENDING) + wb->state = AFS_WBACK_CONFLICTING; + spin_unlock(&vnode->writeback_lock); + if (PageDirty(page)) { + ret = afs_write_back_from_locked_page(wb, page); + if (ret < 0) { + afs_put_writeback(candidate); + _leave(" = %d", ret); + return ret; + } + } + + /* the page holds a ref on the writeback record */ + afs_put_writeback(wb); + set_page_private(page, 0); + ClearPagePrivate(page); + goto try_again; +} + +/* + * finalise part of a write to a page + */ +int afs_commit_write(struct file *file, struct page *page, + unsigned offset, unsigned to) +{ + struct afs_vnode *vnode = AFS_FS_I(file->f_dentry->d_inode); + loff_t i_size, maybe_i_size; + + _enter("{%x:%u},{%lx},%u,%u", + vnode->fid.vid, vnode->fid.vnode, page->index, offset, to); + + maybe_i_size = (loff_t) page->index << PAGE_SHIFT; + maybe_i_size += to; + + i_size = i_size_read(&vnode->vfs_inode); + if (maybe_i_size > i_size) { + spin_lock(&vnode->writeback_lock); + i_size = i_size_read(&vnode->vfs_inode); + if (maybe_i_size > i_size) + i_size_write(&vnode->vfs_inode, maybe_i_size); + spin_unlock(&vnode->writeback_lock); + } + + set_page_dirty(page); + + if (PageDirty(page)) + _debug("dirtied"); + + return 0; +} + +/* + * kill all the pages in the given range + */ +static void afs_kill_pages(struct afs_vnode *vnode, bool error, + pgoff_t first, pgoff_t last) +{ + struct pagevec pv; + unsigned count, loop; + + _enter("{%x:%u},%lx-%lx", + vnode->fid.vid, vnode->fid.vnode, first, last); + + pagevec_init(&pv, 0); + + do { + _debug("kill %lx-%lx", first, last); + + count = last - first + 1; + if (count > PAGEVEC_SIZE) + count = PAGEVEC_SIZE; + pv.nr = find_get_pages_contig(vnode->vfs_inode.i_mapping, + first, count, pv.pages); + ASSERTCMP(pv.nr, ==, count); + + for (loop = 0; loop < count; loop++) { + ClearPageUptodate(pv.pages[loop]); + if (error) + SetPageError(pv.pages[loop]); + end_page_writeback(pv.pages[loop]); + } + + __pagevec_release(&pv); + } while (first < last); + + _leave(""); +} + +/* + * synchronously write back the locked page and any subsequent non-locked dirty + * pages also covered by the same writeback record + */ +static int afs_write_back_from_locked_page(struct afs_writeback *wb, + struct page *primary_page) +{ + struct page *pages[8], *page; + unsigned long count; + unsigned n, offset, to; + pgoff_t start, first, last; + int loop, ret; + + _enter(",%lx", primary_page->index); + + count = 1; + if (!clear_page_dirty_for_io(primary_page)) + BUG(); + if (test_set_page_writeback(primary_page)) + BUG(); + + /* find all consecutive lockable dirty pages, stopping when we find a + * page that is not immediately lockable, is not dirty or is missing, + * or we reach the end of the range */ + start = primary_page->index; + if (start >= wb->last) + goto no_more; + start++; + do { + _debug("more %lx [%lx]", start, count); + n = wb->last - start + 1; + if (n > ARRAY_SIZE(pages)) + n = ARRAY_SIZE(pages); + n = find_get_pages_contig(wb->vnode->vfs_inode.i_mapping, + start, n, pages); + _debug("fgpc %u", n); + if (n == 0) + goto no_more; + if (pages[0]->index != start) { + for (n--; n >= 0; n--) + put_page(pages[n]); + goto no_more; + } + + for (loop = 0; loop < n; loop++) { + page = pages[loop]; + if (page->index > wb->last) + break; + if (TestSetPageLocked(page)) + break; + if (!PageDirty(page) || + page_private(page) != (unsigned