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https://github.com/xen-project/xen.git
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Keir Fraser
6d821524b1
Currently most of the error checking in fs-backend is done by the use of asserts that would terminate the daemon in case of a single error on a single request. This patch replaces the asserts with debugging messages and terminates the connection on which the error occurred. With this patch applied I was able to complete successfully over 1000 live migrations with stubdoms. Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
101 lines
2.8 KiB
C
101 lines
2.8 KiB
C
#ifndef __LIB_FS_BACKEND__
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#define __LIB_FS_BACKEND__
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#include <aio.h>
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#include <xs.h>
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#include <xen/grant_table.h>
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#include <xen/event_channel.h>
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#include <xen/io/ring.h>
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#include <xen/io/fsif.h>
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#include "sys-queue.h"
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#define ROOT_NODE "backend/vfs"
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#define EXPORTS_SUBNODE "exports"
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#define EXPORTS_NODE ROOT_NODE"/"EXPORTS_SUBNODE
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#define WATCH_NODE EXPORTS_NODE"/requests"
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#define MAX_FDS 16
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#define MAX_RING_SIZE 16
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struct fs_export
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{
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int export_id;
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char *export_path;
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char *name;
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struct fs_export *next;
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};
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struct fs_request
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{
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struct fs_mount *mount;
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int id;
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int active;
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void *page; /* Pointer to mapped grant */
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int count;
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struct fsif_request req_shadow;
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struct aiocb aiocb;
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};
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struct fs_mount
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{
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struct fs_export *export;
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int dom_id;
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char *frontend;
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int mount_id; /* = backend id */
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grant_ref_t grefs[MAX_RING_SIZE];
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evtchn_port_t remote_evtchn;
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int evth; /* Handle to the event channel */
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evtchn_port_t local_evtchn;
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int gnth;
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int shared_ring_size; /* in pages */
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struct fsif_back_ring ring;
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int nr_entries;
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struct fs_request *requests;
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unsigned short *freelist;
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int fds[MAX_FDS];
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LIST_ENTRY(fs_mount) entries;
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};
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void terminate_mount_request(struct fs_mount *mount);
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/* Handle to XenStore driver */
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extern struct xs_handle *xsh;
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bool xenbus_create_request_node(void);
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int xenbus_register_export(struct fs_export *export);
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int xenbus_get_watch_fd(void);
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int xenbus_read_mount_request(struct fs_mount *mount, char *frontend);
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bool xenbus_write_backend_node(struct fs_mount *mount);
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bool xenbus_write_backend_state(struct fs_mount *mount, const char *state);
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int xenbus_frontend_state_changed(struct fs_mount *mount, const char *oldstate);
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bool xenbus_watch_frontend_state(struct fs_mount *mount);
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bool xenbus_unwatch_frontend_state(struct fs_mount *mount);
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char* xenbus_read_frontend_state(struct fs_mount *mount);
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/* File operations, implemented in fs-ops.c */
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struct fs_op
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{
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int type; /* Type of request (from fsif.h) this handlers
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are responsible for */
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void (*dispatch_handler)(struct fs_mount *mount, struct fsif_request *req);
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void (*response_handler)(struct fs_mount *mount, struct fs_request *req);
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};
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/* This NULL terminated array of all file requests handlers */
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extern struct fs_op *fsops[];
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static inline void add_id_to_freelist(unsigned int id,unsigned short* freelist)
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{
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freelist[id + 1] = freelist[0];
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freelist[0] = id;
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}
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static inline unsigned short get_id_from_freelist(unsigned short* freelist)
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{
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unsigned int id = freelist[0];
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freelist[0] = freelist[id + 1];
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return id;
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}
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#endif /* __LIB_FS_BACKEND__ */
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