| Message ID | 1385511158-17733-1-git-send-email-timg@tpi.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, 26 Nov 2013 17:12:38 -0700 Tim Gardner <timg@tpi.com> wrote: > According to Microsoft documentation: > http://msdn.microsoft.com/en-us/library/ee441943.aspx > http://msdn.microsoft.com/en-us/library/ff469854.aspx > > The information level codes used in CIFSSMBSetEOF() are not > legal. In practice we have found that they really don't work either. > The specification clearly states that none of the SMB_SET_FILE infornmation > level codes are supported for TRANS2_SET_PATH_INFORMATION. > Well spotted! > You can trigger this function with the following C code. Note that O_CREAT|O_TRUNC > is not a valid combination, but it does serve to illustrate the bug. > FWIW, O_CREAT|O_TRUNC is a valid combination. What's not valid in the program below is the fact that you don't set O_RDWR or O_WRONLY, which may give you problems on some filesystems. > cat <<EOF > truncate.c > > int main(int argc, char *argv[]) > { > char *fname; > int fd; > mode_t mode = S_IRUSR|S_IWUSR; > int flags = O_CREAT|O_TRUNC; > > if (argc == 2) { > fname = argv[1]; > } else { > printf("You must supply a file name.\n"); > exit(1); > } > > if ((fd=open(fname,flags,mode)) < 0) > { > printf("could not open %s with flags %08x\n",fname,flags); > exit(1); > } > printf("Opened %s with flags %08x\n",fname,flags); > > close(fd); > } > EOF > > I used this script: > > cat <<EOF > truncate.sh > LOG=log.txt > SRV=10.0.0.184 > MP=/tmp/mnt > TD=$MP/temp > > gcc -o truncate truncate.c > rm -f $LOG > > sudo mkdir -p $MP > sudo mount -t cifs //$SRV/test $MP --verbose -o noserverino,nounix,user=test,pass=test > > mkdir -p $TD > sudo rm -f $TD/junk.txt > echo 1 > junk.txt > sudo cp junk.txt $TD/junk.txt > sudo dmesg -c > /dev/null > > echo 1 | sudo tee /proc/fs/cifs/cifsFYI > sudo ./truncate $TD/junk.txt > echo 0 | sudo tee /proc/fs/cifs/cifsFYI > > sudo umount $MP > sudo dmesg -c > $LOG > EOF > > The resulting log file: > > [179777.458893] fs/cifs/file.c:cifs_open:447: CIFS VFS: in cifs_open as Xid: 654 with uid: 0 > [179777.458903] fs/cifs/dir.c:build_path_from_dentry:127: name: \junk.txt > [179777.458907] fs/cifs/dir.c:build_path_from_dentry:127: name: \temp\junk.txt > [179777.458922] fs/cifs/file.c:cifs_open:465: inode = 0xffff88005a42b828 file flags are 0x8240 for \temp\junk.txt > [179777.458935] fs/cifs/transport.c:AllocMidQEntry:64: For smb_command 162 > [179777.458938] fs/cifs/transport.c:smb_send_rqst:288: Sending smb: smb_len=114 > [179777.460089] fs/cifs/connect.c:cifs_demultiplex_thread:874: RFC1002 header 0x67 > [179777.460109] fs/cifs/misc.c:checkSMB:316: checkSMB Length: 0x6b, smb_buf_length: 0x67 > [179777.460125] fs/cifs/transport.c:cifs_sync_mid_result:571: cifs_sync_mid_result: cmd=162 mid=20 state=4 > [179777.460134] fs/cifs/inode.c:cifs_get_inode_info:646: Getting info on \temp\junk.txt > [179777.460138] fs/cifs/inode.c:cifs_revalidate_cache:95: cifs_revalidate_cache: revalidating inode 320 > [179777.460141] fs/cifs/inode.c:cifs_revalidate_cache:119: cifs_revalidate_cache: invalidating inode 320 mapping > [179777.460148] fs/cifs/file.c:cifs_open:545: CIFS VFS: leaving cifs_open (xid = 654) rc = 0 > [179777.460153] fs/cifs/inode.c:cifs_setattr:2280: name junk.txt size 0 > [179777.460157] fs/cifs/inode.c:cifs_setattr_nounix:2126: CIFS VFS: in cifs_setattr_nounix as Xid: 655 with uid: 0 > [179777.460160] fs/cifs/inode.c:cifs_setattr_nounix:2129: setattr on file