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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:17:27 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-11 08:17:27 +0000 |
commit | f215e02bf85f68d3a6106c2a1f4f7f063f819064 (patch) | |
tree | 6bb5b92c046312c4e95ac2620b10ddf482d3fa8b /src/VBox/Additions/linux/sharedfolders/utils.c | |
parent | Initial commit. (diff) | |
download | virtualbox-c31cb7e733ae8e33d73383e04db264d4293f0b1a.tar.xz virtualbox-c31cb7e733ae8e33d73383e04db264d4293f0b1a.zip |
Adding upstream version 7.0.14-dfsg.upstream/7.0.14-dfsg
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/VBox/Additions/linux/sharedfolders/utils.c')
-rw-r--r-- | src/VBox/Additions/linux/sharedfolders/utils.c | 1288 |
1 files changed, 1288 insertions, 0 deletions
diff --git a/src/VBox/Additions/linux/sharedfolders/utils.c b/src/VBox/Additions/linux/sharedfolders/utils.c new file mode 100644 index 00000000..b75997a8 --- /dev/null +++ b/src/VBox/Additions/linux/sharedfolders/utils.c @@ -0,0 +1,1288 @@ +/* $Id: utils.c $ */ +/** @file + * vboxsf - VBox Linux Shared Folders VFS, utility functions. + * + * Utility functions (mainly conversion from/to VirtualBox/Linux data structures). + */ + +/* + * Copyright (C) 2006-2023 Oracle and/or its affiliates. + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, + * copy, modify, merge, publish, distribute, sublicense, and/or sell + * copies of the Software, and to permit persons to whom the + * Software is furnished to do so, subject to the following + * conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES + * OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT + * HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, + * WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING + * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR + * OTHER DEALINGS IN THE SOFTWARE. + */ + +#include "vfsmod.h" +#include <iprt/asm.h> +#include <iprt/err.h> +#include <linux/vfs.h> + + +int vbsf_nlscpy(struct vbsf_super_info *pSuperInfo, char *name, size_t name_bound_len, + const unsigned char *utf8_name, size_t utf8_len) +{ + Assert(name_bound_len > 1); + Assert(RTStrNLen(utf8_name, utf8_len) == utf8_len); + + if (pSuperInfo->nls) { + const char *in = utf8_name; + size_t in_bound_len = utf8_len; + char *out = name; + size_t out_bound_len = name_bound_len - 1; + + while (in_bound_len) { +#if RTLNX_VER_MIN(2,6,31) + unicode_t uni; + int cbInEnc = utf8_to_utf32(in, in_bound_len, &uni); +#else + linux_wchar_t uni; + int cbInEnc = utf8_mbtowc(&uni, in, in_bound_len); +#endif + if (cbInEnc >= 0) { + int cbOutEnc = pSuperInfo->nls->uni2char(uni, out, out_bound_len); + if (cbOutEnc >= 0) { + /*SFLOG3(("vbsf_nlscpy: cbOutEnc=%d cbInEnc=%d uni=%#x in_bound_len=%u\n", cbOutEnc, cbInEnc, uni, in_bound_len));*/ + out += cbOutEnc; + out_bound_len -= cbOutEnc; + + in += cbInEnc; + in_bound_len -= cbInEnc; + } else { + SFLOG(("vbsf_nlscpy: nls->uni2char failed with %d on %#x (pos %u in '%s'), out_bound_len=%u\n", + cbOutEnc, uni, in - (const char *)utf8_name, (const char *)utf8_name, (unsigned)out_bound_len)); + return cbOutEnc; + } + } else { + SFLOG(("vbsf_nlscpy: utf8_to_utf32/utf8_mbtowc failed with %d on %x (pos %u in '%s'), in_bound_len=%u!\n", + cbInEnc, *in, in - (const char *)utf8_name, (const char *)utf8_name, (unsigned)in_bound_len)); + return -EINVAL; + } + } + + *out = '\0'; + } else { + if (utf8_len + 1 > name_bound_len) + return -ENAMETOOLONG; + + memcpy(name, utf8_name, utf8_len + 1); + } + return 0; +} + + +/** + * Converts the given NLS string to a host one, kmalloc'ing + * the output buffer (use kfree on result). + */ +int vbsf_nls_to_shflstring(struct vbsf_super_info *pSuperInfo, const char *pszNls, PSHFLSTRING *ppString) +{ + int rc; + size_t const cchNls = strlen(pszNls); + PSHFLSTRING pString = NULL; + if (pSuperInfo->nls) { + /* + * NLS -> UTF-8 w/ SHLF string header. + */ + /* Calc length first: */ + size_t cchUtf8 = 0; + size_t offNls = 0; + while (offNls < cchNls) { + linux_wchar_t uc; /* Note! We renamed the type due to clashes. */ + int const cbNlsCodepoint = pSuperInfo->nls->char2uni(&pszNls[offNls], cchNls - offNls, &uc); + if (cbNlsCodepoint >= 0) { + char achTmp[16]; +#if RTLNX_VER_MIN(2,6,31) + int cbUtf8Codepoint = utf32_to_utf8(uc, achTmp, sizeof(achTmp)); +#else + int cbUtf8Codepoint = utf8_wctomb(achTmp, uc, sizeof(achTmp)); +#endif + if (cbUtf8Codepoint > 0) { + cchUtf8 += cbUtf8Codepoint; + offNls += cbNlsCodepoint; + } else { + Log(("vbsf_nls_to_shflstring: nls->uni2char(%#x) failed: %d\n", uc, cbUtf8Codepoint)); + return -EINVAL; + } + } else { + Log(("vbsf_nls_to_shflstring: nls->char2uni(%.