February 2013 - Wine-Devel - list.winehq.org

Re: [PATCH v3 0/7] Add O_DENY* support for VFS and CIFS/NFS

by Andy Lutomirski

[possible resend -- sorry] On 02/28/2013 07:25 AM, Pavel Shilovsky wrote: > This patchset adds support of O_DENY* flags for Linux fs layer. These flags can be used by any application that needs share reservations to organize a file access. VFS already has some sort of this capability - now it's done through flock/LOCK_MAND mechanis, but that approach is non-atomic. This patchset build new capabilities on top of the existing one but doesn't bring any changes into the flock call semantic. > > These flags can be used by NFS (built-in-kernel) and CIFS (Samba) servers and Wine applications through VFS (for local filesystems) or CIFS/NFS modules. This will help when e.g. Samba and NFS server share the same directory for Windows and Linux users or Wine applications use Samba/NFS share to access the same data from different clients. > > According to the previous discussions the most problematic question is how to prevent situations like DoS attacks where e.g /lib/liba.so file can be open with DENYREAD, or smth like this. That's why one extra flag O_DENYMAND is added. It indicates to underlying layer that an application want to use O_DENY* flags semantic. It allows us not affect native Linux applications (that don't use O_DENYMAND flag) - so, these flags (and the semantic of open syscall that they bring) are used only for those applications that really want it proccessed that way. > > So, we have four new flags: > O_DENYREAD - to prevent other opens with read access, > O_DENYWRITE - to prevent other opens with write access, > O_DENYDELETE - to prevent delete operations (this flag is not implemented in VFS and NFS part and only suitable for CIFS module), > O_DENYMAND - to switch on/off three flags above. O_DENYMAND doesn't deny anything. Would a name like O_RESPECT_DENY be better? Other than that, this seems like a sensible mechanism. --Andy

Feb. 28, 2013

Re: [PATCH 2/2] winmm: MCI_BREAK_HWND handling now matches Wine's 1999 MCI_DefYieldProc.

by Alexandre Julliard

<Joerg-Cyril.Hoehle(a)t-systems.com> writes: > @@ -2063,9 +2063,10 @@ static DWORD MCI_Break(UINT wDevID, DWORD dwFlags, LPMCI_BREAK_PARMS lpParms) > switch (dwFlags & (MCI_BREAK_KEY | MCI_BREAK_OFF)) { > case MCI_BREAK_KEY: > wmd->lpfnYieldProc = MCI_DefYieldProc; > - wmd->dwYieldData = lpParms->nVirtKey; > - if (dwFlags & MCI_BREAK_HWND) > - FIXME("(%x) vkey %02X on window %p\n", dwFlags, lpParms->nVirtKey, lpParms->hwndBreak); > + /* Our MCI_DefYieldProc from 1999-04-11 expects this DWORD splitting, > + * yet tests on w2k-w7 prove wmd->dwYieldData = lpParms->nVirtKey; */ It doesn't make sense to add workarounds for Wine code, it should be fixed instead. -- Alexandre Julliard julliard(a)winehq.org

Feb. 28, 2013

Re: gdiplus: GdipDrawString should handle alignment in both directions same way.

by Vincent Povirk

> How are you handling the case where format is NULL? Never mind, I see what you're doing. But since the block where you now handle the horizontal alignment is inside an if (format->vertalign != StringAlignmentNear), this will break horizontal alignment when a vertical alignment is not set.

Feb. 28, 2013

Re: gdiplus: GdipDrawString should handle alignment in both directions same way.

by Vincent Povirk

> - if (format) halign = format->align; > - else halign = StringAlignmentNear; > - How are you handling the case where format is NULL?

Feb. 28, 2013

[PATCH v3 7/7] NFSD: Pass share reservations flags to VFS

by Pavel Shilovsky

that maps them into O_DENY flags and make them visible for applications that use O_DENYMAND opens. Signed-off-by: Pavel Shilovsky <piastry(a)etersoft.ru> --- fs/locks.c | 1 + fs/nfsd/nfs4state.c | 46 +++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 46 insertions(+), 1 deletion(-) diff --git a/fs/locks.c b/fs/locks.c index 0cc7d1b..593d464 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -874,6 +874,7 @@ deny_lock_file(struct file *filp) locks_free_lock(lock); return error; } +EXPORT_SYMBOL(deny_lock_file); static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock) { diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c index ac8ed96c..766256a 100644 --- a/fs/nfsd/nfs4state.c +++ b/fs/nfsd/nfs4state.c @@ -476,6 +476,19 @@ test_deny(u32 access, struct nfs4_ol_stateid *stp) return test_bit(access, &stp->st_deny_bmap); } +static int nfs4_deny_to_odeny(u32 access) +{ + switch (access & NFS4_SHARE_DENY_BOTH) { + case NFS4_SHARE_DENY_READ: + return O_DENYMAND | O_DENYREAD; + case NFS4_SHARE_DENY_WRITE: + return O_DENYWRITE | O_DENYMAND; + case NFS4_SHARE_DENY_BOTH: + return O_DENYREAD | O_DENYWRITE | O_DENYMAND; + } + return O_DENYMAND; +} + static int nfs4_access_to_omode(u32 access) { switch (access & NFS4_SHARE_ACCESS_BOTH) { @@ -2793,6 +2806,21 @@ nfsd4_truncate(struct svc_rqst *rqstp, struct svc_fh *fh, } static __be32 +nfs4_vfs_set_deny(struct nfs4_file *fp, unsigned long share_access, + unsigned long deny_access) +{ + int oflag, rc; + __be32 status = nfs_ok; + + oflag = nfs4_access_to_omode(share_access); + fp->fi_fds[oflag]->f_flags |= nfs4_deny_to_odeny(deny_access); + rc = deny_lock_file(fp->fi_fds[oflag]); + if (rc) + status = nfserrno(rc); + return status; +} + +static __be32 nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *cur_fh, struct nfs4_ol_stateid *stp, struct nfsd4_open *open) { u32 op_share_access = open->op_share_access; @@ -2813,6 +2841,14 @@ nfs4_upgrade_open(struct svc_rqst *rqstp, struct nfs4_file *fp, struct svc_fh *c } return status; } + status = nfs4_vfs_set_deny(fp, op_share_access, open->op_share_deny); + if (status) { + if (new_access) { + int oflag = nfs4_access_to_omode(op_share_access); + nfs4_file_put_access(fp, oflag); + } + return status; + } /* remember the open */ set_access(op_share_access, stp); set_deny(open->op_share_deny, stp); @@ -3046,7 +3082,7 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf /* * OPEN the file, or upgrade an existing OPEN. - * If truncate fails, the OPEN fails. + * If truncate or setting deny fails, the OPEN fails. */ if (stp) { /* Stateid was found, this is an OPEN upgrade */ @@ -3060,6 +3096,10 @@ nfsd4_process_open2(struct svc_rqst *rqstp, struct svc_fh *current_fh, struct nf status = nfsd4_truncate(rqstp, current_fh, open); if (status) goto out; + status = nfs4_vfs_set_deny(fp, open->op_share_access, + open->op_share_deny); + if (status) + goto out; stp = open->op_stp; open->op_stp = NULL; init_open_stateid(stp, fp, open); @@ -3758,6 +3798,10 @@ nfsd4_open_downgrade(struct svc_rqst *rqstp, } nfs4_stateid_downgrade(stp, od->od_share_access); + status = nfs4_vfs_set_deny(stp->st_file, od->od_share_access, + od->od_share_deny); + if (status) + goto out; reset_union_bmap_deny(od->od_share_deny, stp); update_stateid(&stp->st_stid.sc_stateid); -- 1.8.1.2