junk.txt attrs->iavalid 0xa068 > [179777.460163] fs/cifs/dir.c:build_path_from_dentry:127: name: \junk.txt > [179777.460166] fs/cifs/dir.c:build_path_from_dentry:127: name: \temp\junk.txt > [179777.460170] fs/cifs/cifssmb.c:CIFSSMBSetEOF:5403: In SetEOF > [179777.460175] fs/cifs/transport.c:AllocMidQEntry:64: For smb_command 50 > [179777.460178] fs/cifs/transport.c:smb_send_rqst:288: Sending smb: smb_len=112 > [179777.460810] fs/cifs/connect.c:cifs_demultiplex_thread:874: RFC1002 header 0x23 > [179777.460827] fs/cifs/misc.c:checkSMB:316: checkSMB Length: 0x27, smb_buf_length: 0x23 > [179777.460830] fs/cifs/smb1ops.c:check2ndT2:255: invalid transact2 word count > [179777.460841] fs/cifs/transport.c:cifs_sync_mid_result:571: cifs_sync_mid_result: cmd=50 mid=21 state=4 > [179777.460845] fs/cifs/netmisc.c:map_smb_to_linux_error:891: Mapping smb error code 0xc0000022 to POSIX err -13 > [179777.460849] fs/cifs/cifssmb.c:CIFSSMBSetEOF:5469: SetPathInfo (file size) returned -13 > [179777.460851] fs/cifs/inode.c:cifs_set_file_size:1934: SetEOF by path (setattrs) rc = -13 > [179777.460855] fs/cifs/inode.c:cifs_setattr_nounix:2269: CIFS VFS: leaving cifs_setattr_nounix (xid = 655) rc = -13 > [179777.460863] fs/cifs/file.c:cifsFileInfo_put:385: closing last open instance for inode ffff88005a42b828 > [179777.460866] fs/cifs/file.c:cifsFileInfo_put:403: CIFS VFS: in cifsFileInfo_put as Xid: 656 with uid: 0 > [179777.460869] fs/cifs/cifssmb.c:CIFSSMBClose:2457: In CIFSSMBClose > [179777.460873] fs/cifs/transport.c:AllocMidQEntry:64: For smb_command 4 > [179777.460876] fs/cifs/transport.c:smb_send_rqst:288: Sending smb: smb_len=41 > [179777.461257] fs/cifs/connect.c:cifs_demultiplex_thread:874: RFC1002 header 0x23 > [179777.461267] fs/cifs/misc.c:checkSMB:316: checkSMB Length: 0x27, smb_buf_length: 0x23 > [179777.461280] fs/cifs/transport.c:cifs_sync_mid_result:571: cifs_sync_mid_result: cmd=4 mid=22 state=4 > > Cc: Jeff Layton <jlayton@redhat.com> > Cc: Steve French <sfrench@samba.org> > Signed-off-by: Dean Gehnert <deang@tpi.com> > Signed-off-by: Tim Gardner <timg@tpi.com> > --- > > We encountered this problem whilst backporting the CIFS driver to a kernel and VFS old enough > to still call inode_operations.setattr() when truncating a file. We're not sure it is the > right upstream solution, but it worked for us on this older kernel. > > fs/cifs/cifsproto.h | 3 -- > fs/cifs/cifssmb.c | 98 ----------------------------------------------------- > fs/cifs/smb1ops.c | 36 +++++++++++++++++++- > 3 files changed, 35 insertions(+), 102 deletions(-) > > diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h > index aa33976..fe69b9c 100644 > --- a/fs/cifs/cifsproto.h > +++ b/fs/cifs/cifsproto.h > @@ -296,9 +296,6 @@ extern int CIFSSMBSetAttrLegacy(unsigned int xid, struct cifs_tcon *tcon, > char *fileName, __u16 dos_attributes, > const struct nls_table *nls_codepage); > #endif /* possibly unneeded function */ > -extern int CIFSSMBSetEOF(const unsigned int xid, struct cifs_tcon *tcon, > - const char *file_name, __u64 size, > - struct cifs_sb_info *cifs_sb, bool set_allocation); > extern int CIFSSMBSetFileSize(const unsigned int xid, struct cifs_tcon *tcon, > struct cifsFileInfo *cfile, __u64 size, > bool set_allocation); > diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c > index 124aa02..53f1b9b 100644 > --- a/fs/cifs/cifssmb.c > +++ b/fs/cifs/cifssmb.c > @@ -5453,104 +5453,6 @@ QFSPosixRetry: > return rc; > } > > - > -/* > - * We can not