*Rhxs) failed: %d\n", + RT_MIN(8, cchNls - offNls), &pszNls[offNls], cbNlsCodepoint)); + return -EINVAL; + } + } + if (cchUtf8 + 1 < _64K) { + /* Allocate: */ + pString = (PSHFLSTRING)kmalloc(SHFLSTRING_HEADER_SIZE + cchUtf8 + 1, GFP_KERNEL); + if (pString) { + char *pchDst = pString->String.ach; + pString->u16Length = (uint16_t)cchUtf8; + pString->u16Size = (uint16_t)(cchUtf8 + 1); + + /* Do the conversion (cchUtf8 is counted down): */ + rc = 0; + offNls = 0; + while (offNls < cchNls) { + linux_wchar_t uc; /* Note! We renamed the type due to clashes. */ + int const cbNlsCodepoint = pSuperInfo->nls->char2uni(&pszNls[offNls], cchNls - offNls, &uc); + if (cbNlsCodepoint >= 0) { +#if RTLNX_VER_MIN(2,6,31) + int cbUtf8Codepoint = utf32_to_utf8(uc, pchDst, cchUtf8); +#else + int cbUtf8Codepoint = utf8_wctomb(pchDst, uc, cchUtf8); +#endif + if (cbUtf8Codepoint > 0) { + AssertBreakStmt(cbUtf8Codepoint <= cchUtf8, rc = -EINVAL); + cchUtf8 -= cbUtf8Codepoint; + pchDst += cbUtf8Codepoint; + offNls += cbNlsCodepoint; + } else { + Log(("vbsf_nls_to_shflstring: nls->uni2char(%#x) failed! %d, cchUtf8=%zu\n", + uc, cbUtf8Codepoint, cchUtf8)); + rc = -EINVAL; + break; + } + } else { + Log(("vbsf_nls_to_shflstring: nls->char2uni(%.*Rhxs) failed! %d\n", + RT_MIN(8, cchNls - offNls), &pszNls[offNls], cbNlsCodepoint)); + rc = -EINVAL; + break; + } + } + if (rc == 0) { + /* + * Succeeded. Just terminate the string and we're good. + */ + Assert(pchDst - pString->String.ach == pString->u16Length); + *pchDst = '\0'; + } else { + kfree(pString); + pString = NULL; + } + } else { + Log(("vbsf_nls_to_shflstring: failed to allocate %u bytes\n", SHFLSTRING_HEADER_SIZE + cchUtf8 + 1)); + rc = -ENOMEM; + } + } else { + Log(("vbsf_nls_to_shflstring: too long: %zu bytes (%zu nls bytes)\n", cchUtf8, cchNls)); + rc = -ENAMETOOLONG; + } + } else { + /* + * UTF-8 -> UTF-8 w/ SHLF string header. + */ + if (cchNls + 1 < _64K) { + pString = (PSHFLSTRING)kmalloc(SHFLSTRING_HEADER_SIZE + cchNls + 1, GFP_KERNEL); + if (pString) { + pString->u16Length = (uint16_t)cchNls; + pString->u16Size = (uint16_t)(cchNls + 1); + RT_BCOPY_UNFORTIFIED(pString->String.ach, pszNls, cchNls); + pString->String.ach[cchNls] = '\0'; + rc = 0; + } else { + Log(("vbsf_nls_to_shflstring: failed to allocate %u bytes\n", SHFLSTRING_HEADER_SIZE + cchNls + 1)); + rc = -ENOMEM; + } + } else { + Log(("vbsf_nls_to_shflstring: too long: %zu bytes\n", cchNls)); + rc = -ENAMETOOLONG; + } + } + *ppString = pString; + return rc; +} + + +/** + * Convert from VBox to linux time. + */ +#if RTLNX_VER_MAX(2,6,0) +DECLINLINE(void) vbsf_time_to_linux(time_t *pLinuxDst, PCRTTIMESPEC pVBoxSrc) +{ + int64_t t = RTTimeSpecGetNano(pVBoxSrc); + do_div(t, RT_NS_1SEC); + *pLinuxDst = t; +} +#else /* >= 2.6.0 */ +# if RTLNX_VER_MAX(4,18,0) +DECLINLINE(void) vbsf_time_to_linux(struct timespec *pLinuxDst, PCRTTIMESPEC pVBoxSrc) +# else +DECLINLINE(void) vbsf_time_to_linux(struct timespec64 *pLinuxDst, PCRTTIMESPEC pVBoxSrc) +# endif +{ + int64_t t = RTTimeSpecGetNano(pVBoxSrc); + pLinuxDst->tv_nsec = do_div(t, RT_NS_1SEC); + pLinuxDst->tv_sec = t; +} +#endif /* >= 2.6.0 */ + + +/** + * Convert from linux to VBox time. + */ +#if RTLNX_VER_MAX(2,6,0) +DECLINLINE(void) vbsf_time_to_vbox(PRTTIMESPEC pVBoxDst, time_t *pLinuxSrc) +{ + RTTimeSpecSetNano(pVBoxDst, RT_NS_1SEC_64 * *pLinuxSrc); +} +#else /* >= 2.6.0 */ +# if RTLNX_VER_MAX(4,18,0) +DECLINLINE(void) vbsf_time_to_vbox(PRTTIMESPEC pVBoxDst, struct timespec const *pLinuxSrc) +# else +DECLINLINE(void) vbsf_time_to_vbox(PRTTIMESPEC pVBoxDst, struct timespec64 const *pLinuxSrc) +# endif +{ + RTTimeSpecSetNano(pVBoxDst, pLinuxSrc->tv_nsec + pLinuxSrc->tv_sec * (int64_t)RT_NS_1SEC); +} +#endif /* >= 2.6.0 */ + + +/** + * Converts VBox access permissions to Linux ones (mode & 0777). + * + * @note Currently identical. + * @sa sf_access_permissions_to_vbox + */ +DECLINLINE(int) sf_access_permissions_to_linux(uint32_t fAttr) +{ + /* Access bits should be the same: */ + AssertCompile(RTFS_UNIX_IRUSR == S_IRUSR); + AssertCompile(RTFS_UNIX_IWUSR == S_IWUSR); + AssertCompile(RTFS_UNIX_IXUSR == S_IXUSR); + AssertCompile(RTFS_UNIX_IRGRP == S_IRGRP); + AssertCompile(RTFS_UNIX_IWGRP == S_IWGRP); + AssertCompile(RTFS_UNIX_IXGRP == S_IXGRP); + AssertCompile(RTFS_UNIX_IROTH == S_IROTH); + AssertCompile(RTFS_UNIX_IWOTH == S_IWOTH); + AssertCompile(RTFS_UNIX_IXOTH == S_IXOTH); + + return fAttr & RTFS_UNIX_ALL_ACCESS_PERMS; +} + + +/** + * Produce the Linux mode mask, given VBox, mount options and file type. + */ +DECLINLINE(int) sf_file_mode_to_linux(uint32_t fVBoxMode, int fFixedMode, int fClearMask, int fType) +{ + int fLnxMode = sf_access_permissions_to_linux(fVBoxMode); + if (fFixedMode != ~0) + fLnxMode = fFixedMode & 0777; + fLnxMode &= ~fClearMask; + fLnxMode |= fType; + return fLnxMode; +} + +/** + * Update inode timestamps. + * + * @param pInode Linux inode object. + * @param pObjInfo VBox vboxsf object. + */ +static void vbsf_update_inode_timestamps(struct inode *pInode, PSHFLFSOBJINFO pObjInfo) +{ +#if RTLNX_VER_MIN(6,6,0) + struct timespec64 ts; + vbsf_time_to_linux(&ts, &pObjInfo->ChangeTime); + inode_set_ctime_to_ts(pInode, ts); +#else + vbsf_time_to_linux(&pInode->i_atime, &pObjInfo->AccessTime); + vbsf_time_to_linux(&pInode->i_ctime, &pObjInfo->ChangeTime); + vbsf_time_to_linux(&pInode->i_mtime, &pObjInfo->ModificationTime); +#endif +} + +/** + * Initializes the @a inode attributes based on @a pObjInfo and @a pSuperInfo + * options. + */ +void vbsf_init_inode(struct