remove writeBlankRange()

(keeping it for another branch)

@xen-orchestra/fs/src/_mount.js

@@ -97,8 +97,6 @@ export default class MountHandler extends LocalHandler {
       }
     }
 
-    await this._testWriteBlankRange()
-
     // keep an open file on the mount to prevent it from being unmounted if used
     // by another handler/process
     const keeperPath = `${realPath}/.keeper_${Math.random()

@xen-orchestra/fs/src/abstract.js

@@ -333,15 +333,6 @@ export default class RemoteHandlerAbstract {
     await this._write(fdOut, buffer, offsetOut)
   }
 
-  /**
-   * Writes a succession of zero bytes in a file, server side, and with sparse FS support if possible so that it
-   * doesn't take space.
-   *
-   */
-  async writeBlankRange(fd, offset, blankLength) {
-    await this._write(fd, Buffer.alloc(blankLength), offset)
-  }
-
   async readFile(
     file: string,
     { flags = 'r' }: { flags?: string } = {}
@@ -389,8 +380,6 @@ export default class RemoteHandlerAbstract {
 
   async test(): Promise<Object> {
     const SIZE = 1024 * 1024 * 100
-    const HOLE_SIZE = 1024 * 1024 * 2
-    const HOLE_OFFSET = 30
     const now = Date.now()
     const testFileName = normalizePath(`${now}.test`)
     const testFileName2 = normalizePath(`${now}__dup.test`)
@@ -401,16 +390,15 @@ export default class RemoteHandlerAbstract {
       const writeStart = process.hrtime()
       await this._outputFile(testFileName, data, { flags: 'wx' })
       const writeDuration = process.hrtime(writeStart)
+      let cloneDuration
       const fd1 = await this.openFile(testFileName, 'r+')
       try {
-        step = 'punch hole'
-        await this.writeBlankRange(fd1, HOLE_OFFSET, HOLE_SIZE)
         const fd2 = await this.openFile(testFileName2, 'wx')
         try {
           step = 'duplicate'
           const cloneStart = process.hrtime()
           await this.copyFileRange(fd1, 0, fd2, 0, data.byteLength)
-          const cloneDuration = process.hrtime(cloneStart)
+          cloneDuration = process.hrtime(cloneStart)
           console.log('cloneDuration', cloneDuration)
         } finally {
           await this._closeFile(fd2)
@@ -423,8 +411,6 @@ export default class RemoteHandlerAbstract {
       const readStart = process.hrtime()
       const read = await this._readFile(testFileName, { flags: 'r' })
       const readDuration = process.hrtime(readStart)
-      // put the hole in the expected data
-      data.fill(0, HOLE_OFFSET, HOLE_OFFSET + HOLE_SIZE)
       if (!data.equals(read)) {
         throw new Error('output and input did not match')
       }
@@ -437,9 +423,9 @@ export default class RemoteHandlerAbstract {
         success: true,
         writeRate: computeRate(writeDuration, SIZE),
         readRate: computeRate(readDuration, SIZE),
+        cloneDuration: computeRate(cloneDuration, SIZE),
       }
     } catch (error) {
-      console.log('ERROR', error)
       return {
         success: false,
         step,

@xen-orchestra/fs/src/local.js

@@ -28,19 +28,6 @@ function copyFileRangeSyscall(fdIn, offsetIn, fdOut, offsetOut, dataLen, flags =
   return copied
 }
 
-const FALLOC_FL_PUNCH_HOLE = 0x02
-const FALLOC_FL_KEEP_SIZE = 0x01
-const FALLOC_FL_ZERO_RANGE = 0x10
-
-function fAllocateSyscall(fd, mode, offset, length) {
-  // https://man7.org/linux/man-pages/man2/fallocate.2.html
-  const SYS_fallocate = 285
-  const [result, _, errno] = Syscall6(SYS_fallocate, fd, mode, offset, length)
-  if (result === -1) {
-    throw new Error('Error no ' + errno)
-  }
-}
-
 export default class LocalHandler extends RemoteHandlerAbstract {
   constructor(remote: any, options: Object = {}) {
     super(remote, options)
@@ -143,33 +130,6 @@ export default class LocalHandler extends RemoteHandlerAbstract {
     } while (dataLen - copied > 0)
   }
 
-  async writeBlankRange(fd, offset, blankLength) {
-    if (this._canFallocate) {
-      await fAllocateSyscall(fd.fd, FALLOC_FL_ZERO_RANGE, offset, blankLength)
-    } else {
-      await super.writeBlankRange(fd, offset, blankLength)
-    }
-  }
-
-  async _testWriteBlankRange() {
-    const path = this._getFilePath('test_fallocate.test')
-    const fd = await fs.open(path, 'w')
-    try {
-      await fAllocateSyscall(fd, FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE, 0, 6000)
-      console.log('can fallocate')
-      this._canFallocate = true
-    } catch (e) {
-      console.log('cant fallocate', e)
-      this._canFallocate = false
-    } finally {
-      try {
-        await fs.close(fd)
-      } finally {
-        await this.unlink(path)
-      }
-    }
-  }
-
   async _read(file, buffer, position) {
     const needsClose = typeof file === 'string'
     file = needsClose ? await fs.open(this._getFilePath(file), 'r') : file.fd
@@ -204,7 +164,6 @@ export default class LocalHandler extends RemoteHandlerAbstract {
     const path = this._getRealPath('/')
     await fs.ensureDir(path)
     await fs.access(path, fs.R_OK | fs.W_OK)
-    await this._testWriteBlankRange()
   }
 
   _truncate(file, len) {