use write of zero bytes trick to set file size due to need for > - * large file support. Also note that this SetPathInfo is preferred to > - * SetFileInfo based method in next routine which is only needed to work around > - * a sharing violation bugin Samba which this routine can run into. > - */ > -int > -CIFSSMBSetEOF(const unsigned int xid, struct cifs_tcon *tcon, > - const char *file_name, __u64 size, struct cifs_sb_info *cifs_sb, > - bool set_allocation) > -{ > - struct smb_com_transaction2_spi_req *pSMB = NULL; > - struct smb_com_transaction2_spi_rsp *pSMBr = NULL; > - struct file_end_of_file_info *parm_data; > - int name_len; > - int rc = 0; > - int bytes_returned = 0; > - int remap = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR; > - > - __u16 params, byte_count, data_count, param_offset, offset; > - > - cifs_dbg(FYI, "In SetEOF\n"); > -SetEOFRetry: > - rc = smb_init(SMB_COM_TRANSACTION2, 15, tcon, (void **) &pSMB, > - (void **) &pSMBr); > - if (rc) > - return rc; > - > - if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) { > - name_len = > - cifsConvertToUTF16((__le16 *) pSMB->FileName, file_name, > - PATH_MAX, cifs_sb->local_nls, remap); > - name_len++; /* trailing null */ > - name_len *= 2; > - } else { /* BB improve the check for buffer overruns BB */ > - name_len = strnlen(file_name, PATH_MAX); > - name_len++; /* trailing null */ > - strncpy(pSMB->FileName, file_name, name_len); > - } > - params = 6 + name_len; > - data_count = sizeof(struct file_end_of_file_info); > - pSMB->MaxParameterCount = cpu_to_le16(2); > - pSMB->MaxDataCount = cpu_to_le16(4100); > - pSMB->MaxSetupCount = 0; > - pSMB->Reserved = 0; > - pSMB->Flags = 0; > - pSMB->Timeout = 0; > - pSMB->Reserved2 = 0; > - param_offset = offsetof(struct smb_com_transaction2_spi_req, > - InformationLevel) - 4; > - offset = param_offset + params; > - if (set_allocation) { > - if (tcon->ses->capabilities & CAP_INFOLEVEL_PASSTHRU) > - pSMB->InformationLevel = > - cpu_to_le16(SMB_SET_FILE_ALLOCATION_INFO2); > - else > - pSMB->InformationLevel = > - cpu_to_le16(SMB_SET_FILE_ALLOCATION_INFO); > - } else /* Set File Size */ { > - if (tcon->ses->capabilities & CAP_INFOLEVEL_PASSTHRU) > - pSMB->InformationLevel = > - cpu_to_le16(SMB_SET_FILE_END_OF_FILE_INFO2); > - else > - pSMB->InformationLevel = > - cpu_to_le16(SMB_SET_FILE_END_OF_FILE_INFO); > - } > - > - parm_data = > - (struct file_end_of_file_info *) (((char *) &pSMB->hdr.Protocol) + > - offset); > - pSMB->ParameterOffset = cpu_to_le16(param_offset); > - pSMB->DataOffset = cpu_to_le16(offset); > - pSMB->SetupCount = 1; > - pSMB->Reserved3 = 0; > - pSMB->SubCommand = cpu_to_le16(TRANS2_SET_PATH_INFORMATION); > - byte_count = 3 /* pad */ + params + data_count; > - pSMB->DataCount = cpu_to_le16(data_count); > - pSMB->TotalDataCount = pSMB->DataCount; > - pSMB->ParameterCount = cpu_to_le16(params); > - pSMB->TotalParameterCount = pSMB->ParameterCount; > - pSMB->Reserved4 = 0; > - inc_rfc1001_len(pSMB, byte_count); > - parm_data->FileSize = cpu_to_le64(size); > - pSMB->ByteCount = cpu_to_le16(byte_count); > - rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB, > - (struct smb_hdr *) pSMBr, &bytes_returned, 0); > - if (rc) > - cifs_dbg(FYI, "SetPathInfo (file size) returned %d\n", rc); > - > - cifs_buf_release(pSMB); > - > - if (rc == -EAGAIN) > - goto SetEOFRetry; > - > - return rc; > -} > - > int > CIFSSMBSetFileSize(const unsigned int xid, struct cifs_tcon *tcon, > struct cifsFileInfo *cfile, __u64 