inode *inode, struct vbsf_inode_info *sf_i, PSHFLFSOBJINFO pObjInfo, + struct vbsf_super_info *pSuperInfo) +{ + PCSHFLFSOBJATTR pAttr = &pObjInfo->Attr; + + TRACE(); + + sf_i->ts_up_to_date = jiffies; + sf_i->force_restat = 0; + + if (RTFS_IS_DIRECTORY(pAttr->fMode)) { + inode->i_mode = sf_file_mode_to_linux(pAttr->fMode, pSuperInfo->dmode, pSuperInfo->dmask, S_IFDIR); + inode->i_op = &vbsf_dir_iops; + inode->i_fop = &vbsf_dir_fops; + + /* XXX: this probably should be set to the number of entries + in the directory plus two (. ..) */ + set_nlink(inode, 1); + } + else if (RTFS_IS_SYMLINK(pAttr->fMode)) { + /** @todo r=bird: Aren't System V symlinks w/o any mode mask? IIRC there is + * no lchmod on Linux. */ + inode->i_mode = sf_file_mode_to_linux(pAttr->fMode, pSuperInfo->fmode, pSuperInfo->fmask, S_IFLNK); + inode->i_op = &vbsf_lnk_iops; + set_nlink(inode, 1); + } else { + inode->i_mode = sf_file_mode_to_linux(pAttr->fMode, pSuperInfo->fmode, pSuperInfo->fmask, S_IFREG); + inode->i_op = &vbsf_reg_iops; + inode->i_fop = &vbsf_reg_fops; + inode->i_mapping->a_ops = &vbsf_reg_aops; +#if RTLNX_VER_RANGE(2,5,17, 4,0,0) + inode->i_mapping->backing_dev_info = &pSuperInfo->bdi; /* This is needed for mmap. */ +#endif + set_nlink(inode, 1); + } + +#if RTLNX_VER_MIN(3,5,0) + inode->i_uid = make_kuid(current_user_ns(), pSuperInfo->uid); + inode->i_gid = make_kgid(current_user_ns(), pSuperInfo->gid); +#else + inode->i_uid = pSuperInfo->uid; + inode->i_gid = pSuperInfo->gid; +#endif + + inode->i_size = pObjInfo->cbObject; +#if RTLNX_VER_MAX(2,6,19) && !defined(KERNEL_FC6) + inode->i_blksize = 4096; +#endif +#if RTLNX_VER_MIN(2,4,11) + inode->i_blkbits = 12; +#endif + /* i_blocks always in units of 512 bytes! */ + inode->i_blocks = (pObjInfo->cbAllocated + 511) / 512; + + vbsf_update_inode_timestamps(inode, pObjInfo); + + sf_i->BirthTime = pObjInfo->BirthTime; + sf_i->ModificationTime = pObjInfo->ModificationTime; + RTTimeSpecSetSeconds(&sf_i->ModificationTimeAtOurLastWrite, 0); +} + + +/** + * Update the inode with new object info from the host. + * + * Called by sf_inode_revalidate() and sf_inode_revalidate_with_handle(). + */ +void vbsf_update_inode(struct inode *pInode, struct vbsf_inode_info *pInodeInfo, PSHFLFSOBJINFO pObjInfo, + struct vbsf_super_info *pSuperInfo, bool fInodeLocked, unsigned fSetAttrs) +{ + PCSHFLFSOBJATTR pAttr = &pObjInfo->Attr; + int fMode; + + TRACE(); + +#if RTLNX_VER_MIN(4,5,0) + if (!fInodeLocked) + inode_lock(pInode); +#endif + + /* + * Calc new mode mask and update it if it changed. + */ + if (RTFS_IS_DIRECTORY(pAttr->fMode)) + fMode = sf_file_mode_to_linux(pAttr->fMode, pSuperInfo->dmode, pSuperInfo->dmask, S_IFDIR); + else if (RTFS_IS_SYMLINK(pAttr->fMode)) + /** @todo r=bird: Aren't System V symlinks w/o any mode mask? IIRC there is + * no lchmod on Linux. */ + fMode = sf_file_mode_to_linux(pAttr->fMode, pSuperInfo->fmode, pSuperInfo->fmask, S_IFLNK); + else + fMode = sf_file_mode_to_linux(pAttr->fMode, pSuperInfo->fmode, pSuperInfo->fmask, S_IFREG); + + if (fMode == pInode->i_mode) { + /* likely */ + } else { + if ((fMode & S_IFMT) == (pInode->i_mode & S_IFMT)) + pInode->i_mode = fMode; + else { + SFLOGFLOW(("vbsf_update_inode: Changed from %o to %o (%s)\n", + pInode->i_mode & S_IFMT, fMode & S_IFMT, pInodeInfo->path->String.ach)); + /** @todo we probably need to be more drastic... */ + vbsf_init_inode(pInode, pInodeInfo, pObjInfo, pSuperInfo); + +#if RTLNX_VER_MIN(4,5,0) + if (!fInodeLocked) + inode_unlock(pInode); +#endif + return; + } + } + + /* + * Update the sizes. + * Note! i_blocks is always in units of 512 bytes! + */ + pInode->i_blocks = (pObjInfo->cbAllocated + 511) / 512; + i_size_write(pInode, pObjInfo->cbObject); + + /* + * Update the timestamps. + */ + vbsf_update_inode_timestamps(pInode, pObjInfo); + pInodeInfo->BirthTime = pObjInfo->BirthTime; + + /* + * Mark it as up to date. + * Best to do this before we start with any expensive map invalidation. + */ + pInodeInfo->ts_up_to_date = jiffies; + pInodeInfo->force_restat = 0; + + /* + * If the modification time changed, we may have to invalidate the page + * cache pages associated with this inode if we suspect the change was + * made by the host. How supicious we are depends on the cache mode. + * + * Note! The invalidate_inode_pages() call is pretty weak. It will _not_ + * touch pages that are already mapped into an address space, but it + * will help if the file isn't currently mmap'ed or if we're in read + * or read/write caching mode. + */ + if (!RTTimeSpecIsEqual(&pInodeInfo->ModificationTime, &pObjInfo->ModificationTime)) { + if (RTFS_IS_FILE(pAttr->fMode)) { + if (!