Feb. 28, 2013

[PATCH v3 6/7] NFSv4: Add O_DENY* open flags support

by Pavel Shilovsky

by passing these flags to NFSv4 open request. Signed-off-by: Pavel Shilovsky <piastry(a)etersoft.ru> --- fs/nfs/nfs4xdr.c | 24 ++++++++++++++++++++---- 1 file changed, 20 insertions(+), 4 deletions(-) diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c index 26b1439..58ddc74 100644 --- a/fs/nfs/nfs4xdr.c +++ b/fs/nfs/nfs4xdr.c @@ -1325,7 +1325,8 @@ static void encode_lookup(struct xdr_stream *xdr, const struct qstr *name, struc encode_string(xdr, name->len, name->name); } -static void encode_share_access(struct xdr_stream *xdr, fmode_t fmode) +static void encode_share_access(struct xdr_stream *xdr, fmode_t fmode, + int open_flags) { __be32 *p; @@ -1343,7 +1344,22 @@ static void encode_share_access(struct xdr_stream *xdr, fmode_t fmode) default: *p++ = cpu_to_be32(0); } - *p = cpu_to_be32(0); /* for linux, share_deny = 0 always */ + if (open_flags & O_DENYMAND) { + switch (open_flags & (O_DENYREAD|O_DENYWRITE)) { + case O_DENYREAD: + *p = cpu_to_be32(NFS4_SHARE_DENY_READ); + break; + case O_DENYWRITE: + *p = cpu_to_be32(NFS4_SHARE_DENY_WRITE); + break; + case O_DENYREAD|O_DENYWRITE: + *p = cpu_to_be32(NFS4_SHARE_DENY_BOTH); + break; + default: + *p = cpu_to_be32(0); + } + } else + *p = cpu_to_be32(0); } static inline void encode_openhdr(struct xdr_stream *xdr, const struct nfs_openargs *arg) @@ -1354,7 +1370,7 @@ static inline void encode_openhdr(struct xdr_stream *xdr, const struct nfs_opena * owner 4 = 32 */ encode_nfs4_seqid(xdr, arg->seqid); - encode_share_access(xdr, arg->fmode); + encode_share_access(xdr, arg->fmode, arg->open_flags); p = reserve_space(xdr, 36); p = xdr_encode_hyper(p, arg->clientid); *p++ = cpu_to_be32(24); @@ -1491,7 +1507,7 @@ static void encode_open_downgrade(struct xdr_stream *xdr, const struct nfs_close encode_op_hdr(xdr, OP_OPEN_DOWNGRADE, decode_open_downgrade_maxsz, hdr); encode_nfs4_stateid(xdr, arg->stateid); encode_nfs4_seqid(xdr, arg->seqid); - encode_share_access(xdr, arg->fmode); + encode_share_access(xdr, arg->fmode, 0); } static void -- 1.8.1.2

Feb. 28, 2013

[PATCH v3 5/7] CIFS: Translate SHARING_VIOLATION to -ETXTBSY error code for SMB2

by Pavel Shilovsky

to make it match CIFS and VFS variants. Signed-off-by: Pavel Shilovsky <piastry(a)etersoft.ru> --- fs/cifs/smb2maperror.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/cifs/smb2maperror.c b/fs/cifs/smb2maperror.c index 494c912..11e589e 100644 --- a/fs/cifs/smb2maperror.c +++ b/fs/cifs/smb2maperror.c @@ -356,7 +356,7 @@ static const struct status_to_posix_error smb2_error_map_table[] = { {STATUS_PORT_CONNECTION_REFUSED, -ECONNREFUSED, "STATUS_PORT_CONNECTION_REFUSED"}, {STATUS_INVALID_PORT_HANDLE, -EIO, "STATUS_INVALID_PORT_HANDLE"}, - {STATUS_SHARING_VIOLATION, -EBUSY, "STATUS_SHARING_VIOLATION"}, + {STATUS_SHARING_VIOLATION, -ETXTBSY, "STATUS_SHARING_VIOLATION"}, {STATUS_QUOTA_EXCEEDED, -EDQUOT, "STATUS_QUOTA_EXCEEDED"}, {STATUS_INVALID_PAGE_PROTECTION, -EIO, "STATUS_INVALID_PAGE_PROTECTION"}, -- 1.8.1.2