size, bool set_allocation) > diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c > index 5f5ba0d..14d4832 100644 > --- a/fs/cifs/smb1ops.c > +++ b/fs/cifs/smb1ops.c > @@ -756,6 +756,40 @@ cifs_sync_write(const unsigned int xid, struct cifsFileInfo *cfile, > } > > static int > +smb_set_file_size(const unsigned int xid, struct cifs_tcon *tcon, > + const char *full_path, __u64 size, struct cifs_sb_info *cifs_sb, > + bool set_allocation) > +{ > + int oplock = 0; > + int rc; > + __u16 netfid; > + struct cifsFileInfo cfile; > + > + cifs_dbg(FYI, "smb_set_file_size: %s\n", full_path); > + > + rc = CIFSSMBOpen(xid, tcon, full_path, FILE_OPEN, > + FILE_WRITE_DATA, CREATE_NOT_DIR, > + &netfid, &oplock, NULL, cifs_sb->local_nls, > + cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); > + if (rc) > + return rc; > + > + /* > + * Only 2 fields are required to set the file size. > + */ > + memset(&cfile, 0, sizeof(cfile)); > + cfile.pid = current->tgid; > + cfile.fid.netfid = netfid; > + > + rc = CIFSSMBSetFileSize(xid, tcon, &cfile, size, set_allocation); > + > + if (!rc) > + rc = CIFSSMBClose(xid, tcon, netfid); > + > + return rc; > +} > + > +static int > smb_set_file_info(struct inode *inode, const char *full_path, > FILE_BASIC_INFO *buf, const unsigned int xid) > { > @@ -979,7 +1013,7 @@ struct smb_version_operations smb1_operations = { > .query_path_info = cifs_query_path_info, > .query_file_info = cifs_query_file_info, > .get_srv_inum = cifs_get_srv_inum, > - .set_path_size = CIFSSMBSetEOF, > + .set_path_size = smb_set_file_size, > .set_file_size = CIFSSMBSetFileSize, > .set_file_info = smb_set_file_info, > .set_compression = cifs_set_compression, The basic idea looks correct, though the fact that this now becomes 3 round trips to the server sort of sucks. I don't see a way to avoid that though. Now that I look though, it's clear to me that cifs_set_file_size is just wrong. Currently it calls ops->set_path_size and if that fails with certain error codes it tries to do a SMBLegacyOpen, etc. That's going to fall on its face if this is a SMB2/3 connection. Here's what should be done instead, I think: - get rid of both set_path_size and set_file_size operations. The version specific abstraction was implemented at the wrong level, IMO. - implement a new protocol level operation that basically takes the same args as cifs_set_file_size. cifs_setattr_unix/_nounix should call this operation. - the set_path_size operation for SMB1 should basically be the function that is cifs_set_file_size today (though that should probably be renamed). That function should be restructured to do the following: + look for an open filehandle + if there isn't one, open the file + call CIFSSMBSetFileSize + fall back to zero-length write if that fails + close the file if we opened it Sound reasonable?
diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index aa33976..fe69b9c 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -296,9 +296,6 @@ extern int CIFSSMBSetAttrLegacy(unsigned int xid, struct cifs_tcon *tcon, char *fileName, __u16 dos_attributes, const struct nls_table *nls_codepage); #endif /* possibly unneeded function */ -extern int CIFSSMBSetEOF(const unsigned int xid, struct cifs_tcon *tcon, - const char *file_name, __u64 size, - struct cifs_sb_info *cifs_sb, bool set_allocation); extern int CIFSSMBSetFileSize(const unsigned int xid, struct cifs_tcon *tcon, struct cifsFileInfo *cfile, __u64 size, bool set_allocation); diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 