ShingledFS 2.0
SMR-AwareFUSE-basedFileSystem

shingledfs.c

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00001 
00009 #define FUSE_USE_VERSION 26
00010 
00011 
00012 #include <fuse.h>
00013 #include <errno.h>
00014 #include <stdio.h>
00015 #include <string.h>
00016 #include <stdlib.h>
00017 #include <unistd.h>
00018 #include <sys/types.h>
00019 #include <sys/xattr.h>
00020 #include <limits.h>
00021 
00022 #include "helper.h"
00023 #include "shingledfs.h"
00024 
00025 
00026 
00027 /* ======================= */
00028 /* -- Macro Definitions -- */
00029 /* ======================= */
00030 
00031 #define ARG_COUNT_MIN                   4
00032 
00033 #define ARG_PATH_UNSHINGLED             1
00034 #define ARG_PATH_TMPFS                  2
00035 #define ARG_PATH_EDI                    3
00036 
00037 #define ARG_SINGLE_THREADED             "-s"
00038 #define ARG_FOREGROUND_EXEC             "-f"
00039 //#define ARG_FSNAME                            "-ofsname=ShingledFS"
00040 
00041 
00042 
00043 /* ====================== */
00044 /* -- Static Variables -- */
00045 /* ====================== */
00046 
00050 struct fuse_operations shingledfs_ops = {
00051         .init            = shingledfs_init,
00052 //      .destroy         = shingledfs_destroy,
00053 
00054         .mkdir       = shingledfs_mkdir,
00055     .rmdir       = shingledfs_rmdir,
00056     .opendir     = shingledfs_opendir,
00057     .readdir     = shingledfs_readdir,
00058     .releasedir  = shingledfs_releasedir,
00059 
00060     .mknod       = shingledfs_mknod,
00061     .open        = shingledfs_open,
00062     .read        = shingledfs_read,
00063     .write       = shingledfs_write,
00064     .flush       = shingledfs_flush,
00065     .release     = shingledfs_release,
00066     .rename      = shingledfs_rename,
00067     .unlink      = shingledfs_unlink,
00068     .truncate    = shingledfs_truncate,
00069 
00070     .getattr     = shingledfs_getattr,
00071     .fgetattr    = shingledfs_fgetattr,
00072     .setxattr    = shingledfs_setxattr,
00073     .getxattr    = shingledfs_getxattr,
00074     .listxattr   = shingledfs_listxattr,
00075     .removexattr = shingledfs_removexattr,
00076 
00077     .access      = shingledfs_access,
00078     .utime               = shingledfs_utime,
00079     .chmod       = shingledfs_chmod,
00080     .chown               = shingledfs_chown,
00081 
00082     .symlink     = shingledfs_symlink,
00083     .readlink    = shingledfs_readlink,
00084     .link        = shingledfs_link,
00085     .statfs      = shingledfs_statfs,
00086 
00087 //    .ftruncate   = shingledfs_ftruncate,
00088 //    .fsync       = shingledfs_fsync,
00089 //    .fsyncdir    = NULL,
00090 };
00091 
00092 
00093 
00094 /* ================================================= */
00095 /* -- Usage and Command-line Arguments Processing -- */
00096 /* ================================================= */
00097 
00101 static void
00102 usage(const char *program_name)
00103 {
00104     fprintf(stderr,
00105                 "USAGE: %s <Unshingled path> <tmpFS path> <EDI path> <FUSE mount path>\n",
00106                 program_name);
00107     abort();
00108 }
00109 
00110 
00111 
00127 static void
00128 process_args(int *argc,
00129                          char *argv[]) {
00130         int i, arg_error = 0;
00131         int is_singled_threaded = 0;
00132 
00133 
00134         /* Ensure that the arguments are available */
00135         if (*argc < ARG_COUNT_MIN)
00136                 usage(argv[0]);
00137 
00138 
00139         /* Strip out any terminating /'s in the path to the directories */
00140         i = strlen(argv[ARG_PATH_UNSHINGLED]) - 1;