(fSetAttrs & (ATTR_MTIME | ATTR_SIZE))) { + bool fInvalidate; + if (pSuperInfo->enmCacheMode == kVbsfCacheMode_None) { + fInvalidate = true; /* No-caching: always invalidate. */ + } else { + if (RTTimeSpecIsEqual(&pInodeInfo->ModificationTimeAtOurLastWrite, &pInodeInfo->ModificationTime)) { + fInvalidate = false; /* Could be our write, so don't invalidate anything */ + RTTimeSpecSetSeconds(&pInodeInfo->ModificationTimeAtOurLastWrite, 0); + } else { + /*RTLogBackdoorPrintf("vbsf_update_inode: Invalidating the mapping %s - %RU64 vs %RU64 vs %RU64 - %#x\n", + pInodeInfo->path->String.ach, + RTTimeSpecGetNano(&pInodeInfo->ModificationTimeAtOurLastWrite), + RTTimeSpecGetNano(&pInodeInfo->ModificationTime), + RTTimeSpecGetNano(&pObjInfo->ModificationTime), fSetAttrs);*/ + fInvalidate = true; /* We haven't modified the file recently, so probably a host update. */ + } + } + pInodeInfo->ModificationTime = pObjInfo->ModificationTime; + + if (fInvalidate) { + struct address_space *mapping = pInode->i_mapping; + if (mapping && mapping->nrpages > 0) { + SFLOGFLOW(("vbsf_update_inode: Invalidating the mapping %s (%#x)\n", pInodeInfo->path->String.ach, fSetAttrs)); +#if RTLNX_VER_MIN(2,6,34) + invalidate_mapping_pages(mapping, 0, ~(pgoff_t)0); +#elif RTLNX_VER_MIN(2,5,41) + invalidate_inode_pages(mapping); +#else + invalidate_inode_pages(pInode); +#endif + } + } + } else { + RTTimeSpecSetSeconds(&pInodeInfo->ModificationTimeAtOurLastWrite, 0); + pInodeInfo->ModificationTime = pObjInfo->ModificationTime; + } + } else + pInodeInfo->ModificationTime = pObjInfo->ModificationTime; + } + + /* + * Done. + */ +#if RTLNX_VER_MIN(4,5,0) + if (!fInodeLocked) + inode_unlock(pInode); +#endif +} + + +/** @note Currently only used for the root directory during (re-)mount. */ +int vbsf_stat(const char *caller, struct vbsf_super_info *pSuperInfo, SHFLSTRING *path, PSHFLFSOBJINFO result, int ok_to_fail) +{ + int rc; + VBOXSFCREATEREQ *pReq; + NOREF(caller); + + TRACE(); + + pReq = (VBOXSFCREATEREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq) + path->u16Size); + if (pReq) { + RT_ZERO(*pReq); + RT_BCOPY_UNFORTIFIED(&pReq->StrPath, path, SHFLSTRING_HEADER_SIZE + path->u16Size); + pReq->CreateParms.Handle = SHFL_HANDLE_NIL; + pReq->CreateParms.CreateFlags = SHFL_CF_LOOKUP | SHFL_CF_ACT_FAIL_IF_NEW; + + LogFunc(("Calling VbglR0SfHostReqCreate on %s\n", path->String.utf8)); + rc = VbglR0SfHostReqCreate(pSuperInfo->map.root, pReq); + if (RT_SUCCESS(rc)) { + if (pReq->CreateParms.Result == SHFL_FILE_EXISTS) { + *result = pReq->CreateParms.Info; + rc = 0; + } else { + if (!ok_to_fail) + LogFunc(("VbglR0SfHostReqCreate on %s: file does not exist: %d (caller=%s)\n", + path->String.utf8, pReq->CreateParms.Result, caller)); + rc = -ENOENT; + } + } else if (rc == VERR_INVALID_NAME) { + rc = -ENOENT; /* this can happen for names like 'foo*' on a Windows host */ + } else { + LogFunc(("VbglR0SfHostReqCreate failed on %s: %Rrc (caller=%s)\n", path->String.utf8, rc, caller)); + rc = -EPROTO; + } + VbglR0PhysHeapFree(pReq); + } + else + rc = -ENOMEM; + return rc; +} + + +/** + * Revalidate an inode, inner worker. + * + * @sa sf_inode_revalidate() + */ +int vbsf_inode_revalidate_worker(struct dentry *dentry, bool fForced, bool fInodeLocked) +{ + int rc; + struct inode *pInode = dentry ? dentry->d_inode : NULL; + if (pInode) { + struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(pInode); + struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(pInode->i_sb); + AssertReturn(sf_i, -EINVAL); + AssertReturn(pSuperInfo, -EINVAL); + + /* + * Can we get away without any action here? + */ + if ( !fForced + && !sf_i->force_restat + && jiffies - sf_i->ts_up_to_date < pSuperInfo->cJiffiesInodeTTL) + rc = 0; + else { + /* + * No, we have to query the file info from the host. + * Try get a handle we can query, any kind of handle will do here. + */ + struct vbsf_handle *pHandle = vbsf_handle_find(sf_i, 0, 0); + if (pHandle) { + /* Query thru pHandle. */ + VBOXSFOBJINFOREQ *pReq = (VBOXSFOBJINFOREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq)); + if (pReq) { + RT_ZERO(*pReq); + rc = VbglR0SfHostReqQueryObjInfo(pSuperInfo->map.root, pReq, pHandle->hHost); + if (RT_SUCCESS(rc)) { + /* + * Reset the TTL and copy the info over into the inode structure. + */ + vbsf_update_inode(pInode, sf_i, &pReq->ObjInfo, pSuperInfo, fInodeLocked, 0 /*fSetAttrs*/); + } else if (rc == VERR_INVALID_HANDLE) { + rc = -ENOENT; /* Restore.*/ + } else { + LogFunc(("VbglR0SfHostReqQueryObjInfo failed on %#RX64: %Rrc\n", pHandle->hHost, rc)); + rc = -RTErrConvertToErrno(rc); + } + VbglR0PhysHeapFree(pReq); + } else + rc = -ENOMEM; + vbsf_handle_release(pHandle, pSuperInfo, "vbsf_inode_revalidate_worker"); + + } else { + /* Query via path. */ + SHFLSTRING *pPath = sf_i->path; + VBOXSFCREATEREQ *pReq = (VBOXSFCREATEREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq) + pPath->u16Size); + if (pReq) { + RT_ZERO(*pReq); + RT_BCOPY_UNFORTIFIED(&pReq->StrPath, pPath, SHFLSTRING_HEADER_SIZE + pPath->u16Size); + pReq->CreateParms.Handle = SHFL_HANDLE_NIL; + pReq->CreateParms.CreateFlags = SHFL_CF_LOOKUP | SHFL_CF_ACT_FAIL_IF_NEW; + + rc = VbglR0SfHostReqCreate(pSuperInfo->map.root, pReq); + if (RT_SUCCESS(rc)) { + if (pReq->CreateParms.Result == SHFL_FILE_EXISTS) { + /* + * Reset the TTL and copy the info over into the inode structure. + */ + vbsf_update_inode(pInode, sf_i, &pReq->CreateParms.Info, pSuperInfo, fInodeLocked, 0 /*fSetAttrs*/); + rc = 0; + } else { + rc = -ENOENT; + } + } else if (rc == VERR_INVALID_NAME) { + rc = -ENOENT; /* this can happen for names like 'foo*' on a Windows host */ + } else { + LogFunc(("VbglR0SfHostReqCreate failed on %s: %Rrc\n", pPath->String.ach, rc)); + rc = -EPROTO; + } + VbglR0PhysHeapFree(pReq); + } + else + rc = -ENOMEM; + } + } + } else { + LogFunc(("no dentry(%p) or inode(%p)\n", dentry, pInode)); + rc = -EINVAL; + } + return rc; +} + + +#if RTLNX_VER_MAX(2,5,18) +/** + * Revalidate an inode for 2.4. + * + * This is called in the stat(), lstat() and readlink() code paths. In the stat + * cases the caller will use the result afterwards to produce the stat data. + * + * @note 2.4.x has a getattr() inode operation too, but it is not used. + */ +int vbsf_inode_revalidate(struct dentry *dentry) +{ + /* + * We pretend the inode is locked here, as 2.4.x does not have inode level locking. + */ + return vbsf_inode_revalidate_worker(dentry, false /*fForced*/, true /*fInodeLocked*/); +} +#endif /* < 2.5.18 */ + + +/** + * Similar to sf_inode_revalidate, but uses associated host file handle as that + * is quite a bit faster. + */ +int vbsf_inode_revalidate_with_handle(struct dentry *dentry, SHFLHANDLE hHostFile, bool fForced, bool fInodeLocked) +{ + int err; + struct inode *pInode = dentry ? dentry->d_inode : NULL; + if (!pInode) { + LogFunc(("no dentry(%p) or inode(%p)\n", dentry, pInode)); + err = -EINVAL; + } else { + struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(pInode); + struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(pInode->i_sb); + AssertReturn(sf_i, -EINVAL); + AssertReturn(pSuperInfo, -EINVAL); + + /* + * Can we get away without any action here? + */ + if ( !fForced + && !sf_i->force_restat + && jiffies - sf_i->ts_up_to_date < pSuperInfo->cJiffiesInodeTTL) + err = 0; + else { + /* + * No, we have to query the file info from the host. + */ + VBOXSFOBJINFOREQ *pReq = (VBOXSFOBJINFOREQ *)VbglR0PhysHeapAlloc(sizeof(*pReq)); + if (pReq) { + RT_ZERO(*pReq); + err = VbglR0SfHostReqQueryObjInfo(pSuperInfo->map.root, pReq, hHostFile); + if (RT_SUCCESS(err)) { + /* + * Reset the TTL and copy the info over into the inode structure. + */ + vbsf_update_inode(pInode, sf_i, &pReq->ObjInfo, pSuperInfo, fInodeLocked, 0 /*fSetAttrs*/); + } else { + LogFunc(("VbglR0SfHostReqQueryObjInfo failed on %#RX64: %Rrc\n", hHostFile, err)); + err = -RTErrConvertToErrno(err); + } + VbglR0PhysHeapFree(pReq); + } else + err = -ENOMEM; + } + } + return err; +} + + +/* on 2.6 this is a proxy for [sf_inode_revalidate] which (as a side + effect) updates inode attributes for [dentry] (given that [dentry] + has inode at all) from these new attributes we derive [kstat] via + [generic_fillattr] */ +#if RTLNX_VER_MIN(2,5,18) +# if RTLNX_VER_MIN(6,3,0) +int vbsf_inode_getattr(struct mnt_idmap *idmap, const struct path *path, + struct kstat *kstat, u32 request_mask, unsigned int flags) +# elif RTLNX_VER_MIN(5,12,0) +int vbsf_inode_getattr(struct user_namespace *ns, const struct path *path, + struct kstat *kstat, u32 request_mask, unsigned int flags) +# elif RTLNX_VER_MIN(4,11,0) +int vbsf_inode_getattr(const struct path *path, struct kstat *kstat, u32 request_mask, unsigned int flags) +# else +int vbsf_inode_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *kstat) +# endif +{ + int rc; +# if RTLNX_VER_MIN(4,11,0) + struct dentry *dentry = path->dentry; +# endif + +# if RTLNX_VER_MIN(4,11,0) + SFLOGFLOW(("vbsf_inode_getattr: dentry=%p request_mask=%#x flags=%#x\n", dentry, request_mask, flags)); +# else + SFLOGFLOW(("vbsf_inode_getattr: dentry=%p\n", dentry)); +# endif + +# if RTLNX_VER_MIN(4,11,0) + /* + * With the introduction of statx() userland can control whether we + * update the inode information or not. + */ + switch (flags & AT_STATX_SYNC_TYPE) { + default: + rc = vbsf_inode_revalidate_worker(dentry, false /*fForced*/, false /*fInodeLocked*/); + break; + + case AT_STATX_FORCE_SYNC: + rc = vbsf_inode_revalidate_worker(dentry, true /*fForced*/, false /*fInodeLocked*/); + break; + + case AT_STATX_DONT_SYNC: + rc = 0; + break; + } +# else + rc = vbsf_inode_revalidate_worker(dentry, false /*fForced*/, false /*fInodeLocked*/); +# endif + if (rc == 0) { + /* Do generic filling in of info. */ +# if RTLNX_VER_MIN(6,6,0) + generic_fillattr(idmap, request_mask, dentry->d_inode, kstat); +# elif RTLNX_VER_MIN(6,3,0) + generic_fillattr(idmap, dentry->d_inode, kstat); +# elif RTLNX_VER_MIN(5,12,0) + generic_fillattr(ns, dentry->d_inode, kstat); +# else + generic_fillattr(dentry->d_inode, kstat); +# endif + + /* Add birth time. */ +# if RTLNX_VER_MIN(4,11,0) + if (dentry->d_inode) { + struct vbsf_inode_info *pInodeInfo = VBSF_GET_INODE_INFO(dentry->d_inode); + if (pInodeInfo) { + vbsf_time_to_linux(&kstat->btime, &pInodeInfo->BirthTime); + kstat->result_mask |= STATX_BTIME; + } + } +# endif + + /* + * FsPerf shows the following numbers for sequential file access against + * a tmpfs folder on an AMD 1950X host running debian buster/sid: + * + * block size = r128600 ----- r128755 ----- + * reads reads writes + * 4096 KB = 2254 MB/s 4953 MB/s 