124aa02..53f1b9b 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -5453,104 +5453,6 @@ QFSPosixRetry: return rc; } - -/* - * We can not use write of zero bytes trick to set file size due to need for - * large file support. Also note that this SetPathInfo is preferred to - * SetFileInfo based method in next routine which is only needed to work around - * a sharing violation bugin Samba which this routine can run into. - */ -int -CIFSSMBSetEOF(const unsigned int xid, struct cifs_tcon *tcon, - const char *file_name, __u64 size, struct cifs_sb_info *cifs_sb, - bool set_allocation) -{ - struct smb_com_transaction2_spi_req *pSMB = NULL; - struct smb_com_transaction2_spi_rsp *pSMBr = NULL; - struct file_end_of_file_info *parm_data; - int name_len; - int rc = 0; - int bytes_returned = 0; - int remap = cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR; - - __u16 params, byte_count, data_count, param_offset, offset; - - cifs_dbg(FYI, "In SetEOF\n"); -SetEOFRetry: - rc = smb_init(SMB_COM_TRANSACTION2, 15, tcon, (void **) &pSMB, - (void **) &pSMBr); - if (rc) - return rc; - - if (pSMB->hdr.Flags2 & SMBFLG2_UNICODE) { - name_len = - cifsConvertToUTF16((__le16 *) pSMB->FileName, file_name, - PATH_MAX, cifs_sb->local_nls, remap); - name_len++; /* trailing null */ - name_len *= 2; - } else { /* BB improve the check for buffer overruns BB */ - name_len = strnlen(file_name, PATH_MAX); - name_len++; /* trailing null */ - strncpy(pSMB->FileName, file_name, name_len); - } - params = 6 + name_len; - data_count = sizeof(struct file_end_of_file_info); - pSMB->MaxParameterCount = cpu_to_le16(2); - pSMB->MaxDataCount = cpu_to_le16(4100); - pSMB->MaxSetupCount = 0; - pSMB->Reserved = 0; - pSMB->Flags = 0; - pSMB->Timeout = 0; - pSMB->Reserved2 = 0; - param_offset = offsetof(struct smb_com_transaction2_spi_req, - InformationLevel) - 4; - offset = param_offset + params; - if (set_allocation) { - if (tcon->ses->capabilities & CAP_INFOLEVEL_PASSTHRU) - pSMB->InformationLevel = - cpu_to_le16(SMB_SET_FILE_ALLOCATION_INFO2); - else - pSMB->InformationLevel = - cpu_to_le16(SMB_SET_FILE_ALLOCATION_INFO); - } else /* Set File Size */ { - if (tcon->ses->capabilities & CAP_INFOLEVEL_PASSTHRU) - pSMB->InformationLevel = - cpu_to_le16(SMB_SET_FILE_END_OF_FILE_INFO2); - else - pSMB->InformationLevel = - cpu_to_le16(SMB_SET_FILE_END_OF_FILE_INFO); - } - - parm_data = - (struct file_end_of_file_info *) (((char *) &pSMB->hdr.Protocol) + - offset); - pSMB->ParameterOffset = cpu_to_le16(param_offset); - pSMB->DataOffset = cpu_to_le16(offset); - pSMB->SetupCount = 1; - pSMB->Reserved3 = 0; - pSMB->SubCommand = cpu_to_le16(TRANS2_SET_PATH_INFORMATION); - byte_count = 3 /* pad */ + params + data_count; - pSMB->DataCount = cpu_to_le16(data_count); - pSMB->TotalDataCount = pSMB->DataCount; - pSMB->ParameterCount = cpu_to_le16(params); - pSMB->TotalParameterCount = pSMB->ParameterCount; - pSMB->Reserved4 = 0; - inc_rfc1001_len(pSMB, byte_count); - parm_data->FileSize = cpu_to_le64(size); - pSMB->ByteCount = cpu_to_le16(byte_count); - rc = SendReceive(xid, tcon->ses, (struct smb_hdr *) pSMB, - (struct smb_hdr *) pSMBr, &bytes_returned, 0); - if (rc) - cifs_dbg(FYI, "SetPathInfo (file size) returned %d\n", rc); - - cifs_buf_release(pSMB); - - if (rc == -EAGAIN) - goto SetEOFRetry; - - return rc; -} - int CIFSSMBSetFileSize(const unsigned int xid, struct cifs_tcon *tcon, struct cifsFileInfo *cfile, __u64 size, bool