Feb. 28, 2013

[PATCH v3 4/7] CIFS: Use NT_CREATE_ANDX command for forcemand mounts

by Pavel Shilovsky

forcemand mount option now lets us use Windows mandatory style of byte-range locks even if server supports posix ones - switches on Windows locking mechanism. Share flags is another locking mehanism provided by Windows semantic that can be used by NT_CREATE_ANDX command. This patch combines all Windows locking mechanism in one mount option by using NT_CREATE_ANDX to open files if forcemand is on. Signed-off-by: Pavel Shilovsky <piastry(a)etersoft.ru> --- fs/cifs/dir.c | 1 + fs/cifs/file.c | 6 ++++-- 2 files changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 6975072..139c8bc 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -217,6 +217,7 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, } if (tcon->unix_ext && cap_unix(tcon->ses) && !tcon->broken_posix_open && + ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0) && (CIFS_UNIX_POSIX_PATH_OPS_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))) { rc = cifs_posix_open(full_path, &newinode, inode->i_sb, mode, diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 3ad484c..05191da 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -454,8 +454,9 @@ int cifs_open(struct inode *inode, struct file *file) else oplock = 0; - if (!tcon->broken_posix_open && tcon->unix_ext && - cap_unix(tcon->ses) && (CIFS_UNIX_POSIX_PATH_OPS_CAP & + if (!tcon->broken_posix_open && tcon->unix_ext && cap_unix(tcon->ses) + && ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0) && + (CIFS_UNIX_POSIX_PATH_OPS_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))) { /* can not refresh inode info since size could be stale */ rc = cifs_posix_open(full_path, &inode, inode->i_sb, @@ -623,6 +624,7 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush) oplock = 0; if (tcon->unix_ext && cap_unix(tcon->ses) && + ((cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NOPOSIXBRL) == 0) && (CIFS_UNIX_POSIX_PATH_OPS_CAP & le64_to_cpu(tcon->fsUnixInfo.Capability))) { /* -- 1.8.1.2

