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00019 #include "includes.h"
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00036 #define READAHEAD_MIN (128 * 1024)
00037 #define READAHEAD_MAX (100 * 1024 * 1024)
00038
00039 #define MODULE "cacheprime"
00040
00041 static int module_debug;
00042 static ssize_t g_readsz = 0;
00043 static void * g_readbuf = NULL;
00044
00045
00046
00047
00048
00049 static BOOL prime_cache(
00050 struct vfs_handle_struct * handle,
00051 files_struct * fsp,
00052 int fd,
00053 SMB_OFF_T offset,
00054 size_t count)
00055 {
00056 SMB_OFF_T * last;
00057 ssize_t nread;
00058
00059 last = VFS_ADD_FSP_EXTENSION(handle, fsp, SMB_OFF_T);
00060 if (!last) {
00061 return False;
00062 }
00063
00064 if (*last == -1) {
00065
00066 return False;
00067 }
00068
00069 if ((*last + g_readsz) > (offset + count)) {
00070
00071 return False;
00072 }
00073
00074 DEBUG(module_debug,
00075 ("%s: doing readahead of %lld bytes at %lld for %s\n",
00076 MODULE, (long long)g_readsz, (long long)*last,
00077 fsp->fsp_name));
00078
00079 nread = sys_pread(fd, g_readbuf, g_readsz, *last);
00080 if (nread < 0) {
00081 *last = -1;
00082 return False;
00083 }
00084
00085 *last += nread;
00086 return True;
00087 }
00088
00089 static int cprime_connect(
00090 struct vfs_handle_struct * handle,
00091 const char * service,
00092 const char * user)
00093 {
00094 module_debug = lp_parm_int(SNUM(handle->conn), MODULE, "debug", 100);
00095 if (g_readbuf) {
00096
00097
00098
00099
00100 return SMB_VFS_NEXT_CONNECT(handle, service, user);
00101 }
00102
00103 g_readsz = conv_str_size(lp_parm_const_string(SNUM(handle->conn),
00104 MODULE, "rsize", NULL));
00105
00106 if (g_readsz < READAHEAD_MIN) {
00107 DEBUG(module_debug, ("%s: %ld bytes of readahead "
00108 "requested, using minimum of %u\n",
00109 MODULE, (long)g_readsz, READAHEAD_MIN));
00110 g_readsz = READAHEAD_MIN;
00111 } else if (g_readsz > READAHEAD_MAX) {
00112 DEBUG(module_debug, ("%s: %ld bytes of readahead "
00113 "requested, using maximum of %u\n",
00114 MODULE, (long)g_readsz, READAHEAD_MAX));
00115 g_readsz = READAHEAD_MAX;
00116 }
00117
00118 if ((g_readbuf = SMB_MALLOC(g_readsz)) == NULL) {
00119
00120 g_readsz = 0;
00121 }
00122
00123 return SMB_VFS_NEXT_CONNECT(handle, service, user);
00124 }
00125
00126 static ssize_t cprime_sendfile(
00127 struct vfs_handle_struct * handle,
00128 int tofd,
00129 files_struct * fsp,
00130 int fromfd,
00131 const DATA_BLOB * header,
00132 SMB_OFF_T offset,
00133 size_t count)
00134 {
00135 if (g_readbuf && offset == 0) {
00136 prime_cache(handle, fsp, fromfd, offset, count);
00137 }
00138
00139 return SMB_VFS_NEXT_SENDFILE(handle, tofd, fsp, fromfd,
00140 header, offset, count);
00141 }
00142
00143 static ssize_t cprime_read(
00144 vfs_handle_struct * handle,
00145 files_struct * fsp,
00146 int fd,
00147 void * data,
00148 size_t count)
00149 {
00150 SMB_OFF_T offset;
00151
00152 offset = SMB_VFS_LSEEK(fsp, fd, 0, SEEK_CUR);
00153 if (offset >= 0 && g_readbuf) {
00154 prime_cache(handle, fsp, fd, offset, count);
00155 SMB_VFS_LSEEK(fsp, fd, offset, SEEK_SET);
00156 }
00157
00158 return SMB_VFS_NEXT_READ(handle, fsp, fd, data, count);
00159 }
00160
00161 static ssize_t cprime_pread(
00162 vfs_handle_struct * handle,
00163 files_struct * fsp,
00164 int fd,
00165 void * data,
00166 size_t count,
00167 SMB_OFF_T offset)
00168 {
00169 if (g_readbuf) {
00170 prime_cache(handle, fsp, fd, offset, count);
00171 }
00172
00173 return SMB_VFS_NEXT_PREAD(handle, fsp, fd, data, count, offset);
00174 }
00175
00176 static vfs_op_tuple cprime_ops [] =
00177 {
00178 {SMB_VFS_OP(cprime_sendfile),
00179 SMB_VFS_OP_SENDFILE, SMB_VFS_LAYER_TRANSPARENT},
00180 {SMB_VFS_OP(cprime_pread),
00181 SMB_VFS_OP_PREAD, SMB_VFS_LAYER_TRANSPARENT},
00182 {SMB_VFS_OP(cprime_read),
00183 SMB_VFS_OP_READ, SMB_VFS_LAYER_TRANSPARENT},
00184 {SMB_VFS_OP(cprime_connect),
00185 SMB_VFS_OP_CONNECT, SMB_VFS_LAYER_TRANSPARENT},
00186
00187 {SMB_VFS_OP(NULL), SMB_VFS_OP_NOOP, SMB_VFS_LAYER_NOOP}
00188 };
00189
00190
00191
00192
00193
00194
00195 NTSTATUS vfs_cacheprime_init(void);
00196 NTSTATUS vfs_cacheprime_init(void)
00197 {
00198 return smb_register_vfs(SMB_VFS_INTERFACE_VERSION, MODULE, cprime_ops);
00199 }
00200
00201