set_allocation) diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c index 5f5ba0d..14d4832 100644 --- a/fs/cifs/smb1ops.c +++ b/fs/cifs/smb1ops.c @@ -756,6 +756,40 @@ cifs_sync_write(const unsigned int xid, struct cifsFileInfo *cfile, } static int +smb_set_file_size(const unsigned int xid, struct cifs_tcon *tcon, + const char *full_path, __u64 size, struct cifs_sb_info *cifs_sb, + bool set_allocation) +{ + int oplock = 0; + int rc; + __u16 netfid; + struct cifsFileInfo cfile; + + cifs_dbg(FYI, "smb_set_file_size: %s\n", full_path); + + rc = CIFSSMBOpen(xid, tcon, full_path, FILE_OPEN, + FILE_WRITE_DATA, CREATE_NOT_DIR, + &netfid, &oplock, NULL, cifs_sb->local_nls, + cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); + if (rc) + return rc; + + /* + * Only 2 fields are required to set the file size. + */ + memset(&cfile, 0, sizeof(cfile)); + cfile.pid = current->tgid; + cfile.fid.netfid = netfid; + + rc = CIFSSMBSetFileSize(xid, tcon, &cfile, size, set_allocation); + + if (!rc) + rc = CIFSSMBClose(xid, tcon, netfid); + + return rc; +} + +static int smb_set_file_info(struct inode *inode, const char *full_path, FILE_BASIC_INFO *buf, const unsigned int xid) { @@ -979,7 +1013,7 @@ struct smb_version_operations smb1_operations = { .query_path_info = cifs_query_path_info, .query_file_info = cifs_query_file_info, .get_srv_inum = cifs_get_srv_inum, - .set_path_size = CIFSSMBSetEOF, + .set_path_size = smb_set_file_size, .set_file_size = CIFSSMBSetFileSize, .set_file_info = smb_set_file_info, .set_compression = cifs_set_compression,
According to Microsoft documentation: http://msdn.microsoft.com/en-us/library/ee441943.aspx http://msdn.microsoft.com/en-us/library/ff469854.aspx The information level codes used in CIFSSMBSetEOF() are not legal. In practice we have found that they really don't work either. The specification clearly states that none of the SMB_SET_FILE infornmation level codes are supported for TRANS2_SET_PATH_INFORMATION. You can trigger this function with the following C code. Note that O_CREAT|O_TRUNC is not a valid combination, but it does serve to illustrate the bug. cat <<EOF > truncate.c int main(int argc, char *argv[]) { char *fname; int fd; mode_t mode = S_IRUSR|S_IWUSR; int flags = O_CREAT|O_TRUNC; if (argc == 2) { fname = argv[1]; } else { printf("You must supply a file name.\n"); exit(1); } if ((fd=open(fname,flags,mode)) < 0) { printf("could not open %s with flags %08x\n",fname,flags); exit(1); } printf("Opened %s with flags %08x\n",fname,flags); close(fd); } EOF I used this script: cat <<EOF > truncate.sh LOG=log.txt SRV=10.0.0.184 MP=/tmp/mnt TD=$MP/temp gcc -o truncate truncate.c rm -f $LOG sudo mkdir -p $MP sudo mount -t cifs //$SRV/test $MP --verbose -o noserverino,nounix,user=test,pass=test mkdir -p $TD sudo rm -f $TD/junk.txt echo 1 > junk.txt sudo cp junk.txt $TD/junk.txt sudo dmesg -c > /dev/null echo 1 | sudo tee /proc/fs/cifs/cifsFYI sudo ./truncate $TD/junk.txt echo 0 | sudo tee /proc/fs/cifs/cifsFYI sudo umount $MP sudo dmesg -c > $LOG EOF The resulting log file: [179777.458893] fs/cifs/file.c:cifs_open:447: CIFS VFS: in cifs_open as Xid: 654 with uid: 0 [179777.458903] fs/cifs/dir.c:build_path_from_dentry:127: name: \junk.txt [179777.458907] fs/cifs/dir.c:build_path_from_dentry:127: name: \temp\junk.txt [179777.458922] fs/cifs/file.c:cifs_open:465: inode = 0xffff88005a42b828 file flags are 0x8240 for \temp\junk.txt [179777.458935] fs/cifs/transport.c:AllocMidQEntry:64: For smb_command 162 [179777.458938] fs/cifs/transport.c:smb_send_rqst:288: Sending smb: smb_len=114 [179777.460089] fs/cifs/connect.c:cifs_demultiplex_thread:874: RFC1002 header 0x67 [179777.460109] fs/cifs/misc.c:checkSMB:316: checkSMB Length: 0x6b, smb_buf_length: 0x67 [179777.460125] fs/cifs/transport.c:cifs_sync_mid_result:571: cifs_sync_mid_result: cmd=162 mid=20 state=4 [179777.460134] fs/cifs/inode.c:cifs_get_inode_info:646: Getting info on \temp\junk.txt [179777.460138] fs/cifs/inode.c:cifs_revalidate_cache:95: cifs_revalidate_cache: revalidating inode 320 [179777.460141] fs/cifs/inode.c:cifs_revalidate_cache:119: cifs_revalidate_cache: invalidating inode 320 mapping [179777.460148] fs/cifs/file.c:cifs_open:545: CIFS VFS: leaving cifs_open (xid = 654) rc = 0 [179777.460153] fs/cifs/inode.c:cifs_setattr:2280: name junk.txt size 0 [179777.460157] fs/cifs/inode.c:cifs_setattr_nounix:2126: CIFS VFS: in cifs_setattr_nounix as Xid: 655 with uid: 0 [179777.460160] fs/cifs/inode.c:cifs_setattr_nounix:2129: setattr on file junk.txt attrs->iavalid 0xa068 [179777.460163] fs/cifs/dir.c:build_path_from_dentry:127: name: \junk.txt [179777.460166] fs/cifs/dir.c:build_path_from_dentry:127: name: \temp\junk.txt [179777.460170] fs/cifs/cifssmb.c:CIFSSMBSetEOF:5403: In SetEOF [179777.460175] fs/cifs/transport.c:AllocMidQEntry:64: For smb_command 50 [179777.460178] fs/cifs/transport.c:smb_send_rqst:288: Sending smb: smb_len=112 [179777.460810] fs/cifs/connect.c:cifs_demultiplex_thread:874: RFC1002 header 0x23 [179777.460827] fs/cifs/misc.c:checkSMB:316: checkSMB Length: 0x27, smb_buf_length: 0x23 [179777.460830] fs/cifs/smb1ops.c:check2ndT2:255: invalid transact2 word count [179777.460841] fs/cifs/transport.c:cifs_sync_mid_result:571: cifs_sync_mid_result: cmd=50 mid=21 state=4 [179777.460845] fs/cifs/netmisc.c:map_smb_to_linux_error:891: Mapping smb error code 0xc0000022 to POSIX err -13 [179777.460849] fs/cifs/cifssmb.c:CIFSSMBSetEOF:5469: SetPathInfo (file size) returned -13 [179777.460851] fs/cifs/inode.c:cifs_set_file_size:1934: SetEOF by path (setattrs) rc = -13 [179777.460855] fs/cifs/inode.c:cifs_setattr_nounix:2269: CIFS VFS: leaving cifs_setattr_nounix (xid = 655) rc = -13 [179777.460863] fs/cifs/file.c:cifsFileInfo_put:385: closing last open instance for inode ffff88005a42b828 [179777.460866] fs/cifs/file.c:cifsFileInfo_put:403: CIFS VFS: in cifsFileInfo_put as Xid: 656 with uid: 0 [179777.460869] fs/cifs/cifssmb.c:CIFSSMBClose:2457: In CIFSSMBClose [179777.460873] fs/cifs/transport.c:AllocMidQEntry:64: For smb_command 4 [179777.460876] fs/cifs/transport.c:smb_send_rqst:288: Sending smb: smb_len=41 [179777.461257] fs/cifs/connect.c:cifs_demultiplex_thread:874: RFC1002 header 0x23 [179777.461267] fs/cifs/misc.c:checkSMB:316: checkSMB Length: 0x27, smb_buf_length: 0x23 [179777.461280] fs/cifs/transport.c:cifs_sync_mid_result:571: cifs_sync_mid_result: cmd=4 mid=22 state=4 Cc: Jeff Layton <jlayton@redhat.com> Cc: Steve French <sfrench@samba.org> Signed-off-by: Dean Gehnert <deang@tpi.com> Signed-off-by: Tim Gardner <timg@tpi.com> --- We encountered this problem whilst backporting the CIFS driver to a kernel and VFS old enough to still call inode_operations.setattr() when truncating a file. We're not sure it is the right upstream solution, but it worked for us on this older kernel. fs/cifs/cifsproto.h | 3 -- fs/cifs/cifssmb.c | 98 ----------------------------------------------------- fs/cifs/smb1ops.c | 36 +++++++++++++++++++- 3 files changed, 35 insertions(+), 102 deletions(-)