Feb. 28, 2013

[PATCH v3 3/7] CIFS: Add O_DENY* open flags support

by Pavel Shilovsky

Make CIFSSMBOpen take share_flags as a parm that allows us to pass new O_DENY* flags to the server. Signed-off-by: Pavel Shilovsky <piastry(a)etersoft.ru> --- fs/cifs/cifsacl.c | 6 ++++-- fs/cifs/cifsglob.h | 12 +++++++++++- fs/cifs/cifsproto.h | 9 +++++---- fs/cifs/cifssmb.c | 47 +++++++++++++++++++++++++---------------------- fs/cifs/dir.c | 13 ++++++++----- fs/cifs/file.c | 12 ++++++++---- fs/cifs/inode.c | 11 ++++++----- fs/cifs/link.c | 10 +++++----- fs/cifs/readdir.c | 2 +- fs/cifs/smb1ops.c | 15 ++++++++------- fs/cifs/smb2file.c | 10 +++++----- fs/cifs/smb2inode.c | 4 ++-- fs/cifs/smb2ops.c | 10 ++++++---- fs/cifs/smb2pdu.c | 6 +++--- fs/cifs/smb2proto.h | 14 ++++++++------ 15 files changed, 105 insertions(+), 76 deletions(-) diff --git a/fs/cifs/cifsacl.c b/fs/cifs/cifsacl.c index 5cbd00e..222b989 100644 --- a/fs/cifs/cifsacl.c +++ b/fs/cifs/cifsacl.c @@ -891,7 +891,8 @@ static struct cifs_ntsd *get_cifs_acl_by_path(struct cifs_sb_info *cifs_sb, create_options |= CREATE_OPEN_BACKUP_INTENT; rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, READ_CONTROL, - create_options, &fid, &oplock, NULL, cifs_sb->local_nls, + FILE_SHARE_ALL, create_options, &fid, &oplock, + NULL, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (!rc) { rc = CIFSSMBGetCIFSACL(xid, tcon, fid, &pntsd, pacllen); @@ -952,7 +953,8 @@ int set_cifs_acl(struct cifs_ntsd *pnntsd, __u32 acllen, access_flags = WRITE_DAC; rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, access_flags, - create_options, &fid, &oplock, NULL, cifs_sb->local_nls, + FILE_SHARE_ALL, create_options, &fid, &oplock, + NULL, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (rc) { cERROR(1, "Unable to open file to set ACL"); diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index e6899ce..f1d62ed 100644 --- a/fs/cifs/cifsglob.h +++ b/fs/cifs/cifsglob.h @@ -310,7 +310,7 @@ struct smb_version_operations { struct cifs_sb_info *); /* open a file for non-posix mounts */ int (*open)(const unsigned int, struct cifs_tcon *, const char *, int, - int, int, struct cifs_fid *, __u32 *, FILE_ALL_INFO *, + int, int, int, struct cifs_fid *, __u32 *, FILE_ALL_INFO *, struct cifs_sb_info *); /* set fid protocol-specific info */ void (*set_fid)(struct cifsFileInfo *, struct cifs_fid *, __u32); @@ -947,6 +947,16 @@ struct cifsFileInfo { struct work_struct oplock_break; /* work for oplock breaks */ }; +#define CIFS_DENY_RW_FLAGS_SHIFT 22 +#define CIFS_DENY_DEL_FLAG_SHIFT 23 + +static inline int cifs_get_share_flags(unsigned int flags) +{ + return (flags & O_DENYMAND) ? + (((~(flags >> CIFS_DENY_RW_FLAGS_SHIFT)) & 3) | + ((~(flags >> CIFS_DENY_DEL_FLAG_SHIFT)) & 4)) : FILE_SHARE_ALL; +} + struct cifs_io_parms { __u16 netfid; #ifdef CONFIG_CIFS_SMB2 diff --git a/fs/cifs/cifsproto.h b/fs/cifs/cifsproto.h index 1988c1b..9661607 100644 --- a/fs/cifs/cifsproto.h +++ b/fs/cifs/cifsproto.h @@ -361,10 +361,11 @@ extern int CIFSSMBQueryReparseLinkInfo(const unsigned int xid, const struct nls_table *nls_codepage); #endif /* temporarily unused until cifs_symlink fixed */ extern int CIFSSMBOpen(const unsigned int xid, struct cifs_tcon *tcon, - const char *fileName, const int disposition, - const int access_flags, const int omode, - __u16 *netfid, int *pOplock, FILE_ALL_INFO *, - const struct nls_table *nls_codepage, int remap); + const char *file_name, const int disposition, + const int access_flags, const int share_flags, + const int omode, __u16 *netfid, int *oplock, + FILE_ALL_INFO *, const struct nls_table *nls_codepage, + int remap); extern int SMBLegacyOpen(const unsigned int xid, struct cifs_tcon *tcon, const char *fileName, const int disposition, const int access_flags, const int omode, diff --git a/fs/cifs/cifssmb.c b/fs/cifs/cifssmb.c index 76d0d29..9c4632f 100644 --- a/fs/cifs/cifssmb.c +++ b/fs/cifs/cifssmb.c @@ -1289,10 +1289,11 @@ OldOpenRetry: int CIFSSMBOpen(const unsigned int xid, struct cifs_tcon *tcon, - const char *fileName, const int openDisposition, - const int access_flags, const int create_options, __u16 *netfid, - int *pOplock, FILE_ALL_INFO *pfile_info, - const struct nls_table *nls_codepage, int remap) + const char *file_name, const int disposition, + const int access_flags, const int share_flags, + const int create_options, __u16 *netfid, int *oplock, + FILE_ALL_INFO *file_info, const struct nls_table *nls_codepage, + int remap) { int rc = -EACCES; OPEN_REQ *pSMB = NULL; @@ -1313,26 +1314,28 @@ openRetry: count = 1; /* account for one byte pad to word boundary */ name_len = cifsConvertToUTF16((__le16 *) (pSMB->fileName + 1), - fileName, PATH_MAX, nls_codepage, remap); + file_name, PATH_MAX, nls_codepage, + remap); name_len++; /* trailing null */ name_len *= 2; pSMB->NameLength = cpu_to_le16(name_len); } else { /* BB improve check for buffer overruns BB */ count = 0; /* no pad */ - name_len = strnlen(fileName, PATH_MAX); + name_len = strnlen(file_name, PATH_MAX); name_len++; /* trailing null */ pSMB->NameLength = cpu_to_le16(name_len); - strncpy(pSMB->fileName, fileName, name_len); + strncpy(pSMB->fileName, file_name, name_len); } - if (*pOplock & REQ_OPLOCK) + if (*oplock & REQ_OPLOCK) pSMB->OpenFlags = cpu_to_le32(REQ_OPLOCK); - else if (*pOplock & REQ_BATCHOPLOCK) + else if (*oplock & REQ_BATCHOPLOCK) pSMB->OpenFlags = cpu_to_le32(REQ_BATCHOPLOCK); pSMB->DesiredAccess = cpu_to_le32(access_flags); pSMB->AllocationSize = 0; - /* set file as system file if special file such - as fifo and server expecting SFU style and - no Unix extensions */ + /* + * set file as system file if special file such as fifo and server + * expecting SFU style and no Unix extensions + */ if (create_options & CREATE_OPTION_SPECIAL) pSMB->FileAttributes = cpu_to_le32(ATTR_SYSTEM); else @@ -1347,8 +1350,8 @@ openRetry: if (create_options & CREATE_OPTION_READONLY) pSMB->FileAttributes |= cpu_to_le32(ATTR_READONLY); - pSMB->ShareAccess = cpu_to_le32(FILE_SHARE_ALL); - pSMB->CreateDisposition = cpu_to_le32(openDisposition); + pSMB->ShareAccess = cpu_to_le32(share_flags); + pSMB->CreateDisposition = cpu_to_le32(disposition); pSMB->CreateOptions = cpu_to_le32(create_options & CREATE_OPTIONS_MASK); /* BB Expirement with various impersonation levels and verify */ pSMB->ImpersonationLevel = cpu_to_le32(SECURITY_IMPERSONATION); @@ -1366,20 +1369,20 @@ openRetry: if (rc) { cFYI(1, "Error in Open = %d", rc); } else { - *pOplock = pSMBr->OplockLevel; /* 1 byte no need to le_to_cpu */ + *oplock = pSMBr->OplockLevel; /* 1 byte no need to le_to_cpu */ *netfid = pSMBr->Fid; /* cifs fid stays in le */ /* Let caller know file was created so we can set the mode. */ /* Do we care about the CreateAction in any other cases? */ if (cpu_to_le32(FILE_CREATE) == pSMBr->CreateAction) - *pOplock |= CIFS_CREATE_ACTION; - if (pfile_info) { - memcpy((char *)pfile_info, (char *)&pSMBr->CreationTime, + *oplock |= CIFS_CREATE_ACTION; + if (file_info) { + memcpy((char *)file_info, (char *)&pSMBr->CreationTime, 36 /* CreationTime to Attributes */); /* the file_info buf is endian converted by caller */ - pfile_info->AllocationSize = pSMBr->AllocationSize; - pfile_info->EndOfFile = pSMBr->EndOfFile; - pfile_info->NumberOfLinks = cpu_to_le32(1); - pfile_info->DeletePending = 0; + file_info->AllocationSize = pSMBr->AllocationSize; + file_info->EndOfFile = pSMBr->EndOfFile; + file_info->NumberOfLinks = cpu_to_le32(1); + file_info->DeletePending = 0; } } diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c index 8719bbe..6975072 100644 --- a/fs/cifs/dir.c +++ b/fs/cifs/dir.c @@ -203,6 +203,7 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, FILE_ALL_INFO *buf = NULL; struct inode *newinode = NULL; int disposition; + int share_access; struct TCP_Server_Info *server = tcon->ses->server; *oplock = 0; @@ -293,6 +294,8 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, else cFYI(1, "Create flag not set in create function"); + share_access = cifs_get_share_flags(oflags); + /* * BB add processing to set equivalent of mode - e.g. via CreateX with * ACLs @@ -320,8 +323,8 @@ cifs_do_create(struct inode *inode, struct dentry *direntry, unsigned int xid, create_options |= CREATE_OPEN_BACKUP_INTENT; rc = server->ops->open(xid, tcon, full_path, disposition, - desired_access, create_options, fid, oplock, - buf, cifs_sb); + desired_access, share_access, create_options, + fid, oplock, buf, cifs_sb); if (rc) { cFYI(1, "cifs_create returned 0x%x", rc); goto out; @@ -626,9 +629,9 @@ int cifs_mknod(struct inode *inode, struct dentry *direntry, umode_t mode, if (backup_cred(cifs_sb)) create_options |= CREATE_OPEN_BACKUP_INTENT; - rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_CREATE, - GENERIC_WRITE, create_options, - &fileHandle, &oplock, buf, cifs_sb->local_nls, + rc = CIFSSMBOpen(xid, pTcon, full_path, FILE_CREATE, GENERIC_WRITE, + FILE_SHARE_ALL, create_options, &fileHandle, &oplock, + buf, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (rc) goto mknod_out; diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 8ea6ca5..3ad484c 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -174,6 +174,7 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb, { int rc; int desired_access; + int share_access; int disposition; int create_options = CREATE_NOT_DIR; FILE_ALL_INFO *buf; @@ -209,6 +210,7 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb, *********************************************************************/ disposition = cifs_get_disposition(f_flags); + share_access = cifs_get_share_flags(f_flags); /* BB pass O_SYNC flag through on file attributes .. BB */ @@ -220,8 +222,8 @@ cifs_nt_open(char *full_path, struct inode *inode, struct cifs_sb_info *cifs_sb, create_options |= CREATE_OPEN_BACKUP_INTENT; rc = server->ops->open(xid, tcon, full_path, disposition, - desired_access, create_options, fid, oplock, buf, - cifs_sb); + desired_access, share_access, create_options, + fid, oplock, buf, cifs_sb); if (rc) goto out; @@ -579,6 +581,7 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush) struct inode *inode; char *full_path = NULL; int desired_access; + int share_access; int disposition = FILE_OPEN; int create_options = CREATE_NOT_DIR; struct cifs_fid fid; @@ -643,6 +646,7 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush) } desired_access = cifs_convert_flags(cfile->f_flags); + share_access = cifs_get_share_flags(cfile->f_flags); if (backup_cred(cifs_sb)) create_options |= CREATE_OPEN_BACKUP_INTENT; @@ -658,8 +662,8 @@ cifs_reopen_file(struct cifsFileInfo *cfile, bool can_flush) * not dirty locally we could do this. */ rc = server->ops->open(xid, tcon, full_path, disposition, - desired_access, create_options, &fid, &oplock, - NULL, cifs_sb); + desired_access, share_access, create_options, + &fid, &oplock, NULL, cifs_sb); if (rc) { mutex_unlock(&cfile->fh_mutex); cFYI(1, "cifs_reopen returned 0x%x", rc); diff --git a/fs/cifs/inode.c b/fs/cifs/inode.c index ed6208f..a497dfa 100644 --- a/fs/cifs/inode.c +++ b/fs/cifs/inode.c @@ -396,8 +396,8 @@ cifs_sfu_type(struct cifs_fattr *fattr, const unsigned char *path, tcon = tlink_tcon(tlink); rc = CIFSSMBOpen(xid, tcon, path, FILE_OPEN, GENERIC_READ, - CREATE_NOT_DIR, &netfid, &oplock, NULL, - cifs_sb->local_nls, + FILE_SHARE_ALL, CREATE_NOT_DIR, &netfid, &oplock, + NULL, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (rc == 0) { @@ -987,8 +987,9 @@ cifs_rename_pending_delete(const char *full_path, struct dentry *dentry, tcon = tlink_tcon(tlink); rc = CIFSSMBOpen(xid, tcon, full_path, FILE_OPEN, - DELETE|FILE_WRITE_ATTRIBUTES, CREATE_NOT_DIR, - &netfid, &oplock, NULL, cifs_sb->local_nls, + DELETE|FILE_WRITE_ATTRIBUTES, FILE_SHARE_ALL, + CREATE_NOT_DIR, &netfid, &oplock, NULL, + cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (rc != 0) goto out; @@ -1509,7 +1510,7 @@ cifs_do_rename(const unsigned int xid, struct dentry *from_dentry, /* open the file to be renamed -- we need DELETE perms */ rc = CIFSSMBOpen(xid, tcon, from_path, FILE_OPEN, DELETE, - CREATE_NOT_DIR, &srcfid, &oplock, NULL, + FILE_SHARE_ALL, CREATE_NOT_DIR, &srcfid, &oplock, NULL, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (rc == 0) { diff --git a/fs/cifs/link.c b/fs/cifs/link.c index 51dc2fb..9b4f0db 100644 --- a/fs/cifs/link.c +++ b/fs/cifs/link.c @@ -212,7 +212,7 @@ CIFSCreateMFSymLink(const unsigned int xid, struct cifs_tcon *tcon, create_options |= CREATE_OPEN_BACKUP_INTENT; rc = CIFSSMBOpen(xid, tcon, fromName, FILE_CREATE, GENERIC_WRITE, - create_options, &netfid, &oplock, NULL, + FILE_SHARE_ALL, create_options, &netfid, &oplock, NULL, nls_codepage, remap); if (rc != 0) { kfree(buf); @@ -254,8 +254,8 @@ CIFSQueryMFSymLink(const unsigned int xid, struct cifs_tcon *tcon, FILE_ALL_INFO file_info; rc = CIFSSMBOpen(xid, tcon, searchName, FILE_OPEN, GENERIC_READ, - CREATE_NOT_DIR, &netfid, &oplock, &file_info, - nls_codepage, remap); + FILE_SHARE_ALL, CREATE_NOT_DIR, &netfid, &oplock, + &file_info, nls_codepage, remap); if (rc != 0) return rc; @@ -332,8 +332,8 @@ CIFSCheckMFSymlink(struct cifs_fattr *fattr, pTcon = tlink_tcon(tlink); rc = CIFSSMBOpen(xid, pTcon, path, FILE_OPEN, GENERIC_READ, - CREATE_NOT_DIR, &netfid, &oplock, &file_info, - cifs_sb->local_nls, + FILE_SHARE_ALL, CREATE_NOT_DIR, &netfid, &oplock, + &file_info, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (rc != 0) diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c index cdd6ff4..726b52e 100644 --- a/fs/cifs/readdir.c +++ b/fs/cifs/readdir.c @@ -224,7 +224,7 @@ int get_symlink_reparse_path(char *full_path, struct cifs_sb_info *cifs_sb, char *tmpbuffer; rc = CIFSSMBOpen(xid, ptcon, full_path, FILE_OPEN, GENERIC_READ, - OPEN_REPARSE_POINT, &fid, &oplock, NULL, + FILE_SHARE_ALL, OPEN_REPARSE_POINT, &fid, &oplock, NULL, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (!rc) { diff --git a/fs/cifs/smb1ops.c b/fs/cifs/smb1ops.c index 47bc5a8..d782209 100644 --- a/fs/cifs/smb1ops.c +++ b/fs/cifs/smb1ops.c @@ -671,9 +671,9 @@ cifs_mkdir_setinfo(struct inode *inode, const char *full_path, static int cifs_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *path, - int disposition, int desired_access, int create_options, - struct cifs_fid *fid, __u32 *oplock, FILE_ALL_INFO *buf, - struct cifs_sb_info *cifs_sb) + int disposition, int desired_access, int share_access, + int create_options, struct cifs_fid *fid, __u32 *oplock, + FILE_ALL_INFO *buf, struct cifs_sb_info *cifs_sb) { if (!(tcon->ses->capabilities & CAP_NT_SMBS)) return SMBLegacyOpen(xid, tcon, path, disposition, @@ -682,8 +682,8 @@ cifs_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *path, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); return CIFSSMBOpen(xid, tcon, path, disposition, desired_access, - create_options, &fid->netfid, oplock, buf, - cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & + share_access, create_options, &fid->netfid, oplock, + buf, cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); } @@ -779,8 +779,9 @@ smb_set_file_info(struct inode *inode, const char *full_path, cFYI(1, "calling SetFileInfo since SetPathInfo for times not supported " "by this server"); rc = CIFSSMBOpen(xid, tcon, full_path, FILE_OPEN, - SYNCHRONIZE | FILE_WRITE_ATTRIBUTES, CREATE_NOT_DIR, - &netfid, &oplock, NULL, cifs_sb->local_nls, + SYNCHRONIZE | FILE_WRITE_ATTRIBUTES, FILE_SHARE_ALL, + CREATE_NOT_DIR, &netfid, &oplock, NULL, + cifs_sb->local_nls, cifs_sb->mnt_cifs_flags & CIFS_MOUNT_MAP_SPECIAL_CHR); if (rc != 0) { diff --git a/fs/cifs/smb2file.c b/fs/cifs/smb2file.c index 71e6aed..7dfb50c 100644 --- a/fs/cifs/smb2file.c +++ b/fs/cifs/smb2file.c @@ -58,9 +58,9 @@ smb2_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock) int smb2_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *path, - int disposition, int desired_access, int create_options, - struct