long) wb) { + unlock_page(page); + break; + } + if (!clear_page_dirty_for_io(page)) + BUG(); + if (test_set_page_writeback(page)) + BUG(); + unlock_page(page); + put_page(page); + } + count += loop; + if (loop < n) { + for (; loop < n; loop++) + put_page(pages[loop]); + goto no_more; + } + + start += loop; + } while (start <= wb->last && count < 65536); + +no_more: + /* we now have a contiguous set of dirty pages, each with writeback set + * and the dirty mark cleared; the first page is locked and must remain + * so, all the rest are unlocked */ + first = primary_page->index; + last = first + count - 1; + + offset = (first == wb->first) ? wb->offset_first : 0; + to = (last == wb->last) ? wb->to_last : PAGE_SIZE; + + _debug("write back %lx[%u..] to %lx[..%u]", first, offset, last, to); + + ret = afs_vnode_store_data(wb, first, last, offset, to); + if (ret < 0) { + switch (ret) { + case -EDQUOT: + case -ENOSPC: + set_bit(AS_ENOSPC, + &wb->vnode->vfs_inode.i_mapping->flags); + break; + case -EROFS: + case -EIO: + case -EREMOTEIO: + case -EFBIG: + case -ENOENT: + case -ENOMEDIUM: + case -ENXIO: + afs_kill_pages(wb->vnode, true, first, last); + set_bit(AS_EIO, &wb->vnode->vfs_inode.i_mapping->flags); + break; + case -EACCES: + case -EPERM: + case -ENOKEY: + case -EKEYEXPIRED: + case -EKEYREJECTED: + case -EKEYREVOKED: + afs_kill_pages(wb->vnode, false, first, last); + break; + default: + break; + } + } else { + ret = count; + } + + _leave(" = %d", ret); + return ret; +} + +/* + * write a page back to the server + * - the caller locked the page for us + */ +int afs_writepage(struct page *page, struct writeback_control *wbc) +{ + struct backing_dev_info *bdi = page->mapping->backing_dev_info; + struct afs_writeback *wb; + int ret; + + _enter("{%lx},", page->index); + + if (wbc->sync_mode != WB_SYNC_NONE) + wait_on_page_writeback(page); + + if (PageWriteback(page) || !PageDirty(page)) { + unlock_page(page); + return 0; + } + + wb = (struct afs_writeback *) page_private(page); + ASSERT(wb != NULL); + + ret = afs_write_back_from_locked_page(wb, page); + unlock_page(page); + if (ret < 0) { + _leave(" = %d", ret); + return 0; + } + + wbc->nr_to_write -= ret; + if (wbc->nonblocking && bdi_write_congested(bdi)) + wbc->encountered_congestion = 1; + + _leave(" = 0"); + return 0; +} + +/* + * write a region of pages back to the server + */ +int afs_writepages_region(struct address_space *mapping, + struct writeback_control *wbc, + pgoff_t index, pgoff_t end, pgoff_t *_next) +{ + struct backing_dev_info *bdi = mapping->backing_dev_info; + struct afs_writeback *wb; + struct page *page; + int ret, n; + + _enter(",,%lx,%lx,", index, end); + + do { + n = find_get_pages_tag(mapping, &index, PAGECACHE_TAG_DIRTY, + 1, &page); + if (!n) + break; + + _debug("wback %lx", page->index); + + if (page->index > end) { + *_next = index; + page_cache_release(page); + _leave(" = 0 [%lx]", *_next); + return 0; + } + + /* at this point we hold neither mapping->tree_lock nor lock on + * the page itself: the page may be truncated or invalidated + * (changing page->mapping to NULL), or even swizzled back from + * swapper_space to tmpfs file mapping + */ + lock_page(page); + + if (page->mapping != mapping) { + unlock_page(page); + page_cache_release(page); + continue; + } + + if (wbc->sync_mode != WB_SYNC_NONE) + wait_on_page_writeback(page); + + if (PageWriteback(page) || !PageDirty(page)) { + unlock_page(page); + continue; + } + + wb = (struct afs_writeback *) page_private(page); + ASSERT(wb != NULL); + + spin_lock(&wb->vnode->writeback_lock); + wb->state = AFS_WBACK_WRITING; + spin_unlock(&wb->vnode->writeback_lock); + + ret = afs_write_back_from_locked_page(wb, page); + unlock_page(page); + page_cache_release(page); + if (ret < 0) { + _leave(" = %d", ret); + return ret; + } + + wbc->nr_to_write -= ret; + + if (wbc->nonblocking && bdi_write_congested(bdi)) { + wbc->encountered_congestion = 1; + break; + } + + cond_resched(); + } while (index < end && wbc->nr_to_write > 0); + + *_next = index; + _leave(" = 0 [%lx]", *_next); + return 0; +} + +/* + * write some of the pending data back to the server + */ +int afs_writepages(struct address_space *mapping, + struct writeback_control *wbc) +{ + struct backing_dev_info *bdi = mapping->backing_dev_info; + pgoff_t start, end, next; + int ret; + + _enter(""); + + if (wbc->nonblocking && bdi_write_congested(bdi)) { + wbc->encountered_congestion = 1; + _leave(" = 0 [congest]"); + return 0; + } + + if (wbc->range_cyclic) { + start = mapping->writeback_index; + end = -1; + ret = afs_writepages_region(mapping, wbc, start, end, &next); + if (start > 0 && wbc->nr_to_write > 0 && ret == 0 && + !(wbc->nonblocking && wbc->encountered_congestion)) + ret = afs_writepages_region(mapping, wbc, 0, start, + &next); + mapping->writeback_index = next; + } else if (wbc->range_start == 0 && wbc->range_end == LLONG_MAX) { + end = (pgoff_t)(LLONG_MAX >> PAGE_CACHE_SHIFT); + ret = afs_writepages_region(mapping, wbc, 0, end, &next); + if (wbc->nr_to_write > 0) + mapping->writeback_index = next; + } else { + start = wbc->range_start >> PAGE_CACHE_SHIFT; + end = wbc->range_end >> PAGE_CACHE_SHIFT; + ret = afs_writepages_region(mapping, wbc, start, end, &next); + } + + _leave(" = %d", ret); + return ret; +} + +/* + * write an inode back + */ +int afs_write_inode(struct inode *inode, int sync) +{ + struct afs_vnode *vnode = AFS_FS_I(inode); + int ret; + + _enter("{%x:%u},", vnode->fid.vid, vnode->fid.vnode); + + ret = 0; + if (sync) { + ret = filemap_fdatawait(inode->i_mapping); + if (ret < 0) + __mark_inode_dirty(inode, I_DIRTY_DATASYNC); + } + + _leave(" = %d", ret); + return ret; +} + +/* + * completion of write to server + */ +void afs_pages_written_back(struct afs_vnode *vnode, struct afs_call *call) +{ + struct afs_writeback *wb = call->wb; + struct pagevec pv; + unsigned count, loop; + pgoff_t first = call->first, last = call->last; + bool free_wb; + + _enter("{%x:%u},{%lx-%lx}", + vnode->fid.vid, vnode->fid.vnode, first, last); + + ASSERT(wb != NULL); + + pagevec_init(&pv, 0); + + do { + _debug("attach %lx-%lx", first, last); + + count = last - first + 1; + if (count > PAGEVEC_SIZE) + count = PAGEVEC_SIZE; + pv.nr = find_get_pages_contig(call->mapping, first, count, + pv.pages); + ASSERTCMP(pv.nr, ==, count); + + spin_lock(&vnode->writeback_lock); + for (loop = 0; loop < count; loop++) { + struct page *page = pv.pages[loop]; + end_page_writeback(page); + if (page_private(page) == (unsigned long) wb) { + set_page_private(page, 0); + ClearPagePrivate(page); + wb->usage--; + } + } + free_wb = false; + if (wb->usage == 