00141         if (argv[ARG_PATH_UNSHINGLED][i] == '/')
00142                 argv[ARG_PATH_UNSHINGLED][i] = '\0';
00143 
00144         i = strlen(argv[ARG_PATH_TMPFS]) - 1;
00145         if (argv[ARG_PATH_TMPFS][i] == '/')
00146                 argv[ARG_PATH_TMPFS][i] = '\0';
00147 
00148 
00149         /* Validate the path to the Unshingled partition */
00150         if (!is_valid_dir(argv[ARG_PATH_UNSHINGLED])) {
00151                 arg_error = 1;
00152                 fprintf(stderr,
00153                                 "Error accessing %s. Please ensure it is a valid directory!\n",
00154                                 argv[ARG_PATH_UNSHINGLED]);
00155         }
00156 
00157         /* Validate the path to the tmpFS partition */
00158         if (!is_valid_dir(argv[ARG_PATH_TMPFS])) {
00159                 arg_error = 1;
00160                 fprintf(stderr,
00161                                 "Error accessing %s. Please ensure it is a valid directory!\n",
00162                                 argv[ARG_PATH_TMPFS]);
00163         }
00164 
00165         /* Validate the path to the Emulated Disk Image */
00166         if (!is_valid_file(argv[ARG_PATH_EDI])) {
00167                 arg_error = 1;
00168                 fprintf(stderr,
00169                                 "Error accessing %s. Please ensure it is a valid file!\n",
00170                                 argv[ARG_PATH_EDI]);
00171         }
00172 
00173 
00174         /* Check if there are any errors */
00175         if (arg_error)
00176                 usage(argv[0]);
00177 
00178 
00179         /* Store the arguments */
00180         strcpy(shingledfs_data.path_unshingled, argv[ARG_PATH_UNSHINGLED]);
00181         strcpy(shingledfs_data.path_tmpfs, argv[ARG_PATH_TMPFS]);
00182         strcpy(shingledfs_data.path_edi, argv[ARG_PATH_EDI]);
00183 
00184         dbg("Unshingled path: %s\n", shingledfs_data.path_unshingled);
00185         dbg("tmpFS path: %s\n", shingledfs_data.path_tmpfs);
00186         dbg("EDI path: %s\n", shingledfs_data.path_edi);
00187 
00188 
00189         /* Adjust the argument count and remove the Shingled FS arguments */
00190         *argc -= ARG_COUNT_MIN - 1;
00191         for(i=0; i<(*argc); i++) {
00192                 /* Move the argument forward */
00193                 argv[i] = argv[i + ARG_COUNT_MIN - 1];
00194 
00195                 /* Check if the argument is the -s flag for single-threaded execution */
00196                 if (strcasecmp(argv[i], ARG_SINGLE_THREADED) == 0)
00197                         is_singled_threaded = 1;
00198         }
00199 
00200         /* @todo Ensure that the File System Name is passed */
00201 //      argv[(*argc)++] = ARG_FSNAME;
00202 
00203         /* Ensure that the process is running in single-threaded mode */
00204         if (!is_singled_threaded)
00205                 argv[(*argc)++] = ARG_SINGLE_THREADED;
00206 
00207 #ifdef DEBUG
00208         /* When running in debug mode, ensure that FUSE runs in the foreground */
00209         argv[(*argc)++] = ARG_FOREGROUND_EXEC;
00210 #endif
00211 
00212 
00213         /* Null-terminate the arguments array */
00214         argv[*argc] = NULL;
00215 }
00216 
00217 
00218 
00219 /* =================== */
00220 /* -- Main Function -- */
00221 /* =================== */
00222 
00223 int
00224 main(int argc,
00225          char *argv[]) {
00226     /* Process the arguments */
00227     process_args(&argc, argv);
00228 
00229     /* Reset the umask to ensure all permissions get set exactly as specified */
00230     umask(0);
00231 
00232     /* Kick start FUSE */
00233     return fuse_main(argc, argv, &shingledfs_ops, &shingledfs_data);
00234 }