cifs_fid *fid, __u32 *oplock, FILE_ALL_INFO *buf, - struct cifs_sb_info *cifs_sb) + int disposition, int desired_access, int share_access, + int create_options, struct cifs_fid *fid, __u32 *oplock, + FILE_ALL_INFO *buf, struct cifs_sb_info *cifs_sb) { int rc; __le16 *smb2_path; @@ -87,8 +87,8 @@ smb2_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *path, memcpy(smb2_oplock + 1, fid->lease_key, SMB2_LEASE_KEY_SIZE); rc = SMB2_open(xid, tcon, smb2_path, &fid->persistent_fid, - &fid->volatile_fid, desired_access, disposition, - 0, 0, smb2_oplock, smb2_data); + &fid->volatile_fid, desired_access, share_access, + disposition, 0, 0, smb2_oplock, smb2_data); if (rc) goto out; diff --git a/fs/cifs/smb2inode.c b/fs/cifs/smb2inode.c index 7064824..6af174a 100644 --- a/fs/cifs/smb2inode.c +++ b/fs/cifs/smb2inode.c @@ -54,8 +54,8 @@ smb2_open_op_close(const unsigned int xid, struct cifs_tcon *tcon, return -ENOMEM; rc = SMB2_open(xid, tcon, utf16_path, &persistent_fid, &volatile_fid, - desired_access, create_disposition, file_attributes, - create_options, &oplock, NULL); + desired_access, FILE_SHARE_ALL, create_disposition, + file_attributes, create_options, &oplock, NULL); if (rc) { kfree(utf16_path); return rc; diff --git a/fs/cifs/smb2ops.c b/fs/cifs/smb2ops.c index c9c7aa7..dc38434 100644 --- a/fs/cifs/smb2ops.c +++ b/fs/cifs/smb2ops.c @@ -222,7 +222,8 @@ smb2_is_path_accessible(const unsigned int xid, struct cifs_tcon *tcon, return -ENOMEM; rc = SMB2_open(xid, tcon, utf16_path, &persistent_fid, &volatile_fid, - FILE_READ_ATTRIBUTES, FILE_OPEN, 0, 0, &oplock, NULL); + FILE_READ_ATTRIBUTES, FILE_SHARE_ALL, FILE_OPEN, 0, 0, + &oplock, NULL); if (rc) { kfree(utf16_path); return rc; @@ -432,8 +433,8 @@ smb2_query_dir_first(const unsigned int xid, struct cifs_tcon *tcon, return -ENOMEM; rc = SMB2_open(xid, tcon, utf16_path, &persistent_fid, &volatile_fid, - FILE_READ_ATTRIBUTES | FILE_READ_DATA, FILE_OPEN, 0, 0, - &oplock, NULL); + FILE_READ_ATTRIBUTES | FILE_READ_DATA, FILE_SHARE_ALL, + FILE_OPEN, 0, 0, &oplock, NULL); kfree(utf16_path); if (rc) { cERROR(1, "open dir failed"); @@ -515,7 +516,8 @@ smb2_queryfs(const unsigned int xid, struct cifs_tcon *tcon, u8 oplock = SMB2_OPLOCK_LEVEL_NONE; rc = SMB2_open(xid, tcon, &srch_path, &persistent_fid, &volatile_fid, - FILE_READ_ATTRIBUTES, FILE_OPEN, 0, 0, &oplock, NULL); + FILE_READ_ATTRIBUTES, FILE_SHARE_ALL, FILE_OPEN, 0, 0, + &oplock, NULL); if (rc) return rc; buf->f_type = SMB2_MAGIC_NUMBER; diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c index 41d9d07..45fa2dc 100644 --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -910,8 +910,8 @@ parse_lease_state(struct smb2_create_rsp *rsp) int SMB2_open(const unsigned int xid, struct cifs_tcon *tcon, __le16 *path, u64 *persistent_fid, u64 *volatile_fid, __u32 desired_access, - __u32 create_disposition, __u32 file_attributes, __u32 create_options, - __u8 *oplock, struct smb2_file_all_info *buf) + __u32 share_access, __u32 create_disposition, __u32 file_attributes, + __u32 create_options, __u8 *oplock, struct smb2_file_all_info *buf) { struct smb2_create_req *req; struct smb2_create_rsp *rsp; @@ -940,7 +940,7 @@ SMB2_open(const unsigned int xid, struct cifs_tcon *tcon, __le16 *path, req->DesiredAccess = cpu_to_le32(desired_access); /* File attributes ignored on open (used in create though) */ req->FileAttributes = cpu_to_le32(file_attributes); - req->ShareAccess = FILE_SHARE_ALL_LE; + req->ShareAccess = cpu_to_le32(share_access); req->CreateDisposition = cpu_to_le32(create_disposition); req->CreateOptions = cpu_to_le32(create_options); uni_path_len = (2 * UniStrnlen((wchar_t *)path, PATH_MAX)) + 2; diff --git a/fs/cifs/smb2proto.h b/fs/cifs/smb2proto.h index 2aa3535..edff8f6 100644 --- a/fs/cifs/smb2proto.h +++ b/fs/cifs/smb2proto.h @@ -86,9 +86,10 @@ extern int smb2_create_hardlink(const unsigned int xid, struct cifs_tcon *tcon, extern int smb2_open_file(const unsigned int xid, struct cifs_tcon *tcon, const char *full_path, int disposition, - int desired_access, int create_options, - struct cifs_fid *fid, __u32 *oplock, - FILE_ALL_INFO *buf, struct cifs_sb_info *cifs_sb); + int desired_access, int share_access, + int create_options, struct cifs_fid *fid, + __u32 *oplock, FILE_ALL_INFO *buf, + struct cifs_sb_info *cifs_sb); extern void smb2_set_oplock_level(struct cifsInodeInfo *cinode, __u32 oplock); extern int smb2_unlock_range(struct cifsFileInfo *cfile, struct file_lock *flock, const unsigned int xid); @@ -108,9 +109,10 @@ extern int SMB2_tcon(const unsigned int xid, struct cifs_ses *ses, extern int SMB2_tdis(const unsigned int xid, struct cifs_tcon *tcon); extern int SMB2_open(const unsigned int xid, struct cifs_tcon *tcon, __le16 *path, u64 *persistent_fid, u64 *volatile_fid, - __u32 desired_access, __u32 create_disposition, - __u32 file_attributes, __u32 create_options, - __u8 *oplock, struct smb2_file_all_info *buf); + __u32 desired_access, __u32 share_access, + __u32 create_disposition, __u32 file_attributes, + __u32 create_options, __u8 *oplock, + struct smb2_file_all_info *buf); extern int SMB2_close(const unsigned int xid, struct cifs_tcon *tcon, u64 persistent_file_id, u64 volatile_file_id); extern int SMB2_flush(const unsigned int xid, struct cifs_tcon *tcon, -- 1.8.1.2