0) { + afs_unlink_writeback(wb); + free_wb = true; + } + spin_unlock(&vnode->writeback_lock); + first += count; + if (free_wb) { + afs_free_writeback(wb); + wb = NULL; + } + + __pagevec_release(&pv); + } while (first < last); + + _leave(""); +} + +/* + * write to an AFS file + */ +ssize_t afs_file_write(struct kiocb *iocb, const struct iovec *iov, + unsigned long nr_segs, loff_t pos) +{ + struct dentry *dentry = iocb->ki_filp->f_path.dentry; + struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); + ssize_t result; + size_t count = iov_length(iov, nr_segs); + int ret; + + _enter("{%x.%u},{%zu},%lu,", + vnode->fid.vid, vnode->fid.vnode, count, nr_segs); + + if (IS_SWAPFILE(&vnode->vfs_inode)) { + printk(KERN_INFO + "AFS: Attempt to write to active swap file!\n"); + return -EBUSY; + } + + if (!count) + return 0; + + result = generic_file_aio_write(iocb, iov, nr_segs, pos); + if (IS_ERR_VALUE(result)) { + _leave(" = %zd", result); + return result; + } + + /* return error values for O_SYNC and IS_SYNC() */ + if (IS_SYNC(&vnode->vfs_inode) || iocb->ki_filp->f_flags & O_SYNC) { + ret = afs_fsync(iocb->ki_filp, dentry, 1); + if (ret < 0) + result = ret; + } + + _leave(" = %zd", result); + return result; +} + +/* + * flush the vnode to the fileserver + */ +int afs_writeback_all(struct afs_vnode *vnode) +{ + struct address_space *mapping = vnode->vfs_inode.i_mapping; + struct writeback_control wbc = { + .bdi = mapping->backing_dev_info, + .sync_mode = WB_SYNC_ALL, + .nr_to_write = LONG_MAX, + .for_writepages = 1, + .range_cyclic = 1, + }; + int ret; + + _enter(""); + + ret = mapping->a_ops->writepages(mapping, &wbc); + __mark_inode_dirty(mapping->host, I_DIRTY_PAGES); + + _leave(" = %d", ret); + return ret; +} + +/* + * flush any dirty pages for this process, and check for write errors. + * - the return status from this call provides a reliable indication of + * whether any write errors occurred for this process. + */ +int afs_fsync(struct file *file, struct dentry *dentry, int datasync) +{ + struct afs_writeback *wb, *xwb; + struct afs_vnode *vnode = AFS_FS_I(dentry->d_inode); + int ret; + + _enter("{%x:%u},{n=%s},%d", + vnode->fid.vid, vnode->fid.vnode, dentry->d_name.name, + datasync); + + /* use a writeback record as a marker in the queue - when this reaches + * the front of the queue, all the outstanding writes are either + * completed or rejected */ + wb = kzalloc(sizeof(*wb), GFP_KERNEL); + if (!wb) + return -ENOMEM; + wb->vnode = vnode; + wb->first = 0; + wb->last = -1; + wb->offset_first = 0; + wb->to_last = PAGE_SIZE; + wb->usage = 1; + wb->state = AFS_WBACK_SYNCING; + init_waitqueue_head(&wb->waitq); + + spin_lock(&vnode->writeback_lock); + list_for_each_entry(xwb, &vnode->writebacks, link) { + if (xwb->state == AFS_WBACK_PENDING) + xwb->state = AFS_WBACK_CONFLICTING; + } + list_add_tail(&wb->link, &vnode->writebacks); + spin_unlock(&vnode->writeback_lock); + + /* push all the outstanding writebacks to the server */ + ret = afs_writeback_all(vnode); + if (ret < 0) { + afs_put_writeback(wb); + _leave(" = %d [wb]", ret); + return ret; + } + + /* wait for the preceding writes to actually complete */ + ret = wait_event_interruptible(wb->waitq, + wb->state == AFS_WBACK_COMPLETE || + vnode->writebacks.next == &wb->link); + afs_put_writeback(wb); + _leave(" = %d", ret); + return ret; +}