This is the latest fallocate patchset and is based on 2.6.22. * Following are the changes from TAKE6: 1) We now just have two modes (and no deallocation modes). 2) Updated the man page 3) Added a new patch submitted by David P. Quigley (Patch 3/6). 4) Used EXT_INIT_MAX_LEN instead of 0x8000 in Patch 6/6. 5) Included below in the end is a small testcase to test fallocate. * Following are the changes from TAKE5 to TAKE6: 1) Rebased to 2.6.22 2) Added compat wrapper for x86_64 3) Dropped s390 and ia64 patches, since the platform maintaners can add the support for fallocate once it is in mainline. 4) Added a change suggested by Andreas for better extent-to-group alignment in ext4 (Patch 6/6). Please refer following post: http://www.mail-archive.com/linux-ext4@xxxxxxxxxxxxxxx/msg02445.html 5) Renamed mode flags and values from "FA_" to "FALLOC_" 6) Added manpage (updated version of the one initially submitted by David Chinner). Todos: ----- 1> Implementation on other architectures (other than i386, x86_64, and ppc64). s390(x) and ia64 patches are ready and will be pushed by platform maintaners when the fallocate is in mainline. 2> A generic file system operation to handle fallocate (generic_fallocate), for filesystems that do _not_ have the fallocate inode operation implemented. 3> Changes to glibc, a) to support fallocate() system call b) to make posix_fallocate() and posix_fallocate64() call fallocate() 4> Patch to e2fsprogs to recognize and display uninitialized extents. Following patches follow: Patch 1/6 : manpage for fallocate Patch 2/6 : fallocate() implementation in i386, x86_64 and powerpc Patch 3/6 : revalidate write permissions for fallocate Patch 4/6 : ext4: fallocate support in ext4 Patch 5/6 : ext4: write support for preallocated blocks Patch 6/6 : ext4: change for better extent-to-group alignment Note: Attached below is a small testcase to test fallocate. The __NR_fallocate will need to be changed depending on the system call number in the kernel (it may get changed due to merge) and also depending on the architecture. -- Regards, Amit Arora #include <stdio.h> #include <stdlib.h> #include <fcntl.h> #include <errno.h> #include <linux/unistd.h> #include <sys/vfs.h> #include <sys/stat.h> #define VERBOSE 0 #define __NR_fallocate 324 #define FALLOC_FL_KEEP_SIZE 0x01 #define FALLOC_ALLOCATE 0x0 #define FALLOC_RESV_SPACE FALLOC_FL_KEEP_SIZE int do_fallocate(int fd, int mode, loff_t offset, loff_t len) { int ret; if (VERBOSE) printf("Trying to preallocate blocks (offset=%llu, len=%llu)\n", offset, len); ret = syscall(__NR_fallocate, fd, mode, offset, len); if (ret <0) { printf("SYSCALL: received error %d, ret=%d\n", errno, ret); close(fd); return(1); } if (VERBOSE) printf("fallocate system call succedded ! ret=%d\n", ret); return ret; } int test_fallocate(int fd, int mode, loff_t offset, loff_t len) { int ret, blocks; struct stat statbuf1, statbuf2; fstat(fd, &statbuf1); ret = do_fallocate(fd, mode, offset, len); fstat(fd, &statbuf2); /* check file size after preallocation */ if (mode == FALLOC_ALLOCATE) { if (!ret && statbuf1.st_size < (offset + len) && statbuf2.st_size != (offset + len)) { printf("Error: fallocate succeeded, but the file size did not " "change, where it should have!\n"); ret = 1; } } else if (statbuf1.st_size != statbuf2.st_size) { printf("Error : File size changed, when it should not have!