3668 MB/s + * 2048 KB = 2368 MB/s 4908 MB/s 3541 MB/s + * 1024 KB = 2208 MB/s 4011 MB/s 3291 MB/s + * 512 KB = 1908 MB/s 3399 MB/s 2721 MB/s + * 256 KB = 1625 MB/s 2679 MB/s 2251 MB/s + * 128 KB = 1413 MB/s 1967 MB/s 1684 MB/s + * 64 KB = 1152 MB/s 1409 MB/s 1265 MB/s + * 32 KB = 726 MB/s 815 MB/s 783 MB/s + * 16 KB = 683 MB/s 475 MB/s + * 8 KB = 294 MB/s 286 MB/s + * 4 KB = 145 MB/s 156 MB/s 149 MB/s + * + */ + if (S_ISREG(kstat->mode)) + kstat->blksize = _1M; + else if (S_ISDIR(kstat->mode)) + /** @todo this may need more tuning after we rewrite the directory handling. */ + kstat->blksize = _16K; + } + return rc; +} +#endif /* >= 2.5.18 */ + + +/** + * Modify inode attributes. + */ +#if RTLNX_VER_MIN(6,3,0) +int vbsf_inode_setattr(struct mnt_idmap *idmap, struct dentry *dentry, struct iattr *iattr) +#elif RTLNX_VER_MIN(5,12,0) +int vbsf_inode_setattr(struct user_namespace *ns, struct dentry *dentry, struct iattr *iattr) +#else +int vbsf_inode_setattr(struct dentry *dentry, struct iattr *iattr) +#endif +{ + struct inode *pInode = dentry->d_inode; + struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(pInode->i_sb); + struct vbsf_inode_info *sf_i = VBSF_GET_INODE_INFO(pInode); + int vrc; + int rc; + + SFLOGFLOW(("vbsf_inode_setattr: dentry=%p inode=%p ia_valid=%#x %s\n", + dentry, pInode, iattr->ia_valid, sf_i ? sf_i->path->String.ach : NULL)); + AssertReturn(sf_i, -EINVAL); + + /* + * Do minimal attribute permission checks. We set ATTR_FORCE since we cannot + * preserve ownership and such and would end up with EPERM here more often than + * we would like. For instance it would cause 'cp' to complain about EPERM + * from futimes() when asked to preserve times, see ticketref:18569. + */ + iattr->ia_valid |= ATTR_FORCE; +#if (RTLNX_VER_RANGE(3,16,39, 3,17,0)) || RTLNX_VER_MIN(4,9,0) || (RTLNX_VER_RANGE(4,1,37, 4,2,0)) || RTLNX_UBUNTU_ABI_MIN(4,4,255,208) +# if RTLNX_VER_MIN(6,3,0) + rc = setattr_prepare(idmap, dentry, iattr); +# elif RTLNX_VER_MIN(5,12,0) + rc = setattr_prepare(ns, dentry, iattr); +# else + rc = setattr_prepare(dentry, iattr); +# endif +#else + rc = inode_change_ok(pInode, iattr); +#endif + if (rc == 0) { + /* + * Don't modify MTIME and CTIME for open(O_TRUNC) and ftruncate, those + * operations will set those timestamps automatically. Saves a host call. + */ + unsigned fAttrs = iattr->ia_valid; +#if RTLNX_VER_MIN(2,6,15) + fAttrs &= ~ATTR_FILE; +#endif + if ( fAttrs == (ATTR_SIZE | ATTR_MTIME | ATTR_CTIME) +#if RTLNX_VER_MIN(2,6,24) + || (fAttrs & (ATTR_OPEN | ATTR_SIZE)) == (ATTR_OPEN | ATTR_SIZE) +#endif + ) + fAttrs &= ~(ATTR_MTIME | ATTR_CTIME); + + /* + * We only implement a handful of attributes, so ignore any attempts + * at setting bits we don't support. + */ + if (fAttrs & (ATTR_MODE | ATTR_ATIME | ATTR_MTIME | ATTR_CTIME | ATTR_SIZE)) { + /* + * Try find a handle which allows us to modify the attributes, otherwise + * open the file/dir/whatever. + */ + union SetAttrReqs + { + VBOXSFCREATEREQ Create; + VBOXSFOBJINFOREQ Info; + VBOXSFSETFILESIZEREQ SetSize; + VBOXSFCLOSEREQ Close; + } *pReq; + size_t cbReq; + SHFLHANDLE hHostFile; + /** @todo ATTR_FILE (2.6.15+) could be helpful here if we like. */ + struct vbsf_handle *pHandle = fAttrs & ATTR_SIZE + ? vbsf_handle_find(sf_i, VBSF_HANDLE_F_WRITE, 0) + : vbsf_handle_find(sf_i, 0, 0); + if (pHandle) { + hHostFile = pHandle->hHost; + cbReq = RT_MAX(sizeof(VBOXSFOBJINFOREQ), sizeof(VBOXSFSETFILESIZEREQ)); + pReq = (union SetAttrReqs *)VbglR0PhysHeapAlloc(cbReq); + if (pReq) { + /* likely */ + } else + rc = -ENOMEM; + } else { + hHostFile = SHFL_HANDLE_NIL; + cbReq = RT_MAX(sizeof(pReq->Info), sizeof(pReq->Create) + SHFLSTRING_HEADER_SIZE + sf_i->path->u16Size); + pReq = (union SetAttrReqs *)VbglR0PhysHeapAlloc(cbReq); + if (pReq) { + RT_ZERO(pReq->Create.CreateParms); + pReq->Create.CreateParms.Handle = SHFL_HANDLE_NIL; + pReq->Create.CreateParms.CreateFlags = SHFL_CF_ACT_OPEN_IF_EXISTS + | SHFL_CF_ACT_FAIL_IF_NEW + | SHFL_CF_ACCESS_ATTR_WRITE; + if (fAttrs & ATTR_SIZE) + pReq->Create.CreateParms.CreateFlags |= SHFL_CF_ACCESS_WRITE; + RT_BCOPY_UNFORTIFIED(&pReq->Create.StrPath, sf_i->path, SHFLSTRING_HEADER_SIZE + sf_i->path->u16Size); + vrc = VbglR0SfHostReqCreate(pSuperInfo->map.root, &pReq->Create); + if (RT_SUCCESS(vrc)) { + if (pReq->Create.CreateParms.Result == SHFL_FILE_EXISTS) { + hHostFile = pReq->Create.CreateParms.Handle; + Assert(hHostFile != SHFL_HANDLE_NIL); + vbsf_dentry_chain_increase_ttl(dentry); + } else { + LogFunc(("file %s does not exist\n", sf_i->path->String.utf8)); + vbsf_dentry_invalidate_ttl(dentry); + sf_i->force_restat = true; + rc = -ENOENT; + } + } else { + rc = -RTErrConvertToErrno(vrc); + LogFunc(("VbglR0SfCreate(%s) failed vrc=%Rrc rc=%d\n", sf_i->path->String.ach, vrc, rc)); + } + } else + rc = -ENOMEM; + } + if (rc == 0) { + /* + * Set mode and/or timestamps. + */ + if (fAttrs & (ATTR_MODE | ATTR_ATIME | ATTR_MTIME | ATTR_CTIME)) { + /* Fill in the attributes. Start by setting all to zero + since the host will ignore zeroed fields. */ + RT_ZERO(pReq->Info.ObjInfo); + + if (fAttrs & ATTR_MODE) { + pReq->Info.ObjInfo.Attr.fMode = sf_access_permissions_to_vbox(iattr->ia_mode); + if (iattr->ia_mode & S_IFDIR) + pReq->Info.ObjInfo.Attr.fMode |= RTFS_TYPE_DIRECTORY; + else if (iattr->ia_mode & S_IFLNK) + pReq->Info.ObjInfo.Attr.fMode |= RTFS_TYPE_SYMLINK; + else + pReq->Info.ObjInfo.Attr.fMode |= RTFS_TYPE_FILE; + } + if (fAttrs & ATTR_ATIME) + vbsf_time_to_vbox(&pReq->Info.ObjInfo.AccessTime, &iattr->ia_atime); + if (fAttrs & ATTR_MTIME) + vbsf_time_to_vbox(&pReq->Info.ObjInfo.ModificationTime, &iattr->ia_mtime); + if (fAttrs & ATTR_CTIME) + vbsf_time_to_vbox(&pReq->Info.ObjInfo.ChangeTime, &iattr->ia_ctime); + + /* Make the change. */ + vrc = VbglR0SfHostReqSetObjInfo(pSuperInfo->map.root, &pReq->Info, hHostFile); + if (RT_SUCCESS(vrc)) { + vbsf_update_inode(pInode, sf_i, &pReq->Info.ObjInfo, pSuperInfo, true /*fLocked*/, fAttrs); + } else { + rc = -RTErrConvertToErrno(vrc); + LogFunc(("VbglR0SfHostReqSetObjInfo(%s) failed vrc=%Rrc rc=%d\n", sf_i->path->String.ach, vrc, rc)); + } + } + + /* + * Change the file size. + * Note! Old API is more convenient here as it gives us up to date + * inode info back. + */ + if ((fAttrs & ATTR_SIZE) && rc == 0) { + /*vrc = VbglR0SfHostReqSetFileSize(pSuperInfo->map.root, &pReq->SetSize, hHostFile, iattr->ia_size); + if (RT_SUCCESS(vrc)) { + i_size_write(pInode, iattr->ia_size); + } else if (vrc == VERR_NOT_IMPLEMENTED)*/ { + /* Fallback for pre 6.0 hosts: */ + RT_ZERO(pReq->Info.ObjInfo); + pReq->Info.ObjInfo.cbObject = iattr->ia_size; + vrc = VbglR0SfHostReqSetFileSizeOld(pSuperInfo->map.root, &pReq->Info, hHostFile); + if (RT_SUCCESS(vrc)) + vbsf_update_inode(pInode, sf_i, &pReq->Info.ObjInfo, pSuperInfo, true /*fLocked*/, fAttrs); + } + if (RT_SUCCESS(vrc)) { + /** @todo there is potentially more to be done here if there are mappings of + * the lovely file. */ + } else { + rc = -RTErrConvertToErrno(vrc); + LogFunc(("VbglR0SfHostReqSetFileSize(%s, %#llx) failed vrc=%Rrc rc=%d\n", + sf_i->path->String.ach, (unsigned long long)iattr->ia_size, vrc, rc)); + } + } + + /* + * Clean up. + */ + if (!pHandle) { + vrc = VbglR0SfHostReqClose(pSuperInfo->map.root, &pReq->Close, hHostFile); + if (RT_FAILURE(vrc)) + LogFunc(("VbglR0SfHostReqClose(%s [%#llx]) failed vrc=%Rrc\n", sf_i->path->String.utf8, hHostFile, vrc)); + } + } + if (pReq) + VbglR0PhysHeapFree(pReq); + if (pHandle) + vbsf_handle_release(pHandle, pSuperInfo, "vbsf_inode_setattr"); + } else + SFLOGFLOW(("vbsf_inode_setattr: Nothing to do here: %#x (was %#x).\n", fAttrs, iattr->ia_valid)); + } + return rc; +} + + +static int vbsf_make_path(const char *caller, struct vbsf_inode_info *sf_i, + const char *d_name, size_t d_len, SHFLSTRING **result) +{ + size_t path_len, shflstring_len; + SHFLSTRING *tmp; + uint16_t p_len; + uint8_t *p_name; + int fRoot = 0; + + TRACE(); + p_len = sf_i->path->u16Length; + p_name = sf_i->path->String.utf8; + + if (p_len == 1 && *p_name == '/') { + path_len = d_len + 1; + fRoot = 1; + } else { + /* lengths of constituents plus terminating zero plus slash */ + path_len = p_len + d_len + 2; + if (path_len > 0xffff) { + LogFunc(("path too long. caller=%s, path_len=%zu\n", + caller, path_len)); + return -ENAMETOOLONG; + } + } + + shflstring_len = offsetof(SHFLSTRING, String.utf8) + path_len; + tmp = kmalloc(shflstring_len, GFP_KERNEL); + if (!tmp) { + LogRelFunc(("kmalloc failed, caller=%s\n", caller)); + return -ENOMEM; + } + tmp->u16Length = path_len - 1; + tmp->u16Size = path_len; + + if (fRoot) + RT_BCOPY_UNFORTIFIED(&tmp->String.utf8[0], d_name, d_len + 1); + else { + RT_BCOPY_UNFORTIFIED(&tmp->String.utf8[0], p_name, p_len); + tmp->String.utf8[p_len] = '/'; + RT_BCOPY_UNFORTIFIED(&tmp->String.utf8[p_len + 1], d_name, d_len); + tmp->String.utf8[p_len + 1 + d_len] = '\0'; + } + + *result = tmp; + return 0; +} + + +/** + * [dentry] contains string encoded in coding system that corresponds + * to [pSuperInfo]->nls, we must convert it to UTF8 here and pass down to + * [vbsf_make_path] which will allocate SHFLSTRING and fill it in + */ +int vbsf_path_from_dentry(struct vbsf_super_info *pSuperInfo, struct vbsf_inode_info *sf_i, struct dentry *dentry, + SHFLSTRING **result, const char *caller) +{ + int err; + const char *d_name; + size_t d_len; + const char *name; + size_t len = 0; + + TRACE(); + d_name = dentry->d_name.name; + d_len = dentry->d_name.len; + + if (pSuperInfo->nls) { + size_t in_len, i, out_bound_len; + const char *in; + char *out; + + in = d_name; + in_len = d_len; + + out_bound_len = PATH_MAX; + out = kmalloc(out_bound_len, GFP_KERNEL); + name = out; + + for (i = 0; i < d_len; ++i) { + /* We renamed the linux kernel wchar_t type to linux_wchar_t in + the-linux-kernel.h, as it conflicts with the C++ type of that name. */ + linux_wchar_t uni; + int nb; + + nb = pSuperInfo->nls->char2uni(in, in_len, &uni); + if (nb < 0) { + LogFunc(("nls->char2uni failed %x %d\n", + *in, in_len)); + err = -EINVAL; + goto fail1; + } + in_len -= nb; + in += nb; + +#if RTLNX_VER_MIN(2,6,31) + nb = utf32_to_utf8(uni, out, out_bound_len); +#else + nb = utf8_wctomb(out, uni, out_bound_len); +#endif + if (nb < 0) { + LogFunc(("nls->uni2char failed %x %d\n", + uni, out_bound_len)); + err = -EINVAL; + goto fail1; + } + out_bound_len -= nb; + out += nb; + len += nb; + } + if (len >= PATH_MAX - 1) { + err = -ENAMETOOLONG; + goto fail1; + } + + LogFunc(("result(%d) = %.