Feb. 28, 2013

[PATCH v3 2/7] vfs: Add O_DENYREAD/WRITE flags support for open syscall

by Pavel Shilovsky

If O_DENYMAND flag is specified, O_DENYREAD/WRITE/MAND flags are translated to flock's flags: !O_DENYREAD -> LOCK_READ !O_DENYWRITE -> LOCK_WRITE O_DENYMAND -> LOCK_MAND and set through flock_lock_file on a file. This change affects opens that use O_DENYMAND flag - all other native Linux opens don't care about these flags. It allow us to enable this feature for applications that need it (e.g. NFS and Samba servers that export the same directory for Windows clients, or Wine applications that access the same files simultaneously). Create codepath is slightly changed to prevent data races on newely created files: when open with O_CREAT can return with -ETXTBSY error for successfully created files due to a deny lock set by another task. Signed-off-by: Pavel Shilovsky <piastry(a)etersoft.ru> --- fs/locks.c | 116 +++++++++++++++++++++++++++++++++++++++++++++++------ fs/namei.c | 44 ++++++++++++++++++-- include/linux/fs.h | 6 +++ 3 files changed, 151 insertions(+), 15 deletions(-) diff --git a/fs/locks.c b/fs/locks.c index a94e331..0cc7d1b 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -605,20 +605,81 @@ static int posix_locks_conflict(struct file_lock *caller_fl, struct file_lock *s return (locks_conflict(caller_fl, sys_fl)); } -/* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific - * checking before calling the locks_conflict(). +static unsigned int +deny_flags_to_cmd(unsigned int flags) +{ + unsigned int cmd = LOCK_MAND; + + if (!(flags & O_DENYREAD)) + cmd |= LOCK_READ; + if (!(flags & O_DENYWRITE)) + cmd |= LOCK_WRITE; + + return cmd; +} + +/* + * locks_mand_conflict - Determine if there's a share reservation conflict + * @caller_fl: lock we're attempting to acquire + * @sys_fl: lock already present on system that we're checking against + * + * Check to see if there's a share_reservation conflict. LOCK_READ/LOCK_WRITE + * tell us whether the reservation allows other readers and writers. + * + * We only check against other LOCK_MAND locks, so applications that want to + * use share mode locking will only conflict against one another. "normal" + * applications that open files won't be affected by and won't themselves + * affect the share reservations. */ -static int flock_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) +static int +locks_mand_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) { - /* FLOCK locks referring to the same filp do not conflict with + unsigned char caller_type = caller_fl->fl_type; + unsigned char sys_type = sys_fl->fl_type; + fmode_t caller_fmode = caller_fl->fl_file->f_mode; + fmode_t sys_fmode = sys_fl->fl_file->f_mode; + + /* they can only conflict if they're both LOCK_MAND */ + if (!(caller_type & LOCK_MAND) || !(sys_type & LOCK_MAND)) + return 0; + + if (!(caller_type & LOCK_READ) && (sys_fmode & FMODE_READ)) + return 1; + if (!(caller_type & LOCK_WRITE) && (sys_fmode & FMODE_WRITE)) + return 1; + if (!(sys_type & LOCK_READ) && (caller_fmode & FMODE_READ)) + return 1; + if (!(sys_type & LOCK_WRITE) && (caller_fmode & FMODE_WRITE)) + return 1; + + return 0; +} + +/* + * Determine if lock sys_fl blocks lock caller_fl. FLOCK specific checking + * before calling the locks_conflict(). Boolean is_mand indicates whether + * we should use a share reservation scheme or not. + */ +static int +flock_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl, + bool is_mand) +{ + /* + * FLOCK locks referring to the same filp do not conflict with * each other. */ - if (!IS_FLOCK(sys_fl) || (caller_fl->fl_file == sys_fl->fl_file)) - return (0); - if ((caller_fl->fl_type & LOCK_MAND) || (sys_fl->fl_type & LOCK_MAND)) + if (!IS_FLOCK(sys_fl)) + return 0; + if ((caller_fl->fl_type & LOCK_MAND) || (sys_fl->fl_type & LOCK_MAND)) { + if (is_mand) + return locks_mand_conflict(caller_fl, sys_fl); + else + return 0; + } + if (caller_fl->fl_file == sys_fl->fl_file) return 0; - return (locks_conflict(caller_fl, sys_fl)); + return locks_conflict(caller_fl, sys_fl); } void @@ -697,14 +758,19 @@ static int posix_locks_deadlock(struct file_lock *caller_fl, return 0; } -/* Try to create a FLOCK lock on filp. We always insert new FLOCK locks +/* + * Try to create a FLOCK lock on filp. We always insert new FLOCK locks * after any leases, but before any posix locks. * * Note that if called with an FL_EXISTS argument, the caller may determine * whether or not a lock was successfully freed by testing the return * value for -ENOENT. + * + * Take @is_conflict callback that determines how to check if locks have + * conflicts or not. */ -static int flock_lock_file(struct file *filp, struct file_lock *request) +static int +flock_lock_file(struct file *filp, struct file_lock *request, bool is_mand) { struct file_lock *new_fl = NULL; struct file_lock **before; @@ -760,7 +826,7 @@ find_conflict: break; if (IS_LEASE(fl)) continue; - if (!flock_locks_conflict(request, fl)) + if (!flock_locks_conflict(request, fl, is_mand)) continue; error = -EAGAIN; if (!(request->fl_flags & FL_SLEEP)) @@ -783,6 +849,32 @@ out: return error; } +/* + * Determine if a file is allowed to be opened with specified access and deny + * modes. Lock the file and return 0 if checks passed, otherwise return a error + * code. + */ +int +deny_lock_file(struct file *filp) +{ + struct file_lock *lock; + int error = 0; + + if (!(filp->f_flags & O_DENYMAND)) + return error; + + error = flock_make_lock(filp, &lock, deny_flags_to_cmd(filp->f_flags)); + if (error) + return error; + + error = flock_lock_file(filp, lock, true); + if (error == -EAGAIN) + error = -ETXTBSY; + + locks_free_lock(lock); + return error; +} + static int __posix_lock_file(struct inode *inode, struct file_lock *request, struct file_lock *conflock) { struct file_lock *fl; @@ -1589,7 +1681,7 @@ int flock_lock_file_wait(struct file *filp, struct file_lock *fl) int error; might_sleep(); for (;;) { - error = flock_lock_file(filp, fl); + error = flock_lock_file(filp, fl, false); if (error != FILE_LOCK_DEFERRED) break; error = wait_event_interruptible(fl->fl_wait, !fl->fl_next); diff --git a/fs/namei.c b/fs/namei.c index 43a97ee..c1f7e08 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2559,9 +2559,14 @@ static int atomic_open(struct nameidata *nd, struct dentry *dentry, * here. */ error = may_open(&file->f_path, acc_mode, open_flag); - if (error) + if (error) { fput(file); + goto out; + } + error = deny_lock_file(file); + if (error) + fput(file); out: dput(dentry); return error; @@ -2771,9 +2776,9 @@ retry_lookup: } mutex_lock(&dir->d_inode->i_mutex); error = lookup_open(nd, path, file, op, got_write, opened); - mutex_unlock(&dir->d_inode->i_mutex); if (error <= 0) { + mutex_unlock(&dir->d_inode->i_mutex); if (error) goto out; @@ -2791,8 +2796,32 @@ retry_lookup: will_truncate = false; acc_mode = MAY_OPEN; path_to_nameidata(path, nd); - goto finish_open_created; + + /* + * Unlock parent i_mutex later when the open finishes - prevent + * races when a file can be locked with a deny lock by another + * task that opens the file. + */ + error = may_open(&nd->path, acc_mode, open_flag); + if (error) { + mutex_unlock(&dir->d_inode->i_mutex); + goto out; + } + file->f_path.mnt = nd->path.mnt; + error = finish_open(file, nd->path.dentry, NULL, opened); + if (error) { + mutex_unlock(&dir->d_inode->i_mutex); + if (error == -EOPENSTALE) + goto stale_open; + goto out; + } + error = deny_lock_file(file); + mutex_unlock(&dir->d_inode->i_mutex); + if (error) + goto exit_fput; + goto opened; } + mutex_unlock(&dir->d_inode->i_mutex); /* * create/update audit record if it already exists. @@ -2885,6 +2914,15 @@ finish_open_created: goto stale_open; goto out; } + /* + * Lock parent i_mutex to prevent races with deny locks on newely + * created files. + */ + mutex_lock(&dir->d_inode->i_mutex); + error = deny_lock_file(file); + mutex_unlock(&dir->d_inode->i_mutex); + if (error) + goto exit_fput; opened: error = open_check_o_direct(file); if (error) diff --git a/include/linux/fs.h b/include/linux/fs.h index 7617ee0..347e1de 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1005,6 +1005,7 @@ extern int lease_modify(struct file_lock **, int); extern int lock_may_read(struct inode *, loff_t start, unsigned long count); extern int lock_may_write(struct inode *, loff_t start, unsigned long count); extern void locks_delete_block(struct file_lock *waiter); +extern int deny_lock_file(struct file *); extern void lock_flocks(void); extern void unlock_flocks(void); #else /* !CONFIG_FILE_LOCKING */ @@ -1153,6 +1154,11 @@ static inline void locks_delete_block(struct file_lock *waiter) { } +static inline int deny_lock_file(struct file *filp) +{ + return 0; +} + static inline void lock_flocks(void) { } -- 1.8.1.2

Feb. 28, 2013