\n"); ret = 1; } blocks = ((statbuf2.st_blocks - statbuf1.st_blocks) * 512)/ statbuf2.st_blksize; /* Print report */ printf("# FALLOCATE TEST REPORT #\n"); printf("\tNew blocks preallocated = %d.\n", blocks); printf("\tNumber of bytes preallocated = %d\n", blocks * statbuf2.st_blksize); printf("\tOld file size = %d, New file size %d.\n", statbuf1.st_size, statbuf2.st_size); printf("\tOld num blocks = %d, New num blocks %d.\n", (statbuf1.st_blocks * 512)/1024, (statbuf2.st_blocks * 512)/1024); return ret; } int do_write(int fd, loff_t offset, loff_t len) { int ret; char *buf; buf = (char *)malloc(len); if (!buf) { printf("error: malloc failed.\n"); return(-1); } if (VERBOSE) printf("Trying to write to file (offset=%llu, len=%llu)\n", offset, len); ret = lseek(fd, offset, SEEK_SET); if (ret != offset) { printf("lseek() failed error=%d, ret=%d\n", errno, ret); close(fd); return(-1); } ret = write(fd, buf, len); if (ret != len) { printf("write() failed error=%d, ret=%d\n", errno, ret); close(fd); return(-1); } if (VERBOSE) printf("Write succedded ! Written %llu bytes ret=%d\n", len, ret); return ret; } int test_write(int fd, loff_t offset, loff_t len) { int ret; ret = do_write(fd, offset, len); printf("# WRITE TEST REPORT #\n"); if (ret > 0) printf("\t written %d bytes.\n", ret); else printf("\t write operation failed!\n"); if (ret > 0) return 0; else return 1; } void usage(char **argv) { printf("\n%s <option> <filename-with-path> <offset> <length>\n", argv[0]); printf("option can be one of the following :\n"); printf("\t-f\t: preallocate. This maps to FALLOC_ALLOCATE mode.\n"); printf("\t-F\t: preallocate, but do not change the file size.\n"); printf("\t\t This maps to FALLOC_RESV_SPACE mode.\n"); printf("\t-w\t: write some data to the range.\n"); printf("\t-W\t: preallocate and write some data to the range.\n"); } /* * Arguments: * argv[1] = option (-f/-F/-w/-W/-m) * argv[2] = fname : the file name with path * argv[3] = offset : in bytes * argv[4] = len : in bytes */ int main(int argc, char **argv) { int ret = 1, fd, mode; char *fname; loff_t offset, len; if (argc!=5 || argv[1][0] != '-') { usage(argv); exit(1); } fname = argv[2]; offset = (unsigned long long)atol(argv[3]);; len = (unsigned long long)atol(argv[4]); if (offset < 0 || len <= 0) { printf("%s: Invalid arguments.\n", argv[0]); exit(1); } fd = open(fname, O_CREAT|O_RDWR, 0666); if (fd < 0) { printf("Error opening file %s, error = %d.\n", fname, errno); exit(1); } /* -f */ if (!strcmp(argv[1], "-f")) { mode = FALLOC_ALLOCATE; ret = test_fallocate(fd, mode, offset, len); if (ret) printf("test_fallocate: ERROR ! ret=%d\n", ret); /* -F */ } else if (!strcmp(argv[1], "-F")) { mode = FALLOC_RESV_SPACE; ret = test_fallocate(fd, mode, offset, len); if (ret) printf("test_fallocate: ERROR ! ret=%d\n", ret); /* -w */ } else if (!strcmp(argv[1], "-w")) { ret = test_write(fd, offset, len); /* -W */ } else if (!strcmp(argv[1], "-W")) { mode = FALLOC_ALLOCATE; ret = test_fallocate(fd, mode, offset, len); if (ret) { printf("test_fallocate: ERROR ! ret=%d\n", ret); goto out; } ret = test_write(fd, offset, len); if (ret) printf("test_write: ERROR ! ret=%d\n", ret); } else { printf("%s: Invalid arguments.\n", argv[0]); usage(argv); } out: if (!ret) printf("\n\n### TESTS PASSED ###\n"); else printf("\n\n#!# TESTS FAILED #!#\n"); close(fd); return ret; } - To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