*s\n", len, len, name)); + *out = 0; + } else { + name = d_name; + len = d_len; + } + + err = vbsf_make_path(caller, sf_i, name, len, result); + if (name != d_name) + kfree(name); + + return err; + + fail1: + kfree(name); + return err; +} + + +/** + * This is called during name resolution/lookup to check if the @a dentry in the + * cache is still valid. The actual validation is job is handled by + * vbsf_inode_revalidate_worker(). + * + * @note Caller holds no relevant locks, just a dentry reference. + */ +#if RTLNX_VER_MIN(3,6,0) +static int vbsf_dentry_revalidate(struct dentry *dentry, unsigned flags) +#elif RTLNX_VER_MIN(2,6,0) +static int vbsf_dentry_revalidate(struct dentry *dentry, struct nameidata *nd) +#else +static int vbsf_dentry_revalidate(struct dentry *dentry, int flags) +#endif +{ +#if RTLNX_VER_RANGE(2,6,0, 3,6,0) + int const flags = nd ? nd->flags : 0; +#endif + + int rc; + + Assert(dentry); + SFLOGFLOW(("vbsf_dentry_revalidate: %p %#x %s\n", dentry, flags, + dentry->d_inode ? VBSF_GET_INODE_INFO(dentry->d_inode)->path->String.ach : "<negative>")); + + /* + * See Documentation/filesystems/vfs.txt why we skip LOOKUP_RCU. + * + * Also recommended: https://lwn.net/Articles/649115/ + * https://lwn.net/Articles/649729/ + * https://lwn.net/Articles/650786/ + * + */ +#if RTLNX_VER_MIN(2,6,38) + if (flags & LOOKUP_RCU) { + rc = -ECHILD; + SFLOGFLOW(("vbsf_dentry_revalidate: RCU -> -ECHILD\n")); + } else +#endif + { + /* + * Do we have an inode or not? If not it's probably a negative cache + * entry, otherwise most likely a positive one. + */ + struct inode *pInode = dentry->d_inode; + if (pInode) { + /* + * Positive entry. + * + * Note! We're more aggressive here than other remote file systems, + * current (4.19) CIFS will for instance revalidate the inode + * and ignore the dentry timestamp for positive entries. + */ + unsigned long const cJiffiesAge = jiffies - vbsf_dentry_get_update_jiffies(dentry); + struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(dentry->d_sb); + if (cJiffiesAge < pSuperInfo->cJiffiesDirCacheTTL) { + SFLOGFLOW(("vbsf_dentry_revalidate: age: %lu vs. TTL %lu -> 1\n", cJiffiesAge, pSuperInfo->cJiffiesDirCacheTTL)); + rc = 1; + } else if (!vbsf_inode_revalidate_worker(dentry, true /*fForced*/, false /*fInodeLocked*/)) { + vbsf_dentry_set_update_jiffies(dentry, jiffies); + SFLOGFLOW(("vbsf_dentry_revalidate: age: %lu vs. TTL %lu -> reval -> 1\n", cJiffiesAge, pSuperInfo->cJiffiesDirCacheTTL)); + rc = 1; + } else { + SFLOGFLOW(("vbsf_dentry_revalidate: age: %lu vs. TTL %lu -> reval -> 0\n", cJiffiesAge, pSuperInfo->cJiffiesDirCacheTTL)); + rc = 0; + } + } else { + /* + * Negative entry. + * + * Invalidate dentries for open and renames here as we'll revalidate + * these when taking the actual action (also good for case preservation + * if we do case-insensitive mounts against windows + mac hosts at some + * later point). + */ +#if RTLNX_VER_MIN(2,6,28) + if (flags & (LOOKUP_CREATE | LOOKUP_RENAME_TARGET)) +#elif RTLNX_VER_MIN(2,5,75) + if (flags & LOOKUP_CREATE) +#else + if (0) +#endif + { + SFLOGFLOW(("vbsf_dentry_revalidate: negative: create or rename target -> 0\n")); + rc = 0; + } else { + /* Can we skip revalidation based on TTL? */ + unsigned long const cJiffiesAge = vbsf_dentry_get_update_jiffies(dentry) - jiffies; + struct vbsf_super_info *pSuperInfo = VBSF_GET_SUPER_INFO(dentry->d_sb); + if (cJiffiesAge < pSuperInfo->cJiffiesDirCacheTTL) { + SFLOGFLOW(("vbsf_dentry_revalidate: negative: age: %lu vs. TTL %lu -> 1\n", cJiffiesAge, pSuperInfo->cJiffiesDirCacheTTL)); + rc = 1; + } else { + /* We could revalidate it here, but we could instead just + have the caller kick it out. */ + /** @todo stat the direntry and see if it exists now. */ + SFLOGFLOW(("vbsf_dentry_revalidate: negative: age: %lu vs. TTL %lu -> 0\n", cJiffiesAge, pSuperInfo->cJiffiesDirCacheTTL)); + rc = 0; + } + } + } + } + return rc; +} + +#ifdef SFLOG_ENABLED + +/** For logging purposes only. */ +# if RTLNX_VER_MIN(2,6,38) +static int vbsf_dentry_delete(const struct dentry *pDirEntry) +# else +static int vbsf_dentry_delete(struct dentry *pDirEntry) +# endif +{ + SFLOGFLOW(("vbsf_dentry_delete: %p\n", pDirEntry)); + return 0; +} + +# if RTLNX_VER_MIN(4,8,0) +/** For logging purposes only. */ +static int vbsf_dentry_init(struct dentry *pDirEntry) +{ + SFLOGFLOW(("vbsf_dentry_init: %p\n", pDirEntry)); + return 0; +} +# endif + +#endif /* SFLOG_ENABLED */ + +/** + * Directory entry operations. + * + * Since 2.6.38 this is used via the super_block::s_d_op member. + */ +struct dentry_operations vbsf_dentry_ops = { + .d_revalidate = vbsf_dentry_revalidate, +#ifdef SFLOG_ENABLED + .d_delete = vbsf_dentry_delete, +# if RTLNX_VER_MIN(4,8,0) + .d_init = vbsf_dentry_init